Electric motor excited by permanent magnets
US6803690B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 31, 2003 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Jan 31, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K21/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The electric motor with permanent-magnet excitation has a stator (1), a rotor (7) supported inside the stator and adjacent permanent magnets (8, 9, 10, 11) of opposite polarity arranged next to each other on a rotor surface facing the stator. The rotor (7) has cavities (16, 17, 18, 19) arranged within a rotor interior and indentations (12, 13, 14, 15) in the rotor surface, which are arranged so that radially oriented magnetic flux lines are not interrupted by the cavities and indentations, but magnetic flux lines oriented tangentially to the rotor surface are interrupted by the cavities and indentations so that a magnetic short circuit is formed. These indentations and cavities reduce the rotor heat capacity so that a layer of a magnetic material that forms the permanent magnets (8, 9, 10, 11) can be sprayed onto the rotor surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.