Automotive rotary electric machine
US7358640B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2002 |
| Grant date | Apr 15, 2008 |
| Priority date | — |
| Expiry date | Dec 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K19/36
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention provides an automotive rotary electric machine enabling brush abrasion limit detection reliability to be increased and stable brush abrasion limit detection indication to be performed. The construction thereof is provided with a detecting terminal for sensing a brush abrasion limit when a brush has abraded to a predetermined length by coming into contact with a coil spring that forces the brush, and a determining circuit constructed so as to compare output from the detecting terminal and a threshold value, to enter an ON state (a brush abrasion limit detection state) once the output exceeds the threshold value, and thereafter to maintain the ON state. Thus, because the ON state of the determining circuit is maintained even if output from the detecting terminal fluctuates due to vibration, noise, etc., false detection of the brush abrasion limit resulting from the fluctuations in the output from the detecting terminal can be prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.