Abstract: A filter filters fluid flowing along an axial flow direction and includes a plurality of concentric cylindrical pleated filter elements having a common axis. A plurality of annular radial gaps between filter elements provide additional flow axially through the filter, providing equalized flow and reducing restriction. In further embodiments, a central filter element is concentrically surrounded by a cylindrical pleated outer filter element and provides additional flow axially therethrough.

Abstract: A filter (200) filters fluid flowing along an axial flow direction (14) and includes a plurality of panels (206, 208, 240, 242) of pleated filter elements (44), each filter element having a plurality of pleats defined by wall segments (50) extending along a transverse direction (210) between first and second sets of pleat tips at first and second sets of axially extending bend lines (46, 48), the transverse direction (210) being perpendicular to the axial direction (14). Each of the panels (206, 208, 240, 242) extends along a lateral direction (212) perpendicular to the axial direction (14) and perpendicular to the transverse direction (210). The wall segments (50) extend axially between upstream and downstream ends (52, 54), and define axial flow channels (55) therebetween which are alternately sealed at the upstream and downstream ends.

Abstract: An open flow fluid filter has a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips. The loop has a hollow interior extending along an axis. Fluid to be filtered flows through the main filter element from an upstream dirty side to a downstream clean side, and flows axially in the hollow interior. The main filter element has an axial flow passage extending along the axis and circumscribing the hollow interior and has a flow perimeter greater than the inner perimeter. A safety filter element downstream of the main filter element filters both the axial flow in the hollow interior and additional flow between the flow perimeter and the inner perimeter. A filter with additional flow is also provided.

Abstract: A filter (200) filters fluid flowing along an axial flow direction (14) and includes a plurality of panels (206, 208, 240, 242) of pleated filter elements (44), each filter element having a plurality of pleats defined by wall segments (50) extending along a transverse direction (210) between first and second sets of pleat tips at first and second sets of axially extending bend lines (46, 48), the transverse direction (210) being perpendicular to the axial direction (14). Each of the panels (206, 208, 240, 242) extends along a lateral direction (212) perpendicular to the axial direction (14) and perpendicular to the transverse direction (210). The wall segments (50) extend axially between upstream and downstream ends (52, 54), and define axial flow channels (55) therebetween which are alternately sealed at the upstream and downstream ends.

Abstract: An open flow fluid filter has a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips. The loop has a hollow interior extending along an axis. Fluid to be filtered flows through the main filter element from an upstream dirty side to a downstream clean side, and flows axially in the hollow interior. The main filter element has an axial flow passage extending along the axis and circumscribing the hollow interior and has a flow perimeter greater than the inner perimeter. A safety filter element downstream of the main filter element filters both the axial flow in the hollow interior and additional flow between the flow perimeter and the inner perimeter. A filter with additional flow is also provided.

Abstract: A full flow fluid filter (300, FIG. 15) has a housing (302) extending axially along an axis (304), and a pleated filter element (318) having a plurality of pleats in a closed loop annulus having an outer perimeter (320) defined by a plurality of outer pleat tips, an inner perimeter (322) defined by a plurality of inner pleat tips, and a hollow interior (324) extending along the axis. Fluid flows substantially directly axially through the filter element, with minimal bending and change of direction, minimizing flow restriction.

Abstract: Enhanced performance fibrous media (60) is provided by orienting filter media fibers (62) dominantly parallel to the fluid flow direction (46). Filter media construction is provided by a sheet (80) having an internal pleated subsheet (88) with pleats (92, 94) engaging and packed against each other sufficiently tightly and bonded (104) such that fluid flows along the flow direction through the pleats in parallel therewith, rather than between the pleats and then transversely therethrough. An extended life two-stage fluid filter assembly includes first and second filter elements (80 and 112), wherein the pleats (114, 116) of a main downstream filter element (112) are spaced from each other along a spacing direction (122) transverse to the flow direction (46) and defining a transverse gap (124) therebetween through which fluid flows, and wherein the pleats (92, 94) of an upstream prefilter element (80) are packed against each other without such transverse gap and blocking fluid flow therebetween.

Abstract: A filter (10, 10a) includes a housing (12, 12a) extending along an axis (14). and having an inlet (16, 16a) at one axial end (18, 18a) of the housing and having an outlet (20, 20a) at a distally opposite axial end (22, 22a) of the housing. One or more pleated filter elements (44, 44a, 44b, 44c, 44d) in the housing are pleated along a plurality of bend lines (46, 48) extending axially. The filter element has a plurality of wall segments (50) extending in serpentine manner between the bend lines. The wall segments extend axially between upstream ends (52) and downstream ends (54) and define axial flow channels (58, 62) therebetween. The upstream ends of the wall segments are alternately sealed (56) to each other to defme a first set of flow channels (58) having open upstream ends (60), and a second set of flow channels (62) interdigitated with the first set of flow channels and having closed upstream ends (64).

Abstract: A combination in situ oil filter purge and oil replacement system is provided in a lubrication system, including for an internal combustion engine (10). A purge system backflushes the oil filter (12) and re-circulates backflushed used oil. A replacement system supplies fresh oil to the filter (12).

Abstract: A fluid filter assembly (20) includes an axially extending tubular housing shell (24) having an integral closed end (26), a distally opposite integral open end (28), and a sidewall (30) extending integrally between the ends. An annular filter cartridge (32) is in the housing shell. An adapter plate (48) has a first set of threads (50) thread mounting the adapter plate to the machine (22) from which fluid is filtered, and a second set of threads (54) engaging the threads (56) of the open end of the housing shell in thread tightened engagement. The housing shell is a singular one-piece member of sufficient stock and thickness at the open end to be internally threaded and to structurally support direct threaded engagement with the adapter plate without an intermediate structural support member.

Abstract: A filter (102) for filtering fluid from a machine (104) includes a filter housing (106, 250) having a first inlet (114) receiving a first fluid from the machine, a first outlet (116) returning the first fluid to the machine, a second inlet (118) selectively receiving a second fluid from a source (120) of cleaning fluid, and a second outlet (122) for exhausting the second fluid and for exhausting the first fluid from the dirty side of the main filter element (124) in the housing backwashed by the second fluid. The filter housing has a first flow path (126) therethrough from the first inlet then through the filter element in one direction then to the first outlet, and has a second flow path from the second inlet then through the filter element in the opposite direction then to the second outlet, the first and second flow paths having common but opposite direction portions through the filter element. A second filter element (156) is provided in the second flow path.

Abstract: A reusable oil filter adapted to filter oil used in an engine includes a housing operatively connected to the engine, filter media disposed within the housing, a singular backwashing inlet operatively connected on the housing and an oil drain operatively connected with the housing. Pressurized air delivered through the backwashing inlet forces filtered oil to backflow through the filter media displacing contaminated oil from the filter media and creates an air-oil foam for further cleaning the filter media while the housing remains connected to the engine.