Filter element for use in a filter and filter having a filter element

Abstract

The invention relates to a filter element (2), in particular a replaceable filter element, in particular for separating particles and / or gases and / or liquids, in particular a filter cartridge, for use in a filter, in particular a compressed air filter, in particular as part of a filter having a plurality of filter stages, comprising a substantially tubular main body (27) having an annular end side (21) facing towards a filter head, a lower side (28), a circumferential surface (29), wherein in the region of the end side (21) a plurality of, preferably four, retaining arms (30) extending radially with respect to a central axis (18) are provided, and a circular annular filter element sealing surface (6) is provided at the end side (21), wherein the retaining arms (30) project with respect to the filter element sealing surface (6). The invention also relates to a filter having such a filter element (2).

Description

TECHNICAL FIELD

[0001] The invention relates to a filter element, in particular a replaceable filter element, in particular for separating particles and / or gases and / or liquids, in particular a filter cartridge, which is used in a filter, in particular a compressed air filter, as part of a filter having a plurality of filter stages. The filter element comprises a substantially tubular main body having an annular end side facing towards a filter head, a lower side spaced apart from the end side facing away from the filter head, a peripheral surface extending along a central axis, in particular a rotational axis, wherein the peripheral surface connects the end side and the lower side to one another. A plurality of, preferably four, holding arms extending radially with respect to the central axis are provided in the region of the end side, wherein a circular annular filter element sealing surface is also provided at the end side.

[0002] The invention also relates to a filter having such a filter element. BACKGROUND

[0003] Filter elements are generally used for filtering a flowable medium in a filter. Such a medium can be, for example, a gas, but also a liquid, for example water or fuel, etc. The filter element is traversed by the medium to be filtered, wherein impurities are separated out. Such a filter element generally has a main body in which the filtering medium is present which is traversed. A filter head is generally provided via which the fluid to be filtered is fed and the filtered fluid is discharged. Furthermore, similar filter elements have a securing device by means of which the filter element can be secured with respect to the filter head in order to be sealed with respect to the filter head via a sealing body. To this end, the filter element can be, for example, screwed directly to the filter head. Another type of securing takes place via a filter sleeve or filter head, wherein the filter element is inserted into the filter sleeve and abuts against the closed end of the filter sleeve. Here, the closed end of the filter cartridge forms a seat for the filter head, wherein the filter element is clamped between the filter head and the seat.

[0004] The filter element mentioned at the outset is known from US 2007 / 0095744 A1. There, it is a fluid filter having a replaceable filter cartridge, which has a tubular main body, a closed end and an annular open end side. Furthermore, a holding arm is provided, which is in a recess in the open side of the filter sleeve, wherein the holding arm is retracted with respect to a filter element sealing surface, at which the filter element seals towards the filter head. SUMMARY

[0005] The invention is based on the object of providing a filter element having a structurally improved holding piece.

[0006] The filter element according to the application can be designed as a replaceable filter element for use in a filter, in particular for separating particles and / or gases and / or liquids, in particular in the form of a filter cartridge.

[0007] The filter element comprises a substantially tubular main body having an annular end side facing the filter head. Furthermore, a lower side spaced apart from the end side facing away from the filter head is provided.

[0008] The filter element also has a circumferential surface which extends along the central axis, in particular the rotational axis, and connects the end side and the lower side to one another. In the region of the end side, a plurality of, preferably four, holding arms extending radially with respect to the central axis are provided. A (circular) annular filter element sealing surface is provided at the end side, wherein the holding arms project with respect to the filter element sealing surface. Here, the holding arms serve for positioning the filter element and act as a holder for the filter cartridge, thus explicitly determining the position of the filter cartridge with respect to the filter head. Thereby, a flow through the filter element as determined by the above-described configuration is achieved.

[0009] Due to the holding arms projecting with respect to the filter element sealing surface, an advantageous force introduction is achieved. Furthermore, the projecting holding arms protect the filter element sealing surface from damage when transporting the filter element or when operating / installing the filter element. Furthermore, a material build-up in production can be prevented.

[0010] If an explicit rotational position is desired, at least one of the holding arms can be designed differently from the other holding arms, which then engage into a corresponding receiving device at the filter cartridge.

