Hollow Filter Element, Filter, and Housing Section of a Filter

Abstract

A hollow filter element of a fluid filter has a filter element-associated retention/carrier device of a retention/carrier system retaining the filter element in a first housing section of a filter housing during installation/removal in or from a second housing section by rotation and/or insertion movement. The filter element-associated retention/carrier device has a retention/carrier part extending radially and circumferentially and has through holes adjacent thereto extending circumferentially so as to enable a filter housing-associated retention/carrier part of the retention/carrier system to pass through axially. This retention/carrier part has a tensile face extending circumferentially and radially on a side facing away from an end face of the filter element facing the first housing section. This retention/carrier part has a rear side in circumferential direction. A space axially adjacent to the tensile face is connected on the rear side to a through hole for guiding through the filter housing-associated retention/carrier part.

Claims

1. A hollow filter element of a fluid filter configured to be exchangeably arranged in a filter housing of the fluid filter, wherein the filter housing comprises a first housing section and a second housing section, the hollow filter element comprising: at least one filter element-associated retention/carrier device of a retention/carrier system for retaining and/or carrying the hollow filter element in the first housing section of the filter housing at least during installation and/or removal of the hollow filter element in or from the second housing section of the filter housing, wherein the hollow filter element is configured to be joined with or separated from the first housing section and/or the second housing section by a rotational and/or insertion movement relative to a virtual axis; wherein the at least one filter element-associated retention/carrier device comprises at least one filter element-associated retention/carrier part extending radially relative to the virtual axis and extending circumferentially over at least a portion of a radially inner circumference of the hollow filter element; wherein the at least one filter element-associated retention/carrier device comprises, circumferentially adjacent to the at least one filter element-associated retention/carrier part relative to the virtual axis, one or more through holes extending circumferentially relative to the virtual axis and configured to enable at least one filter housing-associated retention/carrier part of at least one filter housing-associated retention/carrier device of the retention/carrier system to pass through axially; wherein the at least one filter element-associated retention/carrier part comprises a tensile face extending circumferentially and radially, wherein the tensile face is located on a side of the at least one filter element-associated retention/carrier part that is facing axially away, relative to the virtual axis, from an end face of the hollow filter element to be facing the first housing section; wherein the at least one filter element-associated retention/carrier part, viewed in a defined circumferential direction of the hollow filter element, has a rear side and a front side; wherein the one or more through holes include a first through hole adjacent to the rear side of the at least one filter element-associated retention/carrier part; wherein a space axially adjacent to the tensile face is connected on the rear side of the at least one filter element-associated retention/carrier part to the first through hole in a way suitable for guiding through the at least one filter housing-associated retention/carrier part.

2. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier part on a side where the tensile face is located comprises a limit stop that delimits the tensile face at the front side of the at least one filter element-associated retention/carrier part.

3. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier device comprises a free-running annular space configured to accommodate the at least one filter housing-associated retention/carrier part, wherein the free-running annular space extends circumferentially contiguously relative to the virtual axis and is located, when viewed axially relative to the virtual axis from the end face of the hollow filter element to be facing the first housing section, behind the at least one filter element-associated retention/carrier part, wherein the free-running annular space is connected to the one or more through holes of the at least one filter element-associated retention/carrier device in a way suitable for guiding through the at least one filter housing-associated retention/carrier part.

4. The hollow filter element according to claim 3, wherein the one or more through holes include a second through hole adjacent to the front side of the at least one filter element-associated retention/carrier part, wherein the front side of the at least one filter element-associated retention/carrier part comprises a free-running guide configured to guide the at least one filter housing-associated retention/carrier part from the second through hole into and/or out of the free-running annular space.

5. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier device is arranged at least partially in an interior space of the hollow filter element so as to be accessible from the exterior of the hollow filter element.

6. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier part is arranged at least partially in an interior space of the hollow filter element so as to be accessible from the exterior of the hollow filter element.

7. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier device is directly or indirectly connected in a detachable manner or in a non-destruction-free detachable manner to at least one supporting element selected from the group consisting of a support body of the hollow filter element, an end body of the hollow filter element, and a carrier part of the hollow filter element.

8. The hollow filter element according to claim 7, wherein the support body is a support tube, wherein the end body is an end plate, and wherein the carrier part is a carrier ring.

9. The hollow filter element according to claim 7, wherein the at least one filter element-associated retention/carrier device is connected to the carrier ring, wherein the carrier ring is configured as a collar, and wherein the collar is detachably or non-detachably joined to the end body.

10. The hollow filter element according claim 1, further comprising a retention/carrier ring rotatably mounted on a radially inward circumference of the hollow filter element, wherein the filter element-associated retention/carrier device is disposed on the retention/carrier ring.

