Precision Reduction Gear RV, Überblick




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CAT.150430

(Issued on Apr. 30, 2015)

Rev. 004.1

● Nabtesco, VIGOGREASE, RV are registered trademarks or trademarks of Nabtesco Corporation.
● Specifications are subject to change without notice.
● The PDF data of this catalog can be downloaded from the following website.
http://precision.nabtesco.com/
If any addition or modification is made to the published information, the PDF data may be updated before the printed catalog.
Due to this, please note that some contents of the PDF data may be changed or revised from those in this catalog.
● Unauthorized reprinting, reproduction, copying, or translation of this catalog in whole or in part is strictly prohibited.

Europe and Africa

North and South America

China

Asia and others

Nabtesco Precision Europe GmbH

Tiefenbroicher Weg 15, 40472 Düesseldorf, Germany
TEL: +49-211-173790  FAX: +49-211-364677
E-MAIL: info@nabtesco.de   www.nabtesco.de

Nabtesco Motion Control Inc. in U.S.A (North America & South America)

23976 Freeway Park Drive, Farmington Hills, MI 48335, USA
TEL: +1-248-553-3020  FAX: +1-248-553-3070
E-MAIL: engineer@nabtescomotioncontrol.com   www.nabtescomotioncontrol.com

Shanghai Nabtesco Motion-equipment Co., Ltd.

Room 1706, Hong Jia Tower, No. 388 Fu Shan Road, Pudong New Area, Shanghai 200122, China
TEL: +86-21-3363-2200  FAX: +86-21-3363-2655
E-MAIL: info@nabtesco-motion.cn   www.nabtesco-motion.cn

Nabtesco Corporation

Osaka Sales Office

21st Fl, Dojima Avanza, 1-6-20 Dojima, Kita-ku, Osaka 530-0003, Japan
TEL: +81-6-6341-7180  FAX: +81-6-6341-7182

Tsu Plant

594 Icchoda, Katada-cho, Tsu, Mie 514-8533, Japan
TEL: +81-59-237-4600  FAX: +81-59-237-4610
E-MAIL: P_Information@nabtesco.com   http://precision.nabtesco.com/

®

E Series / C Series /

Original Series

Precision Reduction Gear RV

TM

Precision Reduction Gear R

V

TM

E Series / C Series / Original Series

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®

The RV E, C, and Original Series are family of planocentric

reduction gear mechanisms designed for precise motion

control. The mechanisms incorporate a large number of

simultaneously engaged gear teeth, and have compact,

lightweight and highly rigid construction that is strong

against overloading.

Furthermore, minimal backlash, rotary vibration and

inertia assure rapid acceleration, smooth motion and

extremely accurate positioning.

The Precision Reduction Gear RV is ideally suited for preci-

sion mechanical control in factory robots, machine tools, and

assembly and conveying equipment where precise position-

ing, stiffness and shock-load capability are demanded.

1. In the case where Nabtesco confirms that a defect of the Product was caused due to Nabtesco’s design or

manufacture within the Warranty Period of the Product, Nabtesco shall repair or replace such defective

Product at its cost.  The Warranty Period shall be from the delivery of the Product by Nabtesco or its distribu-

tor to you (“Customer”) until the end of one (1) year thereafter, or the end of two thousand (2,000) hours

running of the Product installed into Customer’s equipment, whichever comes earlier.

2. Unless otherwise expressly agreed between the parties in writing, the warranty obligations for the Product

shall be limited to the repair or replacement set forth herein.  OTHER THAN AS PROVIDED HEREIN,

THERE ARE NO WARRATIES ON THE PRODUCT, EXPRESS OR IMPLIED, INCLUDING WITHOUT

LIMITATION ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR

PURPOSE.

3. The warranty obligation under the Section 1 above shall not apply if:

a) the defect was caused due to the use of the Product deviated from the Specifications or the working

conditions provided by Nabtesco;

b) the defect was caused due to exposure to foreign substances or contamination (dirt, sand etc.)
c) lubricant or spare part other than the ones recommended by Nabtesco was used in the Product;
d) the Product was used in an unusual environment (such as high temperature, high humidity, a lot of dust,

corrosive/volatile/inflammable gas,  pressurized/depressurized air, under water/liquid or others except for

those expressly stated in the Specifications);

e) the Product was disassembled, re-assembled, repaired or modified by anyone other than Nabtesco;
f ) the defect was caused due to the equipment into which the Product was installed;
g) the defect was caused due to an accident such as fire, earthquake, lightning, flood or others; or
h) the defect was due to any cause other than the design or manufacturing of the Product.

4. The warranty period for the repaired/replaced Product/part under the Section 1 above shall be the rest of the

initial Warranty Period of the defective Product subjected to such repair/replace.

Warranty

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3

4

5

1

Ordering Information

—————————————————————————————————————————————————

1

2

Application Examples

————————————————————————————————————————————————

3

Considering the use of the RV

TM

E, C, and Original Series

——————————————————————————————————

5

Precision Reduction Gear RV

TM

Technical Data

C

O

N

T

E

N

T

S

Features and Benefits

––––––––––––––

8

Construction and Operation Principle

–––

9

Rotary Direction and Speed Ratio

––––

10

Ratings Table

––––––––––––––––––––––

11

Selection

–––––––––––––––––––––––––––

13

5-1 Selection flow chart –––––––––––––––––––

13

5-2 Strength and service life –––––––––––––––

15

5-2-1 Allowable torque during acceleration or

deceleration

–––––––––––––––––––––––

15

5-2-2 Momentary maximum allowable torque

––––––––––––––––––––––––––––––––––

15

5-2-3 Rated service life –––––––––––––––––––

15

5-3 Capacity of main bearing–––––––––––––––

16

5-3-1 Moment rigidity –––––––––––––––––––––

16

5-3-2 Allowable moment ––––––––––––––––––

16

5-3-3 Momentary maximum allowable

moment

–––––––––––––––––––––––––––

17

Performance Characteristics

–––––

18

6-1 Rigidity (Torsional rigidity and lost

motion) and backlash

––––––––––––––––––

18

6-1-1 Calculation of torsion (an example) ––––––

18

6-2 Vibration –––––––––––––––––––––––––––––

19

6-3 Angular transmission accuracy ––––––––––

19

6-4 No-load running torque ––––––––––––––––

20

6-5 Backdriving torque ––––––––––––––––––––

20

6-6 Low-temperature characteristics ––––––––

21

6-7 Efficiency charts ––––––––––––––––––––––

22

Installation and Assembly

––––––––

23

7-1 Assembly accuracy ––––––––––––––––––––

23

7-2 Installation procedure –––––––––––––––––

23

7-2-1 Bolt clamping output shaft type –––––––

23

7-2-2 Pin/bolt clamping output shaft type ––––

24

7-3 Bolt tightening torque and allowable

transmission torque

–––––––––––––––––––

25

7-4 Installation of input gear –––––––––––––––

26

7-4-1 Precautions for installation

of RV-6E, 20E and 40E input gears

––––

27

7-4-2 Pass-through capacity of input

gear

––––––––––––––––––––––––––––––

27

7-4-3 An example of installation for the

reduction gear with lower speed ratio

––––––––––––––––––––––––––––––––––

28

7-5 Lubrication ––––––––––––––––––––––––––

28

7-5-1 Grease Iubrication ––––––––––––––––––

28

External Dimensions

––––––––––––––

31

Features and Benefits

–––––––––––––

54

Construction and Operation Principle

–––

55

Rotary Direction and Speed Ratio

––––

56

Ratings Table

––––––––––––––––––––––

57

Selection

–––––––––––––––––––––––––––

59

5-1 Selection flow chart –––––––––––––––––––

59

5-2 Strength and service life –––––––––––––––

61

5-2-1 Allowable torque during acceleration or

deceleration

–––––––––––––––––––––––

61

5-2-2 Momentary maximum allowable torque

––––––––––––––––––––––––––––––––––

61

5-2-3 Rated service life –––––––––––––––––––

61

5-3 Capacity of main bearing–––––––––––––––

62

5-3-1 Moment rigidity –––––––––––––––––––––

62

5-3-2 Allowable moment ––––––––––––––––––

62

5-3-3 Momentary maximum allowable

moment

–––––––––––––––––––––––––––

63

Performance Characteristics

–––––

64

6-1 Rigidity (Torsional rigidity and lost

motion) and backlash

––––––––––––––––––

64

6-1-1 Calculation of torsion (an example) –––––

64

6-2 Vibration –––––––––––––––––––––––––––––

65

6-3 Angular transmission accuracy ––––––––––

65

6-4 No-load running torque ––––––––––––––––

66

6-5 Backdriving torque ––––––––––––––––––––

66

6-6 Low-temperature characteristics ––––––––

67

6-7 Efficiency charts ––––––––––––––––––––––

68

Installation and Assembly

––––––––

69

7-1 Assembly accuracy ––––––––––––––––––––

69

7-1-1 Assembly accuracy of RV-10C to 500C
––––––––––––––––––––––––––––––––––

69

7-2 Installation procedure –––––––––––––––––

70

7-2-1 Assembly example of center tube –––––

70

7-2-2 Assembly example with the output shaft

bolt clamping type (RV-10C to

500C)

––––––––––––––––––––––––––––––––––

70

7-2-3 Assembly example of through-bolt

clamping output shaft type (RV-27C,
50C, 100C and 200C)

––––––––––––––––

71

7-2-4 Assembly example of through-bolt

clamping output shaft type (RV-10C

and 320C)

–––––––––––––––––––––––––

71

7-3 Center gear and input gear –––––––––––––

72

7-3-1 Accuracy of center gear and input gear
––––––––––––––––––––––––––––––––––

72

7-3-2 Standard center gear ––––––––––––––––

72

7-4 Bolt tightening torque and allowable

transmission torque

–––––––––––––––––––

73

7-5 Installation of input gear –––––––––––––––

74

7-6 Lubrication ––––––––––––––––––––––––––

74

External Dimensions

––––––––––––––

77

Construction

–––––––––––––––––––––––

91

Rotary Direction and Speed Ratio

––––

92

Ratings Table

––––––––––––––––––––––

93

Selection

–––––––––––––––––––––––––––

95

4-1 Selection flow chart –––––––––––––––––––

95

4-2 Strength and service life –––––––––––––––

97

4-2-1 Allowable torque during acceleration or

deceleration

–––––––––––––––––––––––

97

4-2-2 Momentary maximum allowable torque

––––––––––––––––––––––––––––––––––

97

4-2-3 Rated service life –––––––––––––––––––

97

Performance Characteristics

–––––

98

5-1 Rigidity (Torsional rigidity and lost

motion) and backlash

––––––––––––––––––

98

5-1-1 Calculation of torsion (an example) –––––

98

5-2 Vibration –––––––––––––––––––––––––––––

99

5-3 Angular transmission accuracy

––––––––––

99

5-4 No-load running torque

–––––––––––––––

100

5-5 Backdriving torque

–––––––––––––––––––

100

5-6 Low-temperature characteristics

–––––––

101

5-7 Efficiency charts

–––––––––––––––––––––

102

Installation and Assembly

–––––––

103

6-1 Assembly accuracy

–––––––––––––––––––

103

6-2 Installation ––––––––––––––––––––––––––

104

6-2-1 Reduction gear mounting holes ––––––

104

6-2-2 Fitting the reduction gear –––––––––––

104

6-3 Installation procedure ––––––––––––––––

105

Installation of RV-15, RV-30

–––––––––

105

Installation of RV-60 to RV-550 ––––––

107

6-4 Bolt tightening torque and allowable

transmission torque

––––––––––––––––––

109

6-5 Installation of input gear ––––––––––––––

110

6-5-1 Precautions for installation of RV-15

and RV-30 input gears

––––––––––––––

110

6-5-2 Pass-through capacity of input gear
–––––––––––––––––––––––––––––––––

111

6-5-3 An example of installation for the

reduction gear with lower speed ratio
–––––––––––––––––––––––––––––––––

111

6-6 Lubrication –––––––––––––––––––––––––

111

6-6-1 Grease Iubrication –––––––––––––––––

111

External Dimensions

–––––––––––––

113

1

2

3

4

5

6

7

8

1

2

3

4

5

6

7

8

1

2

3

4

5

6

7

E Series

C Series

Original Series

E Series

C Series

Original Series

6

Appendix

Troubleshooting Checksheet
Application Worksheet
VIGOGREASE

® Ordering Information

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1

Ordering Information

1

■ E series

• Product identification for ordering purpose.

■ C series

• Product identification for ordering purpose.

RV

80  E

121

A

B

Main bearing built-in type

E

Type of input gear or

input spline

Speed ratio (reduction ratio =

1

R )

Standard type A (Narrow type)

A

Standard type B (Big diameter type)

B

Special (none)

Z

〈Ex. RV-80E〉

Notes 1. Refer to the Rating Table for other type.

2. Specify the shaft rotating speed ratio of your

application.

R

shaft rotation

57, 81, 101, 121, 153

RV

100  C

36.75

A

B

Bolt-clamping

output shaft
Through-bolt

clamping output

shaft

B

T

Hollow shaft type

C

Profile of center gear

Speed ratio (reduction ratio =

1

R )

Standard type

A

None

Z

Notes 1. Here, 36.75 applies to the RV-100C.

2. See Ratings Table for speed ratios of other frame

numbers.

3. Specify the shaft rotating speed ratio of your

application.

Frame number

Rated output torque kgf-m

(Nm)

6

6  (58)

20

17  (167)

40

42  (412)

80

80  (784)

110

110 (1078)

160

160 (1568)

320

320 (3136)

450

450 (4410)

Frame number

Rated output torque kgf-m (Nm)

10

10  (98)

27

27  (265)

50

50  (490)

100

100  (980)

200

200 (1,961)

320

320 (3,136)

500

500 (4,900)

Type symbol

Frame No.

Model

Type symbol

Frame No.

Model

Bolt-clamping

output shaft
Bolt/pin clamping

output shaft

B

P

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2

■ Original series

• Product identification for ordering purpose.

RV

60

121

A

T

Standard type

No mark

Standard type A (Narrow type)

A

Standard type B (Big diameter type)

B

Special (none)

Z

〈Ex. RV-60〉

Notes 1. Refer to the rating table for other type.

2. Specify the shaft rotating speed ratio of your

application.

R

shaft rotation

57, 81, 101, 121, 153

Frame number

Rated output torque In-lb(Nm)

15

1,213 (137)

30

2,949 (333)

60

5,642 (637)

160

13,887 (1568)

320

27,774 (3136)

450

39,058 (4410)

550

47,737 (5390)

Type symbol

Frame No.

Model

Bolt-clamping

output shaft
Through-bolt

clamping output

shaft

B

T

Type of input gear or

input spline

Speed ratio (reduction ratio =

1

R )

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3

Application Examples

2

Robot swing axis
C series

•  Allows space-saving design
•  Main bearing is not required on robot side.

