Abstract:
A hybrid foil-magnetic bearing (HFMB) is a combination of the foil bearing and the magnetic bearing, which takes advantage of the strengths of each individual bearing while minimizing each others weaknesses. It is the solution of the coating abrasion problem of foil bearings at low speeds and limited capacity problem of magnetic bearings, meanwhile, load sharing and dynamic characteristics adjusting can be achieved in a HFMB. In this paper, the steady-state characteristics of a HFMB were analyzed. Then a steady-state controller was designed and a searching algorithm was presented to determine the steady-state working position of the HFMB. The searching algorithm which used the equilateral triangle to divide the working plane of the HFMB minimized the deviation between actual force and the predetermined sharing load of the magnetic bearing. Finally, simulations were performed to verify the performances of the steady-stare control system. The results show that the steady-state control was feasible and reliable.