ROTARY MOTION CONTROL
Technical Data Sheet
Roller Pinion Gear System
Nexen offers an advanced new technology that revolutionizes
rotary motion. The Roller Pinion Gear system (RPG) provides
zero backlash, very high positional accuracy, virtually no
velocity ripple, 99% efficiency, high rigidity, low maintenance,
corrosion resistance, and long life. This opens up new design
possibilities and provides the capability to achieve much higher
levels of performance in machine designs.
Precision Operation Maintains Accurate Positioning
The RPG system features an innovative ring gear and roller pinion technology that
provides extremely accurate rotary motion control. The Roller Pinion Gear system also
offers backlash-free performance by maintaining opposing contact with two or more
teeth at all times.
Patented Tooth Design Ensures Quiet Operation
The RPG system is designed with bearing supported rollers that move smoothly along
the face of each tooth. This reduces the noise levels by eliminating tooth slap common
to traditional gear systems and chain drives. This low friction design is more than 99%
efficient in rotary power transmission.
Solid and Segmented Ring Gears Provide Easy Integration and Unlimited
Diameters
Nexen can provide solid ring gears up to 750 mm in diameter. Ring gears larger than
this become segmented and can be virtually any diameter. Arc segments can also be
provided.
Rugged Design Capable of High Speeds
The RPG system maintains accurate positioning at meshing pitch circle peripheral
speeds as high as 11 m/sec (36.1 ft/sec). Even at these speeds, the extremely-low
friction design does not create heat or significant wear on components.
Applications
working head
center column
table
pinion
ring
Synchronized dual-shaft drive
Programmable indexing table
Index table with hollow center column
Cables
Winding and feeding device with less pulsation film, paper, sheet and thin wire
Pivoting drive for robots
Multiple tables orbiting the ring gear
Used in combination with RPS rack
Drive system for radar and satellite dishes, solar tracking, and telescopes
The Nexen RPG Advantage
Eliminates Many of the Short Comings of Other Rotary Drive Technologies
The RPG’s unique design eliminates many of the limitations of current rotary drive systems like:
Spur Gears: Backlash limits positional accuracy, tooth meshing can be noisy and introduce vibration that can affect
control systems, and tend to have high wear and maintenance. Velocity ripple can interfere with scanning, measuring, and
coating operations.
Chain Drives: Backlash limits positional accuracy, meshing can be noisy and introduce vibration that can affect control
systems, and tend to have high wear and maintenance due to stretch. Velocity ripple can interfere with scanning, measuring,
and coating operations.
Belt Drives: Limited by low load capacity, accuracy, and rigidity. Also suffers from backlash and belt stretch.
Direct Drive Rotary Stages: Limited by low torque capacity, high cost, and strong magnetic fields.
Zero Backlash/High Precision
The RPG’s innovative meshing action provides backlash of less than 3.2 µm [0.00013 in.] and positional accuracy up to
± 30 µm [± 0.00118 in.] tangentially at the meshing pitch circle due to an extremely precise manufacturing and inspection
process. The RPG also has almost no velocity ripple making it ideal for applications that involve scanning, measuring,
coating, or where uniformity of motion is critical.
Ring Gear Configurations
The RPG system is available as a solid ring gear when the diameter is under 750 mm. For larger ring gears segments can
be combined to make ring gears of any size. Arc segments can also be provided for applications that only need limited
rotation. Ring gears can have internal or external teeth.
Speed
The RPG system can achieve tangential meshing pitch circle speeds, up to 11 m/s (36.1 ft/s), while providing high positional
accuracy.
Noise
Due to the smooth, backlash free way that the rollers engage the teeth, the RPG system is nearly silent at low speeds and
less than 75 dB at full speed. This is much lower than traditional gear and chain systems with their tooth slap.
Maintenance/Life
The RPG system has very low maintenance. Typically lubrication is required every two million pinion revolutions or six
months. The RPG system has life ratings up to 336,000,000 m [1,102,200,000 ft] of circumferential travel and is based
on providing its full published positional accuracy. Some gear or chain systems can provide good initial performance but
quickly degrade. The RPG system continues to operate beyond its life rating with diminished performance.
Surface Treatment
The RPG system has the Raydent surface treatment, providing stainless steel-like performance without the related high
cost and low wear characteristics. Raydent is not a typical blackening or surface coating that can break down and flake
off. Instead, Raydent permeates the metal surface and permanently bonds with it forming a ceramic oxide surface layer that
will not flake off and is highly resistant to acids, alkalies, and solvents.
