Piston pump

Abstract

The invention relates to a piston pump with a piston that is axially displaceable in a pump bore of a pump housing. To enable making the piston pump with a short structure, the piston is embodied with a tubular guide portion, which on its inside is guided axially displaceably on a guide element solidly connected to the housing and protrudes into the guide portion. In this way, an inlet and outlet valve can be integrated with the piston and with the guide element protruding into the guide portion of the piston, as a result of which the piston pump can be embodied with only a slightly greater structural length than the length of the piston. A further advantage is that a piston restoring spring can be disposed outside the positive displacement chamber, so that an idle volume of the positive displacement chamber at the end of a supply stroke of the piston can be reduced to virtually zero, which improves the efficiency of the piston pump

Dependencies are inferred from the claim text.