11. The hollow filter element according to claim 10, wherein the retention/carrier ring is held in a circumferential groove provided on an interior surface of a central tube of the hollow filter element or of a carrier ring of the hollow filter element.

12. The hollow filter element according to claim 11, wherein the retention/carrier ring is rotatable in relation to the central tube or the carrier ring only after a prescribed limiting torque is overcome.

13. The hollow filter element according to claim 1, wherein the retention/carrier system of which the at least one filter element-associated retention/carrier part is a component is a bayonet-closure-type retention/carrier system.

14. The hollow filter element according to claim 1, wherein at least two of the filter element-associated retention/carrier parts are provided and arranged in an even or an uneven circumferential distribution relative to the virtual axis.

15. The hollow filter element according to claim 1, wherein the at least one filter element-associated retention/carrier part on a side facing axially away from the at least one tensile face relative to the virtual axis is provided with a guide surface configured to guide the at least one filter housing-associated retention/carrier part for mating the first housing section and the hollow filter element.

16. The hollow filter element according to claim 15, wherein, when viewed in the defined circumferential direction, an axial distance of the guide surface, measured relative to the virtual axis, increases relative to the end face of the hollow filter element to be facing the first housing section.

17. The hollow filter element according to claim 1, wherein: the at least one filter element-associated retention/carrier part comprises an essentially radially extending pin and the at least one filter housing-associated retention/carrier part of the retention/carrier system comprises a receptacle groove extending radially and corresponding to an outer contour of the essentially radially extending pin, or the at least one filter housing-associated retention/carrier part comprises an essentially radially extending pin and the at least one filter element-associated retention/carrier part of the retention/carrier system comprises a receptacle groove extending radially and corresponding to an outer contour of the essentially radially extending pin.

18. The hollow filter element according to claim 17, wherein the at least one filter element-associated retention/carrier part provided with the receptacle groove or the filter housing-associated retention/carrier part provided with the receptacle groove comprises at least one clamping face that is axially spaced apart from the receptacle groove.

19. The hollow filter element according to claim 18, wherein the receptacle groove is provided on a receptacle body and the clamping surface is provided on a clamping body that is embodied separate from the receptacle body.

20. The hollow filter element according to claim 1, further comprising a valve seat wherein the at least one filter element-associated retention/carrier part is realized in the vicinity of, on or together with the valve seat valve.

21. The hollow filter element according to claim 1, further comprising a bypass valve, wherein the at least one filter element-associated retention/carrier part is realized in the vicinity of, on or together with the bypass valve or a housing of the bypass valve.

22. A fluid filter comprising: a filter housing comprising at least a first housing section and a second housing section, wherein the first and the second housing sections are at least partly separable from one another for opening the filter housing; at least one hollow filter element that is exchangeably arranged in the filter housing; a retention/carrier system for retaining and/or carrying the at least one hollow filter element in the first housing section of the filter housing at least during installation and/or removal of the hollow filter element in or from the second housing section of the filter housing, wherein the at least one hollow filter element is configured to be joined with or separated from the first housing section and/or the second housing section by a rotational and/or insertion movement relative to a virtual axis; wherein the retention/carrier system comprises at least one filter housing-associated retention/carrier device disposed on the first housing section and further comprises at least one filter element-associated retention/carrier device disposed on the at least one hollow filter element; wherein the at least one filter element-associated retention/carrier device comprises at least one filter element-associated retention/carrier part extending radially relative to the virtual axis and extending circumferentially over at least a portion of a radially inner circumference of the hollow filter element; wherein the at least one filter element-associated retention/carrier device comprises, circumferentially adjacent to the at least one filter element-associated retention/carrier part relative to the virtual axis, one or more through holes extending circumferentially relative to the virtual axis and configured to enable at least one filter housing-associated retention/carrier part of at least one filter housing-associated retention/carrier device of the retention/carrier system to pass through axially; wherein the at least one filter element-associated retention/carrier part comprises a tensile face extending circumferentially and radially, wherein the tensile face is located on a side of the at least one filter element-associated retention/carrier part that is facing axially away, relative to the virtual axis, from an end face of the hollow filter element to be facing the first housing section; wherein the at least one filter element-associated retention/carrier part, viewed in a defined circumferential direction of the hollow filter element, has a rear side and a front side; wherein the one or more through holes include a first through hole adjacent to the rear side of the at least one filter element-associated retention/carrier part; wherein a space axially adjacent to the tensile face is connected on the rear side of the at least one filter element-associated retention/carrier part to the first through hole in a way suitable for guiding through the at least one filter housing-associated retention/carrier part.

