The invention provides a motor for generating rotary power, the motor comprising: a stator for receiving electrical power; a rotor arranged coaxially with respect to the stator and having one or more magnets arranged thereon so that in response to the stator receiving the electrical power, the rotor is caused to rotate; the rotor comprising a rotor housing having an inner wall, the magnets being arranged around the housing, and wherein the inner wall has plural tortuous paths for the flow of coolant extending along the length of the rotor housing. Preferably, the motor has an output shaft arranged at least partially axially within the rotor housing; the inner wall being shaped for engagement with and so as to drive the output shaft.

The invention provides a motor for generating rotary power, the motor comprising: a stator for receiving electrical power; a rotor arranged coaxially with respect to the stator and having one or more magnets arranged thereon so that in response to the stator receiving the electrical power, the rotor is caused to rotate; the rotor comprising a rotor housing having an inner wall, the magnets being arranged around the housing, and wherein the inner wall has plural tortuous paths for the flow of coolant extending along the length of the rotor housing. Preferably, the motor has an output shaft arranged at least partially axially within the rotor housing; the inner wall being shaped for engagement with and so as to drive the output shaft.