Abstract:
A suction-side transmission or engine filter includes a filter bag assembly having an outlet portion and a media bag enclosing an inner support structure, the filter bag assembly is contained at least partially within a housing having an outlet port. The outlet portion and outlet port are aligned and sealed together creating an outside-in fluid flow scheme.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates generally to engine and transmission filters. The present invention relates more specifically to suction-side engine or transmission filters having an outside-in flow scheme. More particularly, the present invention relates to suction-side engine or transmission filters having an outside-in flow scheme.  
         BACKGROUND OF THE INVENTION  
         [0002]    Currently, suction-side transmission filters having a media-in-bag configuration employ the media in an inside to outside fluid flow scheme. Consequently, dirty fluid enters the bag from the transmission filter inlet and is cleaned as it exits the bag into two fluid regions (one above and one below the bag). The clean fluid then travels toward the transmission filter outlet. Typically, there is a region where the two clean flow regions join and then exit the transmission filter outlet.  
           [0003]    Media bags with inside-out flow schemes can be difficult to incorporate into some transmission filter designs, for example, transmission filters with inlets at an angle or inlets particularly close to the side-wall of the filter. Also, transmission filters with media bags configured in an inside-out flow scheme often have areas of minimal flow, that is substantial portions of the media area are not fully utilized. Such inside-out flow transmission filters are thus less efficient than they could be if there were more uniform flow throughout the media.  
           [0004]    Accordingly, it is desirable to provide more flexible and/or more efficient transmission filters having a media-in-bag configuration. In other words, it is desirable to provide transmission filters having a media-in-bag configuration that can be incorporated into a greater number of transmission filter designs, for example also those transmission filters having inlets at an angle or inlets particularly close to the side-wall of the filter. It is also desirable to provide a transmission filter that utilizes as much of the media as possible.  
         SUMMARY OF THE INVENTION  
         [0005]    The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments includes a filter bag assembly incorporated into a transmission or engine filter housing to create an outside-in fluid flow scheme. Some embodiments of transmission or engine filters having such a flow scheme may be more flexible than inside-out transmission or engine filters in that they may be adapted to fit a larger number of filter designs. Some embodiments of transmission or engine filters having an outside-in flow scheme may alternatively, or in addition, have the advantage of being more efficient than inside-out transmission filters in that they more fully utilize the media.  
           [0006]    In accordance with one embodiment of the present invention, a filter bag assembly is provided that includes a media bag with an outlet, the outlet is configured to attach, and preferably seal, to the outlet port of a transmission or engine filter, thereby forming an outside-in flow scheme. The media bag outlet can be fitted with an outlet tube, which on one end is sealed to the media bag outlet and on the other end is configured for attachment, directly or indirectly, to the transmission pump or engine oil pump. An example of indirect attachment includes an embodiment in which the outlet tube is sealed to the transmission filter outlet, and the transmission filter outlet is configured to attach, or preferably seal, to the transmission pump. In some embodiments of the filter bag assembly, the media bag at least partially encloses a support frame.  
           [0007]    In accordance with another embodiment of the present invention, a transmission or engine filter is provided which includes: a transmission or engine filter housing having an outlet port, and a filter bag assembly having a media bag with an outlet portion. The filter bag assembly is positioned, at least partially, within the transmission or engine filter to align and attach together the outlet port with the outlet portion thereby creating an outside-in flow scheme. By “at least partially,” it is understood that in typical embodiments the media bag is located within the housing but portions of the filter bag assembly, for example an optional outlet tube, may extend outside the filter housing. Thus, in some embodiments the transmission or engine filter housing includes a fixing ring extending from the outlet port and the media bag outlet tube extends through the fixing ring and is sealed against the fixing ring.  
           [0008]    In accordance with still another embodiment of the present invention, a transmission or engine filter is provided which includes means for filtering fluid and means for housing the fluid filtering means; the fluid filtering means and the housing means are configured together to form an outside-in flow scheme.  
           [0009]    In accordance with yet another embodiment of the present invention, a method of making a suction-side transmission or engine filter is provided, wherein an oil pan, a filter bag assembly having an outlet portion, and an upper cover having an outlet is provided. The filter bag assembly is positioned on the oil pan, and the upper cover is positioned over the filter bag assembly so that the outlet portion and outlet port align. According to some embodiments, the upper cover and oil pan are welded together to from a housing, at least partially enclosing the filter bag assembly within the housing.  
           [0010]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.  
           [0011]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.  
           [0012]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a cross-section view illustrating a filter bag assembly according to a preferred embodiment of the invention.  
         [0014]    [0014]FIG. 2 is a top view of the filter bag assembly of FIG. 1.  
