GB927900A - Hydrodynamic gas bearing - Google Patents

Abstract

927,900. Fluid-bearings. BRISTOL SIDDELEY ENGINES Ltd. Feb. 28, 1962 [March 9, 1961; Sept. 2, 1961], Nos. 8606/61 and 31634/61. Class 12 (1). In an hydrodynamic gas bearing of which the non- rotary one of the two coacting elements includes two complementary part-cylindrical portions with their longitudinal edges spaced apart, one portion supports the load and provides an anchorage for adjustable means acting radially on the other portion to hold it floatingly in a position for causing the rotating rotary element to be urged towards the load-carrying portion so that the gas in the clearance between them is so affected that the onset of half-speed whirl is raised above the maximum operating speed of the bearing. The said one portion may be a stationary tube which at one side has a part-cylindrical portion 10 acting as an hydrodynamic loading pad and an opposite portion 11 for supporting the load, i.e. the rotary shaft 12 (Figs. 1 and 2). The tube may have an opening to accommodate the loading pad 10 floatingly held by a sphere 17 supported from structure radially outside the tube, e.g. a screw 18 in a hole 19. The portion 11 may be supported by a flange 13 from one side of a diaphragm 15, with a clearance opening 22, to the other side of which a ring 16, providing the anchorage for the pad 10, is made coaxially fast, through the sphere 17, a screw 18 (in the hole 19) clamped by a screw 21 in a cheek 20 (Fig. 3). In a modification the positions of the flange 13a and ring 16a are reversed (Figs. 5 and 6), the diaphragm 15a is between the ring 16a and a part ring 25. A clamping plate 24 is held to the ring 16a by screws 29, 31 to hold the screw 18a as adjusted and the hole 19a is formed by the plate 24 and ring 16a. Instead of an opening the stationary tube may have an internal recess on one side associated with a bleed hole. The load-carrying portion 11c may be formed with a window and assembled within a tube 39 (Figs. 9 and 11), located by a dowel 40, the gaps 38 being vertical and parallel (not radial). The tube 39 has a flange 41 to engage a ring 16c to which is held a ring 16cc to clamp the diaphragm 15c therebetween. The pad 10c is adjusted by a screw 18c in a hole 19c in the ring 16c extending through a hole in the tube 39 to engage the pad 10c through the sphere 17c, the rings 16c and 16cc being gapped near the screw 18c, and a slot 16d is in the ring 16c to split the hole 19c so that a screw 42c can be tightened to hold the screw 18c as adjusted. The recess 37a is vented by a bleed hole 35a. In another form (Fig. 12), the rotary cylindrical bore 44 has a stationary hollow shaft 11d extending therethrough and the sphere 17d is adjustable radially of the shaft by a screw 18d threaded in a cross-bar 45 welded to the bore of the load-carrying portion 11d, the loading pad 10d being in an opening 23d therein. Instead of bearing centrally of the arc of the loading pad, the ball may be made to bear on the pad at a distance from the leading edge which is about two-thirds of the arc.