GB1394516A - Radial piston machine - Google Patents

Abstract

1394516 Reciprocating pumps and motors ROBERT BOSCH GmbH 10 Oct 1973 [10 Oct 1972] 47377/73 Heading F1A In a radial piston pump or motor comprising a rotary cylinder block 31 supported on a pintle valve 3 having inlet and outlet ports 6, 7, the block 31 is centralized on the pintle in operation by the action of pressure fields produced by two pairs of recesses 11, 12, 13, 14 and 15, 16, 17, 18 associated with each port, recesses 11, 12, 17, 18 being inter-connected as one group, and recesses 13, 14, 15, 16 being inter-connected as another group, and the two groups being connected by respective passages 19, 20 to a slide valve 21 responsive to the pressures at diametrically opposite positions in the clearance between the block and the pintle. As shown, ports 6, 7 are connected via check valves 27, 28 to supply working pressure to valve 21, through passage 26, and to ports 45, 46 at diametrically opposite locations in the pintle surface. Recesses 47, 48 in the cylinder block intermittently connect ports 45, 46 to ports 39, 40 in the pintle connected via throttles 43, 44 to end-faces of valve 21. The pressures transmitted by ports 39, 40 to the valve are different when the block is not central on the pintle, so that valve 21 is moved by the pressure differential to connect the appropriate group of pressure field recesses to pressure to centralize the cylinder block. Springs 29, 30 bias valve 21 to its mid position. The valve is located in the pintle, Fig.5 (not shown). In Fig.6 (not shown), one group of pressure field recesses is of larger area than the other, the smaller recesses being continuously connected to high-pressure, and the valve operating to connect the larger recesses to high-pressure as before. In Fig.7 (not shown), high-pressure passage 26 is additionally connected to the endfaces of the slide valve via throttles, and ports 39, 40 are connected between the respective throttles and end-faces.