Abstract:
A filter assembly for a fluid to be filtered, in particular fuel or oil, has a filter housing having a housing lower part that is configured as a single piece and has at least one fluid inlet for the fluid to be filtered and a plurality of filter pots that are arranged next to one another side by side in a shared plane and are fluidically connected to one another via side wall passages An upper housing part closes the filter pots and has a fluid manifold that has at least one fluid outlet for the filtered fluid flowing out from the filter pots. At least two filter elements, one being arranged in each of the filter pots of the filter housing. The filter assembly is a more inexpensively-manufactured and as configured for installation even in confined installation spaces, so as to accommodate a sufficiently large filter surface for a predetermined volume flow of a fluid to be filtered.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a filter assembly for a fluid to be filtered, in particular, fuel or oil, comprising a filter housing and comprising at least two filter elements. 
       BACKGROUND 
       [0002]    Filter elements are used in motor vehicles, for instance, to remove impurities from operating fluids like fuel and oil. Typically, exactly one filter element is provided for a fluid to be filtered. The size of the filter element limits a maximum possible volume flow of the fluid to be filtered. However, the installation space available is not always large enough or shaped as needed. 
         [0003]    EP 0 991 457 B1 discloses a filter system in which a plurality of separate, hollow, cylindrical filter housings each comprising a filter element are bolted onto a shared filter head. The filter head is configured so that a fluid is able to flow in parallel through the filter housings comprising the filter elements. The filter head comprises connections for introducing the fluid to be filtered and for discharging the filtered fluid. The specific filter head is intended to reduce the number of connecting lines required in order to connect the plurality of filter housings to a pre-filtration line for a fluid to be filtered. However, the elaborate filter head significantly increases the overall height in the vertical direction. 
         [0004]    US 2011/0 089 101 A1 discloses a fuel filter in which two hollow, cylindrical filter cartridges allowing parallel through-flow are arranged in a shared housing interior of a filter housing, wherein each filter cartridge is surrounded with a hydrophobic mesh in order to separate out water contained in the fuel. The filter cartridges are mounted onto maintenance covers screwed into the filter housing from the underside, so that the filter cartridges can be easily replaced. Because the filter cartridges are arranged in the shared housing interior, only a slight—if any—reduction in the overall size of the fuel filter as a whole is produced, in comparison to the use of a larger filter cartridge. Moreover, there is no increase in flexibility for the design of an outer contour of the filter housing. 
       SUMMARY 
       [0005]    This disclosure addresses the problem of providing a more inexpensively-manufactured filter assembly that makes it possible, even in confined installation spaces, to accommodate a sufficiently large filter surface for a predetermined volume flow of a fluid to be filtered. 
         [0006]    According to the present invention, a filter assembly for a fluid to be filtered, in particular fuel or oil, is provided with a filter housing. The filter housing has a housing lower part, configured as a single piece. This makes the housing lower part simple and inexpensive to fabricate. At least one fluid inlet for the fluid to be filtered is provided in the housing lower part. The housing lower part is configured so as to comprise a plurality of filter pots. The filter pots are arranged side by side, adjacent to one another in a shared plane. The housing lower part can thus be flexibly adapted to an installation space of a complex or jagged shape, in particular, to a very flat installation space. The filter pots are fluidically connected to one another via side wall passages. This makes it possible to endow the filter pots with a parallel through-flow. The side wall passages may be configured as radial channels, preferably as slits in the side walls, which are open from a separation plane of the housing parts, in order to achieve an unencumbered demolding therethrough. 
         [0007]    The plurality of filter pots also make it possible to filter a predetermined volume flow of the fluid. The filter housing further comprises a housing upper part for closing the filter pots. The housing upper part is typically placed in a sealing, i.e., fluid-tight manner on the filter housing. For this purpose, the filter housing and housing upper part may be adhered to one another. A fluid manifold that comprises at least one fluid outlet for the filtered fluid flowing out of the filter pots is configured on the housing upper part. The filter assembly additionally comprises at least two filter elements, one being arranged in each of the filter pots of the filter housing. Each of the filter pots is thereby divided into an antechamber for the fluid to be filtered and a post-filtration chamber for filtered fluid. The fluid manifold is typically opened to the post-filtration chambers of each of the filter pots. That is to say, filtered fluid can flow from the respective post-filtration chambers into the fluid manifold. 
         [0008]    It may be provided that the filter assembly has, in each case, more than one fluid inlet and/or fluid outlet, such as a pre-filtration liquid inlet and an inlet for fuel returned from an internal combustion engine, and/or two post-filtration liquid outlets that can be connected to separated fuel supply systems. 
