Patent ID: 7456526

Claim:
A linear motor actuator comprising: a track rail having a stationary base portion and a pair of side wall portions extending upright from the stationary base portion, the track rail being formed in a channel-like configuration including a guide passage surrounded by the stationary base portion and the side wall portions, the side wall portions each being provided with a ball rolling groove facing the guide passage; a table structure including a large number of balls that roll in the ball rolling groove, and an endless circulation passage in which the balls circulate, the table structure being mounted between the pair of side wall portions of the track rail through the balls to freely reciprocate within the guide passage; a field magnet fixed to the track rail and having N poles and S poles alternately arranged along a longitudinal direction of the track rail; and an armature mounted to the table structure such that the armature is opposed to the field magnet, the armature constituting a linear motor together with the field magnet and exerting on the table structure a propulsion force or a brake force acting in the longitudinal direction of the track rail, the linear motor actuator being characterized in that: the table structure includes: a pair of sliders each including the endless circulation passage for the balls and moving forwards and backwards within the guide passage of the track rail; and a connecting top board connecting the sliders to each other with a predetermined interval between the sliders and provided with a mounting surface for a movable member; the armature is located within the guide passage of the track rail while being fixed to the connecting top board at a position between the pair of sliders, the armature including an armature core of a comb tooth-like configuration and a coil, the armature core having a plurality of slots and teeth formed at a predetermined pitch along the longitudinal direction of the track rail, the coil being wound around each of the teeth of the armature core so as to fill in each of the slots; and the field magnet is disposed at a position opposed to the armature core fixed to the connecting top board, with the stationary base portion of the track rail serving as a yoke of the field magnet.