Magnetostrictive torque sensor and electrically powered steering apparatus using same
US7497132B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2006 |
| Grant date | Mar 3, 2009 |
| Priority date | — |
| Expiry date | Oct 4, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L3/103
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetostrictive torque sensor comprising a first magnetostrictive film, a second magnetostrictive film, and a third magnetostrictive film formed over the entire circumferential periphery of a surface of a rotating shaft. A first sensor coil, a second sensor coil, and a third sensor coil for sensing changes in impedance are provided for the first, second, and third magnetostrictive films, respectively. Signals according to the changes in impedance outputted from the first through third sensor coils are inputted to a torque calculating unit. The torque calculating unit calculates the torque applied to the rotating shaft on the basis of the output signal from the first sensor coil and the output signal from the second sensor coil. Furthermore, the output signals from the first through third sensor coils are compared, and failures in the first magnetostrictive film or the second magnetostrictive film are detected by a failure detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.