Abstract:
An oil-collecting can ( 500 ) for a filter cartridge ( 300 ) comprises a plurality of capillary ribs ( 530 ) that are sized and shaped to contact filter media in the outlet chamber. The oil-collecting can ( 500 ) can be used in conjunction with a filter cartridge ( 300 ), which is installed in a filter assembly to encourage the downward flow of oil droplets. Such a filter assembly could be used, for example, in a crankcase ventilation system, to remove particulates and other contaminants from piston-bypass fumes.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119 (e) to U.S. Provisional Patent Application No. 61/031,190 filed on Feb. 25, 2008. The entire disclosure of this provisional application is hereby incorporated by reference. If incorporated-by-reference subject matter is inconsistent with subject matter expressly set forth in the written specification (and/or drawings) of the present disclosure, the latter governs to the extent necessary to eliminate indefiniteness and/or clarity-lacking issues. 
     
    
     FIELD 
       [0002]    A crankcase ventilation system including a filter assembly which removes particulates and other contaminants from crankcase fumes. 
       BACKGROUND 
       [0003]    An internal combustion engine (e.g., a diesel engine), can be provided with a ventilation system for venting the fumes that leak past the piston rings and through the circulating oil in the crankcase. The crankcase fumes (i.e., a mixture of air, exhaust, and oil) are commonly passed through a filter assembly. Such a filter assembly can include, for example, an inlet chamber, an outlet chamber, and a filtering media (through which the crankcase fumes must pass to flow from the inlet chamber to the outlet chamber) that removes particulates and other contaminants. Oil will typically migrate through the media with the gas, and oil droplets will form on the filter surface within the outlet chamber. Gravity causes the oil droplets to slide downward and a bottom receptacle can be positioned for collection thereof. 
       SUMMARY 
       [0004]    An oil-collecting can is provided for the filter assembly in a crankcase ventilation system that has capillary ribs to encourage oil droplets to drain downward. The ribs are adapted to contact the filter surface within the outlet chamber to provide a less resistant path than the filter media. When the oil droplets reach the contacting rib region, they will prefer to follow its smooth slide and thereby be quickly transported to the bottom of the can. 
     
    
     
       DRAWINGS 
         [0005]      FIGS. 1A-1D  are each a schematic diagram of an engine that incorporates a crankcase ventilation system. 
           [0006]      FIGS. 2A-2G  are various views of the filter assembly  100  of the crankcase ventilation system. 
           [0007]      FIGS. 3A-3E  are various views of the filter cartridge  300  of the filter assembly  100 . 
           [0008]      FIGS. 4A-4H  are various views of the filter element  400  of the filter cartridge  300 . 
           [0009]      FIGS. 5A-5J  are various views of the oil-collecting can  500  of the filter cartridge  300 . 
       
    
    
     DESCRIPTION 
       [0010]    Referring now to the drawings, and initially to  FIG. 1A , an engine  10  is schematically shown. The engine  10  includes a crankcase  11  (having an oil pan  12 ), and a turbocharger  13  (comprising compressor  14  and turbine  15 ). An air-inlet line  16  supplies air to the compressor  14 , and an air-intake line  17  supplies the compressed air to the intake of the crankcase  11 . On the exhaust side of the engine  10 , an outtake line  18  supplies exhaust to the turbine  15 , and the turbine  15  discharges to an exhaust line  19 . 
         [0011]    The engine  10  incorporates a crankcase ventilation system  20  for venting fumes from within the crankcase  11 . The illustrated system  20  has an engine vent line  21 , a gas exit line  22 , and an oil exit line  23 . The system  20  comprises a filter assembly  100  that receives crankcase-ventilation fumes through the engine vent line  21 , filters the gases and exits it through the line  22 , and removes the oil for exit through line  23 . The gas-exit line  22  can join air-intake line  16  for passage back through the crankcase  11 , and the oil-exit line  23  can return oil to the pan  12 . Alternatively, the gas-exit line  22  can join the exhaust line  19  ( FIGS. 1B and 1D ) and/or the oil-exit line  23  can be drained ( FIGS. 1C and 1D ). 
