Dynamoelectric machine and manufacturing method for stator used therein

Abstract

Respective divided segments of a collet are moved radially outward by moving an arbor axially. The respective divided segments thereby press an inner circumferential surface of a stator core of a stator from radially inside such that the stator is held coaxially by the collet. Next, shaping rollers are lowered so as to press an outer circumferential surface of the stator core. The stator is rotated by rotating the collet in that state. Thus, the inner circumferential surface of the stator core is compressed and plastically deformed so as to conform to the collet and the outer circumferential surface of the stator core is compressed and plastically deformed by the shaping rollers, correcting the inner circumferential surface and the outer circumferential surface of the stator core so as to be coaxial and so as to have a high degree of roundness.

1 . A dynamoelectric machine comprising:
 first and second brackets that each have an interfitting portion that is formed on an inner circumferential portion of an opening end surface, said interfitting portion being constituted by an annular abutting axial end surface that is perpendicular to a central axis, and an interfitting circumferential surface that has a cylindrical surface that is formed on an outer circumferential portion of said abutting axial end surface so as to be coaxial to said central axis, and said first and second brackets being disposed such that said openings face each other;   a shaft that is rotatably supported at central axial positions of said first and second brackets;   a rotor that is fixed to said shaft, and that is disposed inside said first and second brackets;   a stator comprising:
 a cylindrical stator core that is prepared by laminating a thin magnetic plate, and in which a plurality of slots that open on an inner circumferential side are formed so as to line up in a circumferential direction; and 
 a stator winding that is installed in said stator core, 
 said stator being mounted to said first and second brackets so as to surround said rotor such that two axial end portions of an outer circumferential surface of said stator core are fitted together with said interfitting circumferential surfaces and such that outer circumferential portions of two axial end surfaces of said stator core are pressed and held between said abutting axial end surfaces from two axial ends, 
   wherein:   said laminated thin magnetic plate is consolidated and integrated by a thin sheet consolidating weld portion that is formed on an outer circumferential surface of said stator core so as to extend from a first axial end to a second end; and   two axial end portions of an outer circumferential surface of said stator core are constituted by a compressed and plastically worked surface.   
   
   
       2 . A dynamoelectric stator manufacturing method for manufacturing a dynamoelectric stator that has:
 a cylindrical stator core that is prepared by laminating a thin magnetic plate, and in which a plurality of slots that open on an inner circumferential side are formed so as to line up in a circumferential direction; and   a stator winding that is installed in said stator core, said dynamoelectric stator manufacturing method comprising steps of:   preparing a cylindrical stator core by consolidating and integrating said laminated thin magnetic plate by welding said laminated thin magnetic plate so as to extend from a first end portion to a second end portion in a direction of lamination;   holding said stator core in a holding apparatus by pressing an inner circumferential surface of said cylindrical stator core radially outward using a curved surface that has a shape that is formed by dividing a cylindrical surface into a plurality of sections circumferentially; and   shaping two axial end portions of an outer circumferential surface of said stator core by pressing shaping rollers that are rotatable around axes of rotation that are parallel to a central axis of said cylindrical surface onto said two axial end portions of said outer circumferential surface of said stator core while rotating said holding apparatus around said central axis of said cylindrical surface with said stator core in a held state.   
   
   
       3 . A dynamoelectric stator manufacturing method according to  claim 2 , wherein an inner circumferential surface of said stator core is shaped simultaneously in said step of shaping said two axial end portions of said outer circumferential surface of said stator core. 
   
   
       4 . A dynamoelectric stator manufacturing method according to  claim 2 , wherein axial movement of said stator core is restricted by placing annular brace portions in a state of surface contact with outer circumferential portions of two axial end surfaces of said stator core in said step of shaping said two axial end portions of said outer circumferential surface of said stator core. 
   
   
       5 . A dynamoelectric stator manufacturing method according to  claim 2 , wherein said step of preparing said cylindrical stator core further comprising steps of:
 preparing a rectangular parallelepiped laminated body by laminating said thin magnetic plate, and consolidating and integrating said laminated thin magnetic plate by welding said laminated body so as to extend from a first end portion to a second end portion in a direction of lamination; and   bending into a cylindrical shape said laminated body in which said laminated thin magnetic plate has been consolidated and integrated, and integrating said bent laminated body by abutting and welding end surfaces thereof.   
   
   
       6 . A dynamoelectric stator manufacturing method according to  claim 5 , wherein said laminated body is bent into a cylindrical shape after said stator winding has been mounted to said laminated body in which said laminated thin magnetic plate has been consolidated and integrated.