HYDRAULIC CROWD SYSTEM FOR ELECTRIC MINING SHOVEL

A mining shovel (10) includes a hydraulic system comprising a plurality of fixed displacement pumps (104,106,108,110) driven by a variable speed motor (100), and a tank (68) system comprising an upper return tank and a lower supply tank (70). A cylinder manifold (64) is connected to the pump control manifold (112), and includes a directional control valve for directing the extend and retract functions of the cylinder (50), while accepting fluid flow in a single direction from the pump control manifold. The single direction flow allows for the use of smaller fluid conduits (61), such that the hose providing a high pressure supply can be comparatively smaller than the return hose (67).