Frameless Torque Motor

A frameless torque motor is a permanent magnet synchronous motor. It serves as the active torque and speed generating section of a conventional motor, but comes without a shaft, bearings, housing or end brackets. A frameless motor consists of only two components: the rotor and the stator. The rotor, typically the inner assembly, is a rotating steel ring fitted with permanent magnets and can be mounted directly onto the machine shaft. The stator forms the outer assembly, featuring steel laminations with copper windings wound around the teeth; it generates electromagnetic force and is compactly installed inside the machine housing.

Unlike standard servo motors, which are rated by output power, frameless torque motors are specified by output torque. The frameless motor is powered by a drive. The drive generates an electromagnetic field by regulating three-phase UVW current. The permanent-magnet rotor rotates under the action of this magnetic field.

For feedback signals, frameless torque motors can use Hall sensors or externally mounted encoders. The drive compares the feedback value with the target value and adjusts the rotor rotation angle to realize servo control.

• Item	Technical Parameter
  Motor Type	Permanent Magnet Synchronous Frameless BLDC Torque Motor
  Structure Feature	Housing-less, shaft-less, bearing-less, split stator & rotor
  Continuous Torque	Customized according to customer drawings
  Peak Torque	Customized according to customer drawings
  Rated DC Voltage	24V / 48V / Customized
  Rated Speed / Max Speed	Customized based on technical requirements
  Torque Constant	Customized
  Back EMF Constant	Customized
  Phase Resistance / Phase Inductance	Customized per drawing specs
  Cogging Torque	Low cogging design, customizable
  Rotor Inertia	Customized
  Pole Pairs	Customized
  Outer Diameter	Customized
  Hollow Bore Diameter	Customized large hollow shaft available
  Stack Length	Customized
  Feedback Method	Hall sensor / External encoder (customer defined)
  Insulation Class	Class B / F / H (optional)
  Operating Temperature	-20℃ ~ +85℃
  Protection Grade	IP00 (frameless bare motor)
  Customization Service	Strictly produced according to customer finished drawingsNo independent design or design optimization service
  Application	Humanoid robot joint, collaborative robot, robotic arm, medical robot, gimbal, precision automation equipment

 

• Frameless BLDC torque motor, stator & rotor separate assembly
• Large hollow bore for internal wiring
• High torque density, low cogging, zero‑backlash direct drive
• Compact size for robot joint integration
• Support OEM & custom dimensions, torque, winding
• Widely used in humanoid robot, cobot, robotic arm, medical robot

 

• Humanoid robot joints
• Collaborative robot (Cobot) joints
• Robotic arm and manipulator
• Medical robots and surgical automation equipment
• Gimbal & pan-tilt systems
• Precision rotary tables and special automation machinery

 

 

Our company is a 20-year professional manufacturer of high-performance sintered NdFeB neodymium magnets, certified to ISO 9001, IATF 16949, CE and RoHS. With 13 production machines and full in-house quality traceability, we supply N35-N52 grade magnets for automotive, motor, consumer electronics and industrial applications, offering drawing-based customization and serving buyers in North America, Western Europe and Eastern Europe.

Hot Tags: frameless torque motor, manufacturers, suppliers, factory, customized