GB869200A - Improvements in and relating to gas bearings - Google Patents

Abstract

869,200. Fluid-bearings. BRISTOL SIDDELEY ENGINES Ltd. Aug. 19, 1958 [Jan. 13, 1958], No. 1121/58. Class 12 (1). An in-line electric-motor-driven compressor has the compressor rotor 44 and the motor rotor 40 mounted with respect to a fixed central shaft 22 by means of an hydro-dynamic gas bearing in which the ratio of the radial width of the clearance to the radius of the stationary shaft is less than 50 X 10<SP>-4</SP>, and the ratio of the overlapped lengths of the bearing surfaces to their mean diameter is greater than 1. The motor rotor 40 is mounted on a sleeve 38 which carries at its lower end a gas thrust bearing comprising a thrust-plate 59 which coacts with a stationary thrust-plate 61, the latter being mounted in a self-aligning manner with respect to a fixed plate 65 by an interposed plate 63 and balls 62, 64. The surface of the plate 61 is provided with logarithmic spiral grooves 91 to promote an optimum shear effect on the gas in the thrust bearing. A chamber 58 is in communication with the compressor inlet through clearances between the shaft portion 28 and the compressor rotor 48 and is in communication with an outlet annulus 52 through an aperture 57, the pressure of the gas in the chamber 58 being intermediate the inlet and outlet pressures. The gas is also led to the other end of the sleeve 38. In a modification, a textile spinning spindle 72 is mounted on a fixed shaft 73 and a thrust-bearing is provided at the lower end thereof. The thrust bearing comprises a resiliently-mounted ring 81 which coacts with a flange 80 on the base of the spindle 72. The ring 81 is mounted on a spring-ring 82 and is prevented from rotating by pins 85 which engage loosely in holes 84 in the ring 81. The thrust surface of the ring 81 is provided with shallow logarithmic spiral grooves, 91, as shown in Fig. 3.