Filter Element with Venting Function for Suspension on a Filter Head, and a Filter System

Abstract

A filter element for a fluid has a filter medium arranged in annular shape about a longitudinal axis to be flowed through by the fluid to be filtered radially. A coaxial outlet socket is arranged at an end of the filter element facing upwardly in filtering operation. The coaxial outlet socket has a fluid outlet channel for filtered fluid and a venting channel that vents a clean side and/or a raw side of the filter element. The venting channel coaxially surrounds the fluid outlet channel radially and extends at least in sections thereof in axial direction. A filter system is provided with a filter head that has a fluid inlet conduit, a fluid outlet conduit for filtered fluid, and a venting conduit, wherein the filter element is suspended from the filter head.

Claims

1. A filter element for a fluid to be filtered, the filter element configured to be suspended from a filter head, the filter element comprising: an annular filter medium, surrounding a longitudinal axis extending through an open interior of the annular filter medium; an first end disk fixed onto an covering a first axial end of the annular filter medium, the first end disk having a central opening; a coaxial tubular outlet socket, coaxial to the longitudinal axis and arranged at the first axial end of the filter element, the coaxial tubular outlet socket including: at least one actuating member embodied as an axially extending projection projecting axially outwardly away from an axially outer end of the coaxial tubular outlet socket, the at least one actuating member configured to contact against and actuate a valve body of the filter head; wherein the coaxial tubular outlet socket comprises a fluid outlet channel for filtered fluid and a venting channel configured to vent a clean side and/or a raw side of the filter element, wherein the venting channel coaxially surrounds the fluid outlet channel in the radial direction and extends at least in sections thereof in an axial direction of the longitudinal axis, wherein the venting channel at an inlet side is connected by a first capillary channel with a raw side of the filter medium which is upstream of the filter medium relative to fluid flow, wherein the first capillary channel is arranged at a radially outer side of the venting channel and circumferentially surrounding the venting channel and the fluid outlet channel, wherein the raw side is arranged in a fluid flow direction upstream of the filter medium. wherein the first capillary channel is delimited in the radial direction inwardly by the coaxial outlet socket.

2. The filter element according to claim 1, wherein the at least one actuating member is at least two actuating members; wherein a radial through opening for the filtered fluid is formed between two of the at least two actuating members.

3. The filter element according to claim 1, wherein the venting channel at the inlet side is connected by a second capillary channel with the clean side of the filter element, wherein the clean side is arranged in the fluid flow direction downstream of the filter medium.

4. The filter element according to claim 1, wherein the second capillary channel is delimited in the radial inward direction by an end section of a tubular support body of the filter element, wherein the second capillary channel is delimited radially outward by the first end disc of the filter element, wherein the tubular support body is a central tube of the filter element.

5. The filter element according to claim 4, wherein the end section of the tubular support body engages in the axial direction an annular groove of the first end disc, wherein the annular groove is delimited in the radial direction inwardly by a first wall section and outwardly by the second wall section, wherein the first and second wall sections are connected to each other by a back section, and wherein the first and second wall sections and the back section are formed together as one piece.

6. The filter element according to claim 1, wherein the first and second capillary channels are connected in fluid communication to the venting channel by a siphon.

7. The filter element according to claim 1, wherein at least one of the first and second capillary channels extends at least in sections thereof in the axial direction.

8. The filter element according to claim 1, wherein at least one of the first and second capillary channels extends at least in sections thereof in a spiral shape about the longitudinal axis.

9. The filter element according to claim 2, further comprising a second end disc, wherein the filter medium is arranged between the first end disc and the second end disc in the axial direction and fastened with end faces thereof to the first end disc and the second end disc.

10. The filter element according to claim 9, wherein the filter medium is glued or welded to the first end disc and the second end disc or arranged so as to be held by being embedded in a material of the first end disc and the second end disc.

11. The filter element according to claim 1, wherein the filter element is a filter insert or an enclosed exchangeable filter.

12. The filter element according to claim 1, wherein the filter element comprises at least one bayonet connecting part of a bayonet connection configured to detachably couple the filter element with at least one housing component of a filter system.

13. The filter element according to claim 12, wherein the at least one bayonet connecting part is arranged at an end of the filter element that is facing away from the coaxial outlet socket.

