Abstract:
An oil filter assembly ( 10 ) has a receiving chamber that can be closed by a cover element and a spring-loaded supporting tube ( 22 ) that is fixed in the receiving chamber ( 18 ) and is designed to receive a filter element ( 20 ) that can be radially traversed by oil, the supporting tube being axially displaceable between an operating position and a drain position in such a way that, in the operating position when the receiving chamber is closed by the cover element ( 14 ), the tube closes a drain opening ( 42 ) and when the receiving chamber is open in the drain position, the tube releases a drain opening ( 42 ). The cover element ( 14 ) has a supporting tube contact area ( 58 ) on the side facing the receiving chamber in such a way that during the closing of the receiving chamber ( 14 ) when the filter element is located on the supporting tube ( 22 ), pressure is exerted on the tube by the support tube contact area ( 58 ), thus displacing the tube into the operating position.

Description:
This application is the national stage of PCT/EP2007/004475 filed on May 19, 2007 and claims Paris Convention Priority to DE 10 2006 034 485.0 filed Jul. 21, 2006 and to DE 20 2007 002 162.3 filed Feb. 9, 2007. 
     BACKGROUND OF THE INVENTION 
     The invention concerns an oil filter assembly having a receiving chamber that can be closed by a cover element, and a supporting tube that is fixed in the receiving chamber and is spring-loaded for receiving a filter element through which oil can flow in a radial direction, wherein the supporting tube is displaceably disposed in the axial direction between an operating position and a drain position such that, in the operating position, in which the cover element closes the receiving chamber, it closes a drain opening, and in the drain position, when the receiving chamber is opened, it opens a drain opening. In an oil filter assembly of this type, the supporting tube is fixed to the receiving chamber in such a fashion that it remains in the housing when the filter element is exchanged. The receiving chamber can thereby be closed by the cover element e.g. by screwing on the cover element, or by swinging or latching it onto the receiving chamber. A spring element may, in particular, be provided to spring-load the supporting tube towards the drain position. The spring element may thereby be supported directly on the supporting tube and also on a housing that forms the receiving chamber. 
     WO01/17657 A2 (=EP1137470 A2) discloses an oil filter assembly, in which a drain dome is disposed together with a filter insert between a first position in which a drain line is closed, and a second position in which the drain line is opened, such that they can be axially moved, wherein the drain dome is fixed to the filter housing and is urged into its open position by the force of a spring. The drain dome is thereby moved against the action of the spring into its closed position by means of the filter insert that is inserted into the filter housing. 
     EP 1 106 795 A1 (=DE 600 18 360 T2) discloses a fluid filter having a closing element that is suited to enter into a drain channel when a cover of the filter insert closes the receiving chamber, thereby closing the channel. However, the closing element opens the drain channel when the filter insert is removed from the receiving chamber. A stop is provided on the filter insert, which cooperates with the closing element to keep it in the operating position when the cover element is closed in order to retain the closing element in the operating position. In both, WO01/17657 A2 and EP 1 106 795 A1, the filter element must disadvantageously have a certain inherent rigidity in order to keep the drain dome or the closing element in the operating position against the spring load. 
     It is the underlying purpose of the present invention to further develop an oil filter assembly of the above-mentioned type and thereby eliminate the disadvantages of prior art devices. In particular, an oil filter assembly is to be provided, which can be reliably operated and facilitates exchange of the filter element. The construction of the filter element itself should thereby be as simple as possible. 
     SUMMARY OF THE INVENTION 
     This object is achieved by an oil filter assembly comprising the features of the independent claim. In the inventive oil filter assembly, the cover element has a supporting tube abutment area on its side facing the receiving chamber such that, when the filter element is disposed on the supporting tube, the supporting tube is directly loaded by the supporting tube abutment area and displaced into the operating position when the receiving chamber is being closed. In contrast to prior art, the supporting tube is consequently immediately directly brought into the operating position by the cover element via its supporting tube abutment area when the cover is being closed. The supporting tube is thereby directly displaced into the operating position via the cover element that acts against the supporting tube and not via the filter element. This is advantageous in that the filter element itself does not need to have a high intrinsic rigidity and may therefore have a relatively simple construction. In particular, the filter element does not require any components that transmit forces in the axial direction. Prior art devices have shown that, when filter elements are used on a long-term basis, their intrinsic rigidity in the axial direction can decrease, which could cause the supporting tube to be unintentionally displaced into the drain position. In accordance with the invention, it is therefore decisive that the filter element does not retain the supporting tube in its operating position. 
