Patent · US Expired

Flat linear motor

US5723917A · kind A · utility

59Cited by
12References
25Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 30, 1994
Grant dateMar 3, 1998
Priority date
Expiry dateNov 30, 2014

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02K9/00
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A flat linear motor has a single row of permanent magnets mounted upon backplate and an armature having non-overlapping flat coils encapsulated in a block of epoxy resin mounted upon an armature backplate comprised of a magnetic material and having anchoring recesses or protrusions. The armature backplate serves to provide magnetic circuits of low magnetic resistance in the flat linear motor thereby increasing a force generated by the linear motor. A length of the armature backplate is a non-integral number of a pitch length of the permanent magnets so as to reduce cogging. The three non-overlapping flat coils are comprised of square wire windings which provide increased thermal conduction. An embodiment of the invention employs software commutation wherein a position sensing device is used by a controller to determine a position of the armature from which a field polarity is found by means of a formula or a look-up table. Further embodiments of the invention have a cooling manifold, magnetic flux focusing armature backplates, and a modified Halbach magnet array.

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