14. The filter element according to claim 13, wherein the at least one bayonet connecting part points downwardly in the vertical direction in the filtering operation of the filter element.

15. A filter system for a fluid to be filtered, the filter system comprising: a filter head comprising: a fluid inlet conduit for the fluid to be filtered, a fluid outlet conduit for the filtered fluid, and a venting conduit; a filter element, configured to be exchangeably connected to the filter head, according to claim 1.

16. The filter system according to claim 15, wherein the filter head further comprises a valve body arranged in the fluid outlet conduit and configured to be transferred, by connecting the filter element to the filter head, from a closed position that fluid-tightly closes off the fluid outlet conduit into an open position that opens the fluid outlet conduit.

17. The filter system according to claim 16, wherein the filter head further comprises a spring element acting on the valve body, wherein the valve body is transferable against the force of the spring element from the closed position into the open position.

18. The filter system according to claim 16, wherein the filter head comprises a housing pot and the filter system further comprises a housing cover detachably fastened to the housing pot, wherein the housing cover and the housing pot together form a filter housing in which the filter element is arranged.

19. The filter system according to claim 18, wherein the housing cover is configured to be screwed into the housing pot or screwed onto the housing pot.

20. The filter system according to claim 18, wherein the filter element comprises a bayonet connecting part and is coupled detachably with the bayonet connecting part to at least one corresponding bayonet connecting part provided at the housing cover of the filter system.

21. A filter element for a fluid to be filtered, the filter element configured to be suspended from a filter head, the filter element comprising: an annular filter medium, surrounding a longitudinal axis extending through an open interior of the annular filter medium; an end disk fixed onto an covering a first axial end of the annular filter medium, the end disk having a central opening, the end disk forming a first U-shaped annular socket having: an annular second wall section formed as an axially outwardly projecting annular wall on the end disk, the annular second wall section surrounding the central opening of the end disk and projecting axially outwardly away from the annular filter medium; and a first annular wall section formed as an axially projecting annular wall arranged in an interior of the annular second wall section and surrounding the central opening of the end disk, wherein an axially outer portion of the annular second wall section is joined to an axially outer portion of the first annular wall section by a back section of the end disk, such the first U-shaped annular socket opens in a direction towards the annular filter medium; a central tube arranged in the interior of the annular filter medium, the central tube forming a second U-shaped annular socket having: an annular end section formed at an axial end if the central tube, projecting into and engaging into the first U-shaped annular socket of the end disk; and an angled rim section formed at the axial end if the central tube and projecting axially outwardly to contact against a radially inner side of the first annular wall section of the end disk; a venting channel configured to vent a clean side and/or a raw side of the filter element, wherein the venting channel coaxially surrounds the fluid outlet channel in the radial direction and extends at least in sections thereof in an axial direction of the longitudinal axis, wherein the venting channel at an inlet side is connected by a first capillary channel with a raw side of the filter medium which is upstream of the filter medium relative to fluid flow, wherein the first capillary channel is arranged at a radially outer side of the venting channel and circumferentially surrounding the venting channel and the fluid outlet channel, wherein the raw side is arranged in a fluid flow direction upstream of the filter medium.

22. The filter element according to claim 21, wherein a second capillary venting channel is formed in the first U-shaped annular socket of the end disk by a groove formed into either the annular second wall section of the end disk or into the annular end section of the central tube; a coaxial tubular outlet socket engaging onto the angled rim section of the central tube, the coaxial tubular outlet socket and the angled rim section of the central tube forming a central fluid outlet channel; a first capillary venting channel formed between the coaxial tubular outlet socket and the first annular wall section of the top end disk by a groove formed into either the coaxial tubular outlet socket or the first annular wall section of the top end disk.

23. The filter element according to claim 22, wherein the groove forming the first capillary venting channel and/or the second capillary venting channel is a spiral groove, extending as a spiral about the longitudinal axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be explained in the following in more detail with an embodiment illustrated in the drawing.

[0029] FIG. 1 shows a filter system with a filter head and a filter housing for exchangeable accommodation of a filter element, in a perspective view.

[0030] FIG. 2 shows the filter system according to FIG. 1 in a section illustration.

[0031] FIG. 3 shows an exposed view of the filter head of the filter system according to FIG. 1, in a section illustration.

[0032] FIG. 4 shows an enlarged illustration of the detail of the filter system referenced in FIG. 1 with “E”, in a section illustration.