How the RPG System Works
The RPG system achieves its incredible performance by using a pinion consisting of bearing supported pins that engage
a unique tooth profile. Two or more rollers engage the ring gear teeth in opposition at all times eliminating backlash. There
is no tooth slap or sliding friction as with traditional spur gear or chain drive systems, instead the RPG rollers approach the
tooth face in a tangent path and then roll smoothly down the tooth face. This provides a smooth, quiet, low friction, fatigue
free, high efficiency rotary drive system.
The RPG tooth design is conceptually different from traditional spur gear designs. It behaves like a cam and follower versus
the sliding action of spur gears. As illustrated in the figures below, a cycloidal curve is created when a point drawn on a
circle at point P rolls on a curved surface to point P' without slipping. When multiple points are placed on the circle at regular
intervals, the cycloidal curves are repeatedly created on the curved surface, and develop into a tooth-like profile.
A roller is placed at each point to act as pinion teeth and modifies the tooth profile to create the ring gear teeth. Normally,
this concept will not provide zero backlash, but a technical innovation was developed to modify the tooth geometry allowing
two rollers to remain loaded in opposition at all times, eliminating the backlash as the rollers engage the ring gear. The rollers
meet the ring gear teeth smoothly and eliminate the backlash, low precision, tooth slap, sliding friction, fatigue, and noise
associated with traditional spur gear and chain drive systems. Both the rollers and tooth faces are hardened to the upper
RC50’s for exceptionally long service life.
Rollers in
Opposition
P
P'
Angular Transmission Accuracy
The variations shown in the graph below represent minor errors occurring throughout the ring gears rotation. The individual
spikes indicate meshing errors and larger wave patterns demonstrate pinion rotational error. As the horizontal limits
demonstrate, there is no cumulative error. This pattern continues regardless of ring gear diameter, even when crossing
segment joints. This is possible due to the use of special joining plates that align the segments and ensure that the angular
accuracy is passed from segment to segment.
angular error in arcsec
150
100
50 arc sec
50 arc sec
44 arc sec
44 arc sec
50
0
50
100
150
0
36
72
108
144
180
216
angular position of ring gear in degrees
252
288
324
360
Maximum angular transmission error is 94 arcsec and is calculated by the following formula: Θer = Θ2 - (Θ1 X R)
(Θer = Angular Transmission Error Θ1 = Pinion Angle, Θ2 = Ring Gear Angle, R = Reduction Ratio)
Based on RPS16G with 1:5 ratio. Individual spikes represent individual tooth /roller meshing error, repeated wave trends represent pinion error. A
similar pattern will be generated for other RPS sizes and ring gear angular accuracy and backlash will improve as its diameter increases. See general
specifications and calculations for other ring gear diameters.
Precision Roller Pinion Selection Process
Proper RPS size selection requires the application data listed below. These specifications are needed to determine; load
mass, load acceleration, force due to acceleration, force due to gravity, force due to friction and total force of the load.
Sample calculations are shown along with worksheet space to calculate your own application.
This Curve will select
the smallest RPG size
Friction Coefficient (µ)
Rolling Bearing
0.005 ~ 0.02
Sliding Bearing
0.1 ~ 0.2
Velocity
Shock Factor** (K)
Shockless Smooth Operation
1.0 ~ 1.2
Normal Operation
1.2 ~ 1.5
Operation with Impact
1.5 ~ 3.0
t
Time
Application Example:
Programmable electronics assembly indexing table
1 meter in diameter
8 stations equally spaced
60 indexes per minute desired
Dwell time 0.33 sec
Additional information below
Application Data
Required Specifications For RPS Selection
Example Data
Weight to be Driven* (W)
Rotational Moment of Inertia (I)
kg
kgm
or Known Angular Acceleration (ω)
Dwell Time (dt)
20.0 kg
2
10.0 kgm2
IPR
8 IPR
Seconds
0.66 sec
Indexes Per Revolution ( R )
Index Time (It)
Customer Application Data
rad/sec
2
Seconds
Shock/Service Factor** (K) see table above
0.33 sec
1.2
Coefficient of Friction (μ)
Other Forces *** (F1), (F2), etc.
Nm
Angle Gear Rotates Relative To Horizontal Plane
°
0°
Maximum Allowable Ring Gear Tooth Peak OD
mm
400 mm
Minimum Allowable Ring Gear ID
mm
200 mm
±arcsec
±60 arcsec
RPD
10800 RPD
Required Angular Positional Accuracy (P)
Revolutions Per Day
* Weight to be Driven should include everything in motion.
