Thrust magnetic bearing and turbo compressor equipped with same

A thrust magnetic bearing comprising:

• a stator having a coil;
• and
• a rotor,
• the coil allowing a current to flow therethrough and producing a magnetic flux in a magnetic path defined by the stator and the rotor, the magnetic flux supporting the rotor in a non-contact manner,
• the stator having a main stator magnetic pole surface and an auxiliary stator magnetic pole surface,
• the coil and the auxiliary stator magnetic pole surface overlapping each other when viewed along a rotor axial direction,
• the rotor having a main rotor magnetic pole surface and an auxiliary rotor magnetic pole surface, the main rotor magnetic pole surface facing the main stator magnetic pole surface in a rotor axial direction, and the auxiliary rotor magnetic pole surface facing the auxiliary stator magnetic pole surface,
• the auxiliary stator magnetic pole surface including at least one first stator surface that extends in the rotor axial direction, and at least one second stator surface that extends in a rotor radial direction, the at least one first stator surface and the at least one second stator surface being alternately arranged,
• the auxiliary rotor magnetic pole surface includes at least one first rotor surface that extends in the rotor axial direction, and at least one second rotor surface that extends in the rotor radial direction, the at least one first rotor surface and the at least one second rotor surface being alternately arranged, and
• Nr≥1 and Nt≥2, with
• Nr representing a number of pairs of the first stator and rotor surfaces facing each other in the rotor radial direction, and
• Nt representing a number of pairs of the second stator and rotor surfaces facing each other in the rotor axial direction.