Robot arm
C series

•  As cables can be passed through the arm,

environmental resistance increases.

•  Wider operating angle.

Indexing table
C series

•  The table can be made into a hollow shaft

structure.

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4

Robot arm
E series

Robot wrist axis
E series

As shown in the figure(right), the input gear can also

be supported within the reduction gear mechanism.

Please contact Nabtesco for more details.

Robot swing axis
Original series

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5

5

Considering the use of the RV

TM

E, C, and Original Series

•  The standard replacement time for Iubricant is 20,000 hours. However, when operation involves a reduction gear surface

temperature above 40°C, the state of degradation of the lubricant should be checked in advance of that and the grease
replaced earlier as necessary.

•  When the reduction gear is used under high load and at a high duty ratio, it may overheat and the surface temperature

may exceed the allowable temperature. Be aware of conditions so that the surface temperature of the reduction gear
does not exceed 60°C while it is in operation. There is a possibility of damage (to the product) if the surface temperature
exceeds 60°C.

•  The specifications indicated in this catalog are based on Nabtesco evaluation methods. This product should only be

used after confirming that it is appropriate for the operating conditions of your system.

•  When the range of the rotation angle is small (10 degrees or less), the service life of the reduction gear may be reduced

due to poor lubrication or the internal parts being subject to a concentrated load.

Note: Contact us in case the rotation angle is 10 degrees or less.

•  Safety information and detail product instructions are indicated in the operation manual.
The operation manual can be downloaded from the following website.

http://precision.nabtesco.com/

Operating environment

Product specifications indicated in this catalog

Export

Application

Safety measures

Reduction gear output rotation angle

•  When this product is exported from Japan, it may be subject to the export regulations provided in the “Foreign

Exchange Order and Export Trade Control Order”. Be sure to take sufficient precautions and perform the required export
procedures in advance if the final operating party is related to the military or the product is to be used in the manufacture
of weapons, etc.

This product features high precision and high rigidity, however, it is necessary to strictly comply with various restrictions and
make appropriate to maximize the product’s features. Please read this technical document thoroughly and select and adopt
an appropriate model based on the actual operating environment, method, and conditions at your facility.

•  If failure or malfunction of the product may directly endanger human life or if it is used in units which may injure the

human body (atomic facilities, space equipment, medical equipment, safety units, etc.), examination of individual
situations is required. Contact our agent or nearest business office in such a case.

•  Although this product has been manufactured under strict quality control, a mistake in operation or misuse can result in

breakdown or damage, or an accident resulting in injury or death. Be sure to take all appropriate safety measures, such
as the installation of independent safeguards.

Note 1:

2:

Use the reduction gear under the following environment:

·  Location where the ambient temperature is between -10°C

to 40°C.

·  Location where the humidity is less than 85% and no

condensation occurs.

·  Location where the altitude is less than 1000 m.
·   Well-ventilated  location

Do not install the reduction gear at the following locations.

· Location where a lot of dust is collected.
· Outdoors that can be directly affected by wind and rain
· Location near the environment that contains combustible, explosive,

or corrosive gases and flammable materials.

· Location that is heated due to heat transfer and radiation from

peripherals and direct sun.

· Location where the performance of the motor can be affected by

magnetic fields or vibration.

If the required operating environment cannot be established/met, contact us in advance.
When using the reduction gear under special conditions (clean room, equipment for food, concentrated alkali,
high-pressure steam, etc.), contact our agent or nearest business office in advance.

Maintenance

Reduction gear temperature

Manuals

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6

Precision Reduction Gear RV

TM

E

Series

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7

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8

E Series

2-stage reduction

Features and Benefits

1

Benefits:

•  Increases reliabilty
•  Reduces overall cost

Attributed to:

•  Built-in angular ball bearing construction improves

ability to support external loads, increases moment
rigidity and maximum allowable moment.

•  Reduces the number of components required.
•  Simplifies installation and maintenance.

Integrated angular ball bearings

Detail:

•  Crankshafts are supported on both sides of the

reduction gear as shown below.

Benefits:

•  Higher torsional stiffness
•  Less vibration
•  High shock load capability

All main elements are supported on both sides

Attributed to:

•  Use of roller bearings throughout.

Benefits:

•  Excellent starting efficiency
•  Low wear and longer life
•  Low backlash (Less than 1 arc. min.)

Rolling contact elements

Attributed to:

•  Synchromeshing of many RV gear teeth and pins.

Benefits:

•  Very low backlash (Less than 1 arc. min.)
•  Higher shock load capability

Pin & gear structure

Fig. 1

Attributed to:

•  Low speed rotation of the RV gear reduces

vibration.

•  Reduced size of the motor coupling part (input

gear) lowers intertia.

Benefits:

•  Reduces vibration
•  Reduces inertia (GD

2

)

Clearance hole for rigid

supporting structure

Crankshaft

through hole

RV gear

Shaft + hold flange

Rigid supporting structure

Crankshaft bearing supports

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9

Construction and Operation Principle

2

■ Construction

■ Principle of speed reduction

Fig. 2

The E series is a 2-stage reduction gear.

1st stage

…Spur gear reduction

•  An input gear engages with and rotates spur gears that are coupled to crankshafts. Several

overall gear ratios can be provided by selecting various first stage ratios.

2nd stage

…Epicyclic gear reduction

•  Crankshafts driven by the spur gears cause an eccentric motion of two epicyclic gears called

RV gears that are offset 180 degrees from one another to provide a balanced load.

The eccentric motion of the RV gears causes engagement of the cycloidal shaped gear teeth

with cylindrically shaped pins located around the inside edge of the case.

In the course of one revolution of the crankshafts the teeth of the RV gear move the distance

of  one  pin  in  the  opposite  directions  of  the  rotating  cranks.   The  motion  of  the  RV  gear  is
such that the teeth remain in close contact with the pins and many teeth share the load
simultaneously.

•  The output can be either the shaft or the case.  If the case is fixed, the shaft is the output.  If

the shaft is fixed, the case is the output (fig.4).

Fig. 3

Crankshaft rotating angle: 0 degree

Rotating angle: 180 degrees

Rotating angle: 360 degrees

Case

Crankshaft

(Connected to spur gear)

Shaft

RV gear

Pin

Crankshaft

Case

Pin

RV gear

Main bearing

Hold flange

Input gear

(Option)

Shaft

Spur gear

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10

E Series

Rotary Direction and Speed Ratio

3

The E series may be used in various ways.  The following figures show six combinations of the rotary direction and speed ratio.  Use the
following figure to select a mechanism most suitable for your application.

Fig. 4

■ Speed ratio

The overall speed ratio i (of the First and Second reduction stages) will differ depending on the
use, and can be calculated using the speed ratio values displayed in the table below.

With the shaft as output;  R = 1 +

Z

2

Z

1

・Z

4

i =

1

R

Mechanism block diagram

Fig. 5

Reduction

gear

1. Case fixed, shaft output

2. Shaft fixed, case output

3. Input gear fixed, shaft output

Input: Input gear

i =

1

R

Input: Shaft

i = R

Input: Input gear

i = ―

1

———

R ― 1

Input: Case

i = ―(R ― 1)

Input: Case

i =

R ― 1

———

R

Input: Shaft

i =

R

———

R ― 1

Speed

increasing

gear

4. Case fixed, input gear output

5. Shaft fixed, input gear output

6. Input gear fixed, case output

The sign "

i " in the above equations signifies the output shaft rotation

in the same direction as the input shaft. “-” signifies the output shaft
rotation in the opposite direction as the input shaft.

R  :  Speed ratio
Z

1

:  Number of teeth on input gear

Z

2

:  Number of teeth on spur gear

Z

3

:  Number of teeth on RV gear

Z

4

:  Number of pins

i  :  Reduction ratio

Case

Shaft

Crankshaft

RV gear

Pin

Output

Spur gear

Input gear

2nd reduction

1st reduction

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11

Rating Table

4

Table 1

Notes:  1. Set maximum input shaft revolutions to a value equal to or lower than the value of maximum allowable output revolutions multiplied by the above speed ratio for

each type.

2. The input capacity (kW) in the above table is determined by the efficiency of these reduction gears.

3. The output torque (Nm) is so determined that the service life may be maintained constant for any output revolutions.  (N・T = Constant)

4. The rated torque is a torque at an output speed of 15 r/min, which is used as a basis for service life calculations. (Refer to the rated service life, page 15) The

RV-6E, however, has its rated torque determined as the output torque at an output speed of 30 r/min.

5. The inertia moment value is for the reduction gear. It does not include the inertia moment for the input gear.

31

30

43

42

101

81

72

66

62

58

54

RV-6E

53.5

52.5  (10.3)    (8.34)    (7.39)    (6.78)    (6.34)    (6.00)    (5.50)

59

58

79

78

0.07

0.11

0.15

0.19

0.22

0.25

0.30

103

102

57

56

81

80

231

188

167

153

143

135

124

RV-20E

105

104  (23.6)    (19.2)    (17.0)    (15.6)    (14.6)    (13.8)    (12.7)

121

120

141

140

0.16

0.26

0.35

0.43

0.50

0.57

0.70

161

160

57

56

572

465

412

377

353

334

307

81

80

(58.4)    (47.4)    (42.0)    (38.5)    (36.0)    (34.1)    (31.3)

RV-40E 105

104

121

120

0.40

0.65

0.86

1.05

1.23

1.40

1.71

153

152

57

56

1,088

885

784

719

672

637

584

81

80

(111)    (90.3)    (80.0)    (73.4)    (68.6)    (65.0)    (59.6)

RV-80E 101

100

121

120

0.76

1.24

1.64

2.01

2.35

2.67

3.26

*

1

(153)  *

1

(152)

81

80

1,499

1,215

1,078

990

925

875

804

RV-110E

111

110  (153)    (124)    (110)    (101)    (94.4)    (89.3)    (82.0)

161

160

*

2

175.28  174.28

1.05

1.70

2.26

2.76

3.23

3.67

4.49

81

80

2,176

1,774

1,568

1,441

1,343

1,274

101

100

(222)    (181)    (160)    (147)    (137)    (130)

RV-160E 129

128

145

144

1.52

2.48

3.28

4.02

4.69

5.34

171

170

81

80

101

100

4,361

3,538

3,136

2,881

2,695

2,548

118.5

117.5

(445)    (361)    (320)    (294)    (275)    (260)

RV-320E 129

128

141

140

3.04

4.94

6.57

8.05

9.41

10.7

171

170

185

184

81

80

101

100

6,135

4,978

4,410

4,047

3,783

118.5

117.5

(626)    (508)    (450)    (413)    (386)

RV-450E 129

128

*

2

154.8

153.8

4.28

6.95

9.24

11.3

13.2

171

170

*

2

192.4

191.4

Model

Output speed (r/min)

5  10 15 20 25 30 40

Speed ratio

Output  Input Output   Input Output   Input Output   Input Output   Input Output   Input Output   Input

torque

capacity torque capacity torque capacity torque capacity torque capacity torque capacity torque capacity

Shaft Case Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

rotation rotation (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)

10

3

background image

12

E Series

2.63×10

− 6

50

47

2.00×10

− 6

(5.15)    (4.87)

117

196

392

100

117

294

1.5′

20

1.53×10

− 6

2.5

(12)

(20)  (40)

(12)  (30)

(2)

1.39×10

− 6

0.35

0.40

1.09×10

− 6

0.74×10

− 6

9.66×10

− 6

115

110

6.07×10

− 6

(11.8)    (11.2)

372

882

1,764

75

412

833

1′

49

4.32×10

− 6

4.7

(38)

(90)  (180)

(42)  (85)

(5)

3.56×10

− 6

0.81

0.92

2.88×10

− 6

2.39×10

− 6

287

271

3.25×10

− 5

(29.3)    (27.7)

931

1,666

3,332

1,029

2,058

108

2.20×10

− 5

(95)

(170)

(340)

70

(105)

(210)

1′

(11)

1.63×10

− 5

9.3

2.00

2.27

1.37×10

− 5

1.01×10

− 5

546

517

8.16×10

− 5

Bolt joint

(55.7)    (52.8)

1,176

1,960

196

6.00×10

− 5

13.1

(120)

70

(200)

1′

(20)

4.82×10

− 5

3.81

4.33

3.96×10

− 5

Pin/bolt joint

2.98×10

− 5

12.7

9.88×10

− 5

1,470

2,940  5,880

50

2,695  5,390

1′

294

6.96×10

− 5

17.4

(150)  (300)  (600)

(275)  (550)

(30)

4.36×10

− 5

3.89×10

− 5

1.77×10

− 4

2,940

3,920

3,920

392

1.40×10

− 4

(300)  (400)

45

(400)

1′

(40)

1.06×10

− 4

26.4

0.87×10

− 4

0.74×10

− 4

4.83×10

− 4

3.79×10

− 4

4,900

7,840

980

3.15×10

− 4

(500)

35

(800)

1′

(100)

2.84×10

− 4

44.3

2.54×10

− 4

1.97×10

− 4

1.77×10

− 4

8.75×10

− 4

6.91×10

− 4

7,448

8,820

11,025

1,176

5.75×10

− 4

(760)  (900)

25

(1,125)

1′

(120)

5.20×10

− 4

66.4

4.12×10

− 4

3.61×10

− 4

3.07×10

− 4

Bolt joint

2,156

(220)

Pin/bolt joint

1,735

(177)

Bolt joint

4,312

(440)

Pin/bolt joint

2,156

(220)

Bolt joint

3,920

(400)

Pin/bolt joint

3,185

(325)

Bolt joint

7,840

(800)

Pin/bolt joint

6,762

(690)

Bolt joint

7,840

(800)

Pin/bolt joint

6,615

(675)

Bolt joint

14,112

(1,440)

Pin/bolt joint

10,976

(1,120)

Bolt joint

7,056

(720)

Pin/bolt joint

6,174

(630)

Bolt joint

15,680

(1,600)

Pin/bolt joint

12,250

(1,250)

Bolt joint

17,640

(1,800)

Pin/bolt joint

13,524

(1,380)

Bolt joint

22,050

(2,250)

Pin/bolt joint

18,620

(1,900)

50

60

Moment   Allowable  Momentary  Allowable  Allowable  Momentary

Lost

Torsional

Weight

rigidity  moment

max.

max.

acceleration/

max.  motion rigidity (Input inertia)

(Typical Value)  allowable  output   deceleration  allowable   (Typical value)

moment speed  torque  torque

Nm/

Nm

Nm

MAX.

Nm/

arc.min.

(kgf-m) Nm

(kgf-m)

Nm

arc.min.

(kgf-m/arc.min.)

(kgf-m) r/min

(kgf-m)  arc.min. (kgf-m/arc.min.) kg-m

2

kg

Output   Input  Output   Input
torque  capacity  torque  capacity

Nm

kW

Nm

kW

(kgf-m)  (kgf-m)

6.  If a higher speed than the above allowable maximum output speed is required, contact Nabtesco for further information.