[0011] The cross section of the holding arms can be substantially L-shaped. The holding arms can also project radially outward with respect to the filter element sealing surface. It is also advantageous if the holding arms project radially outward at the circumferential surface. With holding arms designed in this way, a particularly advantageous fixation of the filter element towards the filter head can be provided.

[0012] The holding arms are preferably fixedly connected to the filter element sealing surface, preferably configured in one piece with the filter element sealing surface. This achieves a positioning of the holding arms with respect to the filter element sealing surface, whereby an optimal positioning of the filter element with respect to the remainder of the filter is ultimately achieved.

[0013] It is particularly advantageous if the holding arms each have a support surface which points in a direction opposite to that of the filter element sealing surface, wherein the support surface is preferably convexly arched. The convex arching of the support surface extends in the axial direction, wherein the support surface is connected to the free end of the holding arm and has a length in the radial direction of at least 3 mm and at most 10 mm. Thereby, a particularly advantageous force transmission between the holding arms and the filter element sealing surface is achieved. Furthermore, the accommodation of the holding arms in the respective recesses is simplified.

[0014] Additionally, a centering bevel can be provided at the transition between the holding arm and the circumferential surface. Here, the centering bevel extends from the circumferential surface in the direction of the holding arm at an angle of between 5° and 70°, preferably between 20° and 40°, with respect to the center axis. Here, the centering bevel connects the circumferential surface and the support surface to one another. By means of the centering bevel, the positioning of the filter element with respect to the filter head and in the filter sleeve is improved or aligned in the filter sleeve and kept at a certain distance therefrom.

[0015] The holding arm can also have an end surface at the exposed end of the holding arm, which points away from the circumferential surface in the radial direction. Preferably, the distance between the center of the filter element sealing surface and the end surface in the radial direction is between 12 and 18 mm, wherein the distance from the center of the filter element sealing surface can also be between 14 and 16 mm. The minimum distance between the filter element sealing surface and the support surface is between 0 and 4 mm in the axial direction, preferably between 1 and 2 mm. The maximum distance between the filter element sealing surface and the support surface is between 4 and 6 mm. By this dimensioning of the holding arm, an especially stable fit of the holding arm in the corresponding recess is ensured. Furthermore, the end surface serves as an engagement area for removing the filter element from the surrounding filter sleeve, thus simplifying the exchange of the filter element.

[0016] Furthermore, the filter element can be designed such that substantially only an axial force acts on the filter element sealing surface, wherein preferably the holding arm forms a seat against which the axial force is exerted. Here, the axial force is formed by the pressing of a sealing body against the filter element sealing surface. The holding arm can be flexible in the axial direction and serves as a compensation element between the sealing body and the receiving device for the holding arm.

[0017] Furthermore, the sealing body lies against the (circular) ring-shaped filter element sealing surface of the filter element, such that the sealing body separates an outer space, which lies outside the filter element, from an inner space, which lies inside the filter, from one another between the filter head and the filter element. Thereby, the clean gas space is separated from the raw gas and a particularly advantageous connection is created between the filter element and the filter head.

[0018] As a further design feature, the substantially tubular filter sleeve can be provided with an open filter sleeve end side facing the filter head and a filter sleeve outer side running along the side surface, wherein the filter sleeve preferably surrounds the filter element and is separated from the environment. Furthermore, the filter sleeve end side can have a receiving device for holding the arm, wherein the filter element is in contact with the filter sleeve only via the holding arm arranged in the receiving device and the filter element is configured with other parts hanging freely in the filter sleeve. This connection between filter head, filter cartridge and filter sleeve can be realized with particularly few additional components and via simple geometry and is thus particularly inexpensive.

[0019] The receiving device can be formed at least by a continuous cutout, which begins at the filter sleeve end side and runs radially with respect to the central axis, the receiving device preferably accommodating the holding arm. Furthermore, the end of the cutout can form a bearing, which is concavely shaped in a manner matching the convex support surface of the holding arm. Here, the bearing absorbs the forces resulting from the pressing and pressure load of the sealing body. A particularly simple positioning of the filter element is achieved by the cooperation between the receiving device and the holding arm, wherein a simultaneous compensation of the sealing body as well as dimensional deviations is achieved.

