Linear motor with back yoke

A linear motor comprising:

• a linear motor body including:
• a mover including a direct drive shaft capable of reciprocating in an axial direction thereof and a permanent magnet array formed of a plurality of permanent magnets mounted to the direct drive shaft;
• and
• a stator having a plurality of excitation windings disposed along an axial line of the direct drive shaft, the excitation windings being each formed of a winding conductor wound in a coil such that the mover reciprocates in an inner space defined inside the excitation windings;
• and
• a back yoke disposed outside the stator of the linear motor body to partly form a magnetic circuit of the linear motor body, wherein:
• the back yoke assembly includes a first divided assembly and a second divided assembly that are combined such that abutting surfaces of the first and second assemblies extend in the axial direction;
• the stator including an insulating pipe inside of which the mover is disposed and on which the excitation windings are mounted;
• a pair of end brackets are fixed at axial ends of the insulating pipe, the end brackets each having a bearing fixed therein to support the end of the direct drive shaft movably in the axial direction and unrotatably in a circumferential direction;
• the back yoke assembly is disposed across the pair of end brackets;
• the pair of end brackets each include a bracket body portion into which the insulating pipe is inserted and fitted and with which end portions of the back yoke assembly are fitted, and an enlarged portion provided continuously with the bracket body portion and having a larger dimension than the bracket body portion as measured in a direction perpendicular to the axial direction;
• and
• one or more pressing members are fixedly provided along an outer surface of the first divided assembly and operable to press only the first divided assembly onto each bracket body portion, and one or more pressing members are fixedly provided along an outer surface of the second divided assembly and operable to press only the second divided assembly onto each bracket body portion.