7.  If other speed ratio than the above list is required, contact Nabtesco for further information.

8.  *1 RV-80E, R=153 is used only for output shaft bolt-on type.  (page 37,38)

*2 These reduction gear ratios are indivisible figures.  Actually, 175.2=1,227/7, 154.8=2,013/13 and 192.4=1,347/7.

9.  The output revolution is for forward-reverse changeover applications and not applicable for continuous rotation in a single direction.  Contact us when using

the reduction gear for continuous single-direction rotation.

I (=

GD

2

——

4

)

background image

13

Selection

5

5-1 Selection flow chart

Determine load

characteristics

Check the load torque applied to the reduction gear.
An example is shown in on this page.

From the ratings

table

(page 11)

END

END

Temporary selection

of frame number

Service life

calculation (L

h

)

•  Calculate average load

torque (Tm)

•  Calculate average output

speed (Nm)

T

m

N

m

Output speed

Output torque

L

h

≥ Specified Life

(Hrs)

NO

Increase the frame

number or reduce

the load

Choose design of

external bearing

(use RV standard type)

Determine
the input speed

Determine

the acceleration/

deceleration torque

(T

1

, T

3

)

Determine the external

shock torque (T

em

)

due to emergency stop

Determine the external
shock torque (Tout) when
motor shaft speed is zero

Allowable max.

output speed

Input speed.

̶̶̶̶̶̶̶̶̶

Reduction gear ratio

T

em

Tout ≤

T

1

andT

3

Determine

the number of

allowable operation

cycles (Cem)

≤ C

em

NO

NO

NO

NO

NO

NO

NO

NO

Determine
main bearing capacity

Determine output shaft
torsion (θ)
by external moment

W

1

r

1

+

W

2

r

3

θ= ̶̶̶̶̶

̶̶̶(r

2

> b)

M

t X

10

3

(See page 16.)

Increase the frame

number or

reduce the load

Determine
external moment (Mc)

M

c

≤ Allowable moment

Frame selection

Tout: Estimated value

Mc = W

1

r

2

+ W

2

r

3

(r

2

> b)/1,000

(See page 16.)

Check the external load

applied to the reduction gear.

(See page 15)

Allowable

acceleration/

deceleration

torque

Momentary

maximum

allowable

torque

Momentary

maximum

allowable

torque

Number

of operation

cycles

θ ≤

Allowable

torsion

(required value)

θ ≤

Allowable

torsion

(required value)

T

t N T

t N T

t N T

t N t N

t N

m

n

n

n

n

n

· ·

߹ · ·

߹ ··· · ·

· ߹ · ߹ ··· ·

10

3

10

3

10

3

10

3

1

1

1

2

2

2

1

1

2

2

N

t N t N

t N

t t

t

m

n

n

n

ࠋ · ߹ · ߹ ···߹ ·

߹ ߹ ···߹

1

1

2

2

1

2

L

K N

N

T

T

h

o

m

o

m

ࠋ × ×

10

3

( )

C

T

T

N

t

em

o

em

em

em

× ×

( )

×

×

775

5

Z

4

60

10

3

Maximum acceleration torque

Output torque

Output Speed

Time

Maximum

deceleration

torque

N

3

N

1

N

2

T

3

T

2

T

1

t

1

t

2

t

3

0

Constant-speed torque

Constant-speed

operation time

Deceleration

time

Acceleration

time

Time

Fig. 6

Table 2

Conditions to be determined for selection

Duty cycle diagram

For

For

For

For impact due

starting  constant  stopping  to  emergency

(Max)

speed

(Max)

stop

Load torque

Nm

T

1

T

2

T

3

T

em

Speed r/min

N

1

N

2

N

3

N

em

Time sec

t

1

t

2

t

3

t

em

background image

14

E Series

Selection example

Selection conditions

T

1

= 2,500Nm

T

2

= 500Nm

T

3

= 1,500Nm

T

em

= 7,000Nm

t

1

= 0.2sec.

t

2

= 0.5sec.

t

3

= 0.2sec.

t

em

= 0.05sec.

N

1

= N

3

= 10r/min N

2

= 20r/min

N

em

= 20r/min

Z

4

= 40 pins

Determine load characteristic

• Determine average load torque

T

m

=

× + × + ×

10

3

10

3

10

3

10

3

0.2

×10×2,500  +0.5×20×500  + 0.2×10×1,500

02 10 05 20 02 10

.

.

.

= 1,475Nm

• Determine average output speed

0.2×10 + 0.5×20 + 0.2×10

N

m

=—————————————= 15.6r/min

0.2 + 0.5 + 0.2

Provisional selection of the reduction gear.

•  Calculation to determine whether reduction gear

service life meets required specification value.

1,568

1,475

Lh

Hr

=

×

×

=

6,000 15

15 6

7,073

10

3

.

( )

• Determine output speed
Maximum output speed 20r/min < 45r/min

Maximum allowable output speed of RV-160E

• Determine torque during starting and stopping
T

1

= 2,500Nm < 3,920Nm

Allowable acc./dec. torque for RV-160E

T

3

= 1,500Nm < 3,920Nm

Allowable acc./dec. torque for RV-160E

•  Determine emergency stop and external

shock torque

T

em

= 7,000Nm < 7,840Nm

Momentary max. allowable torque for RV-160E

C

em

=

× ×

× ×

=

775 5 1,568

7,000

40 20

60

0 05

1,696

10

3

.

(

)

times

Determine main bearing capacity

• External load conditions
W

1

= 3,000N r

1

= 500mm

W

2

= 1,500N r

3

= 200mm

Determine moment rigidity

•  Determine whether output shaft deflection

angle meets required specification value.

3,000×500 + 1,500×200

θ=———————————— = 0.61(arc.min)

2,940×1,000

• Determine external moment

210.9

r

2

= 500 +——— = 605mm

2

M

c

= 300×0.605 + 1,500×0.20

= 2,115Nm < 3,920Nm

Allowable moment of RV-160E

Since all required specification are
satisfied, select RV-160E-129.

Determine load

characteristics

Check the load torque applied to the reduction gear.
An example is shown in on this page.

From the ratings

table

(page 11)

END

END

Temporary selection

of frame number

Service life

calculation (L

h

)

•  Calculate average load

torque (Tm)

•  Calculate average output

speed (Nm)

T

m

N

m

Output speed

Output torque

L

h

≥ Specified Life

(Hrs)

NO

Increase the frame

number or reduce

the load

Choose design of

external bearing

(use RV standard type)

Determine
the input speed

Determine

the acceleration/

deceleration torque

(T

1

, T

3

)

Determine the external

shock torque (T

em

)

due to emergency stop

Determine the external
shock torque (Tout) when
motor shaft speed is zero

Allowable max.

output speed

Input speed.

̶̶̶̶̶̶̶̶̶

Reduction gear ratio

T

em

Tout ≤

T

1

andT

3

Determine

the number of

allowable operation

cycles (Cem)

≤ C

em

NO

NO

NO

NO

NO

NO

NO

NO

Determine
main bearing capacity

Determine output shaft
torsion (θ)
by external moment

W

1

r

1

+

W

2

r

3

θ= ̶̶̶̶̶

̶̶̶(r

2

> b)

M

t X

10

3

(See page 16.)

Increase the frame

number or

reduce the load

Determine
external moment (Mc)

M

c

≤ Allowable moment

Frame selection

Tout: Estimated value

Mc = W

1

r

2

+ W

2

r

3

(r

2

> b)/1,000

(See page 16.)

Check the external load

applied to the reduction gear.

(See page 15)

Allowable

acceleration/

deceleration

torque

Momentary

maximum

allowable

torque

Momentary

maximum

allowable

torque

Number

of operation

cycles

θ ≤

Allowable

torsion

(required value)

θ ≤

Allowable

torsion

(required value)

T

t N T

t N T

t N T

t N t N

t N

m

n

n

n

n

n

· ·

߹ · ·

߹ ··· · ·

· ߹ · ߹ ··· ·

10

3

10

3

10

3

10

3

1

1

1

2

2

2

1

1

2

2

N

t N t N

t N

t t

t

m

n

n

n

ࠋ · ߹ · ߹ ···߹ ·

߹ ߹ ···߹

1

1

2

2

1

2

L

K N

N

T

T

h

o

m

o

m

ࠋ × ×

10

3

( )

C

T

T

N

t

em

o

em

em

em

× ×

( )

×

×

775

5

Z

4

60

10

3

background image

15

■ 5-2-3 Rated service life

The service life of the E series is based on the life of the roller bearings of the
crankshafts. The service life is set as shown in Table 3 for all models and ratios at
rated torque and at rated output speed.

When in actual service installed in the equipment, calculate the service life
using the following formula because the load condition depends on the types of
reduction gear.

L

h

= K × N

o

N

m

×

T

o

T

m

10

3

5-2 Strength and service life

■ 5-2-1 Allowable torque during acceleration or deceleration

When the Machine starts (or stops) a larger torque than steady-state torque is
applied  to  the  reduction  gear  because  of  the  internal  loads. The  values  in  the
ratings table (see page 11) show the allowable value of the peak torque when the
reduction gear starts or stops.
With the RV-6E, the allowable acceleration/deceleration torque is 200% of the
rated torque; other models in the series have a acceleration/deceleration torque
of 250% of the rated torque.

■ 5-2-2 Momentary maximum allowable torque

A large torque during an emergency stop or external shock may be applied to the
reduction gear.
The maximum allowable torque is shown in the ratings table(see page 11).

Note) 1.  When  shock  torque  is  applied,  be  sure  to  use  at  below  the  limit  cycles(refer  to  selection

flowchart on page 13).

2.  The  momentary  maximum  allowable  torque  differs  between  the  through-bolt  clamping

output shaft type and pin/bolt clamping output shaft type.

L

h

Service life (Hrs)

L

10

K   6,000

Type

Rated torque (T

0

) (Nm)

Rated output speed (N

0

) r/min

RV-6E

58

30

RV-20E

167

RV-40E

412

RV-80E

784

RV-110E

1,078

15

RV-160E

1,568

RV-320E

3,136

RV-450E

4,410

Maximum acceleration torque

Maximum deceleration torque

Momentary maximum torque

Constant speed torque

Load torque

(+)

(ー)

Fig. 7

Table 3

Table 4

Load torque graph

L

h

:  Service life to be obtained (Hr)

N

m

:  Average output speed (r/min)

T

m

:  Average output torque (Nm)

No  :  Rated output speed (r/min)
To  :  Rated output torque (Nm)

background image

16

E Series

5-3 Capacity of main bearing

The E series incorporates angular contact ball bearings so that external loads may
be supported.

■ 5-3-1 Moment rigidity

When an external load is applied to the output shaft, its deflection angle is
proportional to the external moment (where r

2

>b).

The moment rigidity is expressed as an external moment value, which is required
to deflect the output shaft 1 arc. min.

θ=  W

1

r

1

+ W

2

r

3

————————

M

t

×10

3

Table 5

Table 6

Moment rigidity

Size (mm)

Model

Nm/arc.min. *3  a b

RV-6E

117

17.6

91.6

RV-20E

372

20.1

113.3

RV-40E

931

29.6

143.7

RV-80E*

1

1,176

33.4

166.0

RV-80E*

2

1,176

37.4

166.0

RV-110E

1,470

32.2

176.6

RV-160E

2,940

47.8

210.9

RV-320E

4,900

56.4

251.4

RV-450E

7,448

69.0

292.7

*1 Bolt mounting output-shaft type

*2 Pin/bolt mounting output shaft type

*3 The momentary rigidity values are central values.

Allowable moment

Allowable thrust

Model

Nm N

RV-6E

196

1,470

RV-20E

882

3,920

RV-40E

1,666

5,194

RV-80E*

1

2,156

7,840

RV-80E*

2

1,735

7,840

RV-110E

2,940

10,780

RV-160E

3,920

14,700

RV-320E*

1

7,056

19,600

RV-320E*

2

6,174

19,600

RV-450E

8,820

24,500

■ 5-3-2 Allowable moment

Table 6 shows the external moment values(moments during starting and stopping,
etc.) and allowable thrust load that can be supported by the reduction gear.
Refer to figure 9 indicating the range of allowable moment for simultaneous
application of external moment and external thrust.

M

C

≤ Allowable moment

M

C

= {W

1

r

2

+ W

2

r

3

(r

2

> b)} / 1,000

Note) Allowable moment differs depending on two types of model: output shaft bolt-mounting type

and output shaft bolt/pin mounting type.

Fig. 8

θ

: Deflected angle of output shaft (arc.min.)

M

t

: Moment rigidity (Nm/arc.min.)

W

1

, W

2

: Weight (N)

r

1

, r

3

: Arm length (mm)

r

1

= r+

b

2  ― a

r

:  The distance between the output shaft mounting surface and the

loading point (mm)

M

C

: External moment (Nm)

W

1

, W

2

: Weight (N)

r

2

,r

3

: Distance to load point(mm)

r

2

= r+ b ― a

r

: The distance between the output shaft mounting

surface and the loading point (mm)

External loading diagram

*1 Bolt mounting output shaft type

*2 Pin/bolt mounting output shaft type

Output shaft mounting surface

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17

Fig. 9

■ 5-3-3 Momentary maximum allowable moment

A large torque and moment due to emergency stop or external impact may be
applied to the reduction gear.
The maximum allowable moment is shown in the rating table.
(See page 11)

Note)  The momentary maximum allowable moment differs depending on two types of model: output

shaft bolt-mounting type and output shaft bolt/pin mounting type.

2,940

137 196

735 882

1,450

1,666

2,156

0

9,800

7,840

5,194

3,920

3,410

3,040

2,040

1,470

558

RV-40E

RV-80E

RV-6E

RV-20E

Allowable moment (Nm)

Thrust force (N)

2,940 3,920

8,820

9,800

0

10,780

7,920
7,370

4,890
4,380

14,700

19,600

24,500

29,400

RV-450E

RV-320E

RV-160E

RV-110E

2,520

2,170

4,980 5,560

7,056

Allowable moment (Nm)

Thrust force (N)

Allowable moment diagram

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18

E Series

6-1 Rigidity (Torsional rigidity and lost motion) and backlash

When a torque is applied to the output shaft while the input shaft (input gear) is
fixed, torsion is generated according to the torque value and a hysteresis curve
result is shown in Fig. 10.

The rigidity of the reduction gear is expressed by the torsional rigidity and the lost
motion in this curve. RV precision reduction gears are especially superior in their
stiffness characteristics.

•  Torsional rigidity =

b

a

•  Lost motion

The torsion angle at the mid point of the hysteresis curve width at ±3% of

rated torque.

•  Backlash

The torsion angles when the torque indicated by the hysteresis curve is zero.

■ 6-1-1 Calculation of torsion (an example)

Take an example of the RV-160E and find the torsion where a torque is
applied in one direction.
1) If a torque of 30 Nm is applied, the resulting torsion ST

1

, is found as shown

below.

