Patent ID: 6227820
Filing Date: 2001-05-08
Classification: A61M,F04D,F16C

Abstract:
A passive radial magnetic bearing system adapted to support a rotor for rotation about an axis while it is axially confined by mechanical means, comprising,a. Rotor means mechanically free to rotate about an axis,b. Axial motion limiting means to permit said rotor means to rotate while closely confining it axially,c. Mechanical thrust bearing means affixed to said rotor means and to said limiting means,d. A first axially magnetized generally cylindrical permanent magnet mounted to said limiting means in alignment with the axis of rotation of said rotor means, adjacent to one end of said rotor means,e. A second axially magnetized generally cylindrical permanent magnet mounted to said limiting means in alignment with the axis of rotation of said rotor means, adjacent to the other end of said rotor means,f. Force transferring means, comprising a pair of generally cylindrical ferromagnetic structures mounted adjacent to each end of said rotor in axial alignment with the axis of rotation of said rotor which are subject to magnetic forces originating from said first and second permanent magnets to both support said rotor for radial rotation and force it against said thrust bearing means,g. Axial force balancing means comprising means to mount said magnets to said limiting means in position such that the net axial forces exerted on one end of said rotor by said first magnet are almost exactly counter-balanced by the axial forces exerted on the other end of said rotor by said second magnet.