         [0015]    [0015]FIG. 3 is a cross-sectional view of a filter bag assembly according to another embodiment of the present invention.  
         [0016]    [0016]FIG. 4 is a cross-sectional view of an outside-in flow transmission filter in accordance with an embodiment of the present invention.  
         [0017]    [0017]FIG. 5 is a cross-sectional detail view of the outlet port of the outside-in flow transmission filter shown in FIG. 4.  
         [0018]    [0018]FIG. 6 is a cross-sectional detail view of another embodiment of an outlet port of an outside-in flow transmission filter in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0019]    The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a suction-side transmission or engine filter comprising a filter bag having an inner support frame and filter bag outlet coincident with the outlet port of the transmission or engine filter.  
         [0020]    The suction-side transmission or engine filters according to the present invention provide an outside-in flow scheme, i.e. dirty fluid enters the transmission or engine filter through the transmission or engine filter intake port and exists outside the filter bag. The dirty fluid is “purified” by passing through the filter media into the inside of the filter bag. The purified liquid then flows from the inside of the filter bag directly through the filter bag outlet, which is coincident with the transmission or engine filter outlet port, to the transmission pump in the case of a transmission filter and to the engine oil pump in the case of an engine filter.  
         [0021]    By contrast, according to inside-out flow schemes, dirty fluid entering the transmission or engine filter flows through the transmission or engine filter intake port, which is coincident with the filter bag inlet, directly into the inside of the filter bag. The dirty fluid is “purified” by passing through the filter media to the outside of the filter bag. By “purified” it should be understood that the fluid is not necessarily completely rid of impurities, but rather the degree of purification depends, for example, in part on the choice of filtering media. Thus, the term “purified” is intended to mean simply that fluid, which has passed through the filter media is cleaner than fluid entering the transmission or engine filter prior to having passed through the filter media.  
         [0022]    Embodiments according to an outside-in configuration may provide one or more advantages as compared to prior art inside-out configurations. For example, in some outside-in embodiments, the fluid is divided into only two regions (outside the bag and inside the bag), which regions do not intermix. That is, fluid can completely surround the filter bag and then proceed toward the transmission or engine filter outlet after passing through the filter media. By contrast, there can be lost flow areas in filter pans manufactured according to inside-out configurations. That is, there can be substantial portions of the media in inside-out configurations that are not fully utilized.  
         [0023]    As another example, according to some embodiments, the filter bag for transmission or engine filters manufactured according to outside-in configurations, can be manufactured separately from the rest of the transmission or engine filter. Consequently, efficiencies and cost-savings can be gained because a particular outside-in filter bag design may be common to several different outside-in transmission or engine filter designs.  
         [0024]    As yet another example of an advantage that may be associated with some embodiments according to the present invention, improved quality may be associated with the manufacture of outside-in, suction-side transmission or engine filters. For example, in some embodiments, construction of a transmission or engine filter having a filter bag with an outside-in flow scheme separates the sealing of the filter bag from the sealing of the transmission or engine filter into distinct manufacturing steps. Currently, for both composite and all-plastic filters, the sealing of the filter bag and the sealing of the filter occurs simultaneously. Separating the sealing steps provides opportunity to implement additional care and process checks for improving quality.  
         [0025]    As yet another example of a potential advantage that may be associated with some embodiments according to the present invention, for some filter designs, an outside-in flow scheme may be more easily implemented. Specifically, in some outside-in designs, the filter bag assembly is connected to the filter body at the filter outlet. For some filter designs, e.g. filters with inlets at an angle or with inlets particularly close to the side-wall of the filter, it is difficult to employ an inside-out filter bag design.  
         [0026]    For ease in description, the embodiments described hereinafter are referred to as transmission filters or suction-side transmission filters. The description which follows, however is equally applicable to engine filters, particularly suction-side engine filters. A person of ordinary skill in the art, from the teachings herein, should understand that the embodiments described can be adapted for use as engine filters, and particularly suction-side engine filters. An embodiment of a filter bag assembly  10  in accordance with the present invention is illustrated in cross-section in FIG. 1. The filter bag assembly  10  includes: a media bag  12 , an inner support frame  14 , and a media bag outlet  16 .  
         [0027]    The media bag  12  is formed from a single, continuous piece of filtering material  26 . The filtering material  26  is configured into a bag having an outlet portion  18  by folding the filter material  26  and then sealing the resultant opposing sides  20 ,  22  into a media joint  24 . The outlet portion  18  is not sealed, to maintain a pathway for the fluid to flow directly from the interior of the filter bag assembly  10  to the transmission pump (not shown). Suitable methods of sealing are known to persons of ordinary skill in the art, and any of those suitable methods may be used. For example, the open sides may be sealed by either a welding or bonding process.  