     The above-mentioned object is also achieved by an oil filter assembly comprising the following features. The cover element preferably has a supporting tube abutment area on its side facing the receiving chamber. When the filter element is disposed on the supporting tube and the receiving chamber is closed, the supporting tube abutment area directly keeps the supporting tube in the operating position. The supporting tube abutment area is consequently used to keep the supporting tube in its operating position during operation of the oil filter assembly. This is also advantageous in that, during operation of the oil filter assembly, the filter element must not transmit any axial forces in order to keep the supporting tube in the operating position. For this reason, the construction of the filter element is facilitated compared to conventional oil filter assemblies. 
     The supporting tube may naturally have functional components at its free end, wherein the functional components of the supporting tube then cooperate with the supporting tube abutment area. One suitable functional component is, in particular, an overpressure valve that opens when the filter element is clogged and the pressure consequently increases in the area of the unfiltered oil side. The oil can then pass the oil filter assembly without being filtered. 
     For an advantageous cooperation between the supporting element and the cover element during closing of the receiving chamber, or when the receiving chamber is closed, the supporting tube may project in the direction towards the cover when the filter element is disposed on the supporting tube. This forms an advantageous engagement surface for the supporting tube abutment area of the cover. 
     In accordance with a further embodiment of the invention, the cover element may have, in addition to the supporting tube abutment area, a filter element abutment area such that the filter element is displaced directly by the filter element abutment area into an operating position on the supporting tube while the receiving chamber is being closed. If the fitter element is not pushed far enough onto the supporting tube when the filter element is changed, the supporting tube is displaced into its operating position when the receiving chamber is being closed. When the cover is closed, the filter element is in its operating position, and in the operating position of the supporting tube, it is preferably disposed such that substantially no axial forces are transmitted via the filter element. 
     It is thereby feasible for the supporting tube abutment area and the filter element abutment area to be located in different planes in the axial direction and/or for the supporting tube abutment area to be disposed on the cover element in a radial further inward position than the filter element abutment area. This is advantageous in that the supporting tube abutment area is provided in the cover element at a clear separation from the filter element abutment area. 
     The supporting tube abutment area may thereby be formed, in particular, by end faces, facing the supporting tube, of webs or longitudinal ribs that extend in the axial direction in the inside of the cover. This is advantageous in that, when an overpressure valve is disposed at the free end of the supporting tube, oil can flow between the webs or longitudinal ribs to the inlet of the overpressure valve. 
     The filter element abutment area may also be formed by correspondingly designed webs or ribs that are disposed on the cover and project in a radially inward direction such that oil can flow between these ribs around the filter element and to the valve inlet of the overpressure valve. 
     Axially extending connecting pins may be provided, in particular, in the area of the bottom of the receiving chamber for movably fixing the supporting tube in the receiving chamber, and cooperate with pin recesses provided on the supporting tube, wherein the pin recesses are disposed on feet that project in a radially outward direction or on a collar of the supporting tube that projects in a radially outward direction and is circumferential at least in sections. Forces that act in a transverse direction onto the supporting tube or on the filter element disposed onto the supporting tube, can advantageously be diverted to the housing due to these feet or this collar. Moreover, the supporting tube can advantageously be permanently fixed in the housing. For mounting the supporting tube, the supporting tube can be introduced in the axial direction into the receiving chamber such that the connecting pins are immersed into the pin recesses. For permanent fixation of the supporting tube in the receiving chamber, the connecting pins may be designed, in particular, as snap-on or latching pins, which engage behind the areas that surround the pin recesses after insertion of the supporting tube. It is also feasible to design the connecting pins as riveting pins, in particular as welding rivet pins. The riveting pins can be hot riveted after insertion of the supporting tube to yield a suitable connection between the supporting tube and the housing. 