•  Note that the torque is in the lost motion range.
ST

1

=

30

———

47  ×

1(arc.min.)

——————

2

= 0.32 arc.min. or less

2) If a torque of 1,300 Nm is applied, the resulting torsion ST

2

is found as shown

below.

•  Note that the torque is in the rated torque range.
ST

2

=

1

2  +

1,300-47.0

———————

392

= 3.70 arc.min.

Notes) 1.  The above torsion value is that of the reduction gear assembly.

2.  For  special  specifications  of  backlash  and  lost  motion,  contact

Nabtesco.

Fig. 10

Backlash

Torsion angle

Lost motion

±3% of rated torque

Rated torque

Rated torque

ー100%

+100%

a

b

Hysteresis curve

Lost

motion

Model

Torsional rigidity

Lost motion

Measured torque

Backlash

Nm/arc.min.

arc.min.

Nm

arc.min.

RV-6E

20

MAX 1.5

±

1.76

MAX 1.5

RV-20E

49

±

5.00

RV-40E

108

± 12.3

RV-80E

196

± 23.5

RV-110E

294

MAX 1

± 32.3

MAX 1

RV-160E

392

± 47.0

RV-320E

980

± 94.0

RV-450E

1,176

±132.0

Table 7

Performance Characteristics

6

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19

6-3 Angular transmission accuracy

Angular transmission accuracy refers to a difference between the theoretical
output revolution angle and the actual revolution angle (θout) when any revolution
angle (θin) is the input, and is expressed as an angular transmission error (θer).
The angular transmission error is found in the following equation.

θer =  θin

——

R  ― θout (where R = reduction ratio)

The measured example is shown below.

Test conditions
1. Model: RV-320E-171
2. Assembly accuracy:
Recommended accuracy (see page 23)
3. Load conditions: no-load
4. Detector: USR324 + UC101
(manufactured by Nippon Kogaku K.K.)
Resolution: 1 sec

Fig. 12

The vibration is a torsional vibration in the circumferential direction when driven
by a servomotor with an inertia load applied.
The vibration is one of the most important characteristics, especially when
precise contouring control is required.  For example, the industrial robot requires
exact and smooth contour control for its longer arm. An actual measured example
of the vibration characteristics is shown in Fig. 11.

500

0

0.1

0.2

1,000

Servomotor input speed (r/min)

Acceleration
Amplitude

Vibration

Acceleration (G)

Half amplitude (mm)

1,500

2,000

Fig. 11

Test conditions
1. Model: RV-80E
2. Reduction ratio: 1/121
3. Assembly accuracy:
Recommended accuracy (see page 23)
4. Inertia moment on load side:
107.8kgm

2

5. Measured radius: 550 mm

6-2 Vibration

Revolution of output shaft (degrees)

23 sec

Angular transmission error (sec)

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20

E Series

6-4 No-load running torque

6-5 Backdriving torque

The no-load running torque means a torque required on the input shaft (input
gear) side in order to rotate the RV-E reduction gear under no load. Fig. 13 shows the
no-load running torque on the output shaft side, which is converted from the no-load
running torque according to the following equation.
•  No-load running torque converted to motor shaft (Nm)

converted torque on the output shaft side

———————————————————

R

(where R = speed ratio)

Note: The diagram below shows average values obtained after a reduction gear has been run in.

The backdriving torque refers to a torque required for starting the
output shaft, with the reduction gear left under no-load.  If the input
shaft (input gear) is released while a torque equal to or more than
the backdriving torque is kept applied to the output shaft, the input
shaft  (input  gear)  starts  running  at  an  augmented  speed.    Special
care should be given to the backdriving torque required to start the
reduction gear.

60

40

20

20

40

(Nm)

588

392

196

Output shaft speed (r/min)

(kgf-m)

No-load running torque (converted torque on the output shaft side)

60

80

100

0

RV-450E

RV-320E

RV-160E

RV-110E

RV-80E

RV-40E

RV-20E

RV-6E

0

Model

Backdriving torque Nm

RV-6E

10

RV-20E

42

RV-40E

47

RV-80E

70

RV-110E

80

RV-160E

110

RV-320E

220

RV-450E

270

Fig. 13

Table 8

Test conditions
1. Ambient temperature: 30℃
2. Assembly accuracy: recommended
accuracy (see page 23)
3. Lubricant: grease (Molywhite RE00)

Test conditions
Assembly accuracy:  recommended accuracy

(see page 23)

Lubricant: grease (Molywhite RE00)

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21

6-6 Low-temperature Characteristics (No-load running torque under low temperature)

When the reduction gear is used under a low temperature, viscosity of
lubricant increases and causes a larger no-load running torque.
The no-load running torque under low temperature is shown below.

Test conditions
1. Assembly accuracy: recommended accuracy (see page 23)
2. Lubricant: grease (Molywhite RE00)
3. Input speed: 2,000 r/min

10

5

0

0.98

0.49

1/37
1/79

1/103

ー10

0

10

20

RV-6E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

20

10

0

1.96

0.98

1/57

1/105

1/141

ー10

0

10

20

RV-20E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

50

25

0

4.9

2.45

1/57

1/121

1/153

ー10

0

10

20

RV-40E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

50

25

0

4.9

2.45

1/57
1/121

1/171

ー10

0

10

20

RV-80E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

100

50

0

9.8

4.9

1/81
1/111

1/175.28

ー10

0

10

20

RV-110E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

100

50

0

9.8

4.9
1/81
1/129
1/171

ー10

0

10

20

RV-160E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

200

100

0

19.6

9.8

1/81

1/129

1/185

ー10

0

10

20

RV-320E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

200

100

0

19.6

9.8

1/81
1/129
1/192

ー10

0

10

20

RV-450E

Case temperature (℃)

No-load running torque (kgf-cm)

(Nm)

Fig. 14

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22

E Series

6-7 Efficiency charts

Test conditions
1. Case temperature: 30℃
2. Assembly accuracy: recommended accuracy (see page 23)
3. Lubricant: grease (Molywhite RE00)

100

80

60

40

20

0

78.4

(8)

58.8

(6)

39.2

(4)

19.6

(2)

Nm

(kgf-m)

RV-6E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

10 r/min

30 r/min

60 r/min

100

80

60

40

20

0

196

(20)

147

(15)

98

(10)

49

(5)

Nm

(kgf-m)

10 r/min

30 r/min

60 r/min

RV-20E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

100

80

60

40

20

0

392

(40)

490

(50)

294

(30)

196

(20)

98

(10)

Nm

(kgf-m)

10 r/min

25 r/min

50 r/min

RV-40E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

100

80

60

40

20

0

980

(100)

735

(75)

490

(50)

245

(25)

Nm

(kgf-m)

10 r/min

25 r/min

50 r/min

RV-80E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

100

80

60

40

20

0

1,176

(120)

882

(90)

588

(60)

294

(30)

Nm

(kgf-m)

10 r/min

25 r/min

40 r/min

RV-110E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

100

80

60

40

20

0

1,960

(200)

1,470

(150)

980

(100)

490

(50)

Nm

(kgf-m)

10 r/min

25 r/min

40 r/min

RV-160E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

RV-320E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

100

80

60

40

20

0

3,528

(360)

2,646

(270)

1,764

(180)

882

(90)

Nm

(kgf-m)

10 r/min

20 r/min

30 r/min

100

80

60

40

20

0

4,900

(500)

3,675

(375)

2,450

(250)

1,225

(125)

Nm

(kgf-m)

5 r/min

15 r/min

25 r/min

RV-450E

efficiency curve

Efficienc

y (%)

Output torque (Nm)

Fig. 15

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23

Installation and Assembly

7

7-1 Assembly accuracy

7-2 Installation procedure

To get maximum performance from E series, it is important to pay attention to the
assembly accuracy, installation, lubrication and sealing.
Angular ball bearings are used as the main bearings.  When designing the layout,
make sure the bearing retainer will not touch the motor mounting flange.  Refer to
the table to the right.

Design motor mounting flange within tolerances shown in Table 10.
Poor assembly accuracy causes vibration and noise.

•  Typical installation examples for reduction gear are shown below.

Be sure to seal the designated type of grease to the designated
level.  (See page 29)

•  Be  sure  that  seals  are  used  between  mating  parts  on  the  input

side.  Refer to the O-ring seal installation illustrated.

•  If the use of an O-ring seal is impossible because of the design,

use Gasket sealant shown in table 11.

•  Use either outer or inner centering locations for piloting.

Manufacturer Name

ThreeBond 1211

• Silicone-based, solventless type

(ThreeBond Co.)

• Semi-dry gasket

HermeSeal SS-60F

• One-part, non-solvent elastic sealant

(Nihon Hermetics Co.)

• Metal contact side (flange surface) seal

• Any product basically equivalent to ThreeBond 1211

Loctite 515

• Anaerobic flange sealant

(Henkel)

• Metal contact side (flange surface) seal

Notes  1. Do not use these sealants for copper material or copper alloy material.

2. If these sealants need to be used under special conditions such as concentrated alkali,

pressurized steam, etc., please contact Nabtesco.

X

Y

RV-6E

MAX 1.9

MAX φ85

RV-320E

MAX 3.2

MAX φ222.2

RV-450E

MAX 5.5

MAX φ285

With other models, the retainer does not stick out from the casing.

Table 10

Unit: mm

Tolerance for concentricity

Model

a

RV-6E

MAX0.03

RV-20E

MAX0.03

RV-40E

MAX0.03

RV-80E

MAX0.03

Concentricity tolerance

Type

a

RV-110E

MAX0.03

RV-160E

MAX0.05

RV-320E

MAX0.05

RV-450E

MAX0.05

Table 11 Recommended liquid sealant

Table 9

Fig. 16

Fig. 17

Applicable O-ring

RV-6E

S100

RV-20E

S120

RV-40E

AS(ARP)568-258

RV-80E

AS(ARP)568-263

RV-110E  JIS B2401-G190
RV-160E  JIS B2401-G220
RV-320E  JIS B2401-G270
RV-450E  JIS B2401-G300

Note: The sizes of bolts for tightening the output shaft are not all the same.  Make sure that each bolt is tightened with the specified torque after assembling.

Table 12 O-ring (

II)

■ 7-2-1 Bolt clamping output shaft type

Fig. 18

Assembly example

110E or above

O-ring (

II)

Output shaft

Use fluid sealant for mounting

surface (See table 11)

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24

E Series

Note:  The prepared pinhole and the output shaft need to be reamed jointly with a reamer before knocking in the taper pin.

The reduction gear needs to be appropriately covered during reaming to prevent chips from entering inside.

A different method is used on 80E to knock in the taper pin, so follow the next procedure for assembling.

■ 7-2-2 Pin/bolt clamping output shaft type

Installation of 20E, 40E

Installation of 160E, 320E, 450E

Fig. 19

Installation example for 80E

Fig. 21

Fig. 20

1.  Loosely  tighten  the  hexagon

socket head bolt to temporarily

secure the reduction gear shaft

to the output shaft.

2. Remove the taper pin (with M8 screw) installed

in the reduction gear.

3. From the hole of the removed taper pin, drill a hole

for the taper pin (10 mm. dia.) in the output shaft.

At this time, masking is needed to prevent chips

from entering the reduction gear.

4. After  reaming,  remove  the  bolt  to  remove  the

reduction gear, then remove any chips and

burrs.

5.  Install  the  reduction  gear  and  knock

in the taper pin for fixing the output

shaft.

6. Tighten  the  hexagon  socket  headed

bolt securely to fix the reduction gear

to the output shaft.

7.  Knock  in  the  taper  pin

(with M8 screw) to fix the

reduction  gear.  Use  a

taper pin with screw.

a

a

a

Table 13

Dimensions for O-ring (

I) seal

Table 14

O-ring (

II) seal dimensions

Table 15

Dimensions for O-ring (

III) seal

For RV-80E

For RV-110E

For RV-40E

For RV-20E(B)

For RV-20E(A)

For RV-160E

For RV-320E

For RV-450E

Dimensions

O-ring

Groove size

ID No.

Wire dia.

I. D.

Outside dia.: D

Depth: H

Width: G

Height: K

(For reference)

AS(ARP)568-045

φ  1.78±0.07

φ 101.32±0.38

φ 105

1.27±0.05

2.39

3

S100

φ  2.0 ±0.1

φ  99.5 ±0.4

φ 105

1.5

2.7

3

AS(ARP)568-163

φ  2.62±0.07

φ 152.07±0.58

φ 160

2.06±0.05

3.58

3

AS(ARP)568-167

φ  2.62±0.07

φ 152.07±0.58

φ 160

2.06±0.05

3.58

3

AS(ARP)568-265

φ  3.53±0.1

φ 196.44±0.76

φ  204

2.82±0.05

4.78

4

AS(ARP)568-271

φ  3.53±0.1

φ 234.54±0.76

φ 243

2.82±0.05

4.78

4

AS(ARP)568-275

φ  3.53±0.1

φ 266.29±0.76

φ 273

2.82±0.05

4.78

4

(Unit: mm)

(Unit: mm)

0

− 0.1

+ 0.25

0

+ 0.25

0

+ 0.25

0

+ 0.25

0

+ 0.25

0

+ 0.25

0

+ 0.25

0

S132

φ  2.0 ±0.1

φ 131.5 ±0.6

φ 135

1.5

2.7

3

+ 0.25

0

0

− 0.1

For RV-160E

For RV-80E

For RV-40E

For RV-20E

For RV-320E

For RV-450E

ID No.

S120

AS(ARP)568-258

JIS B2401-G220

AS(ARP)568-263

JIS B2401-G270

JIS B2401-G300

For RV-40E

For RV-20E

Dimensions

O-ring

Groove  dimensions

ID No.

Wire dia.

I. D.

Outside dia: D

Depth: H

S12.5

φ  1.5 ±0.1

φ  12

φ  14.8 ±0.1

1

S14

φ  1.5 ±0.1

φ  13.5

φ  16.3 ±0.1

1

(Unit: mm)

Notes  1. Use O-ring seal of either type (A) or type (B)  for RV-20E. (Both of them are available)

2. The part number CO or S type indicates the S-standard O-ring supplied by NOK.

3. The O-ring number AS type indicates an O-ring supplied by Mitsubishi Cable Industries.

4. The ARP in the ID number is a former name.

Outer centering location

Inner centering

location

O-ring (

II)

Groove size for O-ring (

I)

Taper pin

Output shaft

O-ring (

II)

Output shaft

Details of O-ring(

I) groove

Output shaft

Output shaft

O-ring (

II)

Groove for O-ring(

I) groove

Taper pin

(with M8 thread)

0

− 0.1

0

− 0.1

Groove size for O-ring
seal (

III) (4 places)

Output shaft

Output shaft

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25

7-3 Bolt tightening torque and allowable transmission torque

Use hexagonal socket bolts to assemble the RV precision gear and tighten to the
torque as specified below. When the pin/bolt mounting output shaft type is used,
also use the taper pin.  The serrated lock washer is recommended to prevent the
bolt from loosening and protect the bolt seat face from flaws.

