Patent ID: 6806615
Filing Date: 2004-10-19
Classification: H02K

Abstract:
A stator core comprising an annular inner core portion, a rib-shaped core portion extending radially from said annular inner core portion, and an outer peripheral core portion, magnetic pole tooth portions being formed in an annular shape on the outer periphery of said rib-shaped core portion, whereinsaid stator core is composed of a plurality of core pieces having the same shapes as pieces formed by dividing said stator core in a circumferential direction, each of said plurality of core pieces having a concave/convex engage portion at an inner peripheral portion corresponding to an inner periphery of said annular inner core portion, and said plurality of core pieces composing said stator core are fastened to each other by a cylindrical housing having an outer surface formed in concave/convex shape, inserted in said inner peripheral portion so as to engage with the core pieces at said concave/convex engage portions, and changed in diameter relative to said core pieces due to thermal shrinkage or expansion of said cylindrical housing, whereby said core pieces are tightly fitted to each other without any gap between adjacent core pieces.