Wide air gap permanent magnet motors
US4445061A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 23, 1982 |
| Grant date | Apr 24, 1984 |
| Priority date | — |
| Expiry date | Jul 23, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K21/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rotating electric machine with a permanent magnet rotor, provided with a stator composed of a winding and a ferrite structure to provide low power losses and improved efficiency particularly at high rotor revolution rates, is constructed so as to optimize the performance of the permanent magnets on the rotor. In the preferred embodiment of the invention, the ferrite being selected for its low hysteresis and eddy current power losses, generically referred to as core loss and its low loss factor which are frequency dependent, replaces laminated electrical iron. Additionally the permanent magnets selected to exhibit high intrinsic magnetic intensity and low remanent magnetic flux density, are arranged in conjunction with the ferrite to maximize the magnet's energy product as well as the magnetic circuit gap length, which in combination provides a radical improvement in machine energy density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.