Patent ID: 8482174
Filing Date: 2013-07-09
Classification: F16C,H02K

Abstract:
1. An electromagnetic actuator configured to support a body to rotate about a rotational axis, the electromagnetic actuator comprising: an axial actuator target affixed to the body, the axial actuator target having a first end-facing surface and a second end-facing surface; a first axial pole residing apart from the body, the first axial pole adjacent the first end-facing surface of the axial actuator target and adapted to communicate magnetic flux across a gap with the first end-facing surface of the axial actuator target; a second axial pole residing apart from the body, the second axial pole adjacent the second end-facing surface of the axial actuator target and adapted to communicate magnetic flux across a gap with the second end-facing surface of the axial actuator target, the first axial pole and the second axial pole magnetically coupled and cooperating with the axial actuator target to define an axial magnetic control circuit; a radial actuator target affixed to the body, the radial actuator target having a lateral surface, the radial actuator target and the axial actuator target magnetically coupled to each other; a radial pole residing apart from the body and located axially adjacent the first axial pole and on a side opposite the second axial pole, the radial pole adjacent the lateral surface of the radial actuator target and adapted to communicate a magnetic flux with the lateral surface of the radial actuator target and the first axial pole; the axial actuator target, the radial actuator target, the radial pole, the first axial pole, and the second axial pole defining a magnetic bias circuit; an axial control coil adapted to produce the magnetic flux in the axial magnetic control circuit; and a compensation electrical coil concentric with the rotational axis of the body and located between the first axial pole and the radial pole.