Electrical machine with permanent magnet excitation
US4973868A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 28, 1989 |
| Grant date | Nov 27, 1990 |
| Priority date | — |
| Expiry date | Jul 28, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/2128
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Contained in an electrical machine with a field excited by permanent magnets, on the rotor, are pole bodies that extend in ring fashion and coaxially with the rotor shaft, forming between stator pole shoes an air gap. The rotor consists of a specific sequence of permanent magnets and soft iron components which alternately are arranged side by side and jointly embedded in plastic. This gives the rotor a labile structure with a low modulus of elasticity. Apart from the present invention, the air gap could change during operation through vibrations, specifically flexural vibrations. This could lead to losses in efficiency and, most of all, considerable noise generation. A massive damping ring is provided on the free ends of the pole bodies, possibly bearing on the stator housing, which provides for a smooth running of the machine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.