Method and apparatus for testing electric motor rotors
US5404108A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 25, 1993 |
| Grant date | Apr 4, 1995 |
| Priority date | — |
| Expiry date | Feb 25, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L5/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A testing apparatus for rotors of electric motors comprising a test fixture including a fixture shaft on which a rotor is temporarily attached to a known inertial load. A stator creates a rotating magnetic field to cause rotation of the rotor, and an encoder senses the amount of angular rotation of the rotor in short time intervals, which is recorded in a memory and later used to calculate torque. An index mark from the encoder indicates each complete revolution of the rotor and may be used to determine the location of a defective rotor segment by reference to a start point mark placed on the rotor prior to the test. An electronic control circuit initially applies a low value electric current to the stator to create a rotating magnetic field to cause the rotor to rotate at a slower than normal rate to improve the resolution of the torque measurement. After the rotor has accelerated to a predetermined value, the stator voltage may be increased. The amount of actual rotation of the rotor at multiple, known time intervals as the rotor accelerates to a predetermined speed is used to calculate actual torque.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.