Piston pump with at least one stepped piston element

Abstract

A piston pump with at least one driven stepped piston element disposed longitudinally movably in a housing is disclosed. The piston element and housing define a plurality of pressure chambers whose volumes vary as a function of the motion of the stepped piston. A volume of the first pressure chamber is decreased during an intake stroke of the piston that increases the volume of the second pressure chamber. A volume of a third pressure chamber, communicating with the pumping side and defined by the stepped piston element and the housing, is increased by a defined volumetric value during the compression stroke and decreased by the during the intake stroke; the defined volumetric value is less than the change in volume of the second pressure chamber during the compression stroke of the stepped piston element.

Description

PRIOR ART[0001]The invention relates to a piston pump with at least one stepped piston element that can be driven via an eccentric device and is disposed longitudinally in a housing, as generically defined further by the preamble to claim 1.[0002]From German Patent Disclosure DE 199 28 913 A1, a piston pump with a pump housing that has a pump bore and with a piston, disposed in the pump bore and drivable in the axial direction, is known. The piston is embodied as a stepped piston, and together with the pump housing it defines pressure chambers, which can be made to communicate via an inlet valve device for carrying fluid from a first pressure chamber, communicating with an intake region, into a second pressure chamber, and whose volumes vary as a function of a motion of the piston element. A volume of the first pressure chamber is decreased during an intake stroke of the piston that increases the volume of the second pressure chamber, while the volume of the first pressure chamber i...

AI Technical Summary

Benefits of technology

The invention is a piston pump with a stepped piston element that can transmit both tensile and compressive forces. It has two pressure chambers that can communicate with each other through an inlet valve device and an outlet valve device. The volumes of the two pressure chambers vary during the intake and compression strokes of the piston element, resulting in a more uniform distribution of fluid flow and better pumping performance with less operating noise. This design also leads to improved driving comfort in vehicles equipped with the piston pump.

Problems solved by technology

However, it is disadvantageous that fluid compressed by the piston pump only during the pressure stroke or the compression stroke of the piston is pumped out of the second pressure chamber to the pumping side of the piston pump, which because of the uneven pressure pulsation leads to unwanted noise production.

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