Tightening force (F)

Hexagonal socket bolt

Tightening torque

Tightening force (F)

Bolt specification

nominal size x pitch (mm)

Nm

N

M5  × 0.8

9.01 ±  0.49

9,310

M6  × 1.0

15.6  ±  0.78

13,180

M8  × 1.25

37.2  ±  1.86

23,960

M10 × 1.5

73.5  ±  3.43

38,080

M12 × 1.75

128.4  ±  6.37

55,100

M14 × 2.0

204.8  ± 10.2

75,860

M16 × 2.0

318.5  ± 15.9

103,410

Notes  1. The valves listed are for steel or cast iron material.

2. If softer material such as aluminum is used, limit the tightening torque.  Also pay attention to the system torque requirements.

3. Tighten all bolts of the pin/bolt oclamping output shaft type with the specified tightening torque.

•  Hexagonal socket bolt
JIS B 1176
•  Strength class
JIS B 1051 12.9
•  Thread
JIS B 0205 6g or class 2

Calculation of allowable transmission torque of bolts

T

1

= F × D

1

2 × μ × n

1

T

1

:  bolt allowable transmission torque (Nm)

F  :  bolt tightening force (N)
D

1

:  bolt P.C.D. (mm)

μ :  friction factor

μ = 0.15: where lubricants remained
μ = 0.2: where left dried with no lubricant

n

1

:  number of bolts

Calculation of allowable transmission torque of bolt and additional pin(s)

T

2

= T

1

+ π d

2

——

4 × τ ×

D

2

2 × n

2

T

2

:

allowable transmission torque of bolt and additional pin (Nm)

d  :  pin diameter (mm)

τ  :  pin allowable shearing strength (N/mm

2

)

[τ = 196 : pin material S45C-Q]

D

2

:  pin P.C.D. (mm)

n

2

:  number of pins

Table 16

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26

E Series

•  The standard-sized input gear comes from the factory without holes drilled for

motor shafts.

•  The following are reference drawings for installation of input shafts.  Customers

must provide set screw, hexagonal socket bolt, hexagonal nut, and draw bolt.

Some low ratio input gears will not fit through the center of the RV gear.  See 7-4-

3.

7-4 Installation of input gear

Serrated lock washer for hexagonal socket bolt

Name:  Belleville spring washer (made by Heiwa Hatsujyo Industry Co., Ltd.)
Corporation symbol:   CDW-2H – nominal size

CDW-2L – 5 (for only M5)

Material: S50C to S70C
Hardness: HRC40 to 48

ID and OD of washer

Nominal size

d

D

t

H

Basic size

5

5.25

8.5

0.6

0.85

6

6.4

10

1.0

1.25

8

8.4

13

1.2

1.55

10

10.6

16

1.5

1.9

12

12.6

18

1.8

2.2

14

14.6

21

2.0

2.5

16

16.9

24

2.3

2.8

Note: When using any equivalent washer, select it, with special care given to its

outside diameter.

Fig. 22

(Unit: mm)

Table 17

Straight shaft

No female threaded on servomotor

With female threaded on servomotor

Fig. 23

Taper shaft

With male threaded on servomotor

Set screw

Draw bolt

Hexagonal socket bolt

Hexagonal nut

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27

Fig. 24

Fig. 25

■ 7-4-1 Precautions for installation of RV-6E, 20E and 40E

input gears

RV-6E,  RV-20E  and  RV-40E  have  two  spur  gears.    Special  care  must  be  used
when installing the input gear to prevent misalignment.
Insert the input gear.  If the input gear does not engage with the spur gear, insert
the input gear by turning it clockwise or counterclockwise a little.  Make sure that
the motor flange is fitted closely and squarely.  Do not tighten motor with screws
unless the motor is properly aligned.  If the motor flange is at an angle, there is a
possibility that the input gear is installed in an incorrect position.  (See Fig. 24)

■ 7-4-2 Pass-through capacity of input gear

Lower ratio input gears may have diameters too large to pass through the RV gear
center.  The following table shows which ratios can and can not allow the input
gear to pass through.

(Unit: mm)

Table 18

* Not described on the rating table. Please consult Nabtesco if needed.

Incorrect position

Correct position of assembled input gear

Hole dia.  Depth

Speed ratio adequate for shaft passage

Speed ratio inadequate for shaft passage

Model

d

1

d

2

r

Shaft revolution

Case revolution

Shaft revolution  Case revolution

RV-6E

19  21  18

53.5, 59, 79, 103  52.5, 58, 78, 102

31, 43

30, 42

RV-20E  22  24  18.5  81, 105, 121, 141  80, 104, 120, 140

57

56

RV-40E  27  30  23.5  81, 105, 121, 153  80, 104, 120, 152

57

56

RV-80E  37  40  23

81, 101, 121, 153  80, 100, 120, 152

57

56

RV-110E  39  42  20

81, 111, 127.7

80, 110, 126.7

——

——

161, 175.2

160, 174.2

RV-160E  43  47  30

81, 101, 129

80, 100, 128

66*

65*

145, 171

144, 170

RV-320E  47  52  35.5  81, 101, 118.5

80, 100, 117.5

66*

65*

129, 141, 171, 185  128, 140, 170, 184

RV-450E  57  62  43

81, 101, 118.5

80, 100, 117.5

66*

65*

129, 155, 171, 192  128, 154, 170, 191

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28

E Series

7-5 Lubrication

To maximize the performance of the RV precision gear, the use of
VIGOGREASE RE0 manufactured by Nabtesco is recommended.

■ 7-5-1 Grease lubrication

The standard lubrication of the reduction gear is grease.

Table 21

Table 20

Brand of recommended lubricant

Working temperature range (ambient temperature)

Grease

Nabtesco

VIGOGREASE RE0

Note: Please consult Nabtesco if grease or gear oil is to be used beyond the specified

temperature range.

Note: Do not mix the recommended grease or gear oil with any other lubricant.

■ 7-4-3 An example of installation for the reduction gear with

lower speed ratio

The lower the speed ratio, the larger the outside diameter of the input gear.  Therefore,
the installation of the input gear through the reduction gear is not possible with all
ratios.  In such cases a two-piece input gear is required.  An example is shown below:

Fig. 26

Table 19

Model

RV-6E

RV-20E

RV-40E

RV-80E*

1

RV-80E*

2

RV-160E

RV-320E

RV-450E

L

96

95

105

110

110

130

155

200

LA

60

53

58

LB

23

30

30

35

35

38

48

48

D

18

21.5

26.5

36

36

42

46

56

D

1

28

23.5

29.5

36

36

42

46

56

LC

92

90

103

109

105

128

148

195

LD

+ 0.1

0

10.3

11.7

13.9

13.9

13.9

15.1

16.1

17.6

LE

16

17

19

15.5

19.5

21

22

26

LG

±0.1

13

14

16

12

16

17

18

22.5

LH

7.5

9

11.5

16

12

16

20

21

Deep groove ball bearing

6,002

6,003

6,004

6,005

6,005

6,006

6,007

6,008

(Unit: mm)

Note:  Deep groove ball bearing and C-shaped snap rings are to be provided by the customer.

*1: Bolt mounting output shaft type

*2: Pin/bolt mounting output shaft type

C type snap ring for shaft

JISB2804

C type snap ring for hole

JISB2804

Input gear

Input spline

Deep groove ball bearing

Item

Specifications

Allowable temperature diagram
Use the grease with no condensation and the reduc-
tion  gear  circumference  temperature  and  ambient
temperature in the range in the right diagram.

During  proper  operation  of  the  reduction  gear,  the
standard  grease  replacement  time  due  to  lubricant
degradation is 20,000 hours.
However,  when  operation  involves  a  reduction  gear
surface temperature above 40°C (the area in the right
diagram           ), the state of the lubricant should be
checked in advance and the grease replaced earlier
as necessary.

Lubricant

VIGOGREASE RE0

Reduction gear surface temperatur

e(°C)

Ambient temperature(°C)

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29

1) The quantity of grease required for the reduction gear

The reduction gear is not greased when it is shipped from the plant.  Therefore, ensure that
necessary amount of recommended grease is charged when installing the reduction gear.

Note:  The  quantity  required  for  the  reduction  gear  is  shown  below. The  volume  of  grease

listed below does not include the volume required to fill the space between the
reduction  gear  and  the  coupling  components.  If  there  is  any  space,  it  must  also  be
charged with grease.

However, too much filling may causes damage for an oil seal with increase of internal
pressure. Please leave about 10% of the room inside.

2) Grease (gear oil) level in RV-E reduction gear

Table 23

Vertical installation

Model

Quantity

cc

(g)*

RV-6E

42

(38)

RV-20E

87

(78)

RV-40E

195  (176)

RV-80E (Bolt clamping)

383  (345)

RV-80E (Pin/bolt clamping)

345  (311)

RV-110E

432  (389)

RV-160E

630  (567)

RV-320E

1,040  (936)

RV-450E

1,596 (1,436)

Model

Quantity

cc

(g)*

RV-6E

48

(43)

RV-20E

100

(90)

RV-40E

224  (202)

RV-80E (Bolt clamping)

439  (395)

RV-80E (Pin/bolt clamping)

396  (356)

RV-110E

495  (446)

RV-160E

694  (625)

RV-320E

1,193 (1,074)

RV-450E

1,831 (1,648)

Table 22

Horizontal installation

Horizontal installation

Vertical installation (1)

Vertical installation (2)

Fig. 27

Fixed

Rotate

Servomotor

For charging/

discharging

Grease level

For charging/discharging

Rotate

Fixed

For charging/discharging

Servomotor

For charging/

discharging

Rotate

For charging/discharging

Servomotor

Grease level

3/4d

d

For charging/

discharging

Grease level

* Density of VIGO GREASE RE0: 0.9 g/cc
• When using Molywhite RE00, contact our service department.

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30

E Series

3) Interval between grease changes
Change grease at a standard interval of 20,000 hours after initially supplying the
RV-E reduction gear with grease in  the specified quantity (see Fig. 27) in order to
protect the RV-E reduction gear from deteriorated grease.
If grease is contaminated for any reason or used at an ambient temperature of
40℃ or more, check the grease for contamination and deterioration, to determine
the proper maintenance interval.

4) Running-in operation
It  is  recommended  that  the  running-in  operation  is  performed. Abnormal  noise
or torque variation may occur during operation due to the characteristics of the
lubricant. There  is  no  problem  with  the  quality  when  the  symptom  disappears
after the running-in operation is performed for 30 minutes or more (until the
surface temperature of the reduction gear reaches around 50°C).

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31

8-1 R

V-6E

External dimensions of bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-6E-

-

A

-B

External Dimensions

8

Speed ra

tio

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32

E Series

8-2 R

V-6E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-6E-

-

A

-B

Speed ra

tio

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33

8-3 R

V-20E

External dimensions of bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-20E-

57

-

-B

A B

Speed ra

tio

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34

E Series

8-4 R

V-20E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-20E-

-

-B

A B

Speed ra

tio

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35

8-5 R

V-40E

External dimensions of bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-40E-

57

-

-B

A B

Speed ra

tio

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36

E Series

8-6 R

V-40E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-40E-

-

-B

A B

Speed ra

tio

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37

8-7 R

V-80E

External dimensions of bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-80E-

57

-

-B

A B

Speed ra

tio

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38

E Series

8-8 R

V-80E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-80E-

-

-B

A B

Speed ra

tio

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39

8-9 R

V-1

10E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-110E-

-

A

-B

Speed ra

tio

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40

E Series

8-10 R

V-160E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-160E-

-

-B

A B

Speed ra

tio

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41

8-1

1 R

V-320E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-320E-

-

-B

A B

Speed ra

tio

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42

E Series

8-12 R

V-450E

External dimensions of bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-450E-

-

-B

A B

Speed ra

tio

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43

8-13 R

V-20E

External dimensions of pin and bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-20E-

57

-

-P

A B

Speed ra

tio

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44

E Series

8-14 R

V-20E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-20E-

-

-P

A B

Speed ra

tio

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45

8-15 R

V-40E

External dimensions of pin and bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-40E-

57

-

-P

A B

Speed ra

tio

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46

E Series

8-16 R

V-40E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-40E-

-

-P

A B

Speed ra

tio

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47

8-17 R

V-80E

External dimensions of pin and bolt c

lamping output shaft type (2 piece input gear)

Type code RV

-80E-

57

-

-P

A B

Speed ra

tio

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48

E Series

8-18 R

V-80E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-80E-

-

-P

A B

Speed ra

tio

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49

8-19 R

V-160E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-160E-

-

-P

A B

Speed ra

tio

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50

E Series

8-20 R

V-320E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-320E-

-

-P

A B

Speed ra

tio

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51

8-21 R

V-450E

External dimensions of pin and bolt c

lamping output shaft type (1 piece input gear)

Type code RV

-450E-

-

-P

A B

Speed ra

tio

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52

Precision Reduction Gear RV

TM

C

Series

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53

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54

C Series

Features and Benefits

1

Fig. 1

•  Cables and other lines can pass through the reduction gear
•  Allows space saving design

Hollow shaft structure

Benefits:
•  Increases reliabilty
•  Reduces overall cost

Attributed to:

•  Built-in angular ball bearing construction improves

ability to support external loads, increases moment
rigidity and maximum allowable moment.

•  Reduces the number of components required.
•  Simplifies installation and maintenance.

Integrated angular ball bearings

Attributed to:

•  Low speed rotation of the RV gear reduces

vibration.

•  Reduced  size  of  the  motor  coupling  part  (input

gear) lowers intertia.

Benefits:
•  Reduces vibration
•  Reduces inertia (GD

2

)

2-stage reduction

Detail:

•  Crankshafts  are  supported  on  both  sides  of  the

reduction gear as shown below.

Benefits:
•  Higher torsional stiffness
•  Less vibration
•  High shock load capability (5 times rated torque)

All main elements are supported from both sides

Attributed to:
•  Use of roller bearings throughout.

Benefits:
•  Excellent starting efficiency
•  Low wear and longer life
•  Low backlash (Less than 1 arc. min.)

Rolling contact elements

Attributed to:

•  Synchromeshing  of  many  precision  ground  gear

teeth and pins.

Benefits:
•  Very low backlash (Less than 1 arc. min.)
•  Higher shock load capability (5 times rated torque)

Pin & gear structure

Shaft + hold flange

Clearance hole for rigid

supporting structure

Crankshaft

through hole

RV gear

Rigid supporting structure

Crankshaft bearing supports

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55

Construction and Operation Principle

2

■ Construction

■ Principle of speed reduction

Fig. 2

The C series is a 2-stage reduction gear.

1st stage

…Spur gear reduction

•  An  input  gear  engages  with  and  rotates  a  center  gear  which  then  engages  and  rotates

spur gears that are coupled to crankshafts.  Several overall gear ratios can be provided by
selecting various first stage ratios.