** Shock Factor indicates the smoothness of operation
*** Other Forces may include gravitational forces if rotation is not in the horizontal plane with imbalanced loads, springs, counter
balances, fluid dampening systems, wind resistance etc.
Selecting an RPG Gear Set
If the acceleration and deceleration times vary or there are other changes in velocity, calculate the acceleration forces for
each interval and use the highest one for RPG selection purposes. Compare the Torque calculation to the pinion Maximum
Dynamic Torque ratings in the Specifications table on page 8 to select the ideal RPG size.
Application Calculations
Calculations
Application Example
Acceleration Time
At (s) = It (s) ÷ 2
0.66 s ÷ 2 = 0.33 s
Rotation Per Index
θ (rad) = 2� ÷ IPR
θ = 2� ÷ 8 = 0.79 rad
Max Angular Speed*
ω = θ (rad) ÷ It (s) x 2
ω = 0.79 rad ÷ 0.66 s x 2 = 2.39 rad/s
Angular Acceleration
α (rad/s²) = ω (rad/s) ÷ At (s)
α = 2.39 rad/s ÷ 0.33 s = 7.25 rad/s2
Ring Gear Torque
τG (Nm) = I (kg/m²) x α (rad/s²)
τG = 10 kgm2 x 7.25 rad/s2 = 72.50 Nm
Ring Gear Torque with Shock Factor
τS (Nm) = τG x K
τS = 72.50 Nm x 1.2 = 87.00 Nm
Customer Calculations
* Maximum rotational speed is assumed to be twice the average speed due to starting at zero and linearly accelerating to the mid point of the index. If a
non-linear acceleration curve is used, use the highest known speed and acceleration.
Based on the allowed gear diameters listed in the application data section, we can see that RPS16 7:1 part number
966554 is the only one that meets all criteria.
Compare the Ring Gear Torque calculated above to the allowable ring gear torques in the specifications table. From this
we see that the RPS16G 7:1 has more than enough torque, and meets the ring gear ID and OD envelope requirements.
Next verify that maximum pinion RPM is not exceeded: RPM = ω x Gear Ratio x 9.55 = 2.39 rad/sec x 7 x 9.55 = 159.8
RPM
The maximum RPM listed in the specifications table on page 8 for the RPS16G pinion is 1500 RPM so the RPG16G 7:1
gear system is an acceptable choice.
Compare selected gear set accuracy with the application requirements. The RPS25G 7:1 gear set is rated for ±40 arcsec
which is more precise than the required ± 60 arcsec so is acceptable.
If the application requirements call for a more powerful or larger diameter gear set than the listed offerings, refer to page
11 “Specifications For Determining Custom Gear Performance” to evaluate possible RPS custom gear sets.
Pre-Configured Gear Specifications
966659
966679
RPS16P-C020.00MMP2
RPS25P-C030.00MMP2
4.75
7.50
Product Number
Model Number
Module
Number of Rollers
Roller
Pinion
Maximum
Dynamic Torque
Nm
[in-lb]
Maximum Static
Torque
Nm
[in-lb]
50.9
[450]
176.0
[1558]
Torque
Circle Diameter
mm
[in]
8.7
[1.92]
6.9
[3.03]
Bore Size
Weight
Moment of
Inertia
1500
1920
mm [in]
20.0 [0.787]
30.0 [1.181]
kg [lb]
0.8 [1.76]
2.2 [4.85]
kgm
[lbft2]
0.000412
[0.009777]
0.002680
[0.063597]
2
966550
Product Number
Number of Teeth
Maximum RPM
kg
[lb]
Weight
966552
966553
966554
966560
966561
Revolutions
(Millions)
Reduction Ratio
966562
966563
RPS25GC0050T/
360-EP3U
RPS25GC0060T/
360-EP3U
30
40
50
60
70
30
40
50
60
500
375
300
250
214
640
480
384
320
1.7
[3.75]
2.4
[5.29]
3.3
[7.28]
4.8
[10.58]
4.6
[10.14]
6.0
[13.23]
9.1
[20.06]
12.2
[29.90]
15.1
[33.30]
0.15800
[3.74940]
0.33900
[8.04459]
0.64541
[15.31581]
0.0062
0.01688
0.03763 0.07700
kgm2
[lbft2] [0.14618] [0.40569] [0.89297] [1.82724]
Moment of
Inertia
Estimated
Life*
966551
RPS16G- RPS16G- RPS16G- RPS16G- RPS16G- RPS25G- RPS25GC0030T/ C0040T/ C0050T/ C0060T/ C0070T/ C0030T/
C0040T/
360-EP3U 360-EP3U 360-EP3U 360-GP3U 360-EP3U 360-GP3U 360-GP3U
Model Number
System
10
88.0
[774]
25.5
[226]
Maximum RPM
Ring
Gear
10
0.11284 0.05501
