Patent ID: 7528516

Claim:
A rotary electrical machine comprising: a rotor and a stator, the stator comprising a casing, a plurality of notches for receiving armature winding turns, and teeth separating the adjacent notches, each of the teeth comprising a base connecting the tooth to the casing of the stator and an end face facing the rotor, the distance between the end face and the base of each of the teeth defines a height of the tooth, the end face of at least one tooth comprising at least one recess zone in an intermediate angular position or positions between edges of the at least one tooth that delimit the notches, the at least one recess zone provided for reducing the eddy current losses by increasing the path of the current, wherein the at least one recess zone comprising at least one recess being void of any armature windings and extending in the radial direction over a depth that is less than one half of the height of the tooth, wherein the depth being substantially equal to one-third of the height of the tooth, and wherein the at least one tooth including the at least one recess zone is symmetrical relative to a radial line extending through a middle of the end face of the at least one tooth in the circumferential direction.