GB1321476A - Hydrostatic piston pump - Google Patents

Abstract

1321476 Reciprocating pumps KOMBINAT ORSTA-HYDRAULIK VEB 28 Oct 1970 51220/70 Heading F1A An hydraulic axial or radial piston pump, e. g. of the swash-plate type, Fig. 1 (not shown), has a control plate 2 having arcuate high and low pressure parts 8, 9 ports 10, 11 past which ports of the rotating cylinders pass as they move from port 9 to port 8, and ports 12, 13 past which the cylinder ports move during their transition from port 8 to port 9. Each pair of ports 10, 11 and 12, 13 are connected to a common passage 24 having a slide valve 25. As a cylinder port 16 moves out of communication with the port 8 it overlaps port 12 which is connected to the port 17 of a further cylinder by passage 24 and port 13. Port 17 is, in turn, in communication with the low-pressure port 9. Thus fluid flows through ports 12, 13 at a rate determined by the slide valve 25 which covers port 12 by an amount dependent on the pressure from a passage 28 connected to high-pressure port 8. In this way a linear pressure transition can be achieved as the cylinder ports pass between ports 8 and 9 and vice versa. Provision is made for interchanging the function of the ports 8, 9, Fig.5 (not shown).