Fiber optic sensor system for detecting movement or position of a rotating wheel bearing
US5602946A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1995 |
| Grant date | Feb 11, 1997 |
| Priority date | — |
| Expiry date | Dec 22, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/241
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved fiber optic sensor system and integrated sensor bearing assembly for detecting movement or position of a rotating wheel bearing having a multi-pole tone ring which produces an alternating magnetic field indicative of movement and position of the rotating member. A magneto-optical material, such as a bismuth garnet iron (B.I.G.) crystal, having discrete magnetic domains is positioned in the vicinity of the tone ring so that the domains align themselves to the magnetic field generated by the tone ring. A single fiber optic cable, preferably single mode fiber, carries light generated by a source of light to the B.I.G. crystal. The light passes through the B.I.G. crystal and is refracted at domain boundaries in the crystal. The intensity of the refracted light is indicative of the amount of alignment of the domains and therefore the strength of the magnetic field. The refracted light is carried by the fiber optic cable to an optic receiver where the intensity is measured and an electrical signal is generated and sent to a controller indicating the frequency of the changes in light intensity and therefore the rotational speed of the rotating wheel bearing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.