Magnetostrictive torque sensor shaft
US5491369A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1994 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Apr 19, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L3/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method for producing a magnetostrictive torque sensor shaft and a torque sensor shaft made according to the method. Knurl grooves are formed on the surface of shaft base material in oblique relation to the axis thereof, which are then subjected to heat treatment. Subsequently, material having less crystallomagnetic anisotropy and a large magnetostriction constant is deposited by plating, thermal spraying or otherwise at least on the surface of the knurl grooves included in the outer periphery of the shaft base material thereby to form a magnetostrictive layer. Preferably, the magnetostrictive layer is comprised of an FeNi alloy plated layer whose Fe component content is more than 0% but less than 25%. Thus, a sensor shaft is obtained which can be suitably used in constructing a magnetostrictive torque sensor having high performance characteristics. In order to improve the bond between the shaft base material and the magnetostrictive layer, it is preferable to subject the surface of the shaft base material to surface treatment such as shot peening and/or nickel strike plating, prior to the step of magnetostrictive layer forming. This surface treatment makes it possible to obtain a t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.