[0020] The sealing body can be an axially acting seal. Furthermore, the filter sleeve can be sealed towards the filter head by means of a radial seal. In order to form a closed space around the filter element, the filter sleeve can be configured in the form of a pot and accordingly closed at the end facing away from the filter head. On the one hand, this form of seal enables a simple installation of the filter cartridge, on the other hand it can be realized in a particularly space-saving manner.

[0021] At least two of the receiving devices can be configured as receiving locking devices for accommodating the holding arm and a holding peg. The holding peg is preferably attached at the filter head and can be directed radially to the central axis.

[0022] The receiving locking devices are advantageously designed such that the holding peg cooperates with the receiving locking devices in the form of a bayonet connection. A particularly simple exchange of the filter element is achieved by this design, wherein a sufficient axial movement for clamping the sealing body is achieved at the same time.

[0023] For the implementation of the bayonet connection, the receiving locking device has, in addition to the axial cutout of the receiving device, a securing expansion which is preferably formed by a further cutout which extends away from the axial cutout and which extends substantially in the circumferential direction around a portion of the filter sleeve. Additionally, the securing expansion can have a locking undercut which is formed by a recess on the filter head side in the end region of the securing expansion. A bayonet connection designed in this way can be produced particularly inexpensively and enables a particularly secure fixing of the filter sleeve at the filter head, which fixing is ensured by the locking undercut itself in the case of a pressure loading of the filter.

[0024] A further embodiment relates to a filter having at least two filter stages. The filter elements have, for example, different filter properties. The sealing devices for the sealing between the filter elements and the filter head are preferably substantially of the same type. Additionally or alternatively, the receiving devices of the filter sleeve and the holding arms of the filter elements can be substantially of the same type.

[0025] In such a filter system, the seals between the filter elements and the filter head, the filter element-side sealing surface and the filter head-side sealing surface, the receiving devices of the filter sleeve or the holding arms of the filter elements of the different filter stages can be configured identically.

[0026] Such a filter element or sealing device between the filter element and the filter head is designed in such a way that the filter element or the sealing device can be loaded with greater pressure from the outside than from the inside. Preferably, at least one of the filter elements or one of the sealing devices of the entire filter is loaded with pressure in the opposite direction. Thereby, a uniform construction of the different filter stages can be provided. Furthermore, by means of such a construction, the filter elements can be loaded or flowed through from the outside to the inside and from the inside to the outside. Preferably, one of the filter elements is flowed through in the radial direction from the inside to the outside, and the other filter element is flowed through from the outside to the inside, i.e. towards the central axis.

[0027] Such a sealing device can be used, for example, as a seal between a filter element and a filter head of a filter having a plurality of filter stages, especially in the field of compressed air filters. Such a filter element is preferably a filter cartridge.

[0028] The sealing device comprises a ring-shaped, elastic sealing body, a filter head and a filter element sealing face. The sealing body has a filter head side facing towards the filter head sealing face, an oppositely situated filter element side facing towards the filter element sealing face, an inner face which surrounds on the inside, and oppositely situated outer faces which surround at the side surface. The filter head side comprises a surrounding first recess between the inner face and the outer face, wherein the filter element side has a surrounding second recess between the inner face and the outer face. The filter head side at least locally surrounds against the filter head sealing face, wherein the filter element side at least locally surrounds against the filter element sealing face. The filter head sealing face and the filter element sealing face are formed at least by a surrounding inner face and a surrounding outer face.

[0029] Here, the faces of the filter head sealing face and the filter element sealing face rise towards the centre between the faces, so that the spacing of the inner faces from one another is reduced from the inside out and the spacing of the outer faces is reduced from the outside in, essentially in the direction of the centre axis of the sealing body. The faces cooperate with the recesses, so that the sealing body is wedged between the inner faces and / or the outer faces in the case of a pressure loading of the sealing body from the inner face and / or the outer face in the direction of the force.

[0030] By means of the faces which rise towards the centre, an intermediate constriction is formed between the filter head sealing face and the filter element sealing face, which expands outwards from the middle between the two faces on both sides. The constriction cooperates with the corresponding tapering of the sealing body. If the sealing body is loaded with pressure from the inner face or the outer face, the sealing body is pressed against the inclined side walls of the constriction, which are on the side of the force action. Here, the sealing body is inflexible, so that it is not strongly compressed by the pressure loading in normal use, so that the sealing body is pressed through the constriction in the direction of the force action.

