REDUCING BEARING FORCES IN AN ELECTRICAL MACHINE

摘要

A magnetic drive has a rotor 10 driven by a prime mover either via a rotor shaft (12 fig 1) or directly driven. The rotor 10 has a magnet array on a surface thereof, and a further rotor 18 e.g. of a generator, has a magnet array 504 on an outer surface thereof, which outer surface of the rotor is located adjacent to the surface of rotor 10 such that movement of the rotor 10 causes rotation of the rotor 18 about an axis of rotation defined by a shaft 501 of a support member carrying a mechanical bearing 505. Further magnet arrays form a magnetic surface 28 on a flange 502 of the support member and a magnetic surface 26 on the rotor. Interaction between these two surfaces forms a magnetic bearing 506 to resist forces A18 acting along the axis of rotation of the rotor. Alternatively the magnet surfaces may be arranged radially inwards in the space 208 (fig 5a). Various array arrangements of magnets on surfaces 26.28 are disclosed including a Halbach array. Fig 15 (not shown) illustrates a repulsion force magnetic bearing system used to offset the axial force on rotor 18.