Hydraulic drive system with a plurality of hydraulic pumps and an energy recovery

Abstract

The invention relates to a hydraulic drive system (10) having a first and a second hydraulic pump (20, 30), wherein the first and the second hydraulic pump (20, 30) can promote hydraulic fluid to each of at least one associated first (24) and at least one associated second supply consumers (39) with hydraulic fluid, wherein said second hydraulic pump (30) having a fluid input (31) and a fluid output (32), wherein the fluid inlet (31) with a tank (11) is connected, so that the second hydraulic pump (30) of hydraulic fluid from the tank (11) suck in can,. According to the invention, the fluid inlet (31) of the second hydraulic pump (30) via a return line (12) is connected to at least one first consumer (24), that of the at least one first load (24) back-flowing hydraulic fluid at a pressure above ambient pressure in the second hydraulic pump flow (30).

Description

technical field

[0001] The invention relates to a hydraulic drive system according to the preamble of claim 1 . Background technique

[0002] Mobile work machines having first and second hydraulic pumps are already known. A first hydraulic pump (also referred to as a working pump) is used to supply generally a plurality of first consumers, such as travel drives with wheels or tracks, drives for rotatable superstructures, drives for movable booms with multiple joints drive unit or steering system. The movement of the individual consumers is controlled by means of the first control device, in particular by means of a valve group comprising a plurality of valve discs divided for the various consumers. The fluid flow of the first hydraulic pump is distributed to the individual consumers preferably according to the principle of load-dependent flow distribution (LUDV), wherein other control principles are also conceivable, such as load sensing or open center. Working pumps gene...

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