         [0012]    The filter assembly  100  comprises an inlet port  110  (See  FIGS. 2C and 1D ) connected to the vent line  21 , a gas outlet port  120  connected to the gas exit line  22 , and an oil outlet port  130  connected to the oil exit line  23 . The inlet port  110  communicates with an inlet chamber  140  and the outlet ports  120 / 130  communicate with an outlet chamber  150 . As is explained in more detail below, the fumes must pass through a filtering media (e.g., filtering media  410 , introduced below), to flow from the inlet chamber  140  to the outlet chamber  150 . 
         [0013]    The filter assembly  100 , shown more pictorially in the 2 nd  drawing set ( FIGS. 2A-2G ), can comprise a housing  200  and a filter cartridge  300 . The housing  200  can comprise a side wall  210 , a bottom wall  220 , an outlet tube  230 , and an oil spout  240 . The wall  210 , the wall  220 , the tube  230 , and the spout  240  can be formed in one piece (e.g., molded from a polymeric material). 
         [0014]    The side wall  210  has an upper edge  211  (defining the housing&#39;s open top  212 ), a lower edge  213 , an interior surface  215 , and an exterior surface  216 . Interior threads  217  (i.e., on the interior surface  215 ) are situated along the wall&#39;s upper edge  211 , for mating with complementary threads (namely threads  447  introduced below) on the filter cartridge  300 . The cylindrical wall  210  can further comprise a rim  218  extending axially upward and radially outward from its upper edge  211 . 
         [0015]    The bottom wall  220  comprises a radially outer edge  221  transitioning into the lower edge  213  of the side wall, and a radially inner edge  223  defining a central opening  224  (See  FIGS. 2F and 2G ). The side wall  210  has a substantially cylindrical shape and the bottom wall  220  has a substantially annular shape, these shapes being interrupted by a corner opening from which the outlet tube  230  radially (with a downward slope) extends. The oil spout  240  extends downward from the opening  224  in the bottom wall  220 , and includes upper wide portion  257  and a lower narrow portion  258  (See  FIG. 2G ). The tube  230  forms the gas outlet port  120  and the spout  240  forms the oil outlet port  130 . 
         [0016]    Referring now to  FIG. 2D , the housing  200  can further comprise mounting flanges  250  extending, for example, radially from the exterior surface  216  of its cylindrical wall  210 . The location, size and shape of such mounting means will depend upon the intended application of filter assembly  100 . These flanges  250  can (or cannot) be formed in one piece with the cylindrical wall  210  and/or the rest of the housing  200 . 
         [0017]    The filter cartridge  300 , shown alone in the  3 d drawing set, comprises a filter element  400  and an oil-connecting can  500 . The cartridge  300  is intended for periodic replacement in the filter assembly  100  (as opposed to the housing  200 ). The cartridge  300  is preferably pre-assembled by the manufacturer, with the filter element  400  already (and essentially non-removably) secured to the can  500 . But a cartridge  300  that is instead assembled by the user (i.e., the filter element  400  and the can  500  are provided separately by the manufacturer) is possible and contemplated. 
         [0018]    The filter element  400  is shown disassembled from the oil-collecting can  500  in the 4 th  drawing set. As is best seen by referring briefly back to  FIG. 3B , the filter media  410  can be viewed as having an upper portion  401 , which is not surrounded by the oil-collecting can  500 , and a lower portion  402 , that is surrounded by the oil-collecting can  500 . In the filter assembly  100 , the outlet chamber  150  (See  2 E) is the space between the upper portion  418  and the housing&#39;s interior surface  215 , and the space between the lower portion  419  and the can  500  (and more particularly its exterior surface  516 , introduced below). 
         [0019]    Referring now to  FIG. 4A , the filter element  400  comprises a filtering media  410  compiled into a cylindrical pack having an upper face  411 , a lower face  412 , an exterior surface  415 , and interior surface  416  defining a central bore  417 . The illustrated filter element  400  comprises two concentric layers of filtering material, but more (e.g., three, four, etc.) or less (e.g., one) layers of filtering material are possible and contemplated. In any event, the filtering material (e.g., paper) will usually be fibrous and/or rough. 
         [0020]    The illustrated filter element  400  also comprises a top end cap  420 , an inlet tube  430 , a housing-connecting rim  440 , a bottom end cap  450 , a can-engaging rim  460 , and a center tube  470 . The top end cap  420 , the tube  430 , and rim  440  can be formed in one piece (e.g., molded from a polymeric material). Additionally or alternatively, the bottom end cap  450 , the can-engaging rim  460 , and the center tube  470  can be formed in one piece (e.g., molded from a polymeric material). 
