Abstract: An oil filtering device for an in-line filtering configuration. The device has a filter part having a micro-filtration device for filtering oil, wherein axial end faces of the filtering part are formed by the micro-filtration device. The device includes a filter housing having a lid, an inlet port situated outside the filter part for radial flow-filtering of the oil, and an outlet tort in fluid communication with a cylindrical interior space of the filter part. The device also includes a by-pass mechanism formed by an aperture provided in a closing member which sealingly engages an axial end face of the filter part, the aperture connecting the interior space in the filter part to a space exterior to said filter part. The by-pass includes a valve mechanism movable between a closed position at a lowest operating oil pressure to an open position as a function of increasing operating oil pressure.

Abstract: A full-flow microfiltration device (12) and method for filtering fluid in a hydraulic system (10) is provided. The filtration device (12) includes a housing (22) and a filter medium (24) sealingly coupled to and contained within the housing (22). The housing (22) and the filter medium (24) define a central chamber (26) and a concentric chamber (28). The central chamber (26) directly communicates with an entry port (34) and an exit port (36) formed within the housing (22) for directing a first flow through the filter device (12). The concentric chamber (28) directly communicates with an inlet port (38) and an outlet port (40) formed within the housing (22) for directing a second flow through the filter device (12). A portion of the second flow is drawn from the concentric chamber (28) through the filter medium (24) into the central chamber (26) and into the first flow.