Permanent magnet motor with radically magnetized isotropic permanent magnet cylindrical yoke
US5604390A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1995 |
| Grant date | Feb 18, 1997 |
| Priority date | — |
| Expiry date | Jun 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K3/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electric motor with permanent-magnet excitation, particularly an internal-rotor or external-rotor motor, having motor parts which are movable relative to one another. One motor part forms a multi-pole excitation field in an air gap by means of permanent magnets and the other motor part comprises a coil configuration situated in the air gap. The coil configuration is free of soft-magnetic material. The permanent-magnetically excited motor part includes a cylindrical yoke having substantially radial slots which are uniformly spaced about the circumference and in which the permanent magnets are mounted. The permanent magnets are magnetized in a circumferential direction with directions of magnetization which change from magnet to magnet. The cylindrical yoke is made of an isotropic permanent-magnet material which, in the yoke portions between the permanent magnets mounted in the slots, is predominantly radially magnetized in a manner such that the resulting magnetic field in the air gap has the same polarity as the magnetic field produced by the permanent magnets in the slots. The permanent magnets are made of an anisotropic permanent-magnet material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.