Magnet shaping and pole concentration for reduction of cogging torque in permanent magnet motors
US6784582B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2001 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Nov 19, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K1/2733
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rotor for a permanent magnet motor with a rotor yoke and a permanent magnet ring mounted on the rotor yoke, the magnet ring having a plurality of circumferentially spaced poles. One of the rotor yoke and the permanent magnet ring is an annular member including depressed portions along a peripheral edge located around a midpoint between each pole. The depressed portions are shaped so the motor produces a sinusoidal flux density. The other of the rotor yoke and the permanent magnet ring is an annular ring. In another aspect, the rotor has a rotor yoke and a permanent magnet ring mounted on the rotor yoke. The permanent magnet ring includes a plurality of circumferentially spaced poles. One of the rotor yoke and the permanent magnet ring includes a plurality of depressions along an outer peripheral edge shaped so the motor produces a sinusoidal flux density during operation. Each of the plurality of depressions is located around a junction defined by two poles. In either aspect, the rotor yoke can be skewed, and the magnet ring can be tapered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.