Patent attributes
There is provided a pump unit including plurality of hydraulic pump bodies respectively fluidly connected to plurality of hydraulic motor bodies, which are disposed away from the pump unit, so as to form closed circuits, the pump unit including: a housing accommodating the plurality of hydraulic pump bodies so that the plurality of hydraulic pump bodies are operatively driven by a common driving source; a charge pump body operatively driven by the driving source; a suction fluid passage fluidly connected to a suction side of the charge pump body; a discharge fluid passage fluidly connected to a discharge side of the charge pump body; a charge passage for replenishing a part of pressurized fluid in the discharge fluid passage into each of the closed circuits; and a working machine operating fluid passage for supplying a part of the pressurized fluid in the discharge fluid passage toward an external hydraulic actuator.