Electric motor
US4114060A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1977 |
| Grant date | Sep 12, 1978 |
| Priority date | — |
| Expiry date | May 16, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K19/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric motor, particularly for driving a gramophone, a tape recorder or an electric instrument at a low rotational speed whereby an induction effect is utilized to achieve good starting torque and a reluctance effect to give good torque when the motor is locked in and running synchronously. The motor includes a stator assembly with a first plurality of pairs of primary pole pieces each pair constituted by a first metal part for the energization by an in-phase current and a second plurality of pairs of primary pole pieces each pair constituted by a second metal part for energization by an out of phase current. The respective parts also define slots constituting secondary pole pieces. A rotor assembly defines a plurality of further pole pieces having a pitch corresponding to the pitch of the secondary pieces, so that when the secondary pieces associated with the first plurality are opposite to the respective ones of the further pole pieces the secondary pole pieces associated with the second plurality of pieces are displaced with respect to respective ones of the further pole pieces by the phase angle between in-phase and out-of-phase currents.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.