Rare earth bonded magnet, rare earth magnetic composition, and method for manufacturing rare earth bonded magnet
US6143193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1996 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Nov 5, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/059
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A rare earth bonded magnet comprising a rare earth magnet powder bonded with a binder resin is manufactured by extrusion or injection molding. A rare earth bonded magnet manufactured by extrusion molding has a rare earth magnet powder content of 78.1 to 83.0 percent by volume. A rare earth bonded magnet manufactured by injection molding has a rare earth magnet powder content of 68.0 to 76.0 percent by volume. Preferably, the rare earth metal powder is at least one of Sm--Co alloys, R--Fe--B alloys wherein R is at least one of rare earth elements including Y, and Sm--Fe--N alloys. Preferably, the thermoplastic resin include polyamide, liquid crystal polymer, and Polyphenylene sulfide. Preferably, the rare earth bonded metal has a void ratio of 2 percent by volume or less. A rare earth bonded magnet is manufactured by kneading a rare earth magnetic composition comprising a rare earth magnet powder and a thermoplastic resin, and by extruding or injecting the mixture after kneading. A rare earth magnetic composition used for extrusion molding contains a rare earth metal powder of 77.6 to 82.5 percent by volume, and a rare earth magnetic composition used for injection molding contains a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.