GB559134A - Improvements in and relating to magnetic suspensions - Google Patents

Abstract

559,134. Magnetic suspensions. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 18, 1942, No. 16322. Convention date, Nov. 19, 1941. [Class 37] A magnetic suspension for a vertical shaft comprises two relatively movable-permanent magnet systems, one system comprising a single permanent magnet and the other comprising two permanent magnets axially spaced apart, all the magnets being cylindrical and coaxial. A stationary hollow cylindrical permanent magnet 10, Fig. 1, is mounted with its axis vertical on a non- magnetic support 11, the magnetic axis of the magnet being vertical. A vertical rotary shaft 13 has end portions 14, 15 forming guide bearings with stationary pins 16, 17, which may be resilient. Mounted on the shaft 13 is a pair of cylindrical permanent magnets 19, 20 each having a length approximately one-half of the length of the magnet 10. The lower rotary magnet 19 is magnetized oppositely to the stationary magnet 10 so that its lower end attracts and its upper end repels the lower pole of the magnet 10. The upper rotary magnet 20 is magnetized similarly to the stationary magnet 10, so that its lower pole attracts and its upper pole repels the upper pole of the magnet 10. The distance between the bottom ends of the magnets 19, 20 corresponds to the length of the magnets 10. All the magnetic forces are in a direction to lift or support the weight of the rotary assembly. In a modification Fig. 3, a highly permeable frame 12 extends from the lower end of the stationary permanent magnet 10 to a point above the upper rotary magnet 20, so that some of the flux from the lower south pole of the magnet 10 is brought to the upper part of the frame and attracts the upper north pole of the rotary magnet 20. A highly permeable shaft section 13a is employed between the upper north pole of the magnet 20 and the upper south pole of the magnet 19 and is undercut adjacent to the south pole of the magnet 20 so that this is not magnetically shortcircuited. This arrangement creates a magnetic circuit which is closed except at the working gaps. In another modification the stationary system comprises two cylindrical magnets spaced apart and surrounding a single cylindrical magnet carried by the rotating shaft In other arrangements the inner system is stationary and the outer system rotatable. Specification 550,788 is referred to.