         [0009]    The housing upper part may be configured as a single piece or as a plurality of pieces. It is configured so as to comprise one cover element for each filter pot. With a multi-piece housing upper part, at least two of the cover elements may be structurally identical. 
         [0010]    An advantageous embodiment provides that the cover elements each comprise a lengthwise segment of the fluid manifold. This makes it possible to achieve a compact structural design. 
         [0011]    In an especially preferred embodiment, it is provided that the cover element and the respectively-associated lengthwise segment are integrated as a single piece with one another. The fluid manifold is then configured at least in some sections as a component of the housing upper part. This makes it possible to simplify the fabrication and mounting of the filter assembly. 
         [0012]    In an advantageous embodiment, the fluid manifold is longitudinally divided. Preferably, a lower-side partial section of the fluid manifold is formed of a lengthwise segment that is integrated with a cover element. This further simplifies fabrication and enables an especially flat structural design of the filter assembly. 
         [0013]    In a preferred embodiment, the filter assembly is characterized in that the filter elements are supported on the housing upper part. Advantageously, the filter elements are clamped, embedded, or integrally fastened, preferably welded, onto the housing upper part. Alternatively or additionally, the filter element may be plugged—preferably, plugged in a sealing manner—onto a socket section of the housing upper part. The socket section may be sealed off by an O-ring or a sealing seat, which is preferably present at or abuts against an end plate of the filter element. 
         [0014]    This simplifies the mounting of the filter assembly. The filter elements may be pre-mounted onto the housing upper part, for this purpose. At the same time, it can be ensured that the filter elements are attached in a fluid-tight manner to the housing upper part, so that no leakage flow will occur between the respective antechambers and post-filtration chambers. 
         [0015]    In an advantageous embodiment, the filter elements are round elements, in particular, with a filter medium folded into the shape of a star. This enables an especially compact design for the individual filter pots. In an alternative, also advantageous embodiment, the filter elements are flat elements, in particular with a filter medium folded into a zigzag shape. This enables an exceptionally flat design for the filter assembly. 
         [0016]    Preferably, at least two of the filter pots are connected fluidically in parallel to one another on the pre-filtration side. The fluid can then flow in parallel through the filter elements in the at least two filter pots. That is to say, the antechambers in the filter pots are fluidically connected to one another. This makes it possible to obtain a larger effective overall filter element when individual small filter elements are being used. 
         [0017]    In an advantageous development, it is provided that a heating element for the fluid and/or a water separator for separating out water contained in the fluid is/are arranged in one of the filter pots, preferably in a filter pot that allows a serial through-flow, which is especially preferably arranged on the inflow side as a first filter pot of the filter assembly or is a central pot that allows a serial through-flow. The filter pot allowing a serial through-flow is thus connected upstream or downstream of the other filter pots. This makes it possible to integrate additional functions such as heating of the fluid and/or separation of water from the fluid. The consequently requisite equipment need then be provided only once for the entire filter assembly, and not for each individual filter pot or each individual filter element, ie., as a plurality. 
         [0018]    In an advantageous embodiment, it is provided that the housing lower part is configured as an injection-molded part. Preferably, the housing lower part is composed of polyamide. Particularly preferably, PA66 is used. The housing upper part is typically also configured as an injection-molded part, preferably made of polyamide. Advantageously, one or both housing parts may be at least partially composed of an electrically conductive plastic, which is advantageous in order to be able to discharge static electricity created by the through-flow of fuel. Here, the filter assembly in an especially advantageous embodiment may have at least one connection for establishing electrical contact for discharging static electricity, which is preferably arranged at the fluid inlet and/or fluid outlet. 
         [0019]    In an advantageous embodiment, the filter pots differ from one another in the respective overall heights and/or diameters thereof. The filter pots are consequently configured so as to have different depths. This enables an especially favorable fit of the filter assembly into jagged installation spaces. 
         [0020]    In another embodiment, it may be provided that the housing upper part and the housing lower part are connected to one another in a fluid-tight manner, in particular, welded together on a separation plane. The separation plane may then run normal to a longitudinal axis of the filter pots, or run at an angle to the longitudinal axis of the filter pots. Alternatively, the separation plane may be stepped, in particular, have a plurality of steps, wherein preferably at least one separation plane section that runs normal to a longitudinal axis of the filter pots is present and at least one separation plane section that runs at an angle to the longitudinal axis of the filter pots is present. This enables even better adaptation to an installation space, not only in the plane, but also at an inclination of a limitation of the installation space. 
