DPFR-029: ETH-messtechnik gmbh


Examination of cogging torque of electric motors with permanent magnet

Test facility for the development and quality control of electric motors. The holding torque of the permanent magnet is tested, plotted and evaluated.

Customized Solution

Request of our customer:

The motor is used to drive / open and close a car tailgate. In the event of a power failure, the holding force of the permanent magnet must be greater than the weight of the tailgate so that it stops safely. For this purpose, the cogging torque of the permanent magnet poles is measured over one revolution depending on the angle of rotation.


  • Acquisition of torque via rotation angle
  • Graphic recording of the test sequence
  • Storage of the test results in Excel
  • Simultaneous viewing of up to 20 variable test sequences from the database, shown in color.
  • Variable test speed
  • Reproducible test process thanks to constant speed independent of torque