GB1082807A - Hydraulic machines with reciprocatory pistons - Google Patents

Abstract

1,082,807. Reciprocating pumps and motors. SERCKR. & D. Ltd. Nov. 19, 1964, No. 47115/64. Heading F1A. The cylinders 12a, Fig. 3, of a revolving cylinder block 12 of an hydraulic pump or motor communicate successively with two ports 16 and 17, Fig. 2, formed in the end-plate 15 of the machine housing and the invention is concerned with an hydrostatic thrust bearing between the inner surface of the plate 15 and the adjacent surface of the block 12, recesses 21 in the plate being supplied with pressurized liquid from the port 16 via a groove 22 and fine bores 23; to counteract the tendency for the pressurized liquid to be displaced to one end of each recess 21 in use, the plate 15 is provided with grooves 26a, 26b extending adjacent the ends of the recesses 21 and communicating with a part of the machine in which liquid, in use, is at a pressure lower than that within the recesses 21. Alternatively, the recesses and the grooves may be formed in the adjacent surface of the block. The grooves 26a, 26b, which open into the space around the block which is connected to a drain, are interconnected by further grooves 24, 25. During operation of a motor, when the block rotates in an anti-clockwise direction as viewed in Fig. 2, the pressure buildup in the ends of the recesses 21 adjacent the grooves 26a is reduced because no high-pressure liquid can escape from these ends without entering one of the grooves 26a where the liquid loses its pressure. The grooves 26<SP>b</SP> act in a similar way during operation of a pump. To reduce any similar pressure build-up in the ports 16 and 17, a further groove 27 is provided and is connected to the space between the block and the shaft by way of radial grooves 28. A hydrostatic journal bearing .20, Fig. 1 (not shown), for the block 12 is supplied with high-pressure liquid from port 16.