Patent ID: 9054566
Filing Date: 2015-06-09
Classification: B60K,H02K

Abstract:
1. An electric machine comprising a rotor having a rotor field and a stator having coils for magnetic interaction with the rotor field across an air gap defined between the rotor and stator, wherein: the stator is a fixed component with respect to a mounting for the machine and the rotor rotates around the stator externally thereof forming a rotating rotor housing defining a sealed chamber between the rotor and stator incorporating a fluid cooling medium to cool the coils and to transfer heat removed from the coils to the rotating rotor housing, the cooling medium has a boiling point less than a design temperature of operation of the stator and more than a design temperature of operation of the rotating rotor housing, the rotating rotor housing has a heat dissipating external surface accessible by a coolant, the stator is mounted on a stub axle of said mounting and on which stub axle said rotor is rotationally journalled, the electric machine is an axial flux machine, the coils being wound on bars that are disposed circumferentially spaced around a fixed axle of the machine forming a rotational axis of the rotor, the bars are parallel to the rotational axis, the rotor comprising two stages each having permanent magnets interacting with each end of the bars, and the rotor stages each comprise an annular dish, whose outer rims are connected together by a sleeve and which mount said permanent magnets, an inner rim of one stage being journalled on said stub axle, and the other stage being closed by a plate.