U-series brushless frameless direct drive torque motors

Parameter table of frameless inrunner torque motors

The standard frameless motors from Mosrac are very compact in design and lightweight with excellent performance of high precision, high overload capacity, and high torque density. These motors 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.

In the standard U series, Mosrac offers frameless motors that come with voltage ranges from 24 to 48V, outside diameters from 25 to 200mm, continuous torque values from 0.025Nm to 50Nm, and peak torque capabilities reaching up to 1000Nm.

The table below summarizes the main specifications. Click the "model number" to check technical files including catalog, 3D, and CAD drawings for each frameless torque motor.

Model	OD(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	4000	24
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	42	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

Frameless inrunner torque motor solutions

Mosrac specializes in designing & manufacturing frameless (inrunner) torque motors. This design allows the rotor and stator to be integrated directly into the application or assembly, offering maximum flexibility, lightweight, and compact size.

Mosrac is also well-known for developing high-quality special and fully customized torque motors with an outrunner or inrunner design to meet personalized application needs such as space-limited applications and special engineering projects, perfectly matching your facility spacing & industry needs.

Mosrac’s direct-drive frameless brushless (inrunner) torque motors help you achieve your ideal torque, speed, size, and temperature for robotics (most for cobots & humanoid robots), medical devices, aerospace systems, and more.

• U25 Series 25MM Smallest Frameless Motors
• U38 Series 38MM Frameless Torque Motor
• U50 50MM Series Frameless Motor
• U60 60MM Series Frameless BLDC Motor
• U68 68MM Series Frameless Rotary Motors
• U76 Series Brushless DC Frameless Motors
• U85 Series Frameless Brushless Motor
• U94 Series Frameless Inrunner Torque Motor
• U115 Series Frameless Direct Drive Torque Motors
• U130 Series Frameless Servo Motors
• U160 Series Brushless Frameless Motors
• U200 Series BLDC Frameless Motors

Related products - magnetic encoders & outrunner motors:

Direct drives need high-quality position signals to ensure optimal performance. Perfect measuring signals can enhance the surface quality of machined workpieces, reduce the machine frame's vibrations, minimize velocity-dependent motor noise, and prevent excessive heat generation in the motor.

Mosrac recommends using a magnetic encoder to enhance the accuracy, speed stability, and thermal behavior of direct drive axes. Because there is no mechanical transmission between the encoder and the feed unit, the position signals are not susceptible to inaccuracies or delays.

Custom combinations are available on request and contact us.

• 

  Frameless Outrunner Motor

• 

  17-bit S-Series Magnetic Encoders

• 

  24-bit T-Series Magnetic Dual Encoders

Download

• 

  Torque motors brochure.pdf

  More info

Features:

• More than 100+ standard sizes are available
• 12 standard frame sizes from 25mm ( 0.984 inches) to up to 200mm (7.874 inches). ( see above table).
• Custom frame sizes are available for OEM applications
• 12 frame sizes to meet the most popular embedded equipment & collaborative robot (cobot) designs
• Speeds up to 6,000 rpm
• Pole Count from 4 to 64 Poles or custom
• Designed for operation at 24VDC, 48 VDC, and custom voltage range from 24VDC to 380VDC
• Continuous torque range from 0.025 Nm to 50 Nm or custom, Peak torque reaching up to 1000Nm
• High-temperature resistance, Available in low voltage and high voltage, Lower thermal resistance
• Stainless steel rotors for corrosion protection
• Multiple standard windings with custom windings available upon request
• Low Cogging designs
• Ideal for joint of robotic arms and robots
• CE, RoHS, REACH compliant
• Optional Hall sensors or encoders as rotor position feedback devices
• Standard and custom windings to match special speed and torque performance requirements
• Frameless models use the load’s shaft and bearings and can include Hall sensors, and additional position feedback devices such as encoders can be added as separate components

Benefits:

• The thin, adaptable, and compact design reduces both minimum machine size and maintenance, as the load and motor share the same set of bearings, simple mounting, and assembling.
• Direct drive and brushless design significantly decrease rotor inertia, leading to enhanced acceleration.
• High torque density ensures the production of a magnetic field twice as strong as ferrite magnets.
• Standard or custom windings ensure stable torque delivery even at slow rotation rates.
• Optional for low-speed and high-speed windings can enhance versatility and performance across various applications.
• Low cogging ensures smooth low-speed rotation. - Low cogging torque for a smooth, steady operation
• High-cost performance ensures that customers receive significant value for their investment between performance, quality, and price.
• Enhanced cooling and efficiency boost performance in a wide variety of operating conditions.
• Easy machine integration - All U-series motors are supplied as two pieces – a slotless stator coil and a permanent magnet rotor. The hollow rotor mounts
• Directly to a drive axis with no gearing required.
• Hollow shaft design - frameless version and easy to be integrated
• High dynamics
• Optimal speed control
• Low maintenance
• Quiet operation
• High reliability and lifetime

Applications:

Below are some examples of industry applications where torque motors are successfully used, providing our customers in these areas with a distinct competitive advantage.

• High-speed milling / turning tables
• High precision machining centers
• Grinding/finishing machines
• Boring / drilling/tapping machines
• Milling heads
• Transfer lines
• EDM
• Laser / ultrasonic cutting machines
• Stamping machines
• Lathes
• Indexing tables
• Electronic chip testing equipment/Electronics
• Pick-and-place machinery
• High-end printing/scanning machines
• Packaging equipment
• Handling equipment
• Composite materials manufacturing
• Telescopes
• Semiconductor
• Wind turbines
• Robotics/robotic joints

FAQs:

How to order: