Dynamo electric machine with low-noise operating characteristics
US4755698A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1987 |
| Grant date | Jul 5, 1988 |
| Priority date | — |
| Expiry date | Feb 25, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49009
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Operating noise of a dynamo electric machine, and particularly a three-phase vehicular-type alternator, can be reduced by changing the reluctance or permeability of the magnetic path between rotor and stator of adjacent stator teeth by splitting the stator teeth to introduce additional radially extending gaps in the stator teeth or by distributing, non-uniformly or uniformly, ferromagnetic slot closers about the circumference of the stator slots while leaving, adjacent a stator slot with a magnetic closer, open stator slots or slots covered only with non-magnetic slot cover elements, such as treated paper, cardboard, or the like. This changes the frequency of attraction between rotor and stator to a frequency range which is not humanly perceptible or annoying, for example falling below the frequency range at which the alternator can operate, for example below idling speed of an internal combustion engine driving the alternator, or towards a frequency range so high that the operating noise level of the internal combustion engine masks any generator noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.