Variable reluctance magnetic sensor with pole piece and shell projections matched to gear teeth
US4700133A · kind A · utility
35Cited by
12References
2Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 28, 1986 |
| Grant date | Oct 13, 1987 |
| Priority date | — |
| Expiry date | Feb 28, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/488
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A variable reluctance magnetic speed sensor senses the speed of a rotating gear (12). A ferrous outer cylindrical shell (22) extends axially and has a magnet (14) at one axial end and a coil (16) at the other axial end. An inner pole piece (4) in the coil (16) directs magnetic flux across a gap to the gear teeth (10), which flux is returned by the outer pole piece shell (22) to the magnet (14). Particular pole piece gap spacings are disclosed together with various pole piece constructions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.