Patent ID: 6932902

Claim:
A hydraulic oil filtration apparatus comprising: a hydraulic apparatus; a first filter, which filters hydraulic oil discharged from said hydraulic apparatus; a second filter, which filters hydraulic oil leaked from said hydraulic apparatus; a first downstream discharge oil passage, which returns tank-ward the hydraulic oil filtered by said first filter; a second downstream discharge oil passage, which returns tank-ward the hydraulic oil filtered by said second filter; an aspirator structure, which connects said first downstream discharge oil passage and said second downstream discharge oil passage to join the hydraulic oil discharged from said first filter and the hydraulic oil discharged from said second filter; and a joined discharge oil passage, which returns the hydraulic oil joined by said aspirator structure to a tank; wherein: said aspirator structure draws the hydraulic oil flowing in through said second downstream discharge oil passage by the flow of the hydraulic oil flowing in through said first downstream discharge oil passage and joins these flows.