High Torque Motors

Technical characteristics: 

 Parameter  Units  TORQUE 3600  TORQUE 1800
Nominal Torque Nm 3600 1800
Speed rpm 0.8 0.8
Voltage V (DC) 600 600
Ripple torque % 4 4
Cogging Torque Nm 48 22
Maximum Torque Nm 5000 2600
Outside Stator diameter mm 1092 606
Inside Rotor diameter mm 981 471
Motor Lenght mm 100 160

The motors are used to control two-axis transportable radar pedestal in a closed loop servo system. The maximum ripple torque (peak to peak) will be 4% for each motor.

Traditionally, servo drives use high speed rotary motors in combination with mechanical transmissions. These motors are designed to run efficiently at high speed where cogging, speed ripple, and torque ripple are not serious issues. Mechanical transmissions are used to transform the high speed motion of the motor into the low speed, high torque operation required by the application. The gearboxes are expensive, noisy, producers of torque ripple and require additional maintenance.Replacing these systems with direct drives – torque motors, considerably increase performances of the systems, and also, maintenance and operating costs are considerable reduced when implementing direct drive motors.Torque motors eliminate the need for gearboxes, worm-gear drives, or other mechanical transmission elements and enable a direct coupling of the payload to the drive. This enables a drive with high dynamic response without hysteresis.


Industrial and non-industrial applications demand high performances permanent magnet brushless synchronous motors. Although not a high-volume product, torque motors range over wide applications. Fields where they gave good results are, for instance: machine tools, machining centers, metal forming, rotary transfer systems, printing/converting machines, plastics extrusion/injection molding machines, and in the printing industry. Non industrial applications include wind power generation and wave power harvesting. Also its can be used in ocean wave power conversion and in new-generation elevators, replacing hydraulic solutions with lower maintenance cost and simpler installation benefits. In short, torque motors are at home wherever traditional gear trains, chains, or timing belts have been used in the past.

The most unique feature of a torque motor concerns their physical dimensions. They have a relatively large diameter to length ratio, and they also have a rather short axial length. Torque motors are a type of “frameless” motor. This means that the motor does not include a housing, bearings, or feedback device. In this sense the motor is a “kit” motor, meant to be an integral part of the machine structure. To assist in integrating torque motors, they can be provided with a reusable assembly aid called a “bridge”. The bridge is set at the factory to ensure the proper alignment of the rotor and stator for assembly. The bridge also keeps the magnetic field contained within the motor, thereby eliminating the need for a special non-ferrous area for assembly, and protecting the rotor from damage from metal scraps or loose screws.

These direct drive machines can also be used as:

  • Direct drive of telescope or radar stations
  • Rotary tables for NC machine tools
  • NC machine head orientation
  • Indexing tables for transfer machines
  • Large rotary tables (glass, packaging, assembly)
  • Pick and place robots
  • Grinding machines
  • Direct drive of mills (concrete, ceramics, rubber)
  • Large low speed generators (mini hydro, wind power)
  • Metal forming: electric press and bending
  • Direct drive plastic injection machines
  • Elevators