Brushless disc-type DC motor or generator
US4508998A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 1981 |
| Grant date | Apr 2, 1985 |
| Priority date | — |
| Expiry date | Feb 9, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless, preferably coreless, disc-type DC motor or generator characterized by a positive, unidirectional, nearly constant torque is disclosed. The machine in a preferred form comprises a rotor disc mounted for rotation with the shaft and a stator fixedly mounted in coaxial parallel relation to the rotor. The stator contains at least two interleaved sets of coils, with the sets of coils adapted to be alternately energized for current flow in the same direction in the plane of the stator to generate axially extending magnetic fields all of the same polarity. The rotor disc carries in a circular array at least one permanent magnet, asymmetrically shaped in relation to the shape of the stator coils, each having a tip portion and a base portion; and with a magnetic field of common polarity extending in the same axial direction as the magnetic fields of the energized coils. When the tip portions of the magnets are aligned with a first set of coils, that set is energized to create a torque on the rotor. The magnets rotate until the tip portions become aligned with the adjacent set of coils, which are then energized as the first set of coils are simultaneously de-energized. This seque…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.