Patent ID: 8608462

Claim:
A motor stator comprising: a substantially cylindrical stator iron core including: a ring-like yoke, teeth that radially extend from the yoke toward a center, and a plurality of U-shaped grooves, including a first, second and third U-shaped grooves, that are formed on a circumference of the yoke in an axial direction and configured as return passages of refrigerant oil; and insulators as insulating coatings on axial-direction ends of the stator iron core, the insulators each including: a ring-like outer circumference wall, a plurality of hoisting drums that radially extend from the outer circumference wall toward a center, inner guards that extend from inner ends of the hoisting drums in the axial direction, respectively, and at least three engagement claws, including a first, second and third engagement claws, that are located spaced apart in a circumferential direction on outside of the outer circumference wall and fitted in axial-direction ends of the U-shaped grooves, respectively, each of the engagement claws having circumferential-direction width smaller than a width of a respective U-shaped groove to fit in, wherein the first engagement claw is arranged such that a first circumferential-direction side portion of the first engagement claw is in contact with a first side wall of the first U-shaped groove leaving a space between a second circumferential-direction side portion of the first engagement claw and a second side wall of the first U-shaped groove, and the second engagement claw is arranged such that a second circumferential-direction side portion of the engagement claw is in contact with a second side wall of the second U-shaped groove leaving a space between a first circumferential-direction side portion of the second engagement claw and a first side wall of the second U-shaped groove.