         [0028]    The inner support frame  14  is positioned within the media bag  12  to provide support to the filtering material  26 ; thus helping prevent collapse of the media bag  12  due to, for example, fluid pressure and/or suction. Preferably, the inner support frame  14  is constructed so that fluid flowing from any direction into the media bag  12  can still flow out of the media bag  12  through the outlet portion  18 . In the embodiment illustrated, the inner support frame includes molded ribs, also known as flow ribs  32 .  
         [0029]    The filter bag outlet  16  includes an outlet tube  28 , and preferably an outlet seal  30 . The filter bag outlet  16  is attached to the media bag  12  at the outlet portion  18 .  
         [0030]    [0030]FIG. 2 shows the embodiment of FIG. 1, and specifically the media joint  24 , the inner support frame  14 , outlet tube  28  of the filter bag outlet  16 , and outlet portion  18  of the media bag  12  from a top view perspective.  
         [0031]    [0031]FIG. 3 depicts an alternative embodiment of a filter bag assembly  40  according to the present invention. This alternative embodiment is similar to that depicted in FIG. 1, except that multiple pieces of filtering material  42 ,  44  are used, and the media bag  62  is formed by sealing the filtering material  42 ,  44  against a spacer segment  46  to form media joints  48 ,  50 , rather than against itself. The spacer segment  46  can be integral with the inner support frame  52 , and in such embodiments, the filtering material  42 ,  44  is consequently sealed to at least portions of the inner support frame  52 .  
         [0032]    Although the embodiment of FIG. 3 depicts a media bag  62  formed from two pieces of filtering material  42 ,  44 , additional pieces of filtering material could also be used. In such embodiments, the additional pieces of filtering material could be sealed directly against other pieces of filtering material, as in the embodiment depicted in FIG. 1. Likewise, in the embodiment of FIG. 1, additional pieces of filtering material could be used, but these additional pieces should be sealed against each other to maintain separation of the dirty and purified fluid.  
         [0033]    As in the embodiment of FIG. 1, the embodiment depicted in FIG. 3 includes a media bag outlet portion  54 , transmission filter outlet  56 , and inner support frame  52 . The transmission filter outlet  56  includes an outlet tube  58 , and optionally a seal  60 , and is attached to the filtering material  42  at the media bag outlet portion  54 .  
         [0034]    [0034]FIG. 4 illustrates a filter bag assembly  10  incorporated into a pan filter  70 , forming a transmission filter  72 . Consequently, the filter bag assembly  10  includes media bag  12  sealed at the media joint  24 , attached at the outlet portion  18  to a filter bag outlet  16  comprising an outlet tube  28  and optional seal  30 , and enclosing an inner support frame  14 .  
         [0035]    The pan filter  70  includes an oil pan  74 , transmission filter upper cover  76 , filter suction inlet  78 , a filter suction outlet  80 , and spacers, or fixation and distance pins,  82 . The upper cover  76  is attached to the oil pan  74 , for example by welding forming a weld joint  84 . The upper cover includes a fixing ring  86 , defining the filter suction outlet  80 , and through which the filter bag outlet tube  28  passes. In this embodiment, fluid enters the transmission filter  70  through the filter suction inlet  78 , can flow around the filter bag assembly  10 , enters into the inside of the filter bag assembly  10  through the filtering material  26 , and exits the transmission pan filter  70  through the outlet tube  28 .  
         [0036]    In the embodiment depicted in FIG. 4, the outlet tube  28  is directly connected to the transmission pump (not shown). FIG. 5 is a blown-up view of the connection region. As shown in FIG. 5, the upper cover  76  includes a fixing ring  86  that extends above the surface of the upper cover  76  but below the top of the outlet tube  28 . Also as shown, the fixing ring includes a seal  88  which presses against the outlet tube  28 . Alternatively, the seal  88  could be positioned in the outlet tube  28  to press against the fixing ring  86 . The connection also includes an upper cover rib  90  positioned between the upper cover  76  and the filter media  12  at the outlet portion  18 .  
         [0037]    [0037]FIG. 6 illustrates an alternative configuration for connecting transmission filters in accordance with the present invention to a transmission pump. In contrast to the embodiment illustrated in FIG. 5, in this case the fixing ring  94 , rather than ending before the top of the outlet tube  96 , extends beyond the top of the outlet tube  96 . Consequently, the upper cover  92  is connected to the transmission pump. The upper cover  92  can optionally include a seal (not shown) for a more secure fit. As with the embodiment shown in FIG. 5, the embodiment of FIG. 6 includes an upper cover rib  98  positioned between the upper cover  92  and the outlet tube  96 .  
         [0038]    The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.