An electric machine is provided. The electric machine defines a centerline and includes: a stator assembly; a rotor assembly rotatable relative to the stator assembly about the centerline; and an actuator coupled to the rotor assembly, the stator assembly, or both for moving the rotor assembly, the stator assembly, or both along the centerline between a first position and a second position, the rotor assembly positioned closer to the stator assembly when in the first position than when in the second position.