Stator assembly of hairpin winding motor and manufacturing method thereof

Abstract

A stator assembly includes hairpin coils continuously connected along a circumferential direction to form a coil winding, a plurality of stator cores disposed along the circumferential direction and configured to fix the hairpin coils, and a support ring configured to surround an outer circumferential surface of the stator core, wherein each of the stator cores is inserted into the hairpin coils forming the coil winding in a radial direction.

What is claimed is: 
     
         1 . A stator assembly of a hairpin winding motor comprising:
 hairpin coils continuously connected along a circumferential direction to form a coil winding;   a stator core configured to fix the hairpin coils; and   a support ring configured to surround an outer circumferential surface of the stator core,   wherein:   the hairpin coils and the stator core are inserted in a radial direction; and   the stator core includes a yoke formed of a magnetic material to form a magnetic path, teeth protruding in a radial direction from an inner circumferential surface of the yoke, a plurality of coil slots formed between the plurality of teeth and into which the hairpin coils are inserted, and shoes configured to extend in a circumferential direction from both side surfaces of end portions of the teeth.   
     
     
         2 . The stator assembly of  claim 1 , wherein:
 each of the hairpin coils includes a head portion exposed to the outside of the stator core in an axial direction, and leg portions configured to extend from one end and the other end of the head portion to be inserted into a core slot of the stator core; and   the leg portions are formed in a shape which is repeated in a circumferential direction by one pole pitch to be continuously connected.   
     
     
         3 . The stator assembly of  claim 2 , wherein a cross section of the leg portion is formed in a trapezoidal shape of which the outside is broad and the inside is narrow, and thus a width decreases in a direction toward an inner diameter from an outer diameter of the stator core. 
     
     
         4 . The stator assembly of  claim 2 , wherein:
 the hairpin coils are formed of a first coil which is a pair of hairpin coils disposed adjacent to each other in the radial direction, and a second coil which is a pair of hairpin coils disposed adjacent to each other in a radially outward direction from the first coil; and   the first coil and the second coil are repeated in the radial direction.   
     
     
         5 . The stator assembly of  claim 4 , wherein:
 a length of the first coil in the radial direction is greater than a length of the second coil in the radial direction; and   a width of the first coil in the circumferential direction is smaller than a width of the second coil in the circumferential direction.   
     
     
         6 . The stator assembly of  claim 1 , wherein:
 the yoke includes a yoke body part forming a body, a first protruding part protruding from one surface in the circumferential direction at a radially outer side of the yoke body part, a first recessed part recessed in the circumferential direction at a radially inner side of the first protruding part, a second protruding part protruding from the other surface in the circumferential direction at a radially inner side of the yoke body part, and a second recessed part recessed in the circumferential direction at a radially outer side of the second protruding part; and   a side surface of each of the first protruding part and the first recessed part and a side surface of each of the second protruding part and the second recessed part are inclined to form a center angle of the yoke body part.   
     
     
         7 . The stator assembly of  claim 1 , wherein each of the teeth is formed in a rectangular shape, and thus widths of one end and the other end thereof are the same. 
     
     
         8 . A stator assembly of a hairpin winding motor comprising:
 hairpin coils continuously connected along a circumferential direction to form a coil winding;   a plurality of stator cores disposed along the circumferential direction and configured to fix the hairpin coils; and   a support ring configured to surround an outer circumferential surface of the stator core,   wherein:   each of the stator cores includes a yoke formed of a magnetic material to form a magnetic path; and   the yoke includes a protrusion part protruding in a circumferential direction from one surface thereof, and a protrusion groove formed in a shape corresponding to the protrusion part in the other surface thereof, and into which the protrusion part adjacent thereto is inserted.   
     
     
         9 . A method of manufacturing a stator assembly of a hairpin winding motor, in which hairpin coils are wound around a stator core having a plurality of coil slots, the method comprising:
 providing the hairpin coils continuously connected to form a coil winding;   coupling a yoke forming the stator core and the hairpin coils; and   inserting a support ring configured to surround the stator core into an outer   circumferential surface of the stator core,   wherein a plurality of yokes are disposed along a circumferential direction.   
     
     
         10 . The method of  claim 9 , wherein the yokes are moved inward from the outside to be coupled to the hairpin coils in coupling the yokes forming the stator core and the hairpin coils. 
     
     
         11 . The method of  claim 9 , wherein the hairpin coils are moved outward from the inside to be coupled between the plurality of yokes in coupling the yokes forming the stator core and the hairpin coils. 
     
     
         12 . The method of  claim 9 , wherein the yokes are inserted into the hairpin coils in a radially inward direction from the outside of the hairpin coils in inserting the yokes into the hairpin coils. 
     
     
         13 . The method of  claim 12 , wherein an outer diameter of the hairpin coil is formed smaller than an outer diameter of the stator core in inserting the yokes into the hairpin coils. 
     
     
         14 . The method of  claim 12 , wherein in fixing the hairpin coils by the yokes, the outer diameter of the hairpin coil is formed smaller than the outer diameter of the hairpin coil in inserting the yokes into the hairpin coils by pressurization of the yokes. 
     
     
         15 . The method of  claim 12 , wherein:
 teeth protrude in a radial direction from inner circumferential surfaces of the plurality of yokes; and   shoes extend in the circumferential direction from both side surfaces of end portions of the teeth.   
     
     
         16 . The method of  claim 15 , wherein a distance between the shoes which are adjacent to each other is greater than a thickness of the hairpin coil in inserting the yokes forming the stator core into the hairpin coils. 
     
     
         17 . The method of  claim 15 , wherein a distance between the shoes which are adjacent to each other is smaller than a thickness of the hairpin coil in gathering the yokes in the radial direction to fix the hairpin coils. 
     
     
         18 . The method of  claim 9 , wherein the support ring is inserted downward in an axial direction in inserting the support ring configured to surround the stator core into the outer circumferential surface of the stator core.