Patent ID: 7934578

Claim:
A hydraulic pump unit operatively driven by a driving source and fluidly connected to a hydraulic actuator arranged apart and away therefrom, said hydraulic pump unit comprising: a pump shaft operatively connected to said driving source; a pump body driven by the pump shaft; a port block formed with an operating oil passage for supplying/discharging an operating oil to/from said pump body; a pump case connected to said port block so as to define an internal space for accommodating said pump body; and an oil tank for storing a drain oil from said pump body and acting as a charge oil source for the pump body, wherein: said oil tank is supported by an assembly formed by said port block and said pump case, said assembly includes a draw-in port leading to said operating oil passage and a draw-out port leading to said internal space, said oil tank includes an inlet port and an outlet port, said inlet port and said outlet port are fluidly connected to said draw-out port and said draw-in port, respectively, by way of a conduit, said oil tank is supported at said assembly by said conduit, a filter is arranged in said oil tank so as to surround an internal end opening of said outlet port, and said oil tank includes a tank body formed with an access opening through which said filter can be inserted, said outlet port and said inlet port, and a lid removably connected to said tank body so as to liquid-tightly close said access opening.