Valve assembly for hydraulic drive system in mobile working machine, has separate drain valve controlling fluid stream from working connections to tank line, and circulation valve provided for disconnecting and/or releasing pump line

摘要

The assembly (30) has load assemblies (50) provided with working connections (51, 52) for connecting hydraulic loads (12) i.e. double acting cylinders. A pump line (31) and a tank line (32) are interconnected such that a fluid stream flows from a pump (20) to a tank (11). Separate inlet valves (53, 54) control the fluid stream from the pump line to the working connections. A separate drain valve (57) controls the fluid stream from the connections to the tank line. A separate circulation valve (60) i.e. steady adjustable seat valve, is provided for disconnecting and/or releasing the pump line. The load assemblies are designed in a form of a whole mountable unit.