Device for generating a pulsating hydraulic fluid pressure by a drivable working piston guided in a cylinder and an auxiliary piston guided in an auxiliary cylinder wherein the auxiliary piston transfers fluid to an auxiliary channel only in a first stroke section

Abstract

The invention relates to a device for generating a pulsating hydraulic fluid pressure in a working chamber () filled with hydraulic fluid, comprising a driveable working piston () movably guided in a hollow working cylinder, wherein a working chamber () that is in fluid communication with the working piston () is provided, such that, by means of the movement of the working piston () within the hollow working cylinder, a pulsating hydraulic fluid pressure can be generated in the working chamber (). In order to provide a device for generating a pulsating hydraulic fluid pressure and in particular a diaphragm metering pump comprising such a device, which has small dimensions and in addition a rapid passage through the phase between closing the suction valve and opening the pressure valve, according to the invention, an auxiliary piston () is movably guided in a hollow auxiliary cylinder and is in fluid communication with an additional chamber (), wherein a closeable auxiliary channel (), which connects the additional chamber () and the working chamber (), is provided, wherein the auxiliary piston () and the hollow auxiliary cylinder are formed and arranged in such a way that, by moving the auxiliary piston () within the hollow auxiliary cylinder, a hydraulic fluid arranged in the additional chamber () can at least partly be forced out of the additional chamber () into the auxiliary channel () and from the auxiliary channel () into the working chamber ().