Magnestostrictive torque sensor and manufacturing method thereof, and electric power steering system
US8181538B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2009 |
| Grant date | May 22, 2012 |
| Priority date | — |
| Expiry date | Feb 26, 2029 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/4902
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnestostrictive torque sensor detects rotating torque applied to a rod-shaped rotating shaft to work around the rotating shaft based on a change in magnetic characteristics of a magnetostrictive film formed on a surface the rotating shaft so as to extend around a full circumference thereof in a circumferential direction. The magnetostrictive film is formed continuously in an axial direction at a portion on the rotating shaft in the axial direction thereof. The magnetostrictive film has on the continuously formed area a first magnetostrictive film portion and a second magnetostrictive film portion having magnetic anisotropies which are opposite to each other and a third magnetostrictive film portion which is formed between the first and second magnetostrictive film portions. A first detection coil, a second detection coil and a third detection coil are provided for the first magnetostrictive film portion, the second magnetostrictive film portion and the third magnetostrictive film portion, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.