GB1123820A - A hydraulic assembly - Google Patents

Abstract

1,123,820. Hydrostatic fluid-bearings. SOC. GENEVOISE D'INSTRUMENTS DE PHYSIQUE. 22 Nov., 1966 [4 Dec., 1965], No. 52212/66. Heading F2A. A hydrostatic fluid-bearing for rectilinear motion includes a body 1, Fig. 1, that is movable parallel to a surface 3 when hydraulic fluid, e.g. oil, is displaced by a pump 8 into a recess 4 from a reservoir 10 through a flow-restricting passage, or throttle, 7, fluid leaking from the recess 4 being collected in an annular recess 5 and returned to the reservoir through a pipe 12 due to continual evacuation of a space above the fluid 9 in the reservoir by a vacuum pump 13. A by-pass valve 11 opens when pressure on the output-side of the pump becomes excessive. In a second embodiment, Fig. 3, a screw mechansim includes helicoidal grooves 17, 18 in the flanks of a screw-thread of a nut 15 engaging with a screw 16, which grooves are charged with hydraulic fluid through a pair of throttles 21, the leakage fluid being withdrawn from spaces 23, 24 between the meshing screwthreads through a passage 22. Sealing rings 25 are attached to the end faces of the nut, which rings may be made of P.T.F.E. In a third embodiment, Fig. 4, a hydrostatic fluid-thrust-bearing for a rotatable shaft 28 includes annular recesses 31, 32 adjacent an annular shoulder 28a attached to the shaft, which recesses are filled with hydraulic fluid through passages 33, 34, 35 and a cylinder 37 containing a spring-loaded piston 36 to effect automatic variable-throttling of the fluid in accordance with the axial load on the shaft, the leakage fluid being collected in annular recesses 39 and removed therefrom through passages 40, 41, 42. A fourth embodiment, Fig. 5 (not shown), differs from that according to Fig. 4 only in that the cylinder 37 and the piston 36 are replaced by a chamber (45) containing a flexible blade (43) that has an effect similar to that of the piston. Each mechanism or bearing according to Figs. 3 to 5 is connected to a reservoir for hydraulic fluid in a manner similar to that shown in Fig. 1, the space above the fluid in the reservoir being evacuated as aforesaid.