2nd stage …Epicyclic gear reduction

•  Crankshafts driven by the spur gears cause an eccentric motion of two epicyclic gears called

RV gears that are offset 180 degrees from one another to provide a balanced load.

The eccentric motion of the RV gears causes engagement of the cycloidal shaped gear teeth

with cylindrically shaped pins located around the inside edge of the case.

In the course of one revolution of the crankshafts the teeth of the RV gear move the distance

of  one  pin  in  the  opposite  direction  of  the  rotating  cranks.   The  motion  of  the  RV  gear  is
such that the teeth remain in close contact with the pins and many teeth share the load
simultaneously.

•  The output can be either the shaft or the case.  If the case is fixed, the shaft is the output.  If

the shaft is fixed, the case is the output.

Fig. 3

Crankshaft

Case

Pin

RV gear

Main bearing

Hold flange

Input gear

Shaft

Spur gear

Center gear

Crankshaft rotating angle: 0 degree

Rotating angle: 180 degrees

Rotating angle: 360 degrees

Case

Crankshaft

(Connected to spur gear)

Shaft

RV gear

Pin

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56

C Series

Rotary Direction and Speed Ratio

3

The rotary direction and speed ratio of the C series are shown below.

■ Speed ratio

The overall speed ratio i (of the First and Second reduction stages)
will differ depending on the use, and can be calculated using the
speed ratio values displayed in the table below.

With the shaft as output;

R = R

1

×  Z

2

Z

1

i = –

1

R

(R

1

= 1 +  Z

4

Z

3

・Z

6

Mechanism block drawing

Fig.

5

R  :  Overall speed ratio
R

1

:  Speed ratio of a discrete reduction gear

Z

1

:  Number of teeth on input gear

Z

2

:  Number of teeth on large center gear

Z

3

:  Number of teeth on small center gear

Z

4

:  Number of teeth on spur gear

Z

5

:  Number of teeth on RV gear

Z

6

:  Number of pins

i  :  Reduction ratio

Case

Shaft

Crankshaft

RV gear

Pin

Output

Center gear

Note:  The speed ratio values and rotation directions shown above

indicate when the motor (motor fixing component) is installed
on the case side of the reduction gear.

Fig. 4

Reduction

gear

1. Case fixed, shaft output

2. Shaft fixed, case output

3. Input gear fixed, shaft output

Input: Input gear

i =

1

R

1

Input: Shaft

i =  R

1

Input: Input gear

i =

1

———

R

1

-1

Input: Case

i = R

1

-1

Input: Case

i =

R

1

-1

———

R

1

Input: Shaft

i =

R

1

———

R

1

-1

Speed

increasing

gear

4. Case fixed, input gear output

5. Shaft fixed, input gear output

6. Input gear fixed, case output

i = -

1

R

Installation example (motor installed on case side of reduction gear)

1. Case is fixed, shaft output

2. Shaft fixed, case output

i =

1

R

The sign "

i " in the above equations signifies

the output shaft rotation in the same direction
as the input shaft. “-” signifies the output
shaft rotation in the opposite direction as the
input shaft.

2nd reduction

1st reduction

Input gear

Spur gear

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57

Rating Table

4

Table 1

Notes:  1. Set maximum input shaft speed to a value equal to or lower than the value of maximum allowable output speed multiplied by the overall speed ratio for each type.

2. The input capacity (KW) in the above table is determined by the efficiency of these reduction gears.

3. The output torque (Nm) is so determined that the service life may be maintained constant for any output revolutions.  (N・T = Constant)

4. The rated torque is a torque at an output speed of 15 r/min, which is used as a basis for service life calculations. (Refer to the rated service life, page 61.)

5. The

GD

2

——

4

value is a value for a discrete reduction gear, and the

GD

2

——

4

for  center  and  input  gears  is  not  included.   Therefore,  refer  to  the  following  equation

regarding the

GD

2

——

4

converted to motor shaft.

GD

2

——

4

of reduction gear unit

+

GD

2

——

4

of center gear

————————————————————————————————

(Number of teeth on large center gear / Number of teeth on input gear)

2

GD

2

——

4

of input gear

136

111

98

90

84

80

73

68

RV-10C

27

0.09

0.16

0.21

0.25

0.29

0.34

0.41

0.47

(13.9)    (11.3)    (10)    (9.17)    (8.58)    (8.12)    (7.45)    (6.97)

36.57

368

299

265

243

227

215

197

184

RV-27C

0.26

0.42

0.55

0.68

0.79

0.90

1.10

1.29

(1,390/38)

(37.5)    (30.5)    (27)    (24.8)    (23.2)    (21.9)    (20.1)    (18.8)

32.54

681

554

490

450

420

398

366

341

RV-50C

0.48

0.77

1.03

1.26

1.47

1.67

2.04

2.38

(1,985/61) (69.5)    (56.5)    (50)    (45.9)    (42.9)    (40.6)    (37.3)    (34.8)

1362

1107

980

899

841

796

730

RV-100C 36.75

0.95

1.55

2.05

2.51

2.94

3.33

4.08

(139)    (113)    (100)    (91.7)    (85.8)    (81.2)    (74.5)

34.86  2,724

2,215

1,960

1,803

1,686

1,597

RV-200C

1.90

3.09

4.11

5.04

5.88

6.69

(1,499/43) (278)    (226)    (200)    (184)    (172)    (163)

35.61  4,361

3,538

3,136

2,881

2,690

RV-320C

3.04

4.94

6.57

8.05

9.41

(2,778/78) (445)    (361)    (320)    (294)

(275)

6,811

5,537

4,900

4,498

RV-500C 37.34

4.75

7.73

10.26

12.56

(3,099/83) (695)    (56.5)    (500)    (459)

Model

Output speed (r/min)

5  10 15 20 25 30 40 50

Output  Input  Output  Input  Output  Input  Output  Input  Output  Input  Output  Input  Output  Input  Output  Input
torque  capacity  torque  capacity  torque  capacity  torque  capacity  torque  capacity  torque  capacity  torque  capacity  torque  capacity

Speed ratio

of a

discrete

reduction

gear (R

1

)*

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

Nm

kW

(kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)  (kgf-m)

10

3

background image

58

C Series

65

421

686

1,372

245

490

47

0.54

(43)

(70)

(140)

80

(25)

(50)

1

(4.8)

1.34×10

− 5

0.678×10

− 3

4.6

(6.60)

174

1,068

980

1,960

662

1,323

147

1.46

(109)

(100)

(200)

60

(67.5)

(135)

1

(15)

0.628×10

− 4

0.563×10

− 3

8.5

(17.8)

Bolt joint

1,960

1,764

3,528

1,225

2,450

255

50

(250)

1

1.82×10

− 4

0.363×10

− 2

14.6

(200)  (180)  (360)

(125)  Through-bolt joint

(26)

1,960

(200)

Bolt joint

2,813

2,450

4,900

2,450

4,900

510

40

(500)

1

0.47×10

− 3

0.953×10

− 2

19.5

(287)  (250)  (500)

(250)  Through-bolt joint

(52)

3,430

(350)

Bolt joint

9,800

8,820  17,640

4,900

9,800

980

30

(1,000)

1

0.995×10

− 3

1.94×10

− 2

55.6

(1,000)  (900) (1,800)

(500)  Through-bolt joint

(100)

7,350

(750)

12,740

20,580  39,200

7,840

15,680

1,960

(1,300)

(2,100)

(4,000)

25

(800)

(1,600)

1

(200)

0.68×10

− 2

0.405×10

− 1

79.5

24,500

34,300

78,400

12,250

24,500

3,430

(2,500)

(3,500)

(8,000)

20

(1,250)

(2,500)

1

(350)

0.98×10

− 2

154

60

Moment  Allowable  Momentary  Allowable  Allowable  Momentary

Lost

Torsional

Weight

rigidity

moment

max.

max.

acceleration/

max.

motion

rigidity

Inertia

Inertia

Typical value

allowable  output  deceleration  allowable

Typical value  of reduction

of center

moment

speed

torque

torque

gear unit

gear

Nm/

Nm

Nm

MAX.

Nm/

arc.min.  (kgf-m)  Nm

(kgf-m)  Nm

arc.min.

(kgf-m/arc.min.)

(kgf-m)  r/min

(kgf-m)  arc.min. (kgf-m/arc.min.)

kg-m

2

kg-m

2

kg

Output  Input
torque  capacity

Nm

kW

(kgf-m)

6. If a higher speed than the above allowable maximum output speed is required, contact Nabtesco for further information.

7. The output revolution is for forward-reverse changeover applications and not applicable for continuous rotation in a single direction. Contact Nabtesco when

using the reduction gear for continuous single-direction rotation.

8. *1:  The speed ratio values shown above indicate when the motor (motor fixing component) is installed on the case side of the reduction gear. Note that the

values are smaller by 1 when the motor (motor fixing component) is installed on the shaft side of the reduction gear.

I (=

GD

2

——

4

)

I (=

GD

2

——

4

)

( ) ( )

background image

59

Maximum

output speed

Input speed

̶̶̶̶̶̶̶̶̶

Reduction gear ratio

Determine load

characteristic

Check the load torque applied to the speed reduction gear.
An example is shown at right.

From the rating

table

(page 57)

END

Temporary selection

of frame number

Service life

calculation (L

h

)

•  Calculate average load

torque (Tm)

•  Calculate average output

speed (Nm)

T

m

N

m

Output speed

Output torque

L

h

≥ Specified value

NO

Increase the frame

number or reduce

the load

Increase frame number of

reduction gear or

decrease that of load side.

Determine
the input speed

Determine the external

shock torque (T

em

)

due to emergency stop

Determine the external
shock torque (Tout) when
motor shaft speed is zero

Determine

the number of

allowable operation

cycles (Cem)

NO

NO

NO

NO

NO

NO

NO

NO

Determine
main bearing capacity

Determine output shaft
torsion (θ)
by external moment

W

1

r

1

+ W

2

r

3

θ= ̶̶̶̶̶̶̶̶(r

2

> b)

M

t

10

3

(Refer to page 62.)

Increase the frame
number or reduce
the load

Determine
external moment (Mc)

M

c

≤ Allowable moment

(table 1)

Frame selection

Tout: Estimated value

Mc = W

1

r

2

+ W

2

r

3

(r

2

> b)/1,000

(Refer to page 62.)

Check the external load applied to

the reduction gear.

(Refer to page 61)

θ≤

Allowable

torsion

(required value)

θ≤

Allowable

torsion

(required value)

Tout ≤

Momentary

maximum

allowable

torque

T

em

Momentary

maximum

allowable

torque

T

1

or  T

3

≤ C

em

Number

of operation

cycles

Determine

the acceleration/

deceleration torque

(T

1

, T

3

)

Allowable

acceleration/

deceleration

torque

T

t N T

t N T

t N T

t N t N

t N

m

n

n

n

n

n

=

· ·

+

· ·

+

··· · ·

· + · + ··· ·

10

3

10

3

10

3

10

3

1

1

1

2

2

2

1

1

2

2

N

t N t N

t N

t t

t

m

n

n

n

= ·

+

· + ···+ ·

+ +

···+

1

1

2

2

1

2

L

K N

N

T

T

h

o

m

o

m

= ×

×

10

3

( )

C

T

T

N

t

em

o

em

em

em

=

775

5

Z

6

60

10

3

( )

Selection

5

5-1 Selection flow chart

N

3

N

1

N

2

T

3

T

2

T

1

t

1

t

2

t

3

0

Maximum acceleration torque

Output torque

Output speed

Time

Maximum

deceleration

torque

Constant-speed torque

Constant-speed

operation time

Deceleration

time

Acceleration

time

Time

Fig. 6

Table 2

Considerations for selection

Duty cycle diagram

For

For

For

For impact due

starting  constant  stopping  to  emergency

(Max)

speed

(Max)

stop

Load torque

Nm

T

1

T

2

T

3

T

em

Speed r/min

N

1

N

2

N

3

N

em

Time sec

t

1

t

2

t

3

t

em

background image

60

C Series

Maximum

output speed

Input speed

̶̶̶̶̶̶̶̶̶

Reduction gear ratio

Determine load

characteristic

Check the load torque applied to the speed reduction gear.
An example is shown at right.

From the rating

table

(page 57)

END

Temporary selection

of frame number

Service life

calculation (L

h

)

•  Calculate average load

torque (Tm)

•  Calculate average output

speed (Nm)

T

m

N

m

Output speed

Output torque

L

h

≥ Specified value

NO

Increase the frame

number or reduce

the load

Increase frame number of

reduction gear or

decrease that of load side.

Determine
the input speed

Determine the external

shock torque (T

em

)

due to emergency stop

Determine the external
shock torque (Tout) when
motor shaft speed is zero

Determine

the number of

allowable operation

cycles (Cem)

NO

NO

NO

NO

NO

NO

NO

NO

Determine
main bearing capacity

Determine output shaft
torsion (θ)
by external moment

W

1

r

1

+ W

2

r

3

θ= ̶̶̶̶̶̶̶̶(r

2

> b)

M

t

10

3

(Refer to page 62.)

Increase the frame
number or reduce
the load

Determine
external moment (Mc)

M

c

≤ Allowable moment

(table 1)

Frame selection

Tout: Estimated value

Mc = W

1

r

2

+ W

2

r

3

(r

2

> b)/1,000

(Refer to page 62.)

Check the external load applied to

the reduction gear.

(Refer to page 61)

θ≤

Allowable

torsion

(required value)

θ≤

Allowable

torsion

(required value)

Tout ≤

Momentary

maximum

allowable

torque

T

em

Momentary

maximum

allowable

torque

T

1

or  T

3

≤ C

em

Number

of operation

cycles

Determine

the acceleration/

deceleration torque

(T

1

, T

3

)

Allowable

acceleration/

deceleration

torque

T

t N T

t N T

t N T

t N t N

t N

m

n

n

n

n

n

=

· ·

+

· ·

+

··· · ·

· + · + ··· ·

10

3

10

3

10

3

10

3

1

1

1

2

2

2

1

1

2

2

N

t N t N

t N

t t

t

m

n

n

n

= ·

+

· + ···+ ·

+ +

···+

1

1

2

2

1

2

L

K N

N

T

T

h

o

m

o

m

= ×

×

10

3

( )

C

T

T

N

t

em

o

em

em

em

=

775

5

Z

6

60

10

3

( )

Selection example

Selection conditions

T

1

= 600Nm T

2

= 150Nm

T

3

= 300Nm T

em

= 1,700Nm

t

1

= 0.2sec.

t

2

= 0.5sec.

t

3

= 0.2sec.

t

em

= 0.05sec.

N

1

= N

3

= 10r/min N

2

= 20r/min

N

em

= 20r/min Z

6

= 52 pins

Determine load characteristic

• Determine average load torque

T

m

=

× ×

+ × ×

+

× ×

× + × + ×

10

3

10

3

10

3

10

3

02 10 600 05 20 150 02 10 300

02 10 05 20 02 10

.

