A wheel assembly includes a wheel defining a first axis; a first electric motor including a first stator and a first rotor rotatable relative to the first stator about the first axis, the wheel fixed relative to the first rotor; a second electric motor including a second stator and a second rotor rotatable relative to the second stator about a second axis, the first stator fixed relative to the second rotor; and a third electric motor including a third stator and a third rotor rotatable relative to the third stator about a third axis, the second stator coupled to and movable with the third rotor. The first axis, the second axis, and the third axis are mutually transverse.