DMU (Box design) Mechanical Backlash-free

Specially designed machinery is able to eliminate clearance from gearbox inner and from between pinions and racks. Driven by a single servo motor, enclosed mechanical preload system is more efficient than electrical preload system.
Precision Level
Precision Level
Torsional Rigidity
Torsional Rigidity
Price Range
Price Range
Industry Applications
CNC Machine Tools
Special Purpose Machines (SPMs)
Engineering Machinery
Enclosed Gearbox
  • Specially designed machinery is able to eliminate clearance from the gearbox inner and from between pinions and racks. This completely supplements and clears up the backlash of manufacture or/and installation while gearboxes drive both pinions and racks.
Cost saving
  • Mechanical preload system, driven by a single servo motor, can reach the goal of electrical preload system, save controller and driver cost.
  • Backlash eliminating enables processing tool tracks stable, which prolongs tool life.
Easy to set up
  • Parameter setting can be easier for enclosed mechanical preload system, driven by a single servo motor, than electrical preload system.
Better processing surface smooth and accuracy
  • Backlash reducing enables improved processing surface smoothness and accuracy.
Huge Torsional Rigidity
  • For the well-designed structure and high duty material of taper roller bearing, the output shaft of the reducer can bear the huge axial and radial load, which could be wide application.
High Dynamics
  • One-piece output design, special high strength the fewer teeth of pinion and smaller servo motor, achieve the low moment of inertia.
Precise Positioning
  • Precision gear grinding tooth surface smooth, precise tooth.
  • For an excellent design, high accuracy and low moments of inertia.
Long Service Life and Low Noise
  • For the professional gear producing experience and the serious quality control of manufacturing processes.
  • After a long time operation, the preloading force is still maintained.
Configure your planetary gear reducers
This product does not have technical data for 1-stage for reference. We recommend searching for technical data for 2-stage instead.

DMU Technical Data (2-stage) Ratio 32~110

Specifications RatiosDMU140DMU160DMU180DMU210DMU240
Output Torque (1) T2B Nm 3211201770250059209395
4011201770250059209395
449501545222054307950
559501545222054307950
669501545222054307950
779501545222054307950
889501545222054307950
1109501545222054307950
Emergency Stop Torque(2) T2Not Nm 322320365051501280019300
402320365051501280019300
441950314043301099016110
551950314043301099016110
661950314043301099016110
771950314043301099016110
881950314043301099016110
1101950314043301099016110
Nominal Outout Torque T2N Nm 327351150164538906180
407351150164538906180
446251000146035705230
556251000146035705230
666251000146035705230
776251000146035705230
886251000146035705230
1106251000146035705230
Nominal Input Speed n1N rpm 3230003000300025002000
4030003000300025002000
4430003000300025002000
5530003000300025002000
6630003000300025002000
7730003000300025002000
8830003000300025002000
11030003000300025002000
Maximum Input Speed n1Max rpm 3240004000400035003500
4040004000400035003500
4440004000400035003500
5540004000400035003500
6640004000400035003500
7740004000400035003500
8840004000400035003500
11040004000400035003500
Efficiency with Full Load % 32≥93≥93≥93≥93≥93
40≥93≥93≥93≥93≥93
44≥93≥93≥93≥93≥93
55≥93≥93≥93≥93≥93
66≥93≥93≥93≥93≥93
77≥93≥93≥93≥93≥93
88≥93≥93≥93≥93≥93
110≥93≥93≥93≥93≥93
Service Life LH2 h 322000020000200002000020000
402000020000200002000020000
442000020000200002000020000
552000020000200002000020000
662000020000200002000020000
772000020000200002000020000
882000020000200002000020000
1102000020000200002000020000
Mass Moments of Inertia kg‧cm2 3239.7742.8095.73228.50360.00
4039.7742.8095.73228.50360.00
4439.7742.8095.73228.50360.00
5539.7742.8095.73228.50360.00
6639.7742.8095.73228.50360.00
7739.7742.8095.73228.50360.00
8839.7742.8095.73228.50360.00
11039.7742.8095.73228.50360.00
Helical Tooth Pinion (Module) M 23M4M4M5M6M8
40M4M4M5M6M8
44M4M4M5M6M8
55M4M4M5M6M8
66M4M4M5M6M8
77M4M4M5M6M8
88M4M4M5M6M8
110M4M4M5M6M8
Helical Tooth Pinion (N# of Teeth) T 3215T18T15T18T15T
4015T18T15T18T15T
4415T18T15T18T15T
5515T18T15T18T15T
6615T18T15T18T15T
7715T18T15T18T15T
8815T18T15T18T15T
11015T18T15T18T15T
Spur Tooth Pinion (Module) M 32M4M4M5M6M8
40M4M4M5M6M8
44M4M4M5M6M8
55M4M4M5M6M8
66M4M4M5M6M8
77M4M4M5M6M8
88M4M4M5M6M8
110M4M4M5M6M8
Spur Tooth Pinion (N# of Teeth) T 3216T19T16T19T16T
4016T19T16T19T16T
4416T19T16T19T16T
5516T19T16T19T16T
6616T19T16T19T16T
7716T19T16T19T16T
8816T19T16T19T16T
11016T19T16T19T16T
Pitch Circle Diameter (Helical Tooth Pinion) Ø 32Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
40Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
44Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
55Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
66Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
77Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
88Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
110Ø63.66Ø79.39Ø79.58Ø114.59Ø127.32
Pitch Circle Diameter (Spur Tooth Pinion) Ø 32Ø64Ø76Ø80Ø114Ø128
40Ø64Ø76Ø80Ø114Ø128
44Ø64Ø76Ø80Ø114Ø128
55Ø64Ø76Ø80Ø114Ø128
66Ø64Ø76Ø80Ø114Ø128
77Ø64Ø76Ø80Ø114Ø128
88Ø64Ø76Ø80Ø114Ø128
110Ø64Ø76Ø80Ø114Ø128
Circumference (Helical Tooth Pinion) 32200240250360400
40200240250360400
44200240250360400
55200240250360400
66200240250360400
77200240250360400
88200240250360400
110200240250360400
Circumference (Spur Tooth Pinion) 32201.06238.76251.33358.14402.12
40201.06238.76251.33358.14402.12
44201.06238.76251.33358.14402.12
55201.06238.76251.33358.14402.12
66201.06238.76251.33358.14402.12
77201.06238.76251.33358.14402.12
88201.06238.76251.33358.14402.12
110201.06238.76251.33358.14402.12
Addendum Modification Coefficient (Helical Tooth Pinion) 320.355-0.3723-0.355
400.355-0.3723-0.355
440.355-0.3723-0.355
550.355-0.3723-0.355
660.355-0.3723-0.355
770.355-0.3723-0.355
880.355-0.3723-0.355
1100.355-0.3723-0.355
Addendum Modification Coefficient (SpurTooth Pinion) 320.475-0.45-0.4375
400.475-0.45-0.4375
440.475-0.45-0.4375
550.475-0.45-0.4375
660.475-0.45-0.4375
770.475-0.45-0.4375
880.475-0.45-0.4375
1100.475-0.45-0.4375
Note (1) Data are measured at the frequency under 1000 times per hour. Contact us if your data are beyond the presented table above.
Note (2) Operation can be up to 1000 times in product life.