         [0021]    Referring now to  FIG. 4B , the top end cap  420  comprises a radially outer edge  421  (with a seal-receiving groove  422 ), a radially inner edge  423  defining an opening  424 , a top surface  425 , and a bottom surface  426  sealing the media&#39;s upper face  411 . The illustrated end cap  420  has an annular latch  427  and circular ledges  428  extending downward from its bottom surface  426 . The latch  427  engages with similar component on the center tube  470  (namely latch  479  introduced below), and the ledges  428  pierce into the media&#39;s upper face  411 . 
         [0022]    The inlet tube  430  extends upward from the cap&#39;s top surface  425 , communicating with the opening  424 . The house-connecting rim  440  extends downward from the cap&#39;s bottom surface  426  and has threads  447  formed on its exterior surface. In the filter assembly  100 , a seal (e.g., an o-ring) is seated in the groove  422  to seal the interface between the cap&#39;s radially outer edge  421  and the housing&#39;s interior surface  215 . The inlet tube  430  forms the inlet port  110  and it communicates with the central bore  417  of the filter media  410  (See  FIG. 3B ). The threads  447  on the filter rim  440  are threadably engaged with the threads  217  on the housing rim  218  to assemble the filter cartridge  300  to the housing  200 . 
         [0023]    The bottom end cap  450  comprises a radially outer edge  451  with slots  452  (See  FIG. 4C ), a radially inner edge  453  defining an opening  434  (See  FIG. 4F ), a top surface  455 , and bottom surface  456  (See  FIG. 4H ). Annular ledges  457  extend upward from the cap&#39;s top surface  455  and pierce the media&#39;s lower face  412 . A series of holes  458  extend axially through the end cap  450  for receipt of clipping components (namely clips  548  introduced below) in the oil-collecting can  500 . The rim  460  extends upwardly from the cap&#39;s outer edge  451  and includes slots  452  coextensive with the can&#39;s slots  467  (See  4 E and  4 F). In the filter cartridge  300 , the slots  452 / 467  align with rib components (namely capillary ribs  530  introduced below) in the oil-collecting can  500 . 
         [0024]    Referring now to  FIG. 4G , the center tube  470  comprises an upside-down cup  477  and a perforated sleeve  478  that occupy the central bore  417  of the filter media  410 . The cup  477  extends upward from and seals the opening  434  in the bottom end cap  450 , and a perforated sleeve  478  extend upward from the cup  477 . The sleeve  478  has a cap-engaging latch  479  that cooperates with the tube-engaging latch  427  of the top end cap  420 . In the filter assembly  100 , the inlet chamber  140  is formed by the space above the cup  477  in the central bore  417 . 
         [0025]    The oil-collecting can  500  is shown disassembled from the filter element  400  in the 5 th  drawing set (i.e.,  FIGS. 5A-5J .) The can  500  generally comprises a cylindrical side wall  510 , a bottom wall  520 , a plurality of capillary ribs  530 , a set of pedestals  540  (See  FIG. 5C ), and an oil-outlet pipe  550 . These parts are preferably made in one piece (e.g., molded from a polymeric material). 
         [0026]    Referring now to  FIG. 5A , the cylindrical side wall  510  has an upper axial edge  511  defining an open top end  512 , a lower axial edge  513 , an interior surface  515 , and an exterior surface  516 . The cylindrical side wall  510  can be viewed as comprising wall panels  517  separated by the capillary ribs  530 . Each panel  517  (and/or at least one panel  517 , or at least some of the panels  517 ) can include a nub  518  projecting radially outward from its upper edge  511 . The nub shape can be trapezoidal in plan ( FIG. 5G ) and triangular in section ( FIG. 5E ). In the filter assembly  100 , the nubs  518  radially situate (e.g., center) the filter cartridge  300  within the cylindrical wall  210  of the housing  200 . 