23. The filter according to claim 22, wherein the first housing section is a housing cover and the housing cover comprises a bypass valve comprising a bypass valve housing, wherein the at least one filter housing-associated retention/carrier device is disposed on the bypass valve housing.

24. The filter according to claim 23, wherein the at least one filter housing-associated retention/carrier part is disposed on a radially outer face of the bypass valve housing.

25. The filter according to claim 23, wherein the bypass valve housing is rotatable relative to the housing cover only after a prescribed limiting torque is overcome.

26. A first housing section of a filter housing of a filter, wherein the filter housing is configured to be joined to at least one second housing section for sealing off the filter housing and to be separated at least partially from the at least one second housing section for opening the filter housing, wherein the first housing section comprises: at least one filter housing-associated retention/carrier device of a retention/carrier system for retaining and/or carrying a hollow filter element in the first housing section at least during installation and/or removal of the hollow filter element in or from the second housing section, wherein the first housing section is configured to be joined with or separated from the hollow filter element and/or the second housing section by a rotational and/or insertion movement relative to a virtual axis; wherein the at least one filter housing-associated retention/carrier device comprises at least one filter housing-associated retention/carrier part extending radially relative to the virtual axis and circumferentially over at least a portion of a circumference of the at least one filter housing-associated retention/carrier device; wherein the at least one filter housing-associated retention/carrier device comprises, circumferentially adjacent to the at least one filter housing-associated retention carrier part relative to the virtual axis, at least one gap extending circumferentially relative to the virtual axis and configured to enable at least one corresponding filter element-associated retention/carrier part of at least one filter element-associated retention/carrier device of the retention/carrier system to axially pass through; wherein the first housing section comprises a bypass valve and wherein the at least one filter housing-associated retention/carrier device is disposed on the bypass valve.

27. The first housing section according to claim 26, wherein the first housing section is a housing cover configured to close off the second housing section that is a housing pot.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Other advantages, features, and details of the invention shall be made more apparent by the following description, which addresses an exemplary embodiment of the invention in greater detail with reference to the drawing. A person skilled in the art will expediently consider the features disclosed in combination in the drawing, the description, and the claims also individually and combine them into useful further combinations.

[0068] FIG. 1 shows a longitudinal section of an oil filter for engine oil of an internal combustion engine having a filter housing in which a filter element is installed by way of a retention/carrier system.

[0069] FIG. 2 is an isometric view of the filter element of FIG. 1 with a view toward a cover-side end face on which a filter element-associated retention/carrier device of the retention/carrier system is realized.

[0070] FIG. 3 is a longitudinal section of the housing cover with the filter element of the oil filter of FIG. 1 without the housing pot, wherein the retention/carrier system in this case is still separated.

[0071] FIG. 4 is a longitudinal section of the housing cover with the filter element of the oil filter of FIG. 1 in an assembly phase following the separated state of FIG. 3.

[0072] FIG. 5 is a longitudinal section of the housing cover with the filter element of the oil filter of FIG. 1 in an assembly phase during the installation of the housing cover with the filter element in the housing pot, wherein the housing pot is not depicted here.

[0073] FIG. 6 is a longitudinal section of a filter element according to a further embodiment having a carrier ring connected to the top end plate.

[0074] FIG. 7 is a longitudinal section of a filter element according to a further embodiment having a carrier ring connected to the top end plate and retention/carrier ring rotatably mounted therein.

[0075] FIG. 8 is a top view of a filter element according to a further embodiment.

[0076] FIG. 9 is a longitudinal section of an oil filter for engine oil of an internal combustion engine with the filter element of FIG. 8.

[0077] FIG. 10 is a longitudinal section of an oil filter for engine oil of an internal combustion engine having the filter element of FIG. 6.

[0078] FIG. 11 is an isometric view of a bypass valve of a filter according to the invention.

[0079] FIG. 12 is an isometric view of a hollow filter element according to yet another embodiment.

[0080] In the drawings, like components are assigned like reference signs.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0081] In FIG. 1, an oil filter 10 for engine oil of an engine oil circuit of an internal combustion engine of a motor vehicle is depicted in a longitudinal section.

[0082] The oil filter 10 includes a filter housing 12 having a housing pot 14, which is closable with a housing cover 15. The housing pot 14 is fixedly joined to the internal combustion engine or a frame part of the motor vehicle.

[0083] The housing pot 14 has an inlet 16 for engine oil to be filtered. The inlet 16 is joined to the engine oil circuit. The inlet 16 opens out into an unfiltered-oil-side inlet space 18 of the housing pot 14.