[0031] By means of the pressing of the sealing body into the constriction, a wedging or higher compression of the sealing body between the oppositely situated sealing faces is obtained, which in turn leads to an increase in the sealing action. This results in the pressure loading obtained on the outer circumferential surface and on the inner circumferential surface.

[0032] The sealing action is automatically strengthened on an increase in the load from the inner face or the outer face.

[0033] In particular, in the case of a pressure difference between the inner face and the outer face, the sealing cooperation between the faces and the recesses is strengthened by the cooperation between the force and the wedging action. If a greater pressure is applied to the sealing body by means of the pressure difference at the inner face or the outer face of the sealing body than is applied on the oppositely situated face, the sealing body is pressed in the direction of the force, wherein the space between the faces is reduced in this direction. From the cooperation between the force and the constriction between the filter head sealing face and the filter element sealing face, a wedging action results. By means of the wedging action, the sealing is pressed more strongly against the faces, whereby the sealing action is strengthened with the rise in the pressure difference.

[0034] Furthermore, by the ramp-like design an easier positioning of the sealing or filter element relative to the filter head is achieved.

[0035] It is particularly advantageous if the sealing body has a circumferential holding groove on the filter head side for accommodating a holding element. In particular, the holding element is designed to form a detachable locking connection in a manner cooperating with the holding groove, wherein the locking connection holds the filter head side of the sealing body in abutment against the filter head sealing face. Here, the holding groove extends in the region of the recess, preferably in the bottom of the first recess. The holding element protrudes between the two partial faces of the filter head sealing face. Preferably, the holding element protrudes along a circular ring relative to the filter head sealing face. By this locking connection the sealing body can be reliably held at the filter head, wherein the exchange of the sealing body is particularly simplified in case of damage.

[0036] It is also particularly advantageous if the second recess extends at least over half of the width of the filter element side between the inner face and the outer face, preferably over more than two thirds thereof. Additionally, the first recess extends at least over half of the width of the filter head side between the inner face and the outer face, preferably over more than two thirds thereof. By this design it is possible to ensure an especially good sealing fit, since two almost linear sealing faces are formed which in turn prevent the affected faces from being pressed.

[0037] It is therefore also particularly advantageous if the sealing body does not abut against the filter element sealing face in the circumferential partial region of the second recess, preferably in the region of the lowest point of the second recess. It is particularly advantageous if the sealing body does not abut against the sealing body at least locally in the region closest to the filter head sealing face. Thus, a first outer sealing face and a second inner sealing face can be created, which have similar sealing properties, thereby ensuring a similar two-sided loadability of the sealing.

[0038] The holding element and the holding groove can be designed such that a sealing fit exists between the bottom of the holding groove and the region of the holding element closest to the filter element sealing face. This is preferably achieved in that the depth of the holding groove in axial direction is smaller than the height of the holding element in axial direction in the state in which the sealing body is not installed. This achieves that a ring-shaped sealing with small area is created, which already seals fluid-tight in the case of weak pressing of the sealing body.

[0039] The locking connection can be formed by a one-sided expansion at the retaining element and a corresponding recess in the seal body, wherein the expansion projects outwards in the radial direction relative to the central axis of the seal body. Here, the opposite side of the retaining element is not provided with a protrusion and is flat in the direction of the central axis. The cross-section of the retaining element is thus essentially L-shaped. A retaining element designed in this way ensures that the service life of the seal body is maximised, since the retaining groove is loaded only on the outside.

[0040] It is particularly advantageous if the seal body has a hardness of between 60 Shore A and 90 Shore A, preferably between 60 Shore A and 80 Shore A, particularly preferably 70 Shore A. This ensures that the seal body is sufficiently elastic for the seal between the sealing surfaces and at the same time sufficiently rigid in order to ensure a wedging action to the desired extent.

[0041] It is also advantageous if the partial surfaces of the filter head sealing surface and / or the filter element sealing surface have an internal angle a of less than 180°, preferably between 130° and 170°, in the radial direction relative to the central axis. A particularly advantageous range lies between 145° and 155°. By means of this angle, a particularly advantageous distribution of the forces and the formation of a wedging action can be ensured.

