Patent · US Expired

Linear force motor

US4631430A · kind A · utility

22Cited by
10References
23Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 17, 1985
Grant dateDec 23, 1986
Priority date
Expiry dateJun 17, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F7/122
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A linear force motor has an elongated body provided with an annular chamber therewithin. An armature is arranged within the chamber for axial movement relative thereto. Two axially-spaced permanent magnets, with their like poles arranged to face one another, are arranged within the body radially inwardly of the chamber, and are separated by a common polepiece. The force motor has four axially-spaced active air gaps, arranged in various reciprocal pairs and various parallel pairs. When the armature is shifted one direction relative to the body, the majority of each magnet's static flux passes through one parallel pair of air gaps. When the armature is shifted in the other direction relative to the body, the majority of each magnet static flux passes through the other parallel pair of air gaps. The motor has one or more coils operatively arranged to generate control flux in a path which passes through at least one reciprocal pair of air gaps. The control flux, when superimposed on the static flux pattern, creates a net flux, which urges the armature to move in a desired direction relative to the body.

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