Patent ID: 10910935

Abstract:
A linear actuator comprising a first fixed portion comprising a linear array of stator teeth, each surrounded by one or more turns of electrical wire, a controller which generates a set of currents that are applied to phase windings of the first fixed portion to generate a pattern of magnetic poles along the array of stator teeth, a spacing between the magnetic poles being larger than a spacing between adjacent stator teeth of the first fixed portion, a second fixed portion that comprises an alternating set of magnet poles, a spacing between adjacent poles being smaller than the spacing of the magnetic poles of the first fixed portion created by the controller, and a movable output portion that comprises a linear array of pole pieces that extend along a length of the moveable output portion that is greater than a stroke length of the actuator and longer than a length of the fixed portion, whereby in use a length of the movable output portion is at all times located between the first and second fixed portions, in which the pole pieces that are located between the first and second fixed portions shape a magnetic flux acting between the magnetic poles of the first fixed portion and the magnet poles of the second fixed portion, and whereby in use the controller is arranged to cause linear movement of the moveable output portion by moving the magnetic poles of the first fixed portion along the first array.