         [0021]    A welding seam provided between the housing lower part and the housing upper part typically runs circumferentially around. The welding seam may advantageously run in a seam plane. Alternatively, the welding seam may extend along a three-dimensional curve. Welding enables a simple, inexpensive, space-conserving, and reliably fluid-tight connection of the housing lower part to the housing upper part. 
         [0022]    Finally, it may be provided, alternatively or additionally, that a bracing is provided between at least two adjacent filter pots, the bracing preferably constituting or comprising at least one fastening device, in particular, a fastening eyelet or fastening tab, which can be used to fasten the filter assembly, for example, onto a motor vehicle, in particular, in the undercarriage region. 
         [0023]    The filter pots may each have a round, elliptical, polygonal, in particular, rectangular or hexagonal cross-sectional shape. Preferably, all of the filter pots of the filter assembly have the same cross-sectional shape. Alternatively, however, different cross-sectional shapes may be combined within one filter assembly. Selecting a suitable cross-sectional shape for the filter pots makes it possible to further adapt the filter assembly to the installation space available. 
         [0024]    Additional advantages of the invention result from the description and the drawings. The features described in the foregoing and elaborated even further may be used individually by themselves or with other features in any combination. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    In the drawings: 
           [0026]      FIG. 1 a    illustrates a schematic top view of a first embodiment of a filter assembly according to the present invention, comprising four substantially cylindrical filter pots arranged in a row; 
           [0027]      FIG. 1 b    illustrates a schematic side view of the filter assembly from  FIG. 1   a;    
           [0028]      FIG. 1 c    illustrates a schematic longitudinal section along the plane A-A through the filter assembly from  FIG. 1   a;    
           [0029]      FIG. 2 a    illustrates a schematic top view of a second embodiment of a filter assembly according to the present invention, comprising six essentially cylindrical filter pots of different depths in a complex arrangement; 
           [0030]      FIG. 2 b    illustrates a schematic sectional view along the plane A-A through the filter assembly from  FIG. 2   a;    
           [0031]      FIG. 3 a    illustrates a schematic top view of a third embodiment of a filter assembly according to the present invention, comprising six essentially rectangular filter pots arranged next to one another; 
           [0032]      FIG. 3 b    illustrates a schematic side view of the filter assembly from  FIG. 3   a;    
           [0033]      FIG. 3 c    illustrates a schematic longitudinal section along the plane A-A through the filter assembly from  FIG. 3   a;    
           [0034]      FIG. 3 d    illustrates a schematic cross-section along the offset half-planes B-B through the filter assembly from  FIG. 3   a;    
           [0035]      FIG. 4 a    illustrates a greatly-abstracted top view of a fourth embodiment of a filter assembly according to the present invention, comprising five rectangular filter pots arranged in two offset rows; 
           [0036]      FIG. 4 b    illustrates an abstracted top view of a fifth embodiment of a filter assembly according to the present invention, comprising four cross-sectionally hexagonal filter pots that are arranged offset relative to one another; 
           [0037]      FIG. 4 c    illustrates an abstracted top view of a sixth embodiment of a filter assembly according to the present invention, comprising five cylindrical filter pots, one of which is configured as a central pot allowing a through-flow serial to the others and comprising a water separator and a heating element; 
           [0038]      FIG. 5  illustrates a perspective view of another embodiment of the filter assembly according to the present invention, comprising fastening eyelets between the filter pots; 
           [0039]      FIG. 6  illustrates a perspective view of yet another embodiment of the filter assembly according to the present invention, comprising connections to the electrical contact; 
           [0040]      FIG. 7  illustrates a perspective view of an alternative embodiment of the filter assembly according to the present invention, comprising two fluid inlets and outlets; 
           [0041]      FIGS. 8 a  and 8 b    illustrate perspective views of an alternative embodiment of the filter assembly according to the present invention, comprising an inclined separation plane of the housing part; and 
           [0042]      FIGS. 9 a  and 9 b    illustrate longitudinal sectional views each of a filter pot having an accommodated filter element, which is plugged onto a socket section of the housing upper part. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]    FIG.  a  illustrates a schematic top view of a first embodiment of a filter assembly  10  according to the present invention.  FIG. 1 b    depicts the filter assembly  10  from  FIG. 1 a    in a schematic side view. A filter housing  12  of the filter assembly  10  comprises, for example, four essentially cylindrical filter pots  14 . The filter pots  14  are here arranged next to one another along a straight line. The filter pots  14  are here arranged lying side by side in such a manner that side walls of adjacent filter pots  14  merge into one another. The filter pots  14  in the filter assembly  10  then lie in one shared plane. 
