Patent · US Expired

Unitary rotational speed sensor

US5111098A · kind A · utility

31Cited by
22References
53Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 12, 1990
Grant dateMay 5, 1992
Priority date
Expiry dateJan 12, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01P3/487
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

Four embodiments of a reluctance type rotational speed sensor are disclosed. In the first embodiment, an annular magnet circumscribes a sensing coil having a unitary rotor nested within it, and is disposed between two elements which comprise the stator. In a second embodiment, a magnet is disposed between two halves which comprise a rotor, the entire assembly nesting within a sensing coil and being disposed between the two stator elements. In the third embodiment, the rotor carries multiple magnets in an axially opposed position with respect to teeth formed on the stator. The magnetic flux in the magnetic circuit increases and decreases as the rotor magnets alternate between aligned and non-aligned positions enabling measurement of angular speed in accordance with the increase and decrease of magnetic flux. Any of the first three embodiments may be used, with minor modifications, in environments where a rotating shaft turns within a stationary bore, or where a rotting bore turns about a stationary shaft. The fourth embodiment incorporates the features of the first three and further includes a caliper-like stator and coil assembly which may be removed for service without requiring e…

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