Stator iron core of electric motor, manufacturing method thereof, electric motor, and compressor

Abstract

The present invention aims to provide a stator iron core of an electric motor which can eliminate the reduction of efficiency, vibration or noise of the electric motor by decreasing stress generated at a bottom portion of a slot on manufacturing or integrating the electric motor. Plural magnetic pole segments, each having a back yoke portion and a teeth portion projected from the back yoke portion, are connected so as to be bendable via a connection portion provided to the back yoke portion. After winding the coil wire, a stator iron core of the electric motor is circularly formed by bending the connection portion of the plural magnetic pole segments. In the stator iron core, the bottom portion of the slot constituted by the back yoke portion and the teeth portion is made to have a curved line after the stator iron core is circularly formed.

What is claimed is  
     
         1 . A stator iron core of an electric motor comprising plural magnetic pole segments, 
 wherein each of the plural magnetic pole segments has a back yoke portion and a teeth portion projected from the back yoke portion,    wherein each of the plural magnetic pole segments is connected so as to be bendable via a connection portion provided to the back yoke portion,    wherein the stator iron core is circularly formed by bending the connection portions of the plural magnetic pole segments, and    wherein each of the plural magnetic pole segments is made so that a bottom portion of a slot constituted by the back yoke portion and the teeth portion has a curved line after circularly forming the stator iron core.    
     
     
         2 . The stator iron core of the electric motor claimed in    claim 1    further comprising an insulator member placed on the teeth portion for covering a projected portion of the back yoke portion and covering a wall surface of the teeth portion, wherein a wall surface covering the back yoke portion of the insulator member makes an angle of around 90° with the wall surface covering the teeth portion of the insulator member.  
     
     
         3 . A stator iron core of an electric motor comprising plural magnetic pole segments, 
 wherein each of the plural magnetic pole segments has a back yoke portion and a teeth portion projected from the back yoke portion,    wherein each of the plural magnetic pole segments is connected so as to be bendable via a connection portion provided to the back yoke portion,    wherein the stator iron core is circularly formed by bending the connection portions of the plural magnetic pole segments, and    wherein the magnetic pole segment has a notch on an outer circumference of the back yoke portion.    
     
     
         4 . The stator iron core of the electric motor claimed in    claim 3   , wherein the notch is provided at a place opposite to the connection portion in an axial direction on the outer circumference of the back yoke portion.  
     
     
         5 . The stator iron core of the electric motor claimed in    claim 3   , wherein the notch is provided at a place opposite to the teeth portion in an axial direction on the outer circumference of the back yoke portion.  
     
     
         6 . A stator iron core of an electric motor comprising plural magnetic pole segments which are connected and confronted by plural confronting surfaces, 
 wherein two of the confronting surfaces are made to have V-shaped surfaces.    
     
     
         7 . The stator iron core of the electric motor claimed in    claim 6   , 
 wherein the stator iron core includes laminated iron core members, each of which has the plural magnetic pole segments connected via thin connection portions,    wherein the plural confronting surfaces include plural confronting surfaces of the connection portions at both sides of the connection portions, and the two of the confronting surfaces of the end portions having the V-shaped surfaces,    wherein the stator iron core is circularly formed by bending each of the connection portions, joining the plural confronting surfaces of the connection portions, and joining the two of the confronting surfaces of the end portions.    
     
     
         8 . The stator iron core of the electric motor claimed in    claim 6   , wherein each of the two of the confronting surfaces having the V-shaped surfaces is formed by combining a first arc and a second arc, and centers of the first arc and the second arc match to a turning center of bending the connection portion of any magnetic pole segment of the stator.  
     
     
         9 . The stator iron core of the electric motor claimed in    claim 6   , wherein the two of the confronting surfaces form a jut having a top point projected to an outer circumference side of the stator iron core of the electric motor, and the top point of the jut is located inside of the outer circumference of the stator iron core of the electric motor.  
     
     
         10 . An electric motor comprising the stator iron core of the electric motor claimed in    claim 1   .  
     
     
         11 . An electric motor comprising the stator iron core of the electric motor claimed in    claim 3   .  
     
     
         12 . An electric motor comprising the stator iron core of the electric motor claimed in    claim 6   .  
     
     
         13 . A compressor comprising the electric motor claimed in    claim 10   .  
     
     
         14 . A compressor comprising the electric motor claimed in    claim 11   .  
     
     
         15 . A compressor comprising the electric motor claimed in    claim 12   .  
     
     
         16 . A method for manufacturing a stator iron core of an electric motor, comprising: 
 making plural magnetic pole segments, each of which has a back yoke portion and a teeth portion projected from the back yoke portion;    connecting the plural magnetic pole segments so as to be bendable via a connection portion provided to the back yoke portion;    circularly forming the stator iron core by bending the connection portion of the plural magnetic pole segments after winding the coil wire, and    wherein the making the plural magnetic pole segments includes making projected portions so that a bottom portion of a slot constituted by the back yoke portion and the teeth portion has a curved line when the stator iron core is circularly formed.    
     
     
         17 . A method for manufacturing a stator iron core of an electric motor, comprising: 
 making plural magnetic pole segments, each of which has a back yoke portion and a teeth portion projected from the back yoke portion;    providing a notch on an outer circumference of the back yoke portion;    connecting the plural magnetic pole segments so as to be bendable via a connection portion provided to the back yoke portion; and    circularly forming the stator iron core by bending the connection portion of the plural magnetic pole segments after winding the coil wire.    
     
     
         18 . A method for manufacturing a stator iron core of an electric motor, comprising: 
 making plural magnetic pole segments connected via connection portions, having two end portions, wherein each of the plural magnetic pole segments has confronting surfaces at both sides of the connection portions;    making a V-shaped convex contact portion on the confronting surface of one of the two end portions;    making a V-shaped concave contact portion on the confronting surface of another of the two end portions;    joining the confronting surfaces of the connection portions; and    finally joining the confronting surfaces of the end portions so as to form the stator iron core.