     The supporting tube may thereby be detachably connected in the receiving chamber via the connecting pins. Towards this end, the pin recesses may be designed, in particular, like a bayonet. The supporting tube may then be inserted in the axial direction into the receiving chamber such that the connecting pins engage in the pin recesses. In a further step, the free ends of the connecting pins can be hot riveted. If the supporting tube shall be removed from the receiving chamber at a later time, it can be turned about its longitudinal center axis until the rivet heads reach the areas of the pin recesses that have a cross-sectional surface that is larger than the diameter of the hot riveting heads. The supporting tube can then be removed from the receiving chamber in an axial direction. 
     Instead of hot-riveted connecting pins, one can also use connecting pins in the form of screws having a widening that corresponds to a hot riveting head. 
     The housing that forms the receiving chamber may thereby be formed, in particular, from plastic material, wherein the connecting pins may, in particular, be formed on the housing. 
     If the connecting pins have a widening in the area of their free ends, the separation between the bottom of the receiving chamber and the lower edge of the widening advantageously is, in particular, at least slightly larger than the axial thickness of the feet or collar. This enables displacement of the supporting tube in the axial direction from the operating position into the drain position within the receiving chamber. 
     As mentioned above, the mushroom head-like widening can be produced, in particular, through hot riveting after insertion of the supporting tube and thereby of the pin recesses into the connecting pins. 
     It is also feasible to design the pin recesses such that the supporting tube can be turned about its center axis through a defined angle of rotation. The pin recesses may be designed, in particular, like ring segments or, as mentioned above, like a bayonet. The areas of a pin recess that are disposed opposite to each other coaxially along the center longitudinal axis then form rotary stops for limiting the angle of rotation. Due to the fact that the supporting tube can be turned about its longitudinal axis at least to a certain degree, it is possible to open a seal, which is disposed e.g. on the supporting tube side and is stuck in the area of the drain opening, by turning it. It may thereby be sufficient to turn the supporting tube through an angle of rotation of approximately 5° to 15°. 
     In order to enable rotation of the supporting tube, carrier sections, in particular, in the form of carrier ribs, may be provided on the cover element, which can turn the supporting tube and/or the filter element, in particular, for screwing on or unscrewing the cover element. These carrier sections may be provided on or formed by, in particular, the filter element abutment area or the supporting tube abutment area. Recesses may be provided on the supporting tube or on the filter element, which cooperate with the respective carrier sections, for engagement with the carrier sections on the side of the cover element. 
     In accordance with a further embodiment of the invention, the supporting tube may have an extension section on the side facing away from the cover element and in the area that is not covered by the filter element, which is closed in the radial direction, engages in a purified oil space having an oil outlet, and has at least one purified oil outlet opening in its area facing away from the cover element. Purified oil filtered by the filter element may consequently be discharged through the extension section of the supporting tube into the purified oil chamber and from there into the oil outlet. 
     The area of the supporting tube that is covered by the filter element has openings in the radial direction through which purified oil filtered by the filter element can flow into the supporting tube. The filter element is advantageously supported on the supporting tube in a directly sealing fashion in the area of its end caps. 
     A circumferential sealing collar that projects in the radial direction may be formed on the extension section for sealing the purified oil chamber with respect to the receiving chamber that receives the unfiltered crude oil. 
     A closing section, which is disposed in the area of the center longitudinal axis for closing the drain opening in the operating position, may advantageously be provided at the free end of the extension section of the supporting tube. The spring element, which loads the supporting tube into the drain position, may thereby be disposed around the extension section of the supporting tube in the purified oil chamber. 
