Device for driving a variable delivery (displacement, volume) pump

摘要

A description is given of a device for driving a variable delivery pump with the aid of a hydraulically driven directional control valve via which at least one of the working chambers of the variable delivery pump can be pressurised or relieved as a function of the control pressure. In order to ensure that it is possible to provide electrical pressure regulation in the entire operating region (range) of the variable delivery pump by means of a simple, technical design, the directional control valve is provided by a multiport (multiway) proportional valve whose valve piston is subjected in a first direction to the output pressure of an electrically adjustable pressure control valve and in the opposite direction in the output control mode to a pressure which is derived from the pump pressure and reduced with respect to the latter, and in standby mode to the undiminished pump pressure.