Permanent magnet electric machine having reduced cogging torque
US7245054B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 2000 |
| Grant date | Jul 17, 2007 |
| Priority date | — |
| Expiry date | Jan 31, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet electric machine includes a stator with salient stator poles. A rotor includes two or more axial rotor sections that are rotationally offset by an offset angle equal to the cogging angle divided by the number of axial rotor sections. The axial rotor sections include rotor poles with permanent magnets. In one embodiment, the permanent magnet electric machine has a 12/10 slot/pole combination. The permanent magnets have a magnet dimension angle between 31 and 35 degrees. An air gap ratio of the electric machine is between 1.35 and 2.5. A slot opening ratio of the electric machine is less than or equal to one. In another embodiment, the permanent magnet electric machine has an 18/12 slot/pole combination. The permanent magnets have a magnet dimension angle that is between 25 and 28 degrees. An air gap ratio of the electric machine is between 1.35 and 2.5. A slot opening ratio of the electric machine is less than or equal to one.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.