Electric motor
US4755703A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1987 |
| Grant date | Jul 5, 1988 |
| Priority date | — |
| Expiry date | Mar 18, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K37/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to improvement of a motor with a rotor including a permanent magnet. The motor comprises a yoke of soft magnetic material, a plurality of field poles each having a field core of semi-hard magnetic material and a pole piece of soft magnetic material, a plurality of coils wound around the field cores respectively, and a rotor including a permanent magnet. In this constitution, utilizing action of the minor loop of the field cores of semi-hard magnetic material, the residual magnetic flux density of the plurality of field cores is controlled in sequence and the shifting magnetic field is induced thereby the magnetic poles of the rotor are attracted in sequence so as to move the rotor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.