GB1383877A - Radial piston machine - Google Patents

Abstract

1383877 Reciprocating pumps and motors ROBERT BOSCH GmbH 27 Sept 1973 [2 Oct 1972] 45300/73 Heading F1A In a radial piston machine comprising a rotary cylinder block 5 with pistons 7 engaging a track ring 9 of adjustable eccentricity, the block 5 is supported by a stationary pintle valve 4 formed with high and low pressure control ports 16, 17 and peripheral grooves 20, 21 defining sealing webs 22 to 25, Fig. 2 and bearing webs 26, 27, the areas of the bearing webs being smaller adjacent the high-pressure port 16 than adjacent the low-pressure port 17, and/or the width of the grooves being greater adjacent the low-pressure port than adjacent the high-pressure port, to balance the pressure forces on the cylinder block to centralize it on the pintle valve. Reduction of the high-pressure port bearing web area is effected in the embodiment shown by the provision of recesses 29, 30 communicating with the machine housing interior via the pintle valve end-face and groove 28, respectively. In Fig. 3 (not shown), grooves 20, 21 (40, 41) are of constant width, and recesses 29, 30 are replaced by grooves (49, 53) communicating with the housing interior and isolating portions of the bearing webs adjacent the high-pressure control port. Continuous grooves 20, 21 may be replaced by grooves (61-64), Fig. 4 (not shown), extending the length of the respective control ports, each pair of grooves on the respective sides of the control ports being inter-connected by a pressure balancing passage (65), Fig. 5 (not shown).