Linear synchronous motor

A method of manufacturing a linear synchronous motor, the linear synchronous motor comprising:

• a mover including a direct drive shaft reciprocating in an axial direction and one or more permanent magnet arrays each including a plurality of permanent magnets mounted on the direct drive shaft;
• and
• a stator including a stator core unit and a plurality of excitation windings,
• the stator core unit including a plurality of annular magnetic pole portions and a yoke, the annular magnetic pole portions being disposed concentrically with the direct drive shaft to enclose the direct drive shaft and also disposed at an interval in the axial direction, each annular magnetic pole portion having a magnetic pole surface opposed to the permanent magnet arrays of the mover with a predetermined gap therebetween, the yoke magnetically connecting the annular magnetic pole portions;
• and
• the excitation windings exciting the annular magnetic pole portions;
• the annular magnetic pole portions of the stator core unit each having a pair of connected portions, and arranged such that the pairs of connected portions are disposed at a predetermined interval along the direct drive shaft to form a pair of connected portion arrays;
• the annular magnetic pole portions including a pair of end annular magnetic pole portions located at axial ends and one or more intermediate annular magnetic pole portions located between the pair of end annular magnetic pole portions;
• the connected portions of the intermediate annular magnetic pole portions each having formed therein a fitting concave portion that is opened in the axial direction and a direction away from the direct drive shaft;
• and
• the yoke made of a magnetic conductive material and including a pair of yoke assemblies mechanically and magnetically connecting all of the connected portions of the pairs of connected portion arrays, the pair of yoke assemblies contacting the fitting concave portions at outer peripheral portions thereof,
• the method of manufacturing the linear synchronous motor comprising:
• preparing a positioning jig by which the plurality of annular magnetic pole portions are positioned and disposed to form the pair of connected portion arrays, the positioning jig including a base on which the plurality of annular magnetic pole portions are mounted and a spacer projecting from the base for spacing out adjacent two of the annular magnetic pole portions;
• and
• combining the plurality of annular magnetic pole portions and the plurality of excitation windings by mounting the annular magnetic pole portions on the base and disposing each of the excitation windings between adjacent two of the annular magnetic pole portions.