Stator assembly of hairpin winding motor

Abstract

A stator assembly of a hairpin winding motor capable of improving the performance of the winding motor and the insulation performance of a hairpin coil, including a stator core through which a plurality of slots pass in a circumferential direction; and a plurality of hairpin coils respectively fastened to and interconnected with the slots to form a coil winding. The hairpin coil includes a head portion bent in a U shape and exposed to the outside of the stator core, and a pair of leg portions configured to extend in parallel from both ends of the head portion to be inserted into a specific slot and the slot spaced apart from the specific slot by one pole pitch and of which end portions are exposed to the outside of the stator core.

What is claimed is: 
     
         1 . A stator assembly of a hairpin winding motor, comprising:
 a stator core including a plurality of slots passing therethrough in a circumferential direction; and   a plurality of hairpin coils respectively fastened to and interconnected with the slots to form a coil winding,   wherein:   each of the hairpin coils includes a head portion bent in a U-shape and exposed to the outside of the stator core; and a pair of leg portions configured to extend in parallel from both ends of the head portion to be inserted into a specific slot and the slot spaced apart from the specific slot by one pole pitch, and of which end portions are exposed to the outside of the stator core; and   a cross-sectional area of the head portion is greater than cross-sectional areas of the leg portions.   
     
     
         2 . The stator assembly of  claim 1 , wherein a cross-sectional area of the head portion is about 2 to 20% greater than cross-sectional areas of the leg portions. 
     
     
         3 . The stator assembly of  claim 1 , wherein:
 the head portion is formed to have a circular cross-sectional shape; and   each of the pair of leg portions is formed to have a trapezoidal cross-sectional shape, of which the outside is broad and the inside is narrow.   
     
     
         4 . The stator assembly of the  claim 3 , wherein the pair of leg portions has the trapezoidal cross-section in contact with the circular cross-section of the head portion. 
     
     
         5 . The stator assembly of the  claim 1 , wherein:
 the hairpin coil is manufactured using an electric wire having a circular cross section; and
 the head portion is formed by bending the electric wire and the leg portions is formed by rolling an end of the electric wire.