Motor with improved temperature characteristics
US4401906A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1981 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Mar 10, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K37/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The temperature characteristics of a motor which has a ferrite permanent magnet has been improved. The present motor comprises a stator assembly having at least a yoke for providing a magnetic path and a coil wound on said yoke, and a rotor assembly rotatably inserted in said stator assembly, having at least an elongated spindle rotatably supported by said yoke, and a cylindrical permanent magnet made of a ferrite material pierced by said spindle and being symmetrical wth respect to said spindle, said spindle being made of adjusting alloy or adjusting steel having the magnetic characteristics that the magnetic reluctance of the same increases as the temperature of the same increases, and said yoke is made of steel having the magnetic characteristics that the magnetic reluctance is constant irrespective of the change of the temperature. Although the temperature change causes the change of the flux from the ferrite permanent magnet, that change is compensated by the adjusting material of the spindle, and the effective flux which links with the coil of the stator assembly can be constant irrespective of the change of the temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.