[0084] A housing interior space 20 of the filter housing 12 is coaxial with a virtual axis 22. The housing interior space 20 serves as the installation space for a filter element 24.

[0085] The axis 22 coincides in the exemplary embodiment with a housing axis of the filter housing 12, an installation/removal axis of the filter element 24 into/out of the housing pot 14, and an element axis of the filter element 24. The filter element 24 can be brought together, with respect to the virtual axis 22, with the housing cover 15, on the one hand, and the housing pot 14, on the other hand, by combined rotational/insertion movements and be separated from them accordingly by combined rotational/insertion movements. For the sake of better understanding, the element axis, the housing axis and the installation/removal axis are identified with the same reference number 22 in the following and are designated for short as axis 22. It is understood that, depending on context, the housing axis, the element axis and/or the installation/removal axis is intended. Subsequent discussion of “radial,” “coaxial,” “axial,” “circumferential,” and the like is made with respect to the axis 22, unless otherwise indicated.

[0086] On an end face facing the housing cover 15, the housing pot 14 has a coaxial installation opening 26 for the filter element 24. In the operation-ready state, the installation opening 26 is closed off by housing cover 15, as shown in FIG. 1. The housing cover 15 is connected to the housing pot 14 by a screw connection 27. For this purpose, the housing cover 15 has on its radially outer circumferential side a coaxial male thread that corresponds to a corresponding coaxial female thread of the housing pot 14. The threads in the described exemplary embodiment are so-called right-hand threads.

[0087] A coaxial outlet 28 leads out of the housing pot 14 at the bottom. The outlet 28 is joined outside of the filter housing 12 to the engine oil circuit.

[0088] A coaxial ring seal 30 is arranged between a bottom wall of the housing pot 14 and the filter element 24. The ring seal 30 is located on the filter element 24.

[0089] The housing cover 15 carries a bypass valve 32, which is coaxially attached to the inside of the housing cover 15.

[0090] The filter element 24 is exchangeably arranged in the filter housing 12 so as to separate the inlet 16 from the outlet 28.

[0091] The filter element 24, which is shown in detail in FIG. 2, is designed as a so-called round filter element. It has a zig-zag-shaped, circumferentially enclosed filter medium 34 in the form of a non-woven filter pad. On its cover-side end face axially facing the housing cover 15, the filter medium 34 is tightly connected to a ring-shaped, cover-side end plate 36. The bypass valve 32 projects through the coaxial opening of the cover-side end plate 36 in the correct installation state, as shown in FIG. 1.

[0092] The bypass valve 32 closes off a coaxial element internal space 38 of the filter element 24 on the cover-side end face during normal operation. The element-internal space 38 is circumferentially surrounded by the filter medium 34. A radially outer circumferential side of the filter medium 34 forms an inflow side for the engine oil (unfiltered oil) to be filtered on the unfiltered oil side. A radially inner circumferential side of the filter medium 34 forms an outflow side for the filtered engine oil (clean oil) on the filtered oil side of the filter element 24.

[0093] On the pot-side end face axially facing away from the housing cover 15, the filter medium 34 is tightly connected to a pot-side end plate 40. The pot-side end plate 40 is configured in a ring shape having a coaxial outlet opening. The outlet opening is fluidically connected in the installed state to the outlet 28 of the filter housing 12.

[0094] The end plates 36 and 40 are made of plastic. They may be foamed, glued, welded or otherwise connected in a sealing manner to the filter medium 34.

[0095] In the element interior space 38, a support tube 42 made of plastic coaxially extends between the end plates 36 and 40. At the radially outer circumferential side of the support tube 42, the filter medium 34 can be braced with its radially inner circumferential side. The support tube 42 is joined at its respective ends to the end plates 36 and 40. The circumferential wall of the support tube 42 is permeable to engine oil. The support tube 42 can also be clamped only between the end plates 36 and 40 or mounted in a floating manner.

[0096] The oil filter 10 further includes between the filter element 24 and the housing cover 15 a bayonet-closure-type retention/carrier system 44 for holding the filter element 24 on the housing cover 15 in the case of a preassembly and for carrying the filter element 24 with the housing cover 15 when the filter element 24 is installed in the housing pot 14 and removed from housing pot 14. The retention/carrier system 44 includes a filter housing-associated retention/carrier device 46 on the side of the housing cover 15 that can be detachably joined to a filter element-associated retention/carrier device 48 on the side of the filter element 24.