.

.

.

.

.

= 348.9Nm

• Determine average output speed

0.2×10+0.5×20+0.2×10

N

m

=—————————————=15.6r/min

0.2+0.5+0.2

Provisional selection of RV-50C.

•  Calculation to determine whether reduction gear

service life meets required specification value.

L

Hr

=

×

×

( )

=

6,000 15

156

490

348.9

17,897

10

3

.

• Determine output speed

Maximum output speed 20r/min < 50r/min

Maximum allowable output speed of RV-50C

• Determine torque during starting and stopping

T

1

= 600Nm < 1,225Nm

Allowable acc./dec. torque for RV-50C

T

3

= 300Nm < 1,225Nm

Allowable acc./dec. torque for RV-50C

•  Determine emergency stop and external

shock torque

T

em

= 1,700Nm < 2,450Nm

Momentary max. allowable torque for RV-50C

C

em

=

×

×

×

×

=

775 5 490

1,700

52 20

60

0 05

3,023

10

3

.

(

)

times

Determine main bearing capacity

• External load condition
W

1

= 2,500N r

1

= 500mm

W

2

= 1,000N r

3

= 200mm

Determine moment rigidity

•  Determine whether output shaft deflection

angle meets required specification value.

2,500×500+1,000×200

θ=————————————— =0.74(arc.min.)

1,960×1,000

• Determine external moment

187.1

r

2

= 500+——— = 594mm

2

M

c

= 2,500×0.594+1,000×0.2

= 1,685Nm<1,764Nm

Allowable moment of RV-50C

Since all required specification are
satisfied, select RV-50C.

background image

61

■ 5-2-3 Rated service life

The service life of the C series is based on the life of the roller bearings of the
crankshafts. The service life is set as shown in Table 3 for all models and ratios at
rated torque and at rated output speed.

When in actual service installed in the equipment, calculate the service life
using the following formula because the load condition depends on the types of
reduction gear.

L

h

= K × N

o

N

m

× T

o

T

m

10

3

5-2 Strength and service life

■ 5-2-1Allowable torque during acceleration or

deceleration

When the Machine starts (or stops), a larger torque than the steady-state torque
is applied to the reduction gear because of the inertial loads.  The values in the
rating table (see page 57) show the allowable value of the peak torque when the
reduction gear starts or stops.
The allowable acceleration/deceleration torque is 250% of the rated torque.

■ 5-2-2 Momentary maximum allowable torque

A large torque during an emergency stop or external shock may be applied to the
reduction gear. The maximum allowable torque is shown in the ratings table(see
page 57).
Momentary maximum allowable torque is 500% of the rated torque.

Note) When shock torque is applied, be sure to use at or below the limit cycle (refer to selection

flowchart on page 59).

L

h

Service life (Hrs)

L

10

K   6,000

Type

Rated torque (To)

Rated output speed (N

0

)

RV-10C

98Nm

RV-27C

264.6Nm

RV-50C

490Nm

RV-100C

980Nm

15r/min

RV-200C

1,960Nm

RV-320C

3,136Nm

RV-500C

4,900Nm

(+)

(ー)

Acceleration torque

Deceleration torque

Momentary maximum torque

Constant speed torque

Load torque

Fig. 7

Table 3

Table 4

Load torque graph

L

h

:  Service life to be obtained (Hr)

N

m

:  Average output speed (r/min)

T

m

:  Average output torque (Nm)

N

o

:  Rated output speed (r/min)

T

o

:  Rated output torque (Nm)

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62

C Series

5-3 Capacity of main bearing

Angular contact ball bearings are incorporated in the C series so that external
loads may be supported.

■ 5-3-1 Moment rigidity

When an external load is applied to the output shaft, its deflection angle is
proportional to the external moment (wherer

2

>b).

The moment rigidity is expressed as an external moment value, which is required
to deflect the output shaft 1 arc. min.

θ= W

1

r

1

+W

2

r

3

————————

M

t

×10

3

Table 5

Table 6

Moment rigidity (Mt)

Size (mm)

Model

Nm/arc.min.

Typical value

a

b

RV-10C

421

28.0

119.2

RV-27C

1,068

38.2

150.3

RV-50C

1,960

50.4

187.1

RV-100C

2,813

58.7

207.6

RV-200C

9,800

76.0

280.4

RV-320C

12,740

114.5

360.5

RV-500C

24,500

125

413.4

Allowable moment

Allowable thrust

Model

Nm N

RV-10C

686

5,880

RV-27C

980

8,820

RV-50C

1,764

11,760

RV-100C

2,450

13,720

RV-200C

8,820

19,600

RV-320C

20,580

29,400

RV-500C

34,300

39,200

■ 5-3-2 Allowable moment

Table 6 shows the external moment values(moments during starting and stopping,
etc.) that can be supported by the reduction gear.
Refer to figure 9 indicating the range of allowable moment for simultaneous
application of external moment and external thrust.
M

C

≤ Allowable moment value

M

C

= {W

1

r

2

+ W

2

r

3

(

r

2

> b)}/1,000

Fig. 8

θ

:  Deflected angle of output shaft (arc. min.)

M

t

:  Moment rigidity (Nm/arc.min.)  (table 5)

W

1

, W

2

:  Weight (N)

r

1

, r

3

:  Distance to load point (mm)

r

1

= r+

b

2

― a

r

: The distance between the output shaft mounting surface and the

loading point (mm)

M

C

: External moment (Nm)

W

1

, W

2

: Load (N)

r

2

, r

3

: Distance to load point(mm)

r

2

= r+ b ― a

r

: Distance from output shaft mounting face to load point (mm)

External loading diagram

Output shaft mounting face

background image

63

Fig. 9

■ 5-3-3 Momentary maximum allowable moment

A large torque and moment due to emergency stop or external impact may be
applied to the reduction gear.
The rating table (page 57) shows the momentary maximum allowable moment
values.
The momentary maximum allowable moment is twice the allowable moment.

RV-100C

RV-50C

RV-27C

RV-10C

13,720

11,760

8,820

5,880

3,100

0

2,450

1,764

686

2,480
1,715

1,500

980

595

323

254

Thrust force (N)

Allowable moment (Nm)

RV-200C

RV-320C

RV-500C

39,200

29,400

21,658

19,600

14,994

9,800

8,134

0

34,300

29,106

20,580

17,052

8,820

6,664

Thrust force (N)

Allowable moment (Nm)

Allowable moment diagram

background image

64

C Series

Performance Characteristics

6

6-1 Rigidity (Torsional rigidity and lost motion) and backlash

When a torque is applied to the output shaft while the input shaft (center gear) is
fixed, torsion is generated according to the torque value and a hysteresis curve
result is shown in Fig. 10.

The rigidity of the reduction gear is expressed by the torsional rigidity and the lost
motion  in  this  curve.    Reduction  gears  are  especially  superior  in  their  stiffness
characteristics.

•  Torsional rigidity =

b

a

•  Lost motion

The torsion angle at the mid point of the hysteresis curve width at ±3% of

rated torque.

•  Backlash

The torsion angles when the torque indicated by the hysteresis curve is zero.

■ 6-1-1 Calculation of torsion (an example)

Take an example of the RV-100C and find a torsion where a torque is applied in
one direction.
1) If a torque of 10 Nm is applied, the resulting torsion ST

1

, is found as shown

below.

•  Note that the torque is in the lost motion range.
ST

1

=

10

———

29.4 ×

1(arc.min.)

——————

2

= 0.17arc.min.

2) If a torque of 600 Nm is applied, the resulting torsion ST

2

is found as shown

below.

•  Note that the torque is in the rated torque range.
ST

2

=

1

2  +

600-29.4

————————

510

= 1.62arc.min.

Note: The above torsion value is that of the reduction gear assembly.

Fig. 10

ー100%

+100%

a

b

Backlash

Torsion angle

Lost motion

Rated torque

Rated torque

±3% of rated torque

Hysteresis curve

Table 7

Lost

motion

Model

Torsional rigidity

Lost motion

Measured torque

Backlash

Nm/arc.min.

arc.min. Nm

arc.min.

RV-10C

47

±    2.94

RV-27C

147

±    7.94

RV-50C

255

±  14.7

RV-100C

510

MAX 1

±  29.4

MAX 1

RV-200C

980

±  58.8

RV-320C

1,960

±  94.1

RV-500C

3,430

±147.0

background image

65

The vibration is a torsional vibration in the circumferential direction when driven
by a servomotor with an inertia load applied.
The vibration is one of the most important characteristics, especially when
precise contouring control is required.  For example, the industrial robot requires
exact and smooth contour control for its longer arm. An actual measured example
of the vibration characteristics is shown in Fig. 11.

500

0

0.1

0.2

1,000

1,500

2,000

2,500

Acceleration

Amplitude

Vibration

Acceleration (G)

Half amplitude (mm)

Servo motor input speed (r/min)

Fig. 11

Test conditions
1. Model: RV-100C
2. Reduction ratio: 1/161
3. Assembly accuracy:
Recommended accuracy (page 69)
4. Inertia moment on load side:107.8 kgm

2

5. Measured radius: 550 mm

6-2 Vibration

6-3 Angular transmission accuracy

Angular transmission accuracy refers to a difference between the theoretical
output revolution angle and the actual revolution angle (θout) when any revolution
angle (θin) is the input, and is expressed as an angular transmission error (θer).
The angular transmission error is found in the following equation.

θer = θin

——

R  ― θout (where R = reduction ratio)

The measured example is shown below.

Test conditions
1. Model: RV-100C
2. Assembly accuracy:
Recommended accuracy (see page 69)
3. Load conditions: no-load
4. Detector: USR324 + UC101
(manufactured by Nippon Kogaku K.K.)
Resolution: 1 sec

Fig. 12

Revolution of output shaft (degrees)

25 sec

Angular transmission error (sec)

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66

C Series

6-4 No-load running torque

6-5 Backdriving torque

The backdriving torque refers to a torque required for starting the
output shaft, with the RV-C reduction gear left under no-load.  If the
input shaft (input gear) is released while a torque equal to or more
than the backdriving torque is kept applied to the output shaft, the
input  shaft  (center  gear)  starts  running  at  an  augmented  speed.
Special care should be given to the backdriving torque to start the
reduction gear.

8,679

1,736

2,604

868

20

40

60

80

100

0

RV-320C

RV-500C

RV-200C

RV-100C RV-50C

RV-27C

RV-10C

0

(N.m)

294

3,472

392

4,340

490

5,208

588

6,076

686

6,944

784

7,812

882

980

196

98

Output shaft speed (r/min)

No-load running torque (converted torque on the output shaft side) (kgf-m)

Model

Backdriving torque Nm

RV-10C

10

RV-27C

52

RV-50C

95

RV-100C

120

RV-200C

150

RV-320C

220

RV-500C

300

Fig. 13

Table 8

Test conditions
1. Ambient temperature: 30℃
2. Assembly accuracy:  recommended accuracy

(see page 69)

3. Lubricant: grease (Molywhite RE00)

Test conditions
Assembly accuracy:  recommended accuracy

(see page 69)

Lubricant: grease (Molywhite RE00)

The no-load running torque means a torque required on the input shaft (center
gear)  side  in  order  to  rotate  the  reduction  gear  under  no  load.    Fig.  13  shows
the no-load running torque on the output shaft side, which is converted from the
no-load running torque according to the following equation.
• No-load running torque converted to motor shaft (Nm)

T

M

= T

L

×

Z

1

Z

2

+ frictional resistance of center gear

T

L

=

Converted torque on the output shaft side (Nm)

———————————————

R

1

(where R

1

= speed ratio of RV reduction gear)

Note: The diagram below shows average values obtained after a RV-C reduction gear has been run

in. The agitation resistance of center gear is not included in the values.

Z

1

: Number of teeth on input gear

Z

2

: Number of teeth on large center gear

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67

6-6 Low-temperature characteristics (No-load running torque under low temperature)

Test conditions
1. Assembly accuracy: recommended accuracy (page 69)
2. Lubricant: grease (Molywhite RE00)
3. Input speed: 15 r/min
4. Loss at center gear is not included.

1

2

3

4

5

0

ー10

ー20

0

10

20

(Nm)

39.2

49

29.4

19.6

9.8

RV-10C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

2

4

6

8

10

0

ー10

ー20

0

10

20

(Nm)

78.4

98

58.8

39.2

19.6

RV-27C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

4

8

12

16

20

0

ー10

ー20

0

10

20

(Nm)

156.8

196

117.6

78.4

39.2

RV-50C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

10

20

30

40

50

0

ー10

ー20

0

10

20

(Nm)

392

490

294

196

98

RV-100C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

20

40

60

80

100

0

ー10

ー20

0

10

20

(Nm)

784

980

588

392

196

RV-200C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

20

40

60

80

100

0

ー10

ー20

0

10

20

(Nm)

784

980

588

392

196

RV-320C

Case temperature (℃)

No-load running torque

(converted to output shaft) kgf-m

Fig. 14

When the reduction gear is used under a low temperature, viscosity of
lubricant increases and causes a larger no-load running torque.
The no-load running torque under low temperature is shown below.

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68

C Series

6-7 Efficiency charts

Test conditions
1. Case temperature: 30℃
2. Assembly accuracy: recommended accuracy (page 69)
3. Lubricant: grease (Molywhite RE00)
4. Loss at center gear is not included.

0

20

40

60

80

100

10 r/min
30 r/min

60 r/min

24.5

(2.5)

49

(5)

73.5

(7.5)

98

(10)

122.5

(12.5)

Nm

(kgf-m)

RV-10C

efficiency curve

Efficienc

y (%)

Output torque

0

20

40

60

80

100

10 r/min

30 r/min

60 r/min

245

(25)

196

(20)

147

(15)

98

(10)

49

(5)

Nm

(kgf-m)

RV-27C

efficiency curve

Efficienc

y (%)

Output torque

0

20

40

60

80

100

10 r/min

30 r/min

50 r/min

490

(50)

392

(40)

294

(30)

196

(20)

98

(10)

Nm

(kgf-m)

RV-50C

efficiency curve

Efficienc

y (%)

Output torque

0

20

40

60

80

100

10 r/min

25 r/min

40 r/min

784

(80)

588

(60)

392

(40)

196

(20)

Nm

(kgf-m)

RV-100C

efficiency curve

Efficienc

y (%)

Output torque

0

20

40

60

80

100

10 r/min

20 r/min

30 r/min

1,960

(200)

1,470

(150)

980

(100)

490

(50)

Nm

(kgf-m)

RV-200C

efficiency curve

Efficienc

y (%)

Output torque

0

20

40

60

80

100

5 r/min

10 r/min

20 r/min

5,880

(600)

4,900

(500)

3,920

(400)

1,960

(200)

Nm

(kgf-m)

RV-500C

efficiency curve

Efficienc

y (%)

Output torque

5 r/min

10 r/min

20 r/min

0

20

40

60

80

100

RV-320C

efficiency curve

Efficienc

y (%)

Output torque

3,920

(400)

3,136

(320)

2,352

(240)

1,568

(160)

784

(80)

Nm

(kgf-m)

Fig. 15

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69

Installation and Assembly

7

7-1 Assembly accuracy

To get maximum performance from C series, it is important to pay attention to the
assembly accuracy, installation, lubrication and sealing.
Angular ball bearings are used as the main bearings with RV-C Series reduction
gears.  When designing the layout, make sure the bearing retainer will not touch
the motor mounting flange. Refer to the outline drawings on the pages after page
77.

