Design and Analysis of an Electromagnet Biased Integrated Radial-Axial Magnetic Bearing

The theory for a new electromagnetically biased diskless combined radial and axial magnetic bearing is developed. A typical magnetic bearing system is composed of two radial magnetic bearings and an axial magnetic bearing. The axial magnetic bearing with a large axial disk usually limits rotor dynamic performance and makes assembling and disassembling difficult for maintenance work. This paper proposesa novel electromagnet biased integrated radial-axial magnetic bearing without axial disk. The axial magnetic bearing unit in this integrated magnetic bearing utilizes reluctance forces such that the axial disk can be removed from the bearing unit. The 4-pole homopolar type radial magnetic bearing unit is also designed and analyzed. 3-D flux analysis are also provided to illustrate the novel diskless integrated magnetic bearing.