[0097] The filter housing-associated retention/carrier device 46 is made of plastic. The filter housing-associated retention/carrier device 46 has a total of three filter housing-associated retention/carrier parts 50 that are essentially identical in shape and size, only one of which is recognizable in FIGS. 1 and 3 to 5 because of the choice of the section plane. The filter housing-associated retention/carrier parts 50 are arranged evenly distributed around the circumference. The filter housing-associated retention/carrier parts 50 each extend radially outward and circumferentially over a portion of the radially outer circumference of the bypass valve 32. The filter housing-associated retention/carrier parts 50 are integrally formed on a housing of the bypass valve 32 and in this way are realized together with the bypass valve 32.

[0098] Between each two adjacent filter housing-associated retention/carrier parts 50, gaps 52 extending circumferentially are realized through which corresponding filter element-associated retention/carrier parts 54 of the filter element-associated retention/carrier device 48 can be guided axially.

[0099] The filter element 24 comprises the filter element-associated retention/carrier device 48 of the retention/carrier system 44. The filter element-associated retention/carrier device 48 is made of plastic. It has a carrier ring 56 on whose radially inner circumferential side the three filter element-associated retention/carrier parts 54 are each integrally formed thereon. The carrier ring 56 having the filter element-associated retention/carrier parts 54 is located in the vicinity of the cover-side end plate 36 in the element interior space 38. The carrier ring 56 having the filter element-associated retention/carrier parts 54 is accessible from the exterior through the opening of the cover-side end plate 36. The carrier ring 56, and with it the filter element-associated retention/carrier parts 54, are integrally formed on the support tube 42 of the filter element 24 and in a non-destruction-free-separation manner. The carrier ring 56 also forms a filter element-associated valve seat 58 for the bypass valve 32. The element side retention/carrier parts 54 are also realized on the valve seat 58.

[0100] The element side retention/carrier parts 54 are essentially identical in shape and size. They are arranged evenly distributed around the circumference. The filter element-associated retention/carrier parts 54 extend radially and circumferentially over a portion of the radially inner circumferential side of the support ring 56 and, thus, of the filter element 24.

[0101] The filter element-associated retention/carrier device 48 also has three through holes 60 that are essentially identical in shape and size. The through holes 60 are each located circumferentially adjacent to the filter element-associated retention/carrier parts 54, that is, between two circumferentially adjacent, filter element-associated retention/carrier parts 54. The through holes 60 each extend circumferentially over a portion of the radially inner circumferential side of the carrier ring 56 and, therefore, also of the filter element 24.

[0102] The through holes 60 are used for guiding through the filter housing-associated retention/carrier parts 50 of the filter housing-associated retention/carrier device 46 in the axial direction during the preassembly of the filter element 24 in the housing cover 15 and during the separation of the filter element 24 from the housing cover 15.

[0103] Each filter element-associated retention/carrier part 54 has a tensile face 62 extending circumferentially and radially. The tensile faces 62 are located on the side of the respective filter element-associated retention/carrier parts 54 axially facing away from the cover-side end face of the filter element 24.

[0104] A space axially adjacent to each tensile face 62 is, when viewed in a defined circumferential direction 64 of the filter element 24, on the rear side of the corresponding filter element-associated retention/carrier part 54, is connected to the through hole 60 adjacent thereto. The circumferential direction 64 of the filter element 24 is indicated in FIG. 2 by an arrow.

[0105] The filter element-associated retention/carrier parts 54 each have a limit stop 66 on their axial sides on which the tensile faces 62 are located. The limit stops 66 each delimit the corresponding tensile face 62 on the front side when viewed in the circumferential direction 64 of the filter element 24. The limit stops 66 each extend radially and axially.

[0106] The filter element-associated retention/carrier parts 54 further include a filter element-associated guide ramp 68 on a side facing axially away from the filter element-associated tensile face 62. An axial spacing of a guide surface of the guide ramp 68 relative to the cover-side end face of the filter element 24 increases when viewed in the circumferential direction 64 of the filter element 24. A slope of the guide ramp 68 corresponds, with respect to its slope direction, to the slopes of the female thread and the male thread of the screw connection 27 between the housing cover 15 and the housing pot 14. The slope directions of the guide ramp 68 and the female/male thread of the screw connection 27 correspond in the described exemplary embodiment to a standard right-hand thread. The pitch of the guide ramp 68 of the female/male thread may be identical or different.

[0107] The guide ramps 68 serve to guide the filter housing-associated retention/carrier parts 50 when the housing cover 15 and the filter element 24 are brought together. With the guide ramps 68, the housing side retention/carrier parts 50 can be guided to the nearest through hole 60 when the parts are brought together.

[0108] The filter element-associated retention/carrier device 48 also has a free-running annular space 70 for the filter housing-associated retention/carrier parts 50 that is extending circumferentially contiguously. The free-running annular space 70 is located, when viewed axially from the cover-side end face of the filter element 24, behind the filter element-associated retention/carrier parts 54. The free-running annular space 70 is connected to the through holes 60 for passage of the filter housing-associated retention/carrier parts 50. The through holes 60 therefore transition into the free-running annular space 70.

