Rotary dynamo electric machine with protection against demagnetization of low flux portion of permanent magnet poles
US4471252A · kind A · utility
30Cited by
3References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 22, 1982 |
| Grant date | Sep 11, 1984 |
| Priority date | — |
| Expiry date | Nov 22, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K23/42
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A permanent magnet dynamo electric machine is provided with a shield of high saturation flux density at the weaker or lower flux tip or edge of a permanent magnet pole face to prevent both circumferential and axial demagnetization of that portion of the pole face. The shield resides in a recess in the pole face so as to maintain a constant width air gap between the rotor and stator and has a thickness in the range of 5-15% of the overall thickness of the shield and pole combined. The shield and its pole face extend axially at least over the entire axial dimension of the area swept by the rotor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.