     In another advantageous fashion, an engagement section is provided on the side of the cover element facing the receiving chamber for engagement behind filter element sections such that the filter element can be removed from the supporting tube and from the receiving chamber by means of the cover element. The engagement sections may thereby be formed by the filter element abutment area. The filter element sections may thereby be formed, in particular, by the end disc, if provided, of the filter element, which faces the cover. 
     In order to ensure that the engagement sections automatically engage when the cover element is screwed onto the housing, the engagement sections advantageously have insertion slopes on their side facing the filter element. 
     The engagement sections may thereby be formed, in particular, as spring tabs that extend parallel to the center longitudinal axis of the filter element and project from the cover element. The spring tabs may have engagement surfaces that project in a radial inward direction for engagement behind the filter element sections. This design is advantageous in that the engagement sections that are formed like spring tabs yield in a radial outward direction when the cover element is screwed onto the housing and then snap behind the filter element sections in a radially inward direction for engagement. 
     In another embodiment of the invention, the engagement sections are designed as webs that are disposed on the cover and have an edge that extends substantially parallel to the center longitudinal axis of the filter element. The edge has a recess extending in the radial direction for engagement behind the filter element sections. In this embodiment, the engagement sections are consequently, in particular, not elastic in a radial outward direction. An assembly of this type may be used, in particular, when the filter element sections are elastic in an axial inward direction such that they yield when joined with the cover. 
     Further details and advantageous embodiments of the invention can be extracted from the following description by means of which the embodiments shown in the figures are described and explained in more detail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a longitudinal open view of a first oil filter assembly in accordance with the invention; 
         FIG. 2  shows a longitudinal open view of the upper part of the oil filter assembly in accordance with  FIG. 1 ; 
         FIG. 2.1  shows a section of  FIG. 2  of a slightly different embodiment; 
         FIG. 3  shows a longitudinal open view of the lower part of the oil filter assembly in accordance with  FIG. 1 ; 
         FIG. 4  shows an open view in correspondence with  FIG. 3  in an assembly position; 
         FIG. 5  shows a longitudinal open view of a second inventive oil filter assembly; 
         FIG. 6  shows an open view similar to  FIG. 5  from another perspective without filter element; and 
         FIG. 7  shows the individual parts of the supporting tube of  FIGS. 5 and 6 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The oil filter assembly  10  shown in  FIGS. 1 through 4  comprises a housing  12  that can be closed by a cover  14  via a thread  16 . The housing  12  and the cover  14  form a receiving chamber  18  that houses a filter element  20  through which oil can flow in a radial direction.  FIGS. 1 and 2  only show the two end caps  21 ,  23  of the filter element  20  for clear illustration of the function. The filter element  20  is supported by a supporting tube  22  that is can-shaped in the area where it is covered by the filter element  20 . A plurality of openings  24  are provided on the supporting tube such that oil can flow through the supporting tube  22  in a radial direction. On its side facing a bottom  26  of the receiving chamber  18 , the supporting tube comprises a circumferential annular collar  28  that is oriented in a radially outward direction. It is also possible to merely provide annular collar sections or feet, e.g. as shown in the embodiment in accordance with  FIGS. 5 to 7 , instead of the annular collar  28 . 
     A purified oil chamber  30  is provided downstream of the receiving chamber  18  in an axial downward direction, the axial end of which has an oil outlet  32 . An oil inlet  34  extends within the housing  12  parallel to the purified oil chamber  30 , as is clearly illustrated, in particular, in  FIGS. 1 and 3 , through which unfiltered oil can flow into the receiving chamber  18 . The oil flow during operation of the oil filter assembly  10  is indicated by arrows  35  in  FIG. 1 . During operation of the oil filter assembly  10 , oil to be filtered consequently flows from the oil inlet  34  through the filter element  20  and to the oil outlet  32 . 