[0109] Each of the filter element-associated retention/carrier parts 54 on its—when viewed in the circumferential direction 64 of the filter element 24—front side has a free-running guide 72. The free-running guides 72 are each realized on the limit stops 66 of the corresponding filter element-associated retention/carrier parts 54. The free-running guides 72 are used to guide the housing side retention/carrier parts 50 from the adjacent through holes 60 into the free-running annular space 70 and vice-versa.

[0110] For the preassembly, the filter element 24 with its cover-side end plate 36 is moved axially forward to the inside of the housing cover 15. The bypass valve 32 is introduced into the valve seat 58, wherein the filter element-associated retention/carrier device 48 is moved toward the filter housing-associated retention/carrier device 46. The circumferential direction 64 of the filter element 24 is directed in the direction of a closing rotational direction 74 of the screw connection 27 of the housing cover 15 with the housing pot 14.

[0111] The filter element 24 is turned relative to the housing cover 15 counter to the circumferential direction 64 about the axis 22 until the filter housing-associated retention/carrier parts 50 each align with one of the through holes 60 of the filter element-associated retention/carrier device 48. In this position, the filter housing-associated retention/carrier parts 50 may glide along against the guide ramps 68 of the respective filter element-associated retention/carrier parts 54 and are guided with them.

[0112] The filter element 24 is further inserted into the housing cover 15 by a corresponding axial insertion movement. In this arrangement, the housing side retention/carrier parts 50 are each guided through the corresponding through holes 60 onto the side of the corresponding filter element-associated retention/carrier parts 54 that faces axially away from the cover-side end face of the filter element 24

[0113] By a rotational movement of the filter element 24 relative to the housing cover 15 in the circumferential direction 64 of the filter element 24, the filter housing-associated retention/carrier parts 50 are moved on the tensile faces 62 of the filter element-associated retention/carrier parts 54 up to their limit stops 66. The filter housing-associated retention/carrier parts 50, in the connected state of the retention/carrier system 44, operatively hook in behind the tensile faces 62 and against the limit stops 66 of the corresponding filter element-associated retention/carrier parts 54 counter to the circumferential direction 64 of the filter element 24 and counter to the closing rotational direction 74 of the screw connection 27 of the housing cover 15 with the housing pot 14. This assembly phase is shown in FIG. 4. The retention/carrier system 44 can be axially tension-loaded so that the filter element 24 can be retained in the housing cover 15. The filter housing-associated retention/carrier device 46 is detachably joined to the support tube 42, the cover-side end plate 36, the carrier ring 56, and the filter medium 34.

[0114] To assemble the oil filter 10, the housing cover 15 is inserted axially forward into the housing pot 14 along with the filter element 24 retained therein. In this arrangement, the housing cover 15 is first inserted by an axial insertion movement into the housing pot 14.

[0115] The housing cover 15 is joined to the housing pot 14 by a screwing movement in the closing rotational direction 74, that is, also in the circumferential direction 64 of the filter element 24. By a combined rotational/insertion movement of the housing cover 15 relative to the housing pot 14 in axial and circumferential direction resulting from the screwing movement, the filter housing-associated retention/carrier parts 50 are moved, on the one hand, circumferentially away from the limit stops 66 in the direction of the free-running guides 72 and, on the other hand, axially away from the tensile faces 62 of the filter element-associated retention/carrier parts 54 into the free-running annular space 70. With the free-running guides 72, the filter housing-associated retention/carrier parts 50 are guided into the free-running annular space 70. This assembly phase is shown in FIG. 5.

[0116] By continuing the screwing movement of the housing cover 15 relative to the housing pot 14 in circumferential direction 64 of the filter element 24, the screw connection 27 is closed. The filter housing-associated retention/carrier parts 50 are located in the free-running annular space 70 of the filter element-associated retention/carrier device 48. Between the side of the limit stops 66 of the filter element-associated retention/carrier parts 54 that axially faces away from the cover-side end plate 36 and the corresponding filter housing-associated retention/carrier parts 50, there is an axially extending gap 76, which is recognizable, for example, in FIG. 5.

[0117] The filter housing-associated retention/carrier parts 50 can run free relative to the filter element 24 in the circumferential direction when the housing cover 15 in the free-running annular space 70 is turned further. As a result, the screwing movement of the housing cover 15 in the closing rotational direction 74 does not cause the filter element 24 to turn. The filter element 24 remains in a rotational fixed orientation in the housing pot 14, while the housing cover 15 is brought into its end position in the housing pot 14 by the screwing movement in the closing rotational direction 74. The filter element 24 is only axially pressed into the housing pot 14. Therefore, the ring seal 30, which is located between the filter element 24 and the housing pot 14, does not rub against one of the components during the relative movement between the housing cover 15 and the housing pot 14.