         [0044]    The filter housing  12  comprises a housing lower part  16  and a housing upper part  18 . The housing lower part  16  and the housing upper part  18  are in each case configured as a single piece, each as an injection-molded part. The two housing parts may be composed, for example, of polyamide. The housing upper part  18  is welded onto the housing lower part  16  in a fluid-tight manner. The housing upper part  18  constitutes four cover elements  20  for the four filter pots  14 . Each of the cover elements  20  completely covers the respectively-associated filter pot  14 . 
         [0045]    The filter assembly  10  has a fluid inlet  22 . The fluid inlet  22  is arranged on the housing lower part  16 . Fluid to be filtered can flow through the fluid inlet  22  into the filter pots  14 . The filter assembly  10  further comprises a fluid manifold  24 . The fluid manifold  24  is configured on the housing upper part  18 . The fluid manifold  24  opens into a fluid outlet  26 . Filtered fluid can flow out from the filter housing  12  through the fluid outlet  26 . The fluid manifold  24  is formed of lengthwise segments  28  that are each configured on one of the cover elements  20 . In the embodiment of  FIGS. 1 a    and  1   b,  the lengthwise segments  28  merge seamlessly into one another. The fluid manifold  24  is configured as a single piece integrated with the housing upper part  18 . In particular, the lengthwise segments  28  and the respective cover elements  20  are thus also configured as a single piece, integrated with one another. 
         [0046]      FIG. 1 c    illustrates a schematic longitudinal section along the plane A-A (see  FIG. 1 a   ) through the filter assembly  10  according to  FIGS. 1 a    and  1   b.  There is one filter element  30  arranged in each of the filter pots  14 . The filter elements  30  may be configured as round elements having a filter medium (depicted only schematically) that has been folded in the shape of a star. The filter elements  30  may then each further comprise a standpipe  32 . On the lower side, the filter elements  30  are closed in a fluid-tight manner each by a bottom cover  34  that is connected to the corresponding standpipe  32 . On the upper side, the filter elements  30  are supported on the housing upper part  18 . Each one of the filter pots  14  is thus divided by the corresponding filter element  30  into a pre-filtration-side antechamber  36  for the fluid to be filtered, and a post-filtration chamber  38  for the filtered fluid. 
         [0047]    The filter pots  14  are fluidically connected to one another via side wall passages  40 . That is to say, the antechambers  36  in the filter pots  14  can communicate with one another through the side wall passages  40 . The filter pots  14  are thus connected in parallel on the pre-filtration side. The fluid manifold  24  opens toward each of the filter pots  14 . That is to say, each post-filtration chamber  38  has a fluidic connection to the manifold  24 . Consequently, the fluid to be filtered can flow through the filter elements  30  in parallel. 
         [0048]    The fluid manifold  24  broadens, in the through-flow cross-section thereof, toward the fluid outlet  26 . This makes it possible to prevent the flow rate of the filtered fluid in the fluid manifold  24  from increasing toward the fluid outlet  26  during operation of the filter assembly  10 . Through the widening of the through-flow cross-section of the fluid manifold  24  illustrated in  FIG. 2   a,  it is also possible to achieve a uniform through-flow through all of the filter pots  14 . 
         [0049]      FIG. 2 a    illustrates a schematic top view of a second embodiment of a filter assembly  10  according to the present invention. The filter assembly  10  here comprises six essentially cylindrical filter pots  14   a  to  14   f.  The filter pots  14   a  to  14   f  are arranged side by side next to one another in a shared plane. The five filter pots  14   b  to  14   f  are here arranged along a bent or angled line. The filter pot  14   a  is positioned next to this line, so as to be adjacent to two of the linearly-arranged filter pots  14   b,    14   c.  A fluid inlet  22  is here arranged on a filter housing  12  of the filter assembly  10  in such a manner that fluid to be filtered is able to flow tangentially into the filter pot  14   b.    
