Brushless DC motor and encoding technique
US4845411A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 1987 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Sep 30, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless DC motor has no poles. Every 180.degree. electrical 3 coils, each a portion of a total winding, are wound onto the stator in 3 slots and in overlapping fashion. The overlapped portions of the coils are wound in the same flux creating direction. The windings are connected at a central, floating connection. Transistors connected to the remaining ends of the windings direct current to or from the windings so that two coils are always conductive in every 360.degree. electric arcuate length of stator. Hall devices 120.degree. electrical apart have their outputs fed to a logic, commutation circuit that decides, based on rotor positions, which of the transistors to cause to conduct.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.