[0118] In the correct installation state, the bypass valve 32 closes off the opening of the element interior space 38 toward the housing cover 15. Only when an overpressure occurs, for example, in case the filter medium 34 is blocked, the bypass valve 32 opens and in this way enables a bypass—which is not of further interest in this case—for the engine oil to go around the filter medium 34.

[0119] To remove the filter element 24, the housing cover 15 is unscrewed from the housing pot 14 by a screwing movement counter to the closing rotational direction 74 and counter to the circumferential direction 64 of the filter element 24 relative to the housing pot 14. When this happens, the filter housing-associated retention/carrier parts 50 and the corresponding filter element-associated retention/carrier parts 54 hook back in. The retention/carrier system 44 is activated in this way and is loadable for axial tension. By virtue of the limit stops 66 of the filter element-associated retention/carrier parts 54, the retention/carrier system 44 is also mechanically loadable with respect to the rotation counter to the circumferential direction 64 of the filter element 24. In this way, the filter element 24 is carried along with the housing cover 15 when separated from the housing pot 14.

[0120] After separation of the screw connection 27, the housing cover 15 is removed together with the filter element 24 from the housing pot 14. The filter element 24 is turned opposite to the element circumferential direction 64 relative to the housing cover 15, so that the filter housing-associated retention/carrier parts 50 are guided into the through holes 60. Then, the filter element 24 is axially extracted from the housing cover 15.

[0121] Shown in FIGS. 6 and 7 are further embodiments of the hollow filter element 24 that differ from the previously described embodiments in that the filter element-associated retention/carrier device 48 comprising the filter element-associated retention/carrier parts 54 is not present on the central tube, but instead on a separate carrier ring 541. The shown filter elements 24 are filter elements without an element-fixed central tube; they can be used in particular in filter devices that have a housing-fixed central tube in order to achieve the required stability against pressure differential.

[0122] The carrier ring 541 has, respectively, a collar shape and comprises a cylindrical section 541′, which extends into the element interior space 38, and a disk-shaped section 541″ that rests against the top end plate 36 and is joined thereto, preferably glued, welded or clipped on. Other types of connections, detachable or non-detachable, are possible. This design provides the advantage that even hollow filter elements 24 without central tube can be equipped with a filter element-associated retention/carrier device 48 that is located in the element interior space 38. Furthermore, also hollow filter elements 24 that do not have injection-molded (plastic) end plates, in particular metal-free hollow filter elements having end plates made of a foamed foil material, may be outfitted with a filter element-associated retention/carrier device 48 of this type.

[0123] Furthermore, sealing discs 361, 401 that are designed, for example, as felt gaskets are provided for both the top end plate 36 and bottom end plate 40. The reference characters 362, 402 each designate foaming areas of the top end plate 36 and bottom end plate 40 that are made necessary by the manufacture of the end plates 36, 40 of a foam-in-place plastic material; during the foaming process, foamed plastic material penetrates into the spaces between the pleats and thereby connects the pleats to the end plates 36, 40, in particular in an integrally fastened manner.

[0124] The hollow filter element 24 shown in FIG. 7 has the further peculiarity that the filter element-associated retention/carrier device is not directly present on the carrier ring 541, but instead on a separate retention/carrier ring 481 that is rotatably mounted inside the carrier ring 541. More precisely, the retention/carrier ring 481 is inserted in a circumferential groove on an inner surface of the cylindrical section 541′ of the carrier ring 541, so that it cannot fall out when the hollow filter element 24 is not in the installed state. In order to enable the retention/carrier system 44 operation according to the invention, the retention/carrier ring 481 should not be “easily” rotatable in an arbitrary sense, but instead should only be rotatable after a prescribed limiting torque is overcome, which can be achieved, for example, by friction between the surfaces of the carrier ring 541 and retention/carrier ring 481 that are in contact with each other and suitable fit selection. This limiting torque, which is the minimum that must be applied for the rotation of the retention/carrier ring 481 with respect to carrier ring 541, is essentially determined by the torque that is required to bring the filter element-associated retention/carrier parts 54 into engagement with the filter housing-associated retention/carrier parts 50. This design has the advantages that no free-running annular space needs to be provided.