[0033] FIG. 5 shows an enlarged illustration of the detail of the filter system identified in FIG. 2 with “D”, in a section illustration.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0034] In FIGS. 1 and 2, a filter system 10 for filtering contaminants contained in a liquid medium or fluid 12, for example, fuel or oil, is illustrated. The filter system 10 comprises a filter head 14 with a housing pot 16 and a housing cover 18 which can be screwed onto or screwed into the housing pot 16. The housing pot 16 and the housing cover 18 thus form together a filter housing 20 that serves for accommodating a filter element embodied as a filter insert. The filter head 14 comprises according to FIG. 1 a fluid inlet conduit 22 for the fluid 12 to be filtered, a fluid outlet conduit 24 for the filtered fluid as well as a venting conduit 26 through which gas or air collected in the filter element can flow out. The longitudinal axis of the filter system 10 is identified by 28.

[0035] In FIG. 2, the filter system 10 is illustrated in a longitudinal section view. The filter element 30 is connected to the filter head 14, detachably suspended from a connecting region 32 of the filter head 14. The filter element 30 extends thus in the filtering operation in vertical direction 34 downwardly away from the filter head 14. The housing pot 16 comprises an opening 36 which points in vertical direction 34 downwardly in the operational use of the filter system and which, by means of the housing cover 18, can be closed off fluid-tightly and pressure-tightly. According to FIG. 2, the filter element 30 can be detachably coupled by means of a bayonet connection or closure 38 with the housing cover 18. In this way, the filter element 30 can be detached in a simplified way and with a minimal risk of soiling from the filter head 14 and removed from the housing pot 16 or connected to the filter head 14. When the housing cover 18 is comprised of a translucent material, the bayonet closure 38 as well as the exchange of the filter element 30 can be visually controlled and in this way further simplified as a whole.

[0036] The fluid outlet conduit 24 of the filter head 14 is provided with a valve body 40. Here, the valve body 40 is slidably supported in a valve seat 42 of the filter head 14. According to FIG. 2, the valve body 40 can be designed in a cylinder shape and can be moved against the force of a spring element 44 from a closed position illustrated in FIG. 3 into its open position illustrated in FIG. 2. An opening stop 46 of the filter head 14 can be formed, for example, by a closure screw 48 of the filter head 14. By the closure screw 48, the valve seat 42 after mounting of the valve body 40 can be closed in a simple way. At the same time, a type of revision access to the valve seat 42 can be provided in this way. A closure stop 50 of the valve body can be provided according to FIG. 3 by an annular shoulder of the filter head 14 or, as an alternative, by a spring ring which is inserted into a groove, or something similar.

[0037] According to FIG. 2, the filter element 30 comprises a top and a bottom end discs 52, 54. The end discs 52, 54 are here an integral component of the filter element 30 embodied as a filter insert. A filter medium 56 is arranged between the two end discs 52, 54. The filter medium 56 is arranged in an annular shape relative to the central or longitudinal axis of the filter element 30 and can be embodied in particular in the form of a star-shaped folded bellows. The filter medium 56 is fluid-tightly connected to the two end discs 52, 54, respectively. For example, the filter medium 56 can be glued or welded to the end discs 52, 54 or can be fluid-tightly embedded in the material of the end discs 52, 54. Here, the filter medium 56 is configured to be flowed through by the fluid 12 in the operational use (=filtering operation) in the direction of a radial direction relative to the longitudinal axis 58 of the filter element 30 from the exterior to the interior. A mesh-shaped support or central tube 60 serves for radial inner support of the filter medium 56. The central tube 60 surrounds the longitudinal axis 58 of the filter element 30. The filter medium 56 can rest against the central tube 60 directly or indirectly.

[0038] The bottom end disc 54 comprises here a preferably elastomeric sealing element 62 for a sealing seat of the filter element 30 at the housing cover 18. A raw side of the filter element 30 that is upstream of the filter medium 56 in fluid flow direction is identified at 64 and the clean side of the filter element 30 that is downstream of the filter medium in fluid flow direction is identified at 66 as a whole.