     The supporting tube  22  is inserted in the axial direction from the top into the receiving chamber  18  and permanently fixed at that location. Towards this end, axially extending connecting pins  38  are provided in the area of the bottom  26 , which is clearly shown, in particular, in  FIGS. 3 and 4 . In the assembled state, these connecting pins  38  project into pin recesses  40  that are provided on the annular collar  28 . As is clearly shown in  FIG. 1 , these pin recesses  40  are formed as ring segments. For mounting the supporting tube  22 , it is introduced in an axial direction into the receiving chamber such that the connecting pins  38  are immersed into the pin recesses  40 , as is illustrated in  FIG. 4 . 
     After insertion of the supporting tube  22 , the free ends of the connecting pins  38  are e.g. thermally deformed to produce mushroom head-like widenings  39  at their free ends, which are clearly shown in  FIG. 3 . The separation between the bottom  26  of the receiving chamber  18  and the lower edge of the widening  39  is thereby selected such that the supporting tube  22  can be displaced from the operating position shown in  FIGS. 1 through 4  to a drain position, in which the areas of the annular collar  28  that surround the recesses  40  come to rest on the lower side of the recesses. In the operating position, a drain opening  42  provided at the lower end of the purified oil chamber  30  is closed by a closing section  44  of the supporting tube  22 . The closing section  44  has a circumferential seal  46 . 
     When the cover element  14  is removed, the supporting tube  22  is displaced into the drain position by a spring element  48  that is supported on the housing  12  and also on the supporting tube  22 . In the drain position, the areas of the annular collar  28  that surround the recess  40  abut the lower sides of the widenings  39 , and the closing section  44  is also moved out of the area of the drain opening  42 , such that oil can flow out of the receiving chamber  18  via the drain opening  42 . 
     As is clearly shown in  FIGS. 1 ,  3  and  4 , the supporting tube has an extension section  50  on the side facing away from the cover element  14 , which is closed in the radial direction and engages the purified oil chamber  30 . The extension section  50  thereby has a purified oil outlet opening  52  on its side facing away from the cover element  16 , out of which filtered purified oil can flow into the purified oil chamber  30 . The filtered purified oil consequently flows from the purified oil outlet opening  52  through the purified oil chamber  30  to the oil outlet  32  that follows the purified oil chamber  30  in the radial direction. 
     As is particularly shown in  FIG. 3 , the spring element  48  is supported on a shoulder  54  on the purified oil chamber side and also on the end faces of webs  56  of the extension section  50 , which extend in the axial direction. 
     As mentioned above, the supporting tube  22  is in a drain position when the cover element  14  is opened due to the spring pretension of the spring element  48 . In order to transfer the supporting tube  22  together with the filter element  20  that is disposed on the supporting tube  22  into the operating position when the cover element  14  is unscrewed, the cover element  14  has a supporting tube abutment area  58  on its side facing the receiving chamber  18 . The supporting tube abutment area  58 , which is clearly shown, in particular, in  FIGS. 1 and 2 , is thereby formed by ribs  60  that are disposed on the inside of the cover element and project in a radial inward direction. The end faces of the ribs  60  that extend in the radial direction thereby load the end face of the free end  62  of the supporting tube  22 . As is clearly shown, in particular, in  FIG. 2 , in the operating position, the supporting tube  22  or its free end  62  projects past the filter element  20  or its end cap  21  in an axial direction towards the cover. The supporting tube abutment area  58  also ensures that the supporting tube  22  is held in the operating position when the cover element  14  is closed. 
     The supporting tube abutment areas  58  are provided on the cover element  14  to ensure that the filter element  20  advantageously does not need to transmit any axial forces, in particular, in the operating position. The load flow that starts from the spring element  48  extends via the supporting tube  22  into the cover element  14 . 
     Filter element abutment areas  64  are provided on the inner side of the cover element  14  in order to dispose the filter element  20  at an exact position on the supporting tube  22 . The filter element abutment areas  64  are used to displace the filter element  20  into its operating position when the cover element  14  is screwed on. The filter element abutment areas  64  are thereby also realized by correspondingly disposed ribs  66 . The supporting tube abutment areas  58  are, however, disposed radially further inward than the filter element abutment areas  64 . The supporting tube abutment areas  58  are located in the axial direction above the filter element abutment areas  64 . 