[2.67773] [1.30541]
21.444
16.083
12.866
10.722
9.190
21.221
15.915
12.732
10.610
3:1
4:1
5:1
6:1
7:1
3:1
4:1
5:1
6:1
Maximum
Allowable
Dynamic Torque
Nm
[lbft]
70
[51.6]
90
[66.4]
110
[81.1]
140
[103.3]
160
[118.0]
240
[177.0]
330
[243.4]
410
[302.4]
490
[361.4]
Maximum
Allowable Static
Torque
Nm
[lbft]
140
[103.2]
180
[132.8]
220
[182.2]
280
[206.6]
320
[236.0]
480
[354.0]
660
[486.8]
820
[604.8]
980
[722.8]
Center to Center
Distance
mm
[in]
98.0
[3.86]
122.0
[4.80]
146.0
[5.75]
170.0
[6.69]
193.5
[7.62]
154.0
[6.06]
193.0
[7.60]
230.0
[9.06]
268.0
[10.55]
Positional
Accuracy**
arcsec
± 90
± 70
± 60
± 50
± 40
± 60
± 50
± 40
± 30
Meshing Error
per Pitch**
arcsec
60
45
35
30
25
40
30
25
20
Repetitive
Positioning
Precision**
arcsec
30
25
20
15
15
20
15
15
10
Maximum
Backlash
arcsec
18.5
13.9
11.1
9.3
7.9
11.7
8.8
7.0
5.9
Operating
Temp. Range***
-5 to 40
[23 to104]
°C
[°F]
Rack Grease
Part Number
853901
* Life rating is an estimate rounded down to the next 1,000 revolutions and based on maintaining published accuracy specifications and operated with
allowable dynamic loading for 60,000,000 pinion revolutions (10,000 hours) at a constant 100 rpm when properly installed and receiving recommended
lubrication intervals while operated in a clean, dry, 20° C [68° F] environment. Application and environmental conditions, and lubrication intervals will
impact expected product life. The RPG system will continue to operate beyond this point with deteriorating accuracy. Additional ring gear life may be
achieved by replacing the pinion before excessive ring gear wear occurs.
** Positional accuracy dependent on proper installation and measured at 20° C (68° F). To be conservative, transmitting accuracy has been rounded up
to the next 10 arcsec, others have been rounded up to the next 5 arcsec.
Specifications are with systems assembled to Nexen specifications, operated at 20ºC [68º F], and are subject to variations due to mounting surface
irregularities, rigidity, installation accuracy, proper maintenance, and ambient temperature.
*** For applications outside of this temperature range or with wide temperature swings contact Nexen.
Standard Gear Dimensions
RPS16G
B
E
J
G
A
F
D
K
H
~56.0
[~2.205]
12.0
[0.472]
18.0
[0.709]
42.0
[1.654]
Minimum
Shaft Insertion
Ø 42.0
[Ø 1.654]
2.0
[0.079]
12.0
[0.472]
16.0
[0.630]
Ø 20.0H7
[Ø 0.787H7]
C2
20.0
[0.787]
2.0
[0.079]
Ø 67.0
[Ø 2.638]
P.C.D. 33.0 [1.299]
~52.0
[~2.047]
5-M4
11.0
[0.433]
mm [in]
Ring Gear
Product
Number
Mounting Holes
A
B
D
Number
Inner
of Teeth Center to Center Outer
Distance
Diameter Diameter
E
Bolt / Pin
Circle
Diameter
30
98.0
[3.858]
162.0
70.0H7
[6.378] [2.756H7]
90.0
[3.543]
966551
40
122.0
[4.803]
210.0
120.0H7
[8.268] [4.720H7]
145.0
[5.709]
966552
50
146.0
[5.748]
257.0
160.0H7
[10.118] [6.299H7]
180.0
[7.087]
60
170.0
[6.693]
305.0
190.0H7
[12.008] [7.480H7]
220.0
[8.661]
70
193.5
[7.618]
353.0
260.0H7
[13.898] [10.236H7
285.0
[11.221]
966550
966553
966554
G
F
H
Angular Pinning
Pitch Hole Size
J
K
Mounting Bolt
Hole Size
Diameter
of Boss
60°
6 Holes,
2 Holes
Ø7.0[0.276] Thru
Ø6.0H7
Ø11.0[0.443]
[0.236H7]
6.5[0.256]
106.0
[4.173]
15°
45°
8 Holes,
2 Holes
Ø7.0[0.276] Thru
Ø6.0H7
Ø110[0.443]
[0.236H7]
6.5[0.256]
161.0
[6.339]
15°
30°
12 Holes,
2 Holes
Ø7.0[0.276] Thru
Ø6.0H7
Ø11.0[0.443]
[0.236H7]
6.5[0.256]
206.0
[8.110]
30°
12 Holes,
2 Holes
Ø9.0[0.354] Thru
Ø8.H7
Ø14.0[0.551]
[0.315H7]
8.5[0.335]
246.0
[9.690]
30°
12 Holes,
2 Holes
Ø9.0[0.354] Thru 301.0
Ø8.0H7
Ø14.0[0.551]
[11.850]
[0.315H7]
8.5[0.335]
30°
15°
15°
Visit www.nexengroup.com or contact Nexen’s technical support group for up to date technical specifications, drawings,
CAD files, and User Manual to review installation requirements before designing a system.