Note:  Two types of C series are available: bolt clamping output shaft type (refer to pages 77 to 83

for outline drawings, and through bolt clamping output shaft type (refer to pages 84 to 89 for
outline drawings excluding RV-500C). Please be sure to specify when ordering.

Design the assembly side of the C series within tolerances shown in
Table  9.    Poor  assembly  accuracy  causes  vibration  and  particularly
noise or backlash.

■ 7-1-1 Assembly accuracy of RV-10C, 27C, 50C,

100C, 200C, 320C, and 500C

Table 9

(Unit: mm)

Tolerance of center-

Concentricity

Tolerance of

Model

to-center distance X

tolerance a

parallelism b

RV-10C

RV-27C

RV-50C

RV-100C

±0.03

MAX 0.03

MAX 0.03

RV-200C

RV-320C

RV-500C

Fig. 16

R indicates distance from center of reduction gear to center of motor.

Tolerance of center

-to-

center distance

±

X

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70

C Series

7-2 Installation procedure

•  The  typical  installation  examples  for  reduction  gears  are

shown below.  Be sure to seal the designated type of grease to
the designated level. (See page 75)

Slow speed tube and the output surface of the RV-C reduction

gear need to be sealed.

•  Be sure that seals are used between mating parts on the input

side.  Refer to the O-ring seal installation illustrated.

•  If  the  use  of  an  O-ring  seal  is  impossible  because  of  the

design, use Gasket sealant.  See table 10 at right.

Notes  1. Do not use for copper material or copper alloy material.

2. If it is used under special conditions such as concentrated alkali, pressurized steam,

etc., please contact Nabtesco.

Table 10 Recommended Gasket sealant

Fig. 18

Applicable O-ring

RV-10C

AS(ARP)568-048

RV-27C

AS(ARP)568-163

RV-50C

AS(ARP)568-169

RV-100C  AS(ARP)568-173
RV-200C  AS(ARP)568-277
RV-320C  AS(ARP)568-281
RV-500C  JIS B2401 G460

Table 12 O-ring (

II)

Fig. 19

The O-ring (

II) can be applied to both

bolt clamping and through-bolt
clamping output shaft types.

■ 7-2-1 Assembly example of center tube

The center tube is used to protect the cable which runs through
the hollow section and to seal grease filled in the reduction
gear.  The assembly example of center tube is shown in  18 for
reference.

■ 7-2-2 Assembly example with the output shaft bolt clamping

type (RV-10C, 27C, 50C, 100C, 200C, 320C, 500C)

If center tube, oil seal and O-ring (

I) are used together, the seal on the mounting surface of

output shaft side is not required.

Refer to Table 12.

Table 11 Dimensions of O-ring (

I) seal (for reference)

RV-10C

RV-27C

RV-50C

RV-100C

RV-200C

RV-320C

Dimensions

O-ring

Groove

size

ID number

Wire dia.

I. D.

I. D.: d

Width: B

CO 0625

φ  2.4±0.07
φ  29.7
φ  30.2

0

− 0.08

3.2

(Unit: mm)

+ 0.25

0

+ 0.25

0

CO 0634

φ  2.4±0.07
φ  42.2
φ  43.2

0

− 0.08

3.2

CO 0643

φ  3.5 ±0.1
φ  59.6
φ  60.3

0

− 0.10

4.7

+ 0.25

0

S70

φ  2.0 ±0.1
φ  69.5
φ  70.0

0

− 0.05

2.7

+ 0.25

0

JIS B2401 G95

φ  3.1 ±0.1
φ  94.4
φ  95.0

0

− 0.10

4.1

+ 0.25

0

+ 0.25

0

+ 0.25

0

JIS B2401 G135

φ  3.1 ±0.1
φ 134.4
φ 135.0

0

− 0.08

4.1

O-ring (

I)

Oil seal

Center tube

Groove dimension

of O-ring (

I)

RV-500C

JIS B2401 G145

φ  3.1 ±0.1
φ 144.4
φ 145.0

0

− 0.10

4.1

O-ring (

II)

Manufacturer Name

ThreeBond 1211

• Silicone-based, solventless type

(ThreeBond Co.)

• Semi-dry gasket

HermeSeal SS-60F

• One-part, non-solvent elastic sealant

(Nihon Hermetics Co.)

• Metal contact side (flange surface) seal

• Any product basically equivalent to ThreeBond 1211

Loctite 515

• Anaerobic flange sealant

(Henkel)

• Metal contact side (flange surface) seal

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71

Fig. 20

Fig. 21

Table 13

Applicable O-ring (

III)  Applicable O-ring (IV)

RV-27C

S75

S120

RV-50C

S100

S150

RV-100C  JIS B2401-G115  AS(ARP)568-165
RV-200C

S150

AS(ARP)568-271

Table 14

O-ring(

III) seal dimensions (for reference)

RV-10C

RV-320C

Dimensions

O-ring

Groove size

ID number

Wire dia.

I. D.

O. D.: d

Depth: H

Width: B

AS(ARP)568-032

φ  1.78 ±0.07
φ  47.35 ±0.38
φ  51.0

0

+ 0.05

0

1.27 ±0.05

2.39

(Unit: mm)

JIS B2401-G210

φ  5.7 ±0.13
φ 209.3
φ 220.0

+ 0.1

0

5.5 ±0.05

7.5

+ 0.25

0

+ 0.25

0

Table 15

O-ring(

IV) seal dimensions (for reference)

RV-10C

RV-320C

Dimensions

O-ring

Groove size

ID number

Wire dia.

I. D.

O. D.: d

Depth: H

Width: B

S100

φ  2.0 ±0.1
φ  99.5 ±0.4
φ 103.0

+ 0.05

0

1.5

2.7

(Unit: mm)

0

− 0.1

JIS B4201-G290

φ  5.7 ±0.13
φ 289.3
φ 300.0

+ 0.1

0

5.5 ±0.05

7.5

+ 0.25

0

+ 0.25

0

■ 7-2-3 Assembly example of through-bolt clamping output shaft type

(RV-27C, 50C, 100C and 200C)

The O-ring groove is provided at the end face of output shaft of the reduction gear.  Use
O-rings as shown below.

■ 7-2-4  Assembly example of through-bolt clamping output shaft type

(RV-10C and 320C)

Provide  the  O-ring  groove  on  the  counterpart  component.    Dimensions  of  O-rings  are
shown below for reference.

Refer to Table 13.

Refer to Table 13.

Refer to Table 12.

Refer to Table 15.

Refer to Table 14.

Refer to Table 12.

O-ring (

IV)

O-ring (

II)

O-ring (

III)

O-ring (

II)

O-ring (

IV)

O-ring (

III)

Groove dimensions of

O-ring (

III) & (IV)

Notes 1. The  part  number  CO  or  S  type  indicates  the  S-standard  O-ring

supplied by NOK.

2. The  O-ring  number AS  type  indicates  an  O-ring  supplied  by

Mitsubishi Cable Industries.

3. The ARP in the ID number is a former name.

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72

C Series

7-3 Center gear and input gear

■ 7-3-1 Accuracy of center gear and input gear

Poor installation accuracy of center gear and input gear may cause noise and
backlash, so design center gear and input gear to the following tolerances.

Tolerance of

Tolerance of

Tooth grade of

Tooth grade of

Tooth grade of

fitting X

concentricity  a  small center gear  large center gear

input gear

h6

MAX 0.03

JIS 5 class

JIS 4 class

JIS 5 class

Fig. 25

Table 16 Accuracy of center gear and input gear

(Unit: mm)

Table 17

Backlash between input gear and large center gear

RV-10C

0.035 to 0.090

RV-27C

0.040 to 0.110

RV-50C

0.050 to 0.130

RV-100C

0.060 to 0.140

RV-200C
RV-320C

0.075 to 0.180

RV-500C

Table 18

Module

Number of teeth

Addendum modification coefficient

RV-10C

1.0

48

― 0.04

RV-27C

1.0

57

+ 0.2

RV-50C

1.25

61

0

RV-100C

1.75

48

+ 0.3

RV-200C

2.5

43

0

RV-320C

2

78

0

RV-500C

2

83

0

Module

Number of teeth

Addendum modification coefficient

RV-10C

2

57

0

RV-27C

1.25

78

0

RV-50C

2

78

0

RV-100C

1.75

112

0

RV-200C

2

110

0

RV-320C

2

125

0

RV-500C

2

150

0

(Unit: mm)

Specifications of small center gear tooth

■ 7-3-2 Standard center gear

The standard center gears for C series are available from Nabtesco.
If  the  standard  center  gear  is  needed,  please  specify  when  ordering.
Specifications  of  standard  large  center  gears  are  shown  below.    Refer  to  the
external dimension for installation.

Table 19 Specifications of standard large center gear

Small center

gear

Large center

gear

Tolerance of fitting X

Input gear

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73

7-4 Bolt tightening torque and allowable transmission torque

Use hexagonal socket bolts to assemble the RV precision reduction gear and tighten
to the torque as specified below. When the pin/bolt mounting output shaft type is
used, also use the taper pin.  The serrated lock washer is recommended to prevent
the bolt from loosening and protect the bolt seat face from flaws.

Bolt tightening torque and tightening force

Hexagonal socket bolt

Tightening torque

Tightening force(R)

Bolt specification

nominal size x pitch (mm)

Nm

N

M5  × 0.8

9.01±  0.49

9,310

M6  × 1.0

15.6  ±  0.78

13,180

M8  × 1.25

37.2  ±  1.86

23,960

M10 × 1.5

73.5  ±  3.43

38,080

M12 × 1.75

129    ±  6.37

55,100

M14 × 2.0

205    ± 10.2

75,860

M16 × 2.0

319    ± 15.9

103,410

M18 × 2.5

441    ± 22.0

126,720

Table 20

Notes  1. The valves listed are for steel or cast iron material.

2. If softer material such as aluminum is used, limit the tightening torque.  Also pay attention to the system torque requirements.

3. Tighten all bolts of the through-bolt clamping output shaft type with the specified tightening torque.

•  Hexagonal socket bolt
JIS B 1176
•  Strength class
JIS B 1051 12.9
•  Thread
JIS B 0205 6g or class 2

Calculation of allowable transmission torque of bolts

T

1

= F × D

1

2

× μ × n

1

T

1

:  bolt allowable transmission torque (Nmm)

F  :  bolt tightening force (N)
D

1

:  bolt P.C.D. (mm)

μ :  friction factor

μ = 0.15: where lubricants remained
μ = 0.2: where left dried with no lubricant

n

1

:  number of bolts

Serrated lock washer for hexagonal socket bolt

Name:  Belleville spring washer (made by Heiwa Hatsujyo Industry

Co., Ltd.)

Corporation symbol:   CDW-2H – nominal size

CDW-2L – 5 (for only M5)

Material: S50C to S70C
Hardness: HRC40 to 48

O.D. and I.D. of washer

Nominal size

d

D

t

H

Basic size

5

5.25

8.5

0.6

0.85

6

6.4

10

1.0

1.25

8

8.4

13

1.2

1.55

10

10.6

16

1.5

1.9

12

12.6

18

1.8

2.2

14

14.6

21

2.0

2.5

16

16.9

24

2.3

2.8

18

18.9

27

2.6

3.15

Note: When using any equivalent washer, select it, with special care given to its

outside diameter.

Fig. 26

(Unit: mm)

Table 21

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74

C Series

To maximize the performance of the RV precision reduction gear, the use of
VIGOGREASE RE0 manufactured by Nabtesco is recommended. Do not mix with
other lubricants.

1) The quantity of grease required for the reduction gear

The reduction gear is not greased when it is shipped from the plant.  Therefore, ensure that
necessary amount of recommended grease is charged when installing the reduction gear.

Note:  The  quantity  required  for  the  reduction  gear  is  shown  below. The  volume  of  grease  listed

below does not include the volume required to fill the shaded areas in figure 28.  These areas
must also be charged with grease.  When there exists a cavity, such as when a slow-speed
tube is being used, exclude the volume of such cavity.

However,  too  much  filling  may  causes  damage  for  an  oil  seal  with  increase  of  internal
pressure. Please leave about 10% of the room inside.

Table 22

Working temperature range (ambient temperature)

Note: Please contact Nabtesco if grease or gear oil is to be used

beyond the specified temperature range.

Vertical installation

Type

Quantity

cc

(g)*

RV-10C

147 (132)

RV-27C

266 (239)

RV-50C

498 (448)

RV-100C

756 (680)

RV-200C

1,831 (1,648)

RV-320C

3,536 (3,182)

RV-500C

5,934 (5,341)

Type

Quantity

cc

(g)*

RV-10C

167 (150)

RV-27C

305 (275)

RV-50C

571 (514)

RV-100C

857 (771)

RV-200C

2,076 (1,868)

RV-320C

4,047 (3,642)

RV-500C

6,900 (6,210)

Table 23

Horizontal installation

The profile of servomotor shaft and examples of input gear installation are shown
below as a reference for designing.  User must provide set screw, hexagonal socket
bolt or hexagonal nut.

7-5 Installation of input gear

7-6 Lubrication

Straight shaft

(No female threaded on servomotor)

(With female threaded on servomotor)

Fig. 27

Taper shaft

(With male threaded on servomotor)

Note:  A radial load due to the counterforce of torque is applied

by  the  center  gear  on  the  C  series. Therefore,  examine  the
strength of the motor shaft and the service life of bearings
which support the motor shaft.

Setscrew

Hexagonal socket bolt

Hexagonal nut

Item

Specifications

Allowable temperature diagram
Use the grease with no condensation and the reduc-
tion  gear  circumference  temperature  and  ambient
temperature in the range in the right diagram.

During  proper  operation  of  the  reduction  gear,  the
standard  grease  replacement  time  due  to  lubricant
degradation is 20,000 hours.
However,  when  operation  involves  a  reduction  gear
surface temperature above 40°C (the area in the right
diagram           ), the state of the lubricant should be
checked in advance and the grease replaced earlier
as necessary.

Lubricant

VIGOGREASE RE0

Reduction gear surface temperatur

e(°C)

Ambient temperature(°C)

* Density of VIGO GREASE RE0: 0.9 g/cc
• When using Molywhite RE00, contact our service department.

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75

Horizontal installation