     After long-term operation of the oil filter assembly, the sealing element  46  or the closing section  44  may stick to the housing. In order to release a stuck closing section  44  or sealing element  46  for opening the cover element, the ribs  60  and/or the ribs  66  may be formed as carrier ribs that also rotate the supporting tube  22  and/or the filter element  20  when the cover element is turned. The angle of rotation of the supporting tube  22 , which may, in particular, be approximately 15°, is determined by the length of the pin recesses  40  that extend coaxially to the center longitudinal axis. The coaxial opposite sides of the pin recesses  40  thereby form rotary stops  41 ,  43  for the connecting pins  38  that engage in the pin recesses  40 . A stuck supporting tube  20  can be released by turning, thereby enabling automatic axial movement of the supporting tube  22 . In order to also rotate the supporting tube  22  or the filter element  20 , carrier recesses  68  or, in particular, wedge-like carrier elevations  70  (shown as example on the end discs  21  and  23 ) may be provided on the supporting tube  22  and/or on the filter element  20 . 
     In order to prevent undesired flow of unfiltered oil from the receiving chamber  18  along the extension section  50  towards the purified oil chamber  30 , a circumferential sealing collar  72  is formed on the extension section  50 . The sealing collar  52  thereby acts against the wall of the purified oil chamber  30 . The sealing collar  72  is thereby disposed such that it leaves the area of the wall of the purified oil chamber when the supporting tube  22  is axially displaced into the drain position such that unfiltered oil provided in the receiving chamber  18  can freely flow into the purified oil chamber  30  and be discharged from the purified oil chamber  30  via the drain opening  42 . 
     An overpressure valve  74  is disposed at the free end  62  of the supporting tube  22 , which faces the cover element  14  (clearly shown in particular in  FIG. 1 ) and opens when the pressure in the receiving chamber  18  is increased such that unfiltered oil can flow to the inner side of the supporting tube  22 . Due to the supporting tube abutment areas  58  that are formed as ribs  60 , oil can freely flow between the ribs  60  towards the inlet of the overpressure valve  74 . Since the filter element abutment areas  64  are also formed like ribs, oil can also freely flow between the filter element  20  and the cover  14  to the valve  74 . 
       FIGS. 5 through 7  show a second inventive oil filter assembly  100 , wherein the components that correspond with the oil filter assembly  10  in accordance with  FIGS. 1 through 4  are designated by the corresponding reference numerals. 
     Mounting sections in the form of feet  104  that project in a radial outward direction are provided on the supporting tube  102  of the oil filter assembly  100 , as is clearly shown in  FIGS. 6 and 7 . The feet  104  have bayonet-shaped pin recesses  106 , which have a ring segment section  108  that extends about the center longitudinal axis of the supporting tube  102 , and a circular ring section  110  that joins the ring segment section  108 . 
     As is clearly shown, in particular, in  FIG. 6 , connecting pins  112  are provided on the bottom  26  of the receiving chamber  18 , the free ends of which comprise a mushroom head-like widening  114 . The diameter of each mushroom head-like widening  114  is at least slightly smaller than the clear area of the circular ring section  110  and larger than the width of the respective ring segment section  108 . For this reason, the supporting tube  102  can be disposed such that it remains in the receiving chamber  18  like a bayonet. 
     The connecting pins  112  may e.g. be made from plastic material, wherein the connecting pins  112  may initially be cylindrical and obtain their mushroom head-like widening  114  only after insertion of the supporting tube  102 , e.g. through hot riveting. 
     In accordance with the invention, the connecting pins  112  may e.g. also be realized in the form of screws having corresponding screw heads, which can be screwed into the housing. 
