Signal dividing magnetostrictive torque sensor
US4979399A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1990 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Apr 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L3/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A noncontacting method for sensing torque based on the principle of magnetostriction comprises inducing a primary magnetic flux in a shaft (20) via such means as a primary excitation core/coil (30/32), utilizing a secondary core/coil (34/36), and an auxiliary core/coil (48/50), and dividing a secondary signal obtained from the secondary core/coil (34/36) by a signal obtained from the auxiliary core/coil (48/50) to obtain a torque dependent signal. Signal dependence on RPM, temperature, inhomogeneity of shaft permeability magnitude, and air gap is thereby minimized. Another embodiment employs a plurality of sensors (66A/66B) strategically located around the shaft (20) to eliminate spurious signals which are due to bending stress and shaft misalignment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.