Standard Gear Dimensions
B
RPS25G
E
J
G
A
F
D K
H
~72.0
[~2.835]
26.0
[1.024]
14.0
[0.551]
Ø 63.0
[Ø 2.480]
54.0
[2.126]
Minimum
Shaft Insertion
28.0
[1.102]
2.0
[0.079]
2.0
[0.079]
24.0
[0.945]
14.0
[0.551]
C2
Ø 30.0H7
[Ø 1.181H7]
Ø 101.0
[Ø 3.976]
P.C.D. 51.0 [2.008]
12.0
[0.472]
5-M6
mm [in]
~66.0
[~2.598]
Ring Gear
A
Mounting Holes
B
D
E
Inner
Diameter
Bolt / Pin
Circle
Diameter
G
Product
Number
Number
of Teeth Center to Center Outer
Distance
Diameter
966560
30
154.0
[6.063]
254.0
120.0H7
[10.000] [4.720H7]
145.0
[5.709]
30°
966561
40
193.0
[7.596]
331.0
190.0H7
[13.032] [7.480H7]
220.0
[8.662]
15°
50
230.0
[9.055]
405.0
260.0H7
[15.945] [10.236H7]
285.0
[11.221]
60
268.0
[10.551]
481.0
330.0H7
[18.937] [12.992H7]
360.0
[14.173]
966562
966563
F
15°
15°
Angular
Pitch
H
J
K
Pinning Mounting Bolt Hole Diameter
Hole Size
Size
of Boss
60°
6 Holes,
2 Holes
Ø9.0[0.354] Thru
Ø8.0H7
Ø14.0[0.551]
[0.315H7]
8.5[0.335]
176.0
[6.929]
30°
12 Holes,
2 Holes
Ø9.0[0.354] Thru
Ø8.0H7
Ø14.0[0.551]
[31.05H7]
8.5[0.335]
246.0
[9.691]
30°
12 Holes,
2 Holes
Ø9.0[0.354] Thru
Ø8.0H7
Ø14.0[0.551]
[0.315H7]
8.5[0.335]
326.0
[12.835]
22.5°
16 Holes,
2 Holes
Ø11.0[0.433] Thru 406.0
Ø10.0H7
Ø17.5[0.709]
[15.984]
[0.394H7]
10.5[0.413]
Visit www.nexengroup.com or contact Nexen’s technical support group for up to date technical specifications, drawings,
CAD files, and User Manual to review installation requirements before designing a system.
