Patent ID: 7622832

Claim:
A linear motor for providing thrust to a movable unit capable of linearly moving freely in one direction with respect to a stator, comprising: a plurality of permanent magnets arranged on the stator side by lining up a positive pole and a negative pole in said one direction; and a plurality of flat shaped coils arranged along the arrangement direction of permanent magnets and fixed to said movable unit side so as to face the permanent magnets at an electromagnetic gap; wherein said movable unit is made of nonmagnetic and thermal conductive material and has a recessed portion at a surface facing the plurality of flat shaped coils to define an air gap between the coils and the movable unit, wherein each flat shaped coil comprises a plate shaped reinforcement member of nonmagnetic material and a flat coil member wound around the reinforcement member; wherein two side portions of each coil member of each flat shaped coil are substantially fixed to non-recessed portions of the movable unit by thermal conductive fixing member; and wherein a depth of the recessed portion of the movable unit is restricted, so that a surface magnetic flux on said facing surface generated by a magnetic field of facing magnets becomes 1000 gauss or lower.