Magnetostrictive torque sensor and electric power steering apparatus including the same
US6422095B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2000 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Oct 25, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L5/221
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetostrictive torque sensor includes a magnetostrictive film of width W provided along a circumference of a rotational shaft. The film causes magnetostriction in correspondence to a torque applied to the rotational shaft. The torque sensor also includes excitation and detection cores each having substantially U-shaped configuration. These cores are disposed in opposed relation to the film. The excitation core extends through an excitation coil while the detection core extends through a detection coil. The excitation core is disposed on the detection core at right angles. The film has a magnetic path passing therethrough. The magnetic path, the excitation coil, and the detection coil cooperate with each other to provide a magnetic circuit. The excitation coil and the detection coil provides a bridge circuit in cooperation with each other. When a torque is applied to the rotational shaft, the film causes magnetostriction in correspondence to the torque. The magnetostriction is electrically detected by the bridge circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.