Combination radial/axial electromagnetic actuator

An electric machine system comprising:

• a stator;
• a rotor having a rotational axis configured to move relative to the stator;
• a magnetic bearing electromagnetic actuator subassembly comprising:
• a cylindrical actuator target rigidly mounted on the rotor;
• a first axial pole residing apart from the actuator target, the first axial pole adjacent a first end facing surface of the actuator target and adapted to communicate magnetic flux across a gap with the first end facing surface of the actuator target;
• a second axial pole residing apart from the actuator target, the second axial pole adjacent a second end facing surface of the actuator target and adapted to communicate magnetic flux with the second end facing surface of the actuator target;
• an axial back-iron magnetically linking the first axial pole and the second axial pole;
• the actuator target, the first axial pole, the second axial pole and the axial back-iron are magnetically coupled and defining an axial magnetic control circuit;
• an axial control conductive coil adapted to produce a magnetic flux in the axial magnetic control circuit;
• a magnetically permeable annular element located concentric to the rotational axis and including a plurality of radial poles and an electrically isolating radial gap interrupting a conductive path around the rotational axis, the magnetically permeable annular element including a plurality of radial poles residing apart from the actuator target, the plurality of radial poles adjacent a lateral facing surface of the actuator target and adapted to communicate magnetic fluxes with the lateral facing surface of the actuator target, the actuator target and the plurality of radial poles defining a plurality of radial magnetic control circuits, the plurality of radial poles adapted to communicate magnetic fluxes with the lateral facing surface of the actuator target and at least one of the first axial pole or the second axial pole, the actuator target, the plurality of radial poles and at least one of the first axial pole or the second axial pole defining a magnetic bias circuit;
• radial control conductive coils wound around the radial poles and adapted to produce a magnetic flux in the radial magnetic control circuit;
• one or more position sensors configured to sense a position of the actuator target;
• and
• at least one control electronics package configured to control the electric currents in the axial control conductive coil and radial control conductive coils.

A method for exerting axial and radial forces on a cylindrical body having a symmetry axis, the method comprising:

• communicating a first bias magnetic flux through a first axial facing surface of the body;
• communicating a second bias magnetic flux through a second axial facing surface of the body;
• communicating combined the first and the second bias magnetic fluxes through a lateral surface of the cylindrical body;
• communicating an axial control magnetic flux through the first and the second axial facing surfaces of the body;
• communicating a radial control magnetic flux diagonally across the body by means of a stationary radial pole assembly located around the body and separated from it;
• and
• suppressing electrical currents in the stationary radial pole assembly by introducing isolating interrupts of the conductive paths, the stationary radial pole assembly including disjointed laminations that include an annular disjointed lamination to disrupt the continuity of the conductive paths.