         [0027]    Referring now to  FIG. 5F , the bottom wall  520  has a radially-outer edge  521  that transitions from the lower edge  513  of the side wall  510 , a radially-inner edge  523  (See  51 ) that defines an opening  524 , an upper surface  525 , and a lower surface  526 . The wall  520  can include an annular ramp portion  527  (See  FIG. 5F ) and an annular level portion  528 . The ramp portion  527  extends radially inward (and downward) from the wall&#39;s outer edge  521 , and the level portion  528  extends radially inward (and horizontal) from the ramp portion  527  to the inner edge  523 . Referring now to  FIG. 5J , the capillary ribs  530  are circumferentially arranged around the side wall  510 . The can  500  can include at least two, at least four, at least six, and/or at least eight capillary ribs  530 , and they can be spaced equally (or unequally) around the wall circumference. Each rib  530  has a ceiling  531 , a floor  533 , an interior surface  535 , and an exterior surface  536 . The ceilings  531  transition into the upper axial edge  511  of the cylindrical side wall  510 , and the floors  533  transition into the lower axial edge  513  of the cylindrical side wall  510 . The rib ceilings  531  are narrower than their floors  533 , whereby they taper radially outward in the downward direction. The exterior surfaces  536  can curve inward to form semi-circular (in cross-section) grooves  537 , whereby the ribs  530  can have substantially the same thickness as the side wall  510 . The semi-circular grooves  537  also provide channels for water drainage and clean gas flow. 
         [0028]    In the filter assembly  100  and/or the filter cartridge  300 , the capillary ribs  530  are intended to act as guides and/or slides to encourage the downward flow of oil droplets from the media outer surface wall  415 . To this end, the interior surfaces  535  project radially inward from the interior surface  515  of the cylindrical side wall  510 , to thereby contact the filter media  410 . The ribs&#39; interior surfaces  535  are preferably smooth so as to be a path of lesser resistance for the oil droplets (e.g., when compared to the fibrous terrain of the filter media  410 ). The ribs  530  can be radially sized so that at an intermediate can height (e.g., between the ceiling and floor) the ribs&#39; interior surfaces  535  contact the exterior surface  415  of the filter media  410 . (See  FIG. 2F .) As an oil droplet scoots down the exterior surface  415  of the filter media  410 , it passes through the open top end  512  of the can  500 . When it reaches a rib-contacting region, it transfers onto the rib&#39;s smooth interior surface  535 . Once on this smooth surface, it easily slides down to the rib&#39;s floor  533 , through the slots  452 / 467  in the bottom end cap  450  and collecting can  500  respectively (See  4 E- 4 H), onto the ramped wall portion  520  and thereafter down the outlet pipe  550  (See  5 B). 
         [0029]    The pedestals  540  are arranged on the upper surface  525  of the bottom wall  520 . The oil-collecting can  500  can include at least two, and/or at least four pedestals  540 . Each pedestal  540  includes a rectangular skirt  542  projecting upwardly from the wall  520 , a horizontal platform  544  on top of the skirt  542 , an interior surface  545 , and exterior surface  546 . The exterior surface  546  may include an indent  547  corresponding to the skirt  542 , whereby the pedestals  540  can have substantially the same thickness as the bottom wall  520  (See  FIG. 5E ). 
         [0030]    A cross-shaped clip  548  is situated on each platform  544 . In the filter cartridge  300 , these clips  548  are received within the holes  458  in the bottom end cap  450 . (See  FIG. 3E .) In the illustrated cartridge  300 , the end cap  450  has eight holes  458  for the four pedestals  540 , to allow more alignment flexibility during fabrication. In the final cartridge  300 , the “extra” holes  458  are filled with adhesive. 
         [0031]    Referring now to  FIG. 51 , the oil-outlet pipe  550  comprises a cylindrical wall  558  extending downward from the inner radial edge of the level portion  528  of the bottom wall  520  (and thus communicating with the opening  524 ). The pipe  550  and/or the wall  558  can include a seal-seating groove  557 . In the filter assembly  100 , the pipe  550  (and the seal seated within the groove  557 ) is inserted into the oil spout  240  of the housing  200 . (See  FIG. 2G .) Although the engine  10 , the ventilation system  20 , the filter assembly  100 , the housing  200 , the cartridge  300 , the filter element  400 , and/or the oil-collecting can  500  have been shown and described with respect to certain embodiments, equivalent alterations and modifications should occur to others skilled in the art upon review of this specification and drawings. If an element (e.g., component, assembly, system, device, composition, method, process, step, means, etc.), has been described as performing a particular function or functions, this element corresponds to any functional equivalent (i.e., any element performing the same or equivalent function) thereof, regardless of whether it is structurally equivalent thereto. And while a particular feature may have been described with respect to less than all of the embodiments, such feature can be combined with one or more other features of the other embodiments.