This product does not have dimensions for 1-stage for reference. We recommend searching for dimensions for 2-stage instead.

DMU dimensions (2-stage ratio 32 / 40 / 44 / 55 / 66 / 77 / 88 / 110)[mm]

DMU series dimensions double stage
Frame size DMU140 DMU160 DMU180 DMU210 DMU240
stage 2 2 2 2 2
H1 220 270 320 380 420
H2 32.5 35 35 50 60
H3 155 200 250 280 300
H4 45 60 70 100 90
H5 65 75 90 90 120
H6 130 150 180 180 24
L1 470 530 600 720 815
L2 405 460 530 620 695
L3 32.5 35 35 50 60
L4 202.5 230 265 310 347.5
L5 189 207 240 270 320
L6 353 386 458 512 600
W1 43 43 54 65 88
W2 3 6 - - 4
W3 62 64 68 86.5 115
W4 50 60 80 90 90
W5 55 65 75 105 95
W6 110 130 150 210 180
W7 132.5 157.5 192.5 247.5 232.5
W8 309 336.5 385 480.5 519.5
※W9 51.5 52 61 56 48
※W10 422.5 452.5 514 623 682.5
※W11 10 15 15 10 10
※W12/td> 82 82.5 98 85 83.5
※W13 176 176 176 176 190
D1(F7) max. 38 38 42 48 55
※D2 114.3 114.3 114.3 114.3 180
D3 9.5 9.5 11.5 13.5 13.5
※D4 200 200 200 200 215
M1 M12*P1.75 M16*P2 M20*P2.5 M20*P2.5 M20*P2.5
※M12 M12*P1.75 M12*P1.75 M12*P1.75 M12*P1.75 M12*P1.75

※Actual dimensions marked above may vary from different servo motors.
We persistently research in and develop our products, and we have made every effort to maintain the specification data above correct. If there is any discrepancy between the data and real dimensions, please refer to products or may contact us for updated data.

DMU dimensions(Input shaft type) (2-stage ratio 32 / 40 / 44 / 55 / 66 / 77 / 88 / 110)[mm]

DMU series dimensions double stage
Frame size DMU140 DMU160 DMU180 DMU210 DMU240
Stage 2 2 2 2 2
H1 220 270 320 380 420
H2 32.5 35 35 50 60
H3 155 200 250 280 300
H4 45 60 70 100 90
H5 65 75 90 90 120
H6 130 150 180 180 24
L1 470 530 600 720 815
L2 405 460 530 620 695
L3 32.5 35 35 50 60
L4 202.5 230 265 310 347.5
L5 189 207 240 270 320
L6 353 386 458 512 600
W1 43 43 54 65 88
W2 3 6 - - 4
W3 62 64 68 86.5 115
W4 50 60 80 90 90
W5 55 65 75 105 95
W6 110 130 150 210 180
W7 132.5 157.5 192.5 247.5 232.5
W8 292.5 313 366 450.5 493.5
W9 88 88 102 115 111
W10 422.5 465 536 652 719.5
W11 73 73 83 85 85
W12 70 70 80 82 82
D1(k6) max. 40 40 42 50 55
D2 9.5 9.5 11.5 13.5 13.5
M1 M12*P1.75 M16*P2 M20*P2.5 M24*P3 M30*P3.5

※Actual dimensions marked above may vary from different servo motors.
We persistently research in and develop our products, and we have made every effort to maintain the specification data above correct. If there is any discrepancy between the data and real dimensions, please refer to products or may contact us for updated data.

DMU mechanical anti-backlash reducer purchasing information

Mounting positions

Ordering information Installation orientation
DMU series implementation rack drive
Rack

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Frame Sizes 140-240
Ratios 2-stage: 32-110
Torque Value 1120-9395
Backlash -