Electronically commutated motor and method of making same
US4005347A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1974 |
| Grant date | Jan 25, 1977 |
| Priority date | — |
| Expiry date | Jun 24, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A brushless DC motor is constructed with photosensitive devices for detecting rotor shaft position. Arcuate permanent magnets on the rotor provide a DC flux field while distributed stator windings, each spanning a fixed number of slots in the armature assembly, provide mutually perpendicular magnetic fields. A logic circuit comprising NOR gates and transistor switches and drivers activated in response to signals from the shaft position sensors are utilized to control current switching in the stator windings of the motor. A light interrupting shutter mounted to the rotor cooperates with the light sensitive devices which are mounted to a supporting bracket fixed to the stator assembly in a manner to selectively preset advancement of commutation of the stator windings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.