Patent ID: 7538456
Filing Date: 2009-05-26
Classification: H02K

Abstract:
1. A moving magnet type linear actuator comprising: a stator having a stator base and an armature including a magnetic iron core fixed on the stator base and an armature winding wound around the magnetic iron core; and a movable body having a field permanent magnet arranged oppositely to the magnetic iron core through a magnet gap and a magnetic holder supporting the field permanent magnet and movably arranged on the stator base, wherein the magnet holder is made of a non-magnetic substance, a magnetic back yoke is arranged on the side opposite to the armature with respect to the field permanent magnet, a width thereof being approximately equal to a width of the field permanent magnet, a length thereof being not smaller than the stroke of the movable body, and both ends thereof in the longitudinal direction being fixed to the stator, the field permanent magnet being positioned only on one side of the magnetic back yoke, the field permanent magnet being positioned only on one side of the armature winding, and a gap is formed between the magnetic yoke and the field permanent magnet.