Mosrac direct drive torque motors

Frameless Torque Motor Comparison

Our standard frameless torque motors come with voltage ranges from 24 to 48V and outside diameters from 25 to 200mm, covering the widest size range in the market, select frameless motors tailored to your application.


They offer a very compact design, high precision, higher overload capacity, high torque density, and lightweight, suitable for industries such as robotics including humanoid or bipedal robots, medical, and aerospace. These models have industry-leading performance and are cost-effective. Additionally, if the performance and cost differ, we offer customized solutions to control your product costs better.


The table below summarizes the main specifications of each series of frameless motors. Click the "Model Number" button to check technical files including specs, 3D, and CAD drawings for each frameless direct-drive torque motor.

How to choose Frameless Torque Motor
ModelOD(mm)ID(mm)Height(mm)Weight(kg)Rated Torque(Nm)Rated Power(W)Rated Speed(rpm)Voltage(V)
U2510
U2515
U2523		 25 11.6 10.8
15.2
23.4		 0.024
0.036
0.052		 0.025
0.05
0.075		 10.48
20.96
31.44		 400024
U3815
U3822
U3834		 38 18 15.3
22.3
34.3		 0.048
0.068
0.099		 0.1
0.2
0.35		 31.4
62.9
110		 3000 48
U5019
U5024
U5037		 50 28 19.8
24.3
37.9		 0.12
0.157
0.266		 0.27
0.42
0.7		 84.89
132.05
220.08		 3000 48
U6017
U6022
U6035		 60 33 17.7
22.2
35.8		 0.146
0.205
0.361		 0.45
0.6
0.96		 141.48
188.64
301.82		 3000 48
U6818
U6822
U6836		 68 37 18.3
22.8
36.4		 0.197
0.266
0.474		 0.63
0.86
1.54		 198.07
270.38
484.18		 3000 48
U7618
U7623
U7636		 76 42 18.6
23.1
36.7		 0.245
0.333
0.606		 0.89
1.23
2.06		 279.82
386.71
647.66		 3000 48
U8519
U8523
U8537		 85 47 19.3
23.8
37.4		 0.306
0.414
0.736		 1.21
1.65
2.69		 380.42
518.76
845.74		 3000 48
U9419
U9424
U9437		 94 51 19.7
24.2
37.8		 0.382
0.522
0.93		 1.58
2.05
3.67		 496.75
644.52
576.92		 3000 48
U11526
U11530
U11544		 115 65 26.3
30.8
44.4		 0.655
0.85
1.45		 3
3.9
6.1		 943.2
1021.8
958.92		 3000
2500
1500		 48
U13025
U13035
U13060		 130 84 25.9
35.9
60.9		 0.9
1.3
2.7		 5
9
18		 419.2
471.6
754.56		 800
500
400		 48
U16025
U16035
U16060		 160 106 25.9
35.9
60.9		 1.1
1.6
3.3		 9
15
32		 471.6
471.6
670.72		 500
300
200		 48
U20025
U20035
U20060		 200 140 25.9
35.9
60.9		 1.7
2.9
5.5		 13
24
50		 408.72
503.04
524		 300
200
100		 48

Available Frameless Torque Motor Solutions

Mosrac designs and manufactures direct-drive frameless brushless DC (BLDC) torque motors. This design allows the rotor and stator to be integrated directly into the application or assembly, offering maximum flexibility, being lightweight, and being a very compact size.


It is especially suitable for space-limited applications to meet special engineering projects, perfectly matching your facility spacing & industry needs. Simultaneously our frameless brushless direct-drive torque motors help you achieve your ideal torque, speed, size, and temperature for advanced robotics, medical devices, aerospace systems, and more.


Mosrac is also famous well known for its development of special and fully customized torque motors.



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Your Next Robotic Design Starts Here

The U-series frameless motors are the newest addition to Mosrac's complete line of robotic motors. They're typically used to drive the joints of collaborative robots (humanoid robots). They are also designed for a wide range of demanding applications in industries such as medical, aerospace, and defense. You will find these advanced motors suitable for meeting your unique requirements.

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The Frameless Torque Motor Advantage

High Torque Density
Rare-earth magnets on the rotor ring produce a magnetic field twice as strong as ferrite magnets. Star winding ensures stable torque delivery even at slow rotation rates.
Very Compact Design
U series direct-drive torque motors are very compact, hollow-shaft & brushless, easy to install in tight spaces, and do not require additional fittings or accessories to transmit force to driven machines.
High Efficiency
With additional moving parts and direct drive technology, these frameless motors minimize energy loss and increase overall system efficiency.
Low Maintenance
Frameless brushless motors eliminate the necessity for mechanical transmissions such as gearboxes, belts, and speed reducers.
Integrated thermal sensor
Frameless brushless motors eliminate the necessity for mechanical transmissions such as gearboxes, belts, and speed reducers.
Low Cogging
Frameless direct drive torque motors are designed to minimize cogging torque, ensuring smooth and consistent motion.

Part no. description

Torque Motor Series

U: Frameless torque motor

1
2
3
4
5
6
7
8
9
Cable length
03:300mm
00: please consult for custom length
Standard/Customized
None: Standard
C: Customized
Voltage
48：DC48V
24：DC24V
(except u25 series, custom for other series)
12：DC12V
(Please consult for a custom voltage range)
Environmental:
Default: -25℃~85℃
Please consult for a custom temperature range
Temperature control
Nothing: w/o temperature control
T: w/ temperature control
Encoder type
H: Hall
E: Photoelectric incremental (analog)
E1: Photoelectric incremental type (digital)
E2: Photoelectric absolute type
S1: 17-bit magnetic encoder
S2: 24-bit magnetic encoder
T: 24-bit magnetic dual encoder
Rated torque
for example: 0.2Nm, 3Nm, 15Nm, or custom
Size:
for example:
Height: 10.8mm, 30.8mm, or custom
OD: 25mm,115mm, or custom
Rotor type
I: inner rotor
E: outer rotor
eg：
UI：inner rotor frameless motor
UE：outer rotor frameless motor

For example

U3815: U series frameless torque motor, OD 38mm， height 15.3mm， rated torque 0.1Nm， inner rotor;

U11544: U series frameless torque motor， OD 115mm， height 44.4mm， rated torque 6.1Nm， inner rotor;

UE2506: U series frameless torque motor, OD 25.3mm， height 6.2mm， rated torque 0.04Nm， outer rotor;

Specification

Insulation level Grade F
Insulation withstand voltage AC1500 V 60s
Insulation resistance 10MΩ or more DC500V
Excitation method three-phase permanent magnet motor
Environmental Requirements Temperature -25℃~85℃
Humidity 20%~85%RH
The atmospheric environment does not produce strong magnetism, no corrosion,no explosive gas, no oil mist, no dust; the altitude is below 1000 meters.

Not sure which is the best
solution for your application?

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