Permanent magnet magnetic bearing

The invention relates to a permanent magnet magnetic bearing which is a composite bearing system comprising a mechanic bearing and a permanent magnet magnetic bearing. The permanent magnet magnetic bearing comprises a magnetic bearing consisting of an annular static permanent magnet magnetic array and an annular rotary permanent magnet magnetic array, and a plurality of mechanic bearing sets, wherein the magnetic bearing is in charge of the axial suspension of a rotor, and the mechanic bearing sets limit the rest four degrees of freedom of a rotation system. The invention has simple structure, stable running, large buoyancy of a magnetic bearing which can float heavy rotors of hundreds of tons, and low cost of construction; and mechanic bearing only has the function of keeping a rotating shaft near an equilibrium point, thereby having very little load (thus the mechanical wear and the energy loss are very less). The invention is suitable for a flywheel accumulation system and verticalaxis wind driven generato