Patent ID: 6582203
Filing Date: 2003-06-24
Classification: F04B

Abstract:
A radial piston pump (1) comprising:a pump body (2) in which pistons (4) and cylinders (5) are arranged in a radial array about a cam (14); wherein upon a radially inward movement of the piston (4), the piston (4) draws a fluid through at least one pressure port (7) and into the corresponding cylinder (5); upon a radially outward movement of the piston (4), the piston (4) conveys the fluid through a check valve (9) and a pressure port (7) in an outer end wall (6) of the cylinder (5) and into a plenum (10); each piston (4) includes a connection bore (32) located in the base of the piston (4) and connecting between the corresponding cylinder (5) and the cam (14), and each connection bore (32) includes an associated pressure relief valve (18); and when a pressure in the cylinder (5) exceeds an opening pressure of the pressure relief valve (18), the fluid flows through the pressure relief valve (18) and to the cam (14) to reduce a pressure peak in the cylinder (5) and to provide a fluid buffer between the base of the piston (4) and the cam (14).