Brushless dc motor and rotor magnet
US5095238A · kind A · utility
66Cited by
6References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1990 |
| Grant date | Mar 10, 1992 |
| Priority date | — |
| Expiry date | Apr 3, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K1/2791
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless dc motor comprising a stator, and a rotor incorporating a hollow cylindrical permanent magnet. The rotor magnet has sectors magnetized radially in opposite directions to define poles of opposite polarity extending around the circumference of the magnet. The magnet is completely magnetized so as to leave no non-magnetized sectors between the poles of the magnet. The magnet has grooves in its surface facing the stator, the grooves extending in the longitudinal direction of the magnet. Each groove is offset from, or non-symmetrical with respect to, the center of the rotor pole in which it is located.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.