Method of making permanent magnet rotors
US5288447A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1993 |
| Grant date | Feb 22, 1994 |
| Priority date | — |
| Expiry date | Feb 22, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/58
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A plastic binder is milled to a powder, preferably having a particle size equal to the mean size of flakes of permanent magnet material, and dry mixed with the magnetic flakes. A molding fixture is heated to a temperature higher than that of the melting point of the plastic binder. A rotor core, having a rounded upper edge for molding a thin cylindrical magnet thereon, of solid or laminated soft magnetic material is prepared and placed in the molding fixture and brought up to the molding temperature. The mixture is poured in measured amounts into the upper chamber of the hot molding fixture and then compressed and melted. The fluid mixture is transferred into a molding cavity surrounding the rotor core in the lower chamber and cooled. After cooling, the finished permanent magnet rotor is ejected. Advantageously, by this method, the proportion of magnetic material to plastic may be increased to approximately 80%/20% magnetic material to plastic by volume, and the magnets may be made thinner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.