Patent ID: 8030804

Claim:
A linear motor comprising: a field magnet part having a plurality of permanent magnets arranged to form N and S poles alternately; a core having a plurality of salient poles arranged facing the field magnet part; a three-phase coil wound around the salient poles of the core; an armature having the three-phase coil and the core, said armature moving linearly relative to the field magnet part; an auxiliary core having a magnetic body provided on at least one side of the armature in a relative moving direction of the armature; and a distance between a center of the auxiliary core and a center of a center salient pole among the salient poles in the relative moving direction of the armature which is set to be substantially ¼×(2N+1)× a magnetic pole pitch between said N poles of the field magnet part (N: an integer equal to or greater than 1).