Device for improving the stability of rotation of the rotor of a single-phase synchronous motor
US4812691A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Apr 16, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K21/185
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to a device for improving the stability of rotation of the rotor of a single-phase synchronous motor mounted in an apparatus housing. The motor exhibits an average motor torque on which strong alternating torques are superimposed and which drives a preferably rotating load. The rotating load may be a small domestic appliance such as a citrus-juice extractor, a knife sharpener, or a dry-shaver with rotatary cutters. The device is constructed in such a way that the rotor is influenced by an additional mechanical compensation torque which acts outside the load-transmission path and which counteracts the electro-mechanical alternating torques of the motor for a given, preferably positive, direction of rotation of the rotor, the positive direction of rotation being that direction in which the torque exerted on the rotor by the current becomes initially zero and in which subsequently, shifted through a small angle, the magnetic detent torque, which exists when the stator coils are not energized, also becomes zero. And in this position a stable rest position of the rotor is provided and the opposite direction of rotation is blocked. Blocking is effected by means of a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.