Brushless motor
US5510664A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 7, 1993 |
| Grant date | Apr 23, 1996 |
| Priority date | — |
| Expiry date | Sep 7, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S310/06
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a brushless motor, the number of coreless armature coils is set to 3n when the number of magnetic poles of a magnet for a magnetic field is set to 2n where n is a positive integer. An opening angle of each of the armature coils is set to 360/3n degrees. A notch portion is formed in an outer circumferential portion of the magnet for a magnetic field. A recessed portion is formed by this notch portion and an inner circumferential portion of a yoke. The recessed portion constitutes a groove for correcting a balance of each of the magnet for a magnetic field and a rotating body when this magnet and the rotating body are rotated. A motor housing and a harness are electrically connected to a printed board. The housing is connected to the ground through this harness and a harness for power. In this brushless motor, a magnetizing frequency is reduced and driving efficiency of a control circuit can improved when the brushless motor is rotated at a high speed. Further, it is possible to prevent an iron or copper loss from being caused so that an increase in temperature of the brushless motor can be restrained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.