Patent · US Expired

Strain detector

US5062307A · kind A · utility

4Cited by
2References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 26, 1990
Grant dateNov 5, 1991
Priority date
Expiry dateApr 26, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01N27/72
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A strain detector wherein external and internal magnetic fields are magnetically separated from each other to eliminate an influence of such disturbance magnetic field to assure accurate and stabilized detection of strain in a drive shaft. The detector comprises a magnetic layer made of a soft magnetic material having a high permeability and suitable magnetostriction fixedly mounted on an outer periphery of a driven shaft, a pair of bearings or bearing stands made of a soft magnetic material having a high permeability for supporting the driven shaft for rotation thereon, a detecting coil disposed around the magnetic layer for detecting a variation of the permeability of the magnetic layer arising from strain of the magnetic layer caused by an external force applied to the driven shaft, and a shield disposed on an outer periphery of the detecting coil and magnetically connected at the axial opposite end portions thereof to the bearings or bearing stands.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.