Method for magnetizing ring magnet and magnetic encoder
US7498914B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2005 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | May 30, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F13/003
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An insert member (42) having an identical permeability is fitted in the circular center hole(41a) of a magnetic ring (41) which is then fitted in the circular hollow section (43a) of a fitting-over member (43) having an identical permeability. Under that state, the magnetic ring (41) is placed in a parallel magnetic field. Lines of magnetic flux passing through the magnetic ring (41) held between the insert member (42) and the fitting-over member (43) become linear without substantially inclining against the parallel magnetic field. Under that state, harmonic noise causing a deterioration in detection precision will scarcely appear in the output of a magnetic sensor for detecting the rotating magnetic field of a ring magnet (40) obtained by performing two-pole magnetization on the magnetic ring (41). When the ring magnet (40) is employed, a deterioration in the detection precision of a magnetic encoder (1) due to the magnetization state of the ring magnet (40) can be avoided, and the deterioration in detection precision can be suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.