Stator structure for electric machine

摘要

An electric machine includes a stator stack of laminations, pierced with a cylindrical passage for housing a rotatable rotor therein. The stator includes a magnetic circuit of laminations stacked between first and second terminal faces crossed by the passage and by a series of slots housing conductors, which are folded over to form coils. An electrically insulating reinforcing wedge piece is interposed between an internal wall of a first tubular end and a corresponding portion of a block of resin surrounding a region of winding heads of the conductors, which follow a looped path in the block of resin. A wedging unit wedges the insulating reinforcing piece in position to prevent the insulating reinforcing piece from protruding axially internally on the internal wall with respect to the region so as to leave a determined annular sector of the internal wall in direct adhering contact with the block of resin.

主权项

1. An electric machine structure comprising:
a stator; a rotor that rotates about an axis such that an air gap is present between the rotor and the stator; a casing enclosing the stator and the rotor; a thin and flexible electrically insulating reinforcing piece; and a wedge, wherein the stator includes a magnetic circuit having first and second terminal parts bounded by end faces and crossed, between the end faces, by a cylindrical passage to house the rotor and by a series of slots that accommodate conductors, the conductors being bent over at the end faces to pass from one of the slots to a next one of the slots to thereby form loops of a winding head, wherein the casing includes a sleeve with first and second tubular ends, the magnetic circuit being fixed inside the sleeve between the first and second tubular ends such that the magnetic circuit is able to withstand magnetic torques generated in the air gap during operation, wherein at least one loop of the winding head is coated, in continuity with pieces of the magnetic circuit, in a block of potting resin, which extends radially outside as far as a corresponding tubular end wall, wherein the reinforcing piece is interposed between an internal wall of the first tubular end and a portion of the block of potting resin originating out of the end face of the first terminal part surrounding a region of the winding head in which the conductors follow a looped path in the block of potting resin, and wherein the wedge wedges the reinforcing piece in position to prevent the reinforcing piece from protruding axially internally on the internal wall with respect to the region of the winding head so as to leave a determined annular sector of the internal wall in direct adhering contact with the block of potting resin.