Patent ID: 7579735

Claim:
An electric motor stator, comprising: a plurality of teeth radially disposed so as to be centered about a center axis; an insulator covering the teeth and having upper and lower axial ends which are each axially asymmetrical, each of the upper and lower axial ends defining a conductor wind-on starting side and a conductor wind-on ending side; and a plurality of coils provided on the teeth by winding a conductor onto the insulator such that the conductor is arranged on each of the upper and lower axial ends to extend from the conductor wind-on starting side to the conductor wind-on ending side; wherein a radius of curvature R 2 of a first portion of each of the upper and lower axial ends of the insulator on the conductor wind-on ending side is larger than a radius of curvature R 1 of a second portion thereof on the conductor wind-on starting side.