An electric motor is disclosed, comprising a stator and a rotor mounted relative to the stator to form a gap between a surface of the stator and a surface of the rotor, the gap having a width. One of the stator and the rotor is mounted for movement relative to the other of the stator and the rotor about a central axis, and one of the stator and the rotor is mounted for movement relative to the other of the stator and the rotor along the central axis in response to thermal expansion of at least one of the stator and the rotor to maintain the width of the gap.