A Novel Homopolar Four Degrees of Freedom Hybrid Magnetic Bearing

In this article, a novel four degrees of freedom (4-DOF) homopolar hybrid magnetic bearing (HMB) is put forward to reduce the magnetic field coupling of radial 4-DOF. It consists of two pairs of symmetrical radial stators and one rotor, and the radial stators on each side have two pieces, namely, X and Y stator core. Due to the special design of X and Y magnetic poles in the different radial stator cores, the magnetic circuits of X and Y channels are independent of each other. The configuration and operating principle of the homopolar HMB are first discussed, and then, the mathematical model of radial suspension force is deduced by the equivalent magnetic circuit method (EMCM). Besides, some main parameters are given in accordance with the given maximum radial suspension force. Finally, 3-D finite-element (FE) model of the homopolar 4-DOF HMB is established with MagNet software. Meanwhile, the magnetic flux distributions, the magnetic flux density, the force-current relationship of X channel with displacement and current of Y channel are simulated and analyzed. The simulation results indicate that the presented 4-DOF HMB has good performance, and the magnetic fields of X and Y channels decouple well from each other.