Powder for high strength dust core, high strength dust core and method for making same
US6749767B2 · kind B2 · utility
Inventors
Key dates
| Filing date | Mar 19, 2002 |
| Grant date | Jun 15, 2004 |
| Priority date | — |
| Expiry date | Oct 24, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F1/26
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A mixed powder useful as a starting material for dust core comprises a uniform mixture of a soft magnetic powder and a binder resin so that the resultant dust core has an electric resistance capable of suppressing an eddy current between the soft magnetic powdery particles and high mechanical strength at room temperatures and also at high temperatures. In the mixed powder, the binder resin is made of a phenolic resin powder which has a methylol groups in the molecule and preferably has an average particle size of 30 &mgr;m or below and wherein when the phenolic resin powder is dissolved in boiling methanol in large excess, a content of an undissolved matter is at least 4 wt % based on the total of the phenolic resin. A dust core obtained from the mixed powder and its fabrication method are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.