Electric Water Pump With Stator Cooling

An electric pump comprises an outer housing including a motor cavity and a controller cavity separated by a partition wall. An inner housing is positioned within the motor cavity of the outer housing. One of the inner and outer housings includes radially extending ribs positioned adjacent to the other of the inner and outer housings to define a coolant flow path between the inner housing and the outer housing. The flow path is partially defined by the partition wall. An electric motor is positioned within the inner housing and includes a hollow rotor shaft driving a pump member. The hollow rotor shaft forms a portion of the coolant path and interconnects a volume between the inner and outer housings with a low pressure cavity containing the pump member. A controller is positioned within the controller cavity in heat transfer relation with the partition wall.