Bi-directional linear actuator

Abstract

Abstract An electromagnetic device includes a stator having first and second closed flux-carrying paths defined by first and second cores, each having a plurality of concentric cylindrical pole surfaces and each defining an air gap opening between the outermost of the pole surfaces and the second outermost of the pole surfaces, with each core having at least one further pole surface. Coils are provided for generating electromagnetic flux in the first and second closed flux-carrying paths with the direction of flux flow across the air gaps being substantially radial with respect to the cylindrical pole surfaces. An armature defines a first and a second plurality of concentric cylindrical armature surfaces. The armature is mounted to be movable in a direction substantially parallel to the pole surfaces with each of the first and second cylindrical armature surfaces overlapping a corresponding one of the concentric cylindrical pole surfaces by an area dependent upon the position of the armature. The area of overlap between the outermost pole surfaces and their respective armature surfaces is substantially equal to the sum of the areas of overlap between the others of the pole surfaces and their respective armature surfaces. The pole surfaces are defined by tapered ring portions of the stator, which portions have nonuniform cross-sectional areas in the direction parallel to the direction of movement of the armature. Similarly, the armature surfaces are defined by tapered ring portions of the armature with the tapered portions having nonuniform cross-sectional areas in a direction parallel to the direction of movement of the armature. A plurality of coils may be used to generate the electromagnetic flux in the cores.

Inventors

• 👤 John L. Myers

Bibliographic Details