Abstract: A motor housing and cooling fin assembly for an electric motor comprises a stator support having a longitudinal base and a series of fin plates protruding radially from the base, the fin plates for directing fluid coolant through the motor, a cylindrical support sleeve comprising a thin wall, the thin wall containing a series of slots for receiving distal ends of the fin plates; and a motor housing having a cylindrical inner wall, the support sleeve positioned between the stator support and the motor housing in an interference fit.

Abstract: A method for manufacturing a rotor assembly. The method includes providing a stub shaft having a first part and a second part, providing a magnet between the first part and the second part, and compressing the magnet between the first part and the second part using a connecting device. The method also includes drilling a hole through the first part and the magnet, cooling an inner shaft, and inserting the inner shaft into the hole.

Abstract: A motor housing and cooling fin assembly for an electric motor comprises a stator support having a longitudinal base and a series of fin plates protruding radially from the base, the fin plates for directing fluid coolant through the motor, a cylindrical support sleeve comprising a thin wall, the thin wall containing a series of slots for receiving distal ends of the fin plates; and a motor housing having a cylindrical inner wall, the support sleeve positioned between the stator support and the motor housing in an interference fit. By reducing the thickness of the motor housing by more than the thickness of the added cylindrical support sleeve, the motor housing is lighter. Instead of machining slots directly into the motor housing, they are machined the cylindrical support sleeve, which is of simple geometry, thereby reducing the difficulty and cost of manufacturing.