ELECTROMAGNETIC APPARATUS FOR PRODUCING LINEAR MOTION

摘要

Electromagnetic apparatus for producing an axially directed force comprising a stator (1) having a plurality of axially spaced coils (2) around a working volume within which an armature in the form of a free piston (3) is axially displaceable, the armature having means for producing a magnetic field a substantially radially directed part of which intersects at least some of the coils of the stator such that a resultant axially directed force is generated when a current flows in the coils.