10
Specifications For Determining Custom Gear Set Performance
System Specifications
RPG16
RPG20
RPG25
RPG32
RPG40
RPG4014
16
[0.630]
20
[0.787]
25
[0.984]
32
[1.260]
40
[1.575]
40
[1.575]
30.7 / 23.5
30.1 / 23.5
30.7 / 23.5
30.1 / 23.5
30.0 / 23.5
30.0 / 23.5
mm
[in]
4.8
[0.19]
6.0
[0.24]
7.5
[0.30]
9.5
[0.37]
12.0
[0.47]
12.0
[0.47]
Torque Circle Tangential Positional
Accuracy
±μm
[±in]
30
[0.00118]
30
[0.00118]
30
[0.00118]
30
[0.00118]
30
[0.00118]
30
[0.00118]
Maximum Torque Circle Tangential
Backlash
μm
[in]
3.2
[0.00013]
3.2
[0.00013]
3.2
[0.00013]
3.2
[0.00013]
3.2
[0.00013]
3.2
[0.00013]
Maximum Torque Circle Tangential
Speed
m/s
[ft/s]
4
[13.1]
5
[16.4]
8
[26.2]
11
[36.1]
6
[19.7]
6
[19.7]
Maximum Dynamic Torque Circle
Tangential Thrust
N
[lbf]
1000
[225]
1500
[337]
2200
[495]
3600
[809]
6000
[1349]
14000
[3147]
Maximum Static Torque Circle
Tangential Thrust
N
[lbf]
2000
[450]
3000
[674]
4400
[990]
7200
[1618]
12000
[2698]
21000
[4721]
mm
[in]
Tooth/Roller Pitch
Maximum / Average
Pressure Angle
Degrees
Module
Estimated Torque Circle
Tangential Life*
m 9,600,000 12,000,000 15,000,000 23,040,000 28,800,000 336,000,000
[ft] [31,496,000] [39,370,000] [49,230,000] [75,590,000] [94,480,000] [1,102,200,000]
Roller Pinion
RPG16
RPG20
RPG25
RPG32
RPG40
RPG4014
Product Number
966659
966669
966679
966689
966699
966693
Number of Rollers
Maximum RPM
10
10
10
12
12
14
1500
1500
1920
1719
750
643
Maximum Dynamic Torque
Nm
[in-lb]
25.5
[226]
47.7
[422]
87.5
[774]
220.0
[1946]
458.4
[4057]
1247.8
[11044]
Maximum Static Torque
Nm
[in-lb]
50.9
[450]
95.5
[884]
175.1
[1558]
440.0
[3894]
916.8
[8119]
1871.6
[16565]
Mounting Bore Diameter
mm
[in]
20.0
[0.79]
25.0
[0.98]
30.0
[1.18]
45.0
[1.77]
60.0
[2.36]
60.0
[2.36]
Torque Circle Diameter
mm
[in]
1.91
[48.7]
61.5
[2.42]
76.9
[3.03]
116.9
[4.60]
147.7
[5.81]
172.3
[6.78]
Tangential Distance per
Revolution
mm
[in]
160.0
[6.30]
200.0
[7.87]
250.0
[9.84]
384.0
[15.12]
480.0
[18.90]
560.0
[22.1]
Mass Weight
kg
[lb]
0.8
[1.76]
1.3
[2.87]
2.2
[4.85]
6.4
[14.11]
12.4
[27.34]
20.9
[46.08]
0.00041
[0.0098]
0.00105
[0.0249]
0.00268
[0.0636]
0.01690
[0.4010]
0.05940
[1.4096]
0.11800
[2.8005]
RPG16
RPG20
RPG25
RPG32
RPG40
RPG4014
0.07
[0.154]
0.16
[0.353]
0.24
[0.529]
0.52
[1.146]
1.35
[2.976]
1.74
[3.836]
Moment Of Inertia
kgm²
[lbft²]
Ring Gear Or Arc Segment
Approximate Mass Per Tooth
kg
[lb]
** See page 8 note * for life rating details
Useful Formulas
Ring Gear Dynamic Torque (N) = Pinion Dynamic Tangential Thrust X Ring Gear Torque Circle Radius (m)
Ring Gear Static Torque (N) = 2 X Ring Gear Dynamic Torque
Gear System Ratio = Ring Gear Torque Circle Diameter (m) / Pinion Torque Circle Diameter (m)
Positional Accuracy In Radians Based On Ring Gear Torque Circle Radius = Tangential Positional Accuracy (m) / Ring Gear Torque Circle Radius (m)
Backlash In Radians Based On Ring Gear Torque Circle Radius = Pinion Tangential Backlash (m) / Ring Gear Torque Circle Radius (m)
Convert Radians To Arc Seconds = Radians X 206264.8
Ring Gear Mass (kg) = Ring Gear Torque Circle Radius (m) X 6.283 X Tooth Mass (kg) **
Ring Gear Inertia (kgm2) = Ring Gear Mass (kg) X Ring Gear Torque Circle Radius2 (m2) **
** For Segments Divide By Fraction Of Full Ring Gear
11
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In accordance with Nexen’s established policy of constant product
improvement, the specifications contained in this document are subject
to change without notice. Technical data listed in this document are
based on the latest information available at the time of printing and are
also subject to change without notice. For current information, please
consult www.nexengroup.com
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