Magnetic bearing, compressor and air conditioner

A magnetic bearing, comprising:

• an axial iron core, a permanent magnet, a magnetic conductive ring and a magnetic steel fixing frame, wherein the permanent magnet comprises a first permanent magnet located on a side of the magnetic conductive ring and a second permanent magnet located on another side of the magnetic conductive ring in an axial direction of the magnetic conductive ring, the first permanent magnet is located between the magnetic conductive ring and the axial iron core and is connected to the magnetic conductive ring and the axial iron core, and the second permanent magnet is located between the magnetic conductive ring and the axial iron core and is connected to the magnetic conductive ring and the axial iron core, wherein the magnetic steel fixing frame is capable of fixing and supporting a radial inner side of the permanent magnet,
• wherein the magnetic bearing further comprises:
• a bearing rotor and a radial iron core, wherein the axial iron core is in a concave shape in a radial cross section, and wherein the radial iron core, the permanent magnet, and the magnetic conductive ring are all located in a space surrounded by the axial iron core;
• and
• a radial control winding and an axial control winding, wherein the radial control winding is wound on the radial iron core, and wherein the axial control winding is located on a radial outer side of the magnetic conductive ring.