[0042] It is also particularly advantageous if the filter head side of the seal body has two circular annular surrounding sealing partial surfaces, the retaining groove extends into the seal body between the sealing partial surfaces and the two sealing partial surfaces form an external angle a1 of less than 180°, preferably between 125° and 175°, in the radial direction relative to the central axis. A particularly advantageous range here lies between 140° and 150°. Thus, an optimum interaction between the sealing surface of the filter head side and the sealing partial surfaces on the filter head side of the seal body is ensured, in turn ensuring a high sealing action and the formation of a wedging action.

[0043] It is also advantageous if, in the uninstalled state, the second recess has a greater depth in the direction of the central axis than the height offset of the partial surface. The height offset of the partial surface is understood here to be the distance along the axial direction over which the partial surface extends opposite the filter head. Preferably, the height of the partial surface is less than 70% of the depth of the second recess. By means of the greater depth of the second recess, a gap is provided between the filter head sealing surface and the filter element sealing surface which compensates for inaccuracies in the positioning of the two surfaces relative to one another.

[0044] In a further particularly preferred embodiment, the sealing device is designed for use in a filter in which the filter element of the filter follows the filter head along an installation axis which runs parallel to or is identical to the central axis of the seal body. This enables particularly simple installation and removal of the filter element.

[0045] The filter head of the corresponding filter preferably has a hollow-cylindrical filter sleeve end-side recess which extends from the lateral side of the end side and substantially axially symmetrically with respect to the central axis of the filter element into the filter head and accommodates the filter sleeve end side. Here, the filter sleeve end-side recess is located radially with respect to the central axis outside the filter head sealing surface. This achieves a particularly compact configuration.

[0046] Furthermore, the corresponding filter head can have two radially extending retaining pin holes with respect to the central axis, which are preferably opposite one another, wherein the retaining pin holes accommodate retaining pins which are part of the bayonet connection. Preferably, a metal-on-metal conical seal for sealing towards the environment is provided between the retaining pin and the filter head. A particularly simple and inexpensive production is achieved by this design.

[0047] It can also be particularly advantageous if the sealing device is configured such that the inner face and the outer face of the sealing body do not abut against the filter head side nor against the filter element side. Correspondingly, the sealing body is substantially sealed with respect to the filter head sealing surface and the filter element sealing surface only via an axial force. Such an axial sealing of the sealing body likewise achieves a particularly simple installation and removal of the filter element, since significantly less path is required in the axial direction to achieve a sufficient sealing action.

[0048] The installation state of the filter element with the compressed sealing body is in principle in the above embodiments as far as this is relevant for the corresponding explanation. In this state, the sealing body seals between the inner space and the outer space. Insofar as the embodiments refer to a removal state with the uncompressed sealing body, this will be explicitly mentioned.

[0049] The filter according to the invention can have only the main features as well as any combination of the other described features. Furthermore, the various features of the embodiments can also be combined with one another arbitrarily even in different embodiments. In addition to this, the invention also relates to a filter having the described filter element, to a filter having the described sealing device, as well as to the sealing device and the filter element itself, or any combination of the filter element and the sealing device. BRIEF DESCRIPTION OF DRAWINGS

[0050] In the following, the invention is explained on the basis of the described figures. The figures show:

[0051] Figure 1 a partial view showing a cross section of a filter stage with a sealing device and a filter element,

[0052] Figure 2 a partial view showing a cross section of a sealing device,

[0053] Figure 3 an enlarged partial view showing a cross section of a sealing device,

[0054] Figure 4 diagram showing the force action of the seal body on the axial and circumferential sides,

[0055] Figure 5 diagram showing a perspective view of a filter element,

[0056] Figure 6 diagram showing a perspective view of a filter cartridge with a filter element,

[0057] Figure 7 diagram showing a partial sectional view of a lower view of a filter head, and

[0058] Figure 8 diagram showing a side view of a multi-stage filter. DETAILED DESCRIPTION

[0059] Figure 1 and Figure 2 A sealing device 1 for a filter, in particular a compressed air filter, is shown, which serves as a seal between a filter element 2, in particular a filter cartridge, and a filter head 3, in particular as part of a filter having a plurality of filter stages 45. Furthermore, an annular, elastic seal body 4, a filter head and filter element sealing surface 5, 6 is shown.

[0060] The seal body 4 has a filter head side 7 facing towards the filter head sealing surface 5, an oppositely situated filter element side 8 facing towards the filter element sealing surface 6, an inner face 9 which surrounds on the inside, and an oppositