Patent ID: 8427015

Claim:
A multihead-type coreless linear motor comprising: a stator including a permanent field magnet having permanent magnets linearly arranged in a first direction such that different magnetic poles appear alternately; a first moving part movable with respect to the stator in the first direction and including a first armature facing the permanent field magnet with a magnetic gap therebetween, the first armature having M 1 first armature coils connected in three phases; and a second moving part movable with respect to the stator in the first direction and including a second armature facing the permanent field magnet with a magnetic gap therebetween, the second armature having M 2 second armature coils connected in three phases, the first and second moving parts being relatively movable with respect to each other in the first direction, the first armature being provided to face P 1 permanent magnets of the permanent field magnet, the second armature being provided to face P 2 permanent magnets of the permanent field magnet, a ratio of P 1 to M 1 being different from a ratio of P 2 to M 2 .