US Patent 10263481 Electric motor or generator

An electric motor or generator having a stator with stator teeth for mounting electrical coils and a rotor, wherein the stator has a first surface that is substantially perpendicular to an axis of rotation of the rotor and the rotor has a second surface that is formed in substantially the same radial position as the stator's first surface, wherein upon the rotor being pivoted perpendicular to the axis of rotation of the rotor the first surface and the second surface are arranged to prevent the rotor coming into contact with the stator teeth.