Decoupling active and passive hybrid axial and radial magnetic bearing

This paper proposes a DHARMB (decoupled hybrid axial and radial magnetic bearing), which consists of a PRMB (passive radial magnetic bearing) and an AAMB (active axial magnetic bearing). The proposed DHARMB can simultaneously produce axial active controllable suspension force, axial passive suspension force and radial passive suspension force. In this paper, the structure and operating principle of DHARMB are firstly introduced. By using the PMAPM (permanent magnet affixed to a plane magnetizer), the axial force produced by PRMB is analyzed. After that, the mathematical model of axial suspension force calculation in AAMB is presented by means of equivalent magnetic circuit. Finally, the results from analytical and numerical calculation are compared. The results show that, the flux of each component: the flux from the PRMB, the active control flux and the permanent magnet bias flux from AAMB are decoupling. The analytical results agree well with the numerical calculation results.