Patent ID: 7633189
Filing Date: 2009-12-15
Classification: H02K

Abstract:
1. A moving part of a cylinder-type linear motor, comprising a linear motion shaft which is arranged on an axis line of a cylindrical fixed part so as to reciprocate on the axis line in the axial direction; and a permanent magnet assembly which is provided on the linear motion shaft and is configured so that a plurality of permanent magnets magnetized in the axial direction are disposed so that the end faces thereof face each other, characterized in that the permanent magnet assembly has a pair of permanent magnets magnetized in the axial direction, and arranged so that the end faces with the same polarity face each other; a pair of ring-shaped fixing members each having an outside diameter smaller than the outside diameter of the paired permanent magnets, and fixed on the linear motion shaft so as to be in contact with both sides of the paired permanent magnets; and a pair of ring-shaped permanent magnets magnetized in the radial direction so that the polarity on the outer peripheral surface is different from the polarity on the opposed end face of the paired permanent magnets, and provided on the outer peripheral surfaces of the paired ring-shaped fixing members.