Direct current motor having a decreasing cogging torque
US5610464A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1994 |
| Grant date | Mar 11, 1997 |
| Priority date | — |
| Expiry date | Dec 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K29/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In the direct current motor having Ns pieces of stator teeth and Nr pieces of magnetic poles, each of the plural magnetic poles is disposed shifted with the predetermined shift angles .DELTA..theta.i around a rotor from the angular reference position defined by even angles around the axis of the rotor, respectively, and the shift angles .DELTA..theta.i are defined by the below-mentioned expression concerning the least common multiple Nc between the Ns and the Nr; EQU -180/Nc.ltoreq.shift angle.DELTA..theta.i.ltoreq.+180/Nc, wherein, signs "-" and "+" in the expression show a shift direction from the angular reference position in the circumferential direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.