DC Electric motor having field poles of permanent magnet
US4823037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 1987 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Oct 28, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K23/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A DC electric motor which comprises: a reversibly rotatable rotor having an armature core, an armature winding and a commutator; a stator having a yoke and a plurality of field poles provided on an inner circumference of the yoke and each having a permanent magnet and an auxiliary pole; and brush means including a plurality of brushes arranged to be slidably electrically conductively in contact with the commutator; in which the auxiliary pole of each of the field poles is disposed at an exit side of the field pole in the normal foward rotating direction of the rotor; each of the brushes is held movably between a first position corresponding to a position near a geometrically neutral point between a pair of adjacent field poles and a second position corresponding to a position separated at the maximum by an electrical angle of 90 degrees from the geometrically neutral point reversely to the normal rotating direction, and each of the brushes is fixed in the vicinity of the second position in normal use.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.