[0039] The filter element 30 comprises at its end 68, facing upwardly in vertical direction 34 in filtering operation, a coaxial outlet socket 70 with, here, a central fluid outlet channel 72 for the filtered liquid medium 12 and with a venting channel 74 for venting of the filter element 30 at the clean side and raw side. The coaxial outlet socket 70 extends in axial direction into the filter head 14. The coaxial outlet socket 70 can be seal-tightly resting externally in radial direction at the filter head 14 by means of sealing elements 62. A venting channel 74 surrounds the fluid outlet channel 72 at least in sections thereof in a radial direction relative to the longitudinal axis 58 of the filter element 30. The coaxial outlet socket 70 comprises in other words two socket segments 70a, 70b arranged to extend coaxially and embodied here together as one piece between which the venting channel 74 is formed. The coaxial outlet socket 70 is here arranged, held by clamping, in a central opening of the first (top) end disc 52 of the filter element 30 in radial press fit. The coaxial outlet socket 70 is resting circumferentially in radial direction inwardly at a central tube 60, in particular the rim section 96, and in radial direction outwardly at the top end disc 52 of the filter element 30. In addition to the central tube 60, the filter element has presently a coaxially arranged end separator arranged therein which essentially also constitutes a central tube. End separator is to be understood, for example, as a hydrophobic screen that is permeable for fuel and retains water. The end separator comprises, for example, a support structure on which, radially inwardly or outwardly, a screen fabric with a predetermined mesh width is fastened. Therefore, it can be in particular provided that a section of the end separator comprises the aforementioned rim section 96 at which the coaxial outlet socket 70 is resting radially inwardly.

[0040] According to FIG. 2, at one end of the coaxial outlet socket 70 one or a plurality of actuating members 76 for the valve body 40 of the filter head 14 are arranged. The actuating members can be formed in particular integrally at the coaxial outlet socket 70 so that the latter is embodied as an injection-molded part. The actuating member or members 76 extend preferably in axial, in particular precisely axial, direction away from the coaxial outlet socket 70. Between at least two of the plurality of actuating members 76 illustrated in the embodiment, a radial through opening 78 for the filtered fluid is formed so that the filtered fluid 12 can flow out of the fluid outlet channel of the coaxial outlet socket via the fluid outlet conduit 24 of the filter head 14.

[0041] For venting the raw side 64 of the filter element 30, a first capillary channel 80 is provided which, according to FIGS. 2 and 4, is in fluid communication with the venting channel 74. For venting the clean side 66 of the filter element 30, a second capillary channel 82 is provided which, at the outlet side, is in fluid communication with the venting channel 74.

[0042] The first or top end disc 52 of the filter element 30 comprises an annular groove 84 which is open toward the second end disc 54, i.e., in filtering operation downwardly in vertical direction 34. The annular groove 84 is delimited in radial direction inwardly by a first wall section 86 of the top end disc 52 and in radial direction outwardly by a second wall section 88 of the top end disc 52, wherein the first and the second wall sections 86, 88 are connected by a back section 90 to each other as one piece. The first capillary channel 80 is delimited in radial direction inwardly by the coaxial outlet socket 70 and in radial direction outwardly by the first wall section 86 of the end disc 52. The second capillary channel 82 is delimited in radial direction, on the one hand, by an end section 92 of the central tube 60 which engages the annular groove of the top end disc 52 and, on the other hand, by the second wall section 88 of the top end disc 52. The two capillary channels 80, 82 can be arranged so as to extend spirally about the longitudinal axis 58 of the filter element 30, respectively. Each capillary channel 80, 82 is connected in fluid communication by a siphon 94 with the venting channel 74.

[0043] The coaxial outlet socket 70 is here embodied as one piece. Alternatively, the coaxial socket can also be of a multi-part configuration. In the latter case, the socket segments 70a, 70b preferably comprise spacer elements in the form of ribs, knobs or the like, by means of which the two tubular sockets are resting against each other in sections thereof.

[0044] In FIG. 5, the detail of the filter system 10 that is identified in FIG. 2 by “D” is shown in enlarged illustration. The coaxial outlet socket 70 is positioned at the inner circumference circumferentially at an angled rim section 96 of the central tube 60 in a seal-tight way. The rim section 96 and the coaxial outlet socket 70 in this context can be in a mutual threaded engagement in order to secure the coaxial outlet socket 70 at the central tube 60 in a pull-resistant way. Alternatively, the rim section 96 and the coaxial outlet socket 70 can be connected by a snap connection, in particular an annular snap connection.