Piston pump for hydraulic system with non-return type inlet valve

摘要

The piston bounds the work chamber as a movable wall. The pump has an inlet and an outlet valve, and a bypass bridging the inlet valve temporarily. The piston contains an inclined face (31) forming with the bypass a throttle, open when the piston is at its BDC, but closed during the piston pressure stroke.The inclined face starts at the piston (17) front side, facing the work chamber. Pref. to the bypass belongs a throttling recess (29) in the wall (25) of the cylinder (26), formed as a small dia. radial bore. The inclined face may be formed by a frusto-conical annular face.