Permanent magnet electric motor with reduced cogging torque
US7342338B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2003 |
| Grant date | Mar 11, 2008 |
| Priority date | — |
| Expiry date | Apr 7, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2201/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet electric motor 10 comprises a rotor 30 provided with two stages of permanent magnets in the axial direction on an outer circumferential face of a rotor iron core, and having a shaft shifted by a stage skew angle θr in electrical angle to decrease a first frequency component of cogging torque in the circumferential direction of the rotor iron core between two stages of the permanent magnets, a stator iron core 21 of cylindrical shape provided with the stator winding for producing a rotating magnetic field causing the rotor 30 to be rotated, and a stator 20 dividing the stator iron core 21 into plural blocks in the axial direction, and shifted by a stage skew angle θs in electrical angle to decrease a second frequency component of the cogging torque in the circumferential direction of the stator iron core 21.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.