Patent ID: 7732951
Filing Date: 2010-06-08
Classification: H02K

Abstract:
1. A moving-magnet type linear motor comprising: a magnet yoke forming an even-number polygonal cylinder with a plurality of flat walls and movable in the axial direction of the even-number polygonal cylinder; a plurality of magnet constructs respectively attached to outer surfaces of the flat walls of the magnet yoke and composed of a plurality of permanent magnets; a stator base provided to surround the magnet yoke; a plurality of coreless coils attached to the stator base and arranged to respectively face the plurality of magnet constructs each with a magnetic clearance relative to the associated magnet construct; and at least one cooling member attached to the stator base each to follow a part of circumferential surface of the associated coreless coil and allowing coolant to flow inside for cooling the associated coreless coil; wherein the at least one cooling member has in its base end portion a fluid passage for enabling coolant to flow therethrough and at its extreme end portion a plurality of sheet-like protrusions, and wherein the plurality of sheet-like protrusions are arranged along the part of the circumferential surface of the associated coreless coil with a clearance between each protrusion to the next and are jointed thermally closely with the associated coreless coil at extreme ends thereof.