US Patent 7677038 Pump unit

There is provided a pump unit including plurality of hydraulic pumps respectively fluidly connected to plurality of hydraulic motors, which are disposed away from the pump unit, so as to form closed circuits, the pump unit including a pump case accommodating the plurality of hydraulic pumps so that the plurality of hydraulic pumps are operatively driven by a common power source; and a filter mounted at the pump case so as to be inserted in a charge passage for replenishing operation fluid from a fluid sump to the closed circuits.