Motor commutation
US5325005A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1992 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Jun 3, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S310/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless electric motor with Hall-effect sensors is configured to provide its stator structure with a portion which projects axially away from a main armature. The projecting portion is radially congruent with a second, smaller armature coaxial with the main armature, with a portion of a sleeve in which the sensors are disposed in circumferentially spaced configuration, and with a laminated annular shield iron. The annular shield iron is radially interposed between the projecting portion of the stator structure and the sensors. In this configuration, the shield iron serves to close the magnetic field originating from the second armature and interacting with the sensors while simultaneously shielding the sensors from field effects attributable to current flow in the axially projecting portion of the stator structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.