Electric machine having an axial electrodynamic bearing

An electric machine extending along an axis Z, and comprising:

• 1) a rotor portion configured for rotating around the Z axis at a defined position along the Z axis and comprising a field source having an upper field source arrangement and a lower field source arrangement producing a magnetic field, and comprising a plurality of p pole pairs uniformly distributed around the Z axis;
• 2) a stator portion comprising at least one pair of windings comprising each an upper and a lower winding, comprising each a plurality of p pole pairs uniformly distributed around the Z axis, at least one of the upper winding or the lower winding having a positive reference terminal and a negative reference terminal, a positive current flowing into a positive reference terminal producing a positive flux in said winding, wherein for the or each pair of windings:
• each winding and the field source are arranged in such a way that either alternative:
• (a) a flux from the field source in said upper winding is equal to the flux from the field source in said lower winding;
• or
• (b) a flux from the field source in said upper winding is opposite to the flux from the field source in said lower winding;
• is realized at any time when the rotor portion rotates around the Z axis at said defined position along the Z axis;
• each winding and the field source are arranged in such a way that the amplitude of a flux from the field source increases in a winding of said pair of windings and decreases in the other winding of said pair of windings when position of the rotor portion along the Z axis is different from said defined position;
• the positive reference terminal of the upper winding is connected to the positive reference terminal of the lower winding and the negative reference terminal of the upper winding is connected to the negative reference terminal of the lower winding when alternative (a) is realized and the positive reference terminal of the upper winding is connected to the negative reference terminal of the lower winding and the negative reference terminal of the upper winding is connected to the positive reference terminal of the lower winding when alternative (b) is realized, forming a closed circuit path;
• wherein the connections between the upper and lower windings comprise terminals of the electric machine directly connectable to an electric power supply or to an electric load.