[0125] FIG. 8 shows yet another embodiment of the hollow filter element 24 according to the invention, which differs from the previously described designs in that the filter element-associated retention/carrier device 48 present on the inner circumference has only two filter element-associated retention/carrier parts 54 that are evenly distributed around the circumference. Furthermore, the hollow filter element 24 is symmetrically designed along a plane of symmetry running normal to the longitudinal axis, that is, it has a filter element-associated retention/carrier device 48 at each of the two longitudinal side ends; this makes it possible for the hollow filter element 24 to be installable in any desired orientation, because corresponding filter element-associated retention/carrier parts 54, which can be brought into functional engagement with the corresponding filter housing-associated retention/carrier parts 50, are present both on its bottom side and on its top side. In the illustration of FIG. 8, the filter element-associated retention/carrier parts 54 present in the region of the bottom end plate on the central tube 42 (at the rear in the image plane) show through between the two filter element-associated retention/carrier parts 54 present in the region of the top end plate 36 on the central tube 42.

[0126] In FIG. 9, reference being had in this context essentially to the description of FIGS. 1 to 5 because the modes of operation essentially correspond, a filter 10 according to the invention is shown according to a further embodiment that comprises the hollow filter element 24 of FIG. 8. However, the depicted embodiment differs by the integration of the free-running action of the filter element-associated retention/carrier device 48 compared to the housing side retention/carrier device 46 of the previously described embodiments. Here it is provided to rotatably mount the bypass valve 32 with its bypass valve housing 321 in the housing cover 15 in order to achieve the previously described free-running property. The bypass valve housing 321 is snap fit by latch noses 322 in the housing cover 15. The clamping force of these latch noses 322 is designed overall in such a way that they can transmit a prescribed limiting torque, i.e., a rotation of the bypass valve housing 321 relative to the housing cover 15 is possible only after this limiting torque is overcome.

[0127] This makes it possible, on the one hand, that the filter element-associated retention/carrier parts 54, more precisely its tensile faces 62, are brought into operative contact with the filter housing-associated retention/carrier parts 50 by a rotation of the housing cover 15 relative to the housing pot 14. On the other hand, this provided that the hollow filter element 24 turns together with the housing cover 15 when the latter is unscrewed only when the hollow filter element 24 has been pulled out of the sealing seat on the lower end plate 40 at least far enough that a friction torque occurring there can no longer damage the retention/carrier system 44 with its filter housing-associated retention/carrier parts 50 and filter element-associated retention/carrier parts 54.

[0128] A filter 10 that essentially corresponds to the filter 10 shown in FIG. 9 is shown in FIG. 10; a difference exists only with regard to the filter element 24 used, wherein here it is the filter element 24 shown in FIG. 6, which has no central tube and for which the filter element-associated retention/carrier 48 is present on a separate carrier ring 541. The implementation of the free-running property of the hollow filter element 24 with respect to the housing cover 15 is in turn realized by the bypass valve housing 321, which is rotatably mounted in the housing cover 15; reference is being had to the description of FIG. 9 in this context.

[0129] A bypass valve 32 having a bypass valve housing 321 for a filter 10 according to a further embodiment is shown in FIG. 11. The filter housing-associated retention/carrier parts 50 are constructed in this case of one receptacle body 50′ and one clamping body 50″ each, which are spaced at an axial distance from each other. The receptacle body 50′ has a receptacle groove 501, in which a radially extending pin 540 that is present on the hollow filter element 24 (see FIG. 12) can be accommodated. A clamping surface 502 is provided on the clamping body 50″ that faces the receptacle body 50′ and that can have a clamping effect on the pin 540 in a state in which the pin 540 is held in the receptacle groove 501. An axial protuberance is provided for both circumferential directions adjacent to the receptacle groove 501 by means of which the pin 540 of the hollow filter element 24 can be held. A space between the protuberances and the axially opposite clamping surface 502 is dimensioned in such a way that the pin 540 can slide across it by the effect of a prescribed engagement torque in order to be held in the receptacle groove 501.

[0130] Finally, a hollow filter element 24 according to this further embodiment is shown in FIG. 12. Four pins 540, which can have a cylindrical cross-section and extend radially inward are provided here as filter element-associated retention/carrier parts 54. The filter element-associated retention/carrier parts 54 are present on a carrier ring 541 or, more precisely, on its cylindrical section 541′. The design of the filter element-associated retention/carrier parts 54 as pins 540 has the advantage that, in the manufacture of the carrier ring 541, they can easily be demolded as plastic injection-molded parts, for example, using a rotary core. However, the design of the filter element-associated retention/carrier parts 54 as pins 540 is not limited to an embodiment having a carrier ring 541; rather, they can also be combined in embodiments of the hollow filter element 24 that have a central tube.

[0131] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.