         [0050]      FIG. 2 b    depicts a schematic sectional view along the plane designated as A-A in  FIG. 2   a,  through the filter assembly  10 . The filter housing  12  of the filter assembly  10  comprises a housing lower part  16  and a housing upper part  18 . The filter pots  14   a  to  14   f,  which here have different depths, are configured in the housing lower part  16 . That is to say, provided are filter pots  14   a  to  14   f  that have different overall heights H 1 , H 2 , H 3 . There is one filter element  30  arranged in each of the filter pots  14   a  to  14   f.  The filter elements  30  are configured here as round elements that extend almost above the entire overall height H 1 , H 2 , H 3  of the respective filter pots  14   a  to  14   f.  The filter elements  30  may occupy, in particular, in each case more than 80% of the respective overall heights H 1 , H 2 , H 3 . Each of the filter pots  14   a  to  14   f  is fluidically connected to at least one of the adjacent filter pots  14   a  to  14   f  via at least one side wall passage  40 . This makes it possible to distribute fluid to be filtered, which is flowing into the filter housing  12  from the inlet  22 , to all of the filter pots  14   a  to  14   f.    
         [0051]    A fluid manifold  24  is configured on the housing upper part  18 . The fluid manifold  24  is configured here so as to be longitudinally divided. The fluid manifold  24  consequently comprises here a bottom section  24   a  and a cover section  24   b.  The bottom section  24   a  and the cover section  24   b  are adjacent to one another in a longitudinal seam  42 . The longitudinal seam  42  is here configured as a welding seam. It is thus possible to achieve a fluid-tight connection between the bottom section  24   a  and the cover section  24   b.  The bottom section  24   a  is configured as a single piece, integrated with the housing upper part  18 . Connecting pieces  44  may extend one into each of the filter pots  14  from the bottom section  42 . Through the connecting pieces  44 , filtered fluid can flow into the fluid manifold  24 . A fluid outlet  26  of the fluid manifold  24  is here configured as a single piece integrated with the bottom section  24   a  or the housing upper part  18 . 
         [0052]      FIG. 3 a    illustrates a schematic top view of a third embodiment of a filter assembly  10  according to the present invention.  FIG. 3 b    schematically depicts a side view of the filter assembly  10  of  FIG. 3 a   . The filter assembly  10  comprises six filter pots  14  having a polygonal—here, essentially rectangular—cross-sectional shape. The filter pots  14  are here arranged next to one another in a regular rectangle pattern. Each of the filter pots  14  is thus adjacent on the narrow side and on the long side, on at least one side, to another one of the filter pots  14 . 
         [0053]    The filter pots  14  are configured in a housing lower part  16  of a filter housing  12 . The housing lower part  16  is closed on the upper side by a housing upper part  18  of the filter housing  12 . For this, here, the housing lower part  16  is horizontally circumferentially welded to the housing upper part  18 . A fluid inlet  22  is arranged on the housing lower part  16 . The housing upper part  28  has a fluid outlet  26 . 
         [0054]      FIG. 3 c    illustrates a schematic longitudinal view along the plane A-A (see  FIG. 3 a   ) through the filter assembly  10  according to  FIGS. 3 a    and  3   b.    FIG. 3 d    depicts the filter assembly  10  from  FIGS. 3 a  to 3 c    schematically, in the cross-section along the offset half-planes B-B (see  FIG. 3 a   ). There is one filter element  30  arranged in each of the filter pots  14 . The filter elements  30  are here configured as flat elements having a filter medium (not individually depicted) that has been folded in a zigzag shape. 
         [0055]    Adjacent filter pots  14  are fluidically connected to one another via side wall passages  40  that allow a through-flow. The side wall passages  40  are here configured as channels in partition regions  46  of the housing lower part  16  between the filter pots  40 . 
         [0056]    A fluid manifold  24  is configured in the housing upper part  18 . The fluid manifold  24  opens into the fluid outlet  26 . Here, there is one cover element  20  of the housing upper part  18  associated with each one of the filter pots  14 . In each of the cover elements  20 , a lengthwise segment  28  of the fluid manifold  24  is configured as a single piece integrated with the corresponding cover element  20 . Adjacent cover elements  20  and lengthwise segments  28  are each delimited from one another by upper-side indentations  48  of the housing upper part  18 . 
         [0057]      FIG. 4 a    illustrates a greatly-abstracted top view of a fourth embodiment of a filter assembly  10  according to the present invention. The filter assembly  10  comprises here five rectangular filter pots  14  that are arranged in two offset, parallel rows. 
