Differential torque motor
US5475277A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 21, 1993 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Jul 21, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A PM (permanent magnet) motor is described, that uses electromagnetic current to release or pull a PM, which has increased starting torque and a large power output in a small volume. The motor includes phase units (60, FIG. 3 ) each having three electromagnets (46A-46C) and each having two PMs (44A, 44B) of Nd-B-Fe permanent magnet material. At a start position, a PM (44B) of each phase unit is centered between the cores (50B, 50C) of two electromagnets, and there is slight overlap (90, FIG. 6 ) of each of the two core faces (64B, 64C) with the PM face (62A). Each PM face has a longer circumferential length (D) than that (G) of each core face. Each PM face and each core face, has an axial length (E, FIG. 1 ) which is much larger than its circumferential length (D, G). The interface end of each electromagnet coil lies a small distance (K) from the core face.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.