     In the oil filter assembly  100  in accordance with  FIGS. 5 through 7 , the separation between the bottom  26  of the receiving chamber  18  and the lower edge of the widening  114  is approximately two to ten times and, in particular, approximately 5 times as large as the axial thickness d of the two feet  104 . This realizes a limited motion of the supporting tube  102  in the axial direction. Towards this end, the supporting tube  102  can be axially displaced from an operating position assumed when the receiving chamber  18  is closed, into a drain position assumed when the receiving chamber  18  is open or the cover  14  is removed. For automatic displacement of the supporting tube  102  from the operating position into the drain position, a spring element  116  is provided which is supported on the bottom  26  of the receiving chamber  18  and also on the supporting tube  102  or the side of the feet  104  facing the bottom  26 . 
     As is clearly shown in  FIGS. 5 and 6 , the supporting tube  102  engages a purified oil chamber  30  on the side facing away from the filter element  20  or the cover  14 . The supporting tube  102  has purified oil outlet openings  118  in the section of the supporting tube  102 , which is entirely disposed in the purified oil chamber  30  in the operating position shown in  FIGS. 5 and 6 . On the side facing the feet  104 , the purified oil outlet openings  118  are followed by a circumferential sealing collar  120 . In the operating position shown in the figures, the sealing collar  120  sealingly acts against a housing section that corresponds to the sealing collar  120  in the transition area between the receiving chamber  18  and the oil outlet  32 . In the operating position, the filtered oil that flows through the filter element  20  in a radial direction, flows via the oil outlet  32  out of the oil filter assembly  100  to the user. 
     When the housing cover  14  is opened, the supporting tube  102  is displaced in an axially upward direction by the spring element  116  until the feet  104  abut the lower side of the widenings  114 . In this drain position, the purified oil outlet openings  118  communicate with the receiving chamber  18  such that the oil that is present in the receiving chamber  18  flows into the purified oil chamber  30  via the purified oil outlet openings  118  and further into the drain opening  42 . 
     The supporting tube  102  has openings  24  (indicated in  FIG. 7 ) in the area where it cooperates with the filter element  20 , through which oil can flow in a radial direction. 
     Wedge-like webs  122  are formed on the inner side of the cover element  14 , the sides of which facing the free end of the supporting tube  102  form support tube abutment areas  124 . The supporting tube  102  is transferred into the operating position via these supporting tube abutment areas  124  when the cover element  14  is screwed onto the housing  12 , and held in the operating position when the cover element  14  is screwed on. Projections  126  that extend in the axial direction are moreover provided on the inner side of the cover element  14 , the free ends of which form filter element abutment areas  128 . The filter element  20  is pushed via the filter element abutment areas  128  into the intended operating position when the cover element  14  is screwed on. The spring force of the spring element  116 , which loads the supporting tube  102  into the drain position is, however, exclusively diverted into the cover element  14  via the supporting tube abutment sections  126 . 
     As is clearly shown in  FIG. 2 , engagement sections  76  may be provided on the cover element  14 , which engage behind the upper end cap  21  of the filter element  20  when the cover element  14  is closed. The engagement sections  76  shown in  FIG. 2  have the shape of spring tabs and comprise an engagement surface  78  that extends substantially perpendicularly to the center longitudinal axis of the oil filter assembly. When the housing cover is opened, this engagement surface  78  acts against the edge  80  of the end cap  21  facing the engagement surface  78 . For this reason, the filter element  20  can be removed from the supporting tube  22  when the cover element  14  is removed, and be removed from the receiving chamber  18 . The engagement surfaces  78  are spaced apart from the lower edge  80  of the end cap  21  when the cover element  14  is closed for compensation for the axial play (shown in  FIG. 2 ). 
     The engagement sections  76  have insertion slopes  82  on their radially inner lower side, which enable the engagement sections  76  to deviate in a radially outward direction when the cover element  14  is screwed on, and then snap in an axially inward direction when the engagement surfaces  78  pass the lower edge  80 . 
     As is indicated in the section of  FIG. 2.1 , it is also possible to use engagement sections  76 , which are designed as webs  84  provided in the form of cover elements. These engagement sections have radially outwardly extending recesses  86 , which engage behind the end cap  21  in the finally assembled state.