Rotating machine with sintered magnet and method for producing sintered magnet
US8350430B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2012 |
| Grant date | Jan 8, 2013 |
| Priority date | — |
| Expiry date | Apr 23, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/0577
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An R—Fe—B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 μm or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 μm to 500 μm from the magnet surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.