         [0058]      FIG. 4 b    depicts an abstracted top view of a fifth embodiment of a filter assembly  10  according to the present invention. The filter assembly  10  has here four cross-sectionally hexagonal (honeycomb-shaped) filter pots  14 . The filter pots  14  are arranged in a zigzag-shaped line. Adjacent filter pots  14  therefore adjoin one another in a flat manner. A filter element  30  configured as a round element is arranged in each of the cross-sectionally hexagonal filter pots  14 . 
         [0059]      FIG. 4 c    illustrates an abstracted top view of a sixth embodiment of a filter assembly  10  according to the present invention. The filter assembly  10  comprises here five cylindrical filter pots  14   g  to  14   k.  A filter element  30  configured here as a round element is arranged in each of the filter pots  14   h  to  14   k.  The filter pot  14   g  is configured here as a central pot  50 . The central pot  50  allows for serial through-flow to the filter pots  14   h  to  14   k.  Fluid to be filtered flows here first through the central pot  50  and then through one of the filter pots  14   h  to  14   k.  The filter pots  14   h  and  14   j  are then fed directly out from the filter pot  14   g,  configured as the central pot  50 . The filter pots  14   i,    14   k  are fluidically connected via side wall passages (not depicted) to the filter pots  14   h,    14   j.  As an example, a water separator  52  may be arranged in the central pot  50 . The water separator  50  is used to separate water entrained in the fluid from the fluid and hold same back in the central pot  50 . Furthermore, a heating element  54  is arranged in the central pot  50 . With the heating element  54 , the fluid can be pre-heated prior to filtration, for example, in order to improve flow properties of the fluid. 
         [0060]      FIG. 5  illustrates another embodiment of the filter assembly  10  according to the present invention, characterized in that a bracing  168  is provided between two adjacent filter pots  14 , the bracing constituting a fastening eyelet  168 ′ or fastening hole via which the filter assembly  10  can be mounted, for example, onto a motor vehicle, in particular, in the undercarriage region. 
         [0061]    According to yet another embodiment depicted in  FIG. 6 , a connection  262  for establishing electrical contact is provided at the fluid inlet  26  and fluid outlet  22  each. This is advantageous for being able to discharge static electricity, for example, to a motor vehicle body; for this purpose, the connections  262  configured as contact tongues are connected in an electrically conductive manner. An embodiment with electrical contacts is especially advantageous if the housing is composed of an electrically conductive plastic—for example, a PA66 with GF22 and/or CF8 or the like—at least in the regions in which the connections are present. 
         [0062]      FIG. 7  illustrates an alternative embodiment of the filter assembly  10  according to the present invention, which comprises two fluid inlets  26  and two fluid outlets  22 . The fluid outlets  22  are present at free ends of the manifold  24 , whereas one of the fluid inlets  26  opens tangentially into a filter pot  14  that is on the left in the drawing and a second fluid inlet  26  opens radially from the left into a filter pot  14  that is second in the drawing. The fluid inlets  26  are thus fluidically connected to a radially-outer side of a filter element accommodated in the filter pot  14 , while there is a flow from radially outward to radially inward through the filter element. The fluid outlets  22  may be connected, for example, to separated fuel supply systems, such as to an injection unit of an internal combustion engine and a regeneration system for a diesel particle filter, or an auxiliary heating system or the like. Of the fluid inlets  26 , one may be a pre-filtration inlet from the tank, and the other may be, for example, a recirculation connection for fuel that is returned from the injection system. 
         [0063]      FIGS. 8 a  and 8 b    illustrate an alternative embodiment in which a separation plane (dotted line) at which the housing upper part  18  and housing lower part  16  are connected runs at an angle relative to a normal direction of the filter pots  14 . This enables an even better adaptation to an available installation space, for example, in the undercarriage region of a motor vehicle. In order to make the best possible use of the volume available in the filter pots  14  for filtration, the filter element used may be clipped obliquely to the longitudinal axis, so as to impart the shape of a cylinder section. 
         [0064]      FIGS. 9 a  and 9 b    illustrate each a detailed longitudinal sectional view of a filter pot  14 , in which a filter element  30  is accommodated in each case. The housing upper part  18  has in each case a socket section  44  onto which the filter element  30  is plugged in a sealing manner. In the variant illustrated in  FIG. 9   a,  the sealing-off is provided by an O-ring  400  that is accommodated in a retracted shoulder of the end plate  301 . Alternatively, the sealing-off may also be provided without an O-ring, namely, through a sealing seat  302  that is present radially inwards on the end plate  301 , i.e., on the inner circumference, the end plate  301  has a sealing property, e.g., inherently due to the end plate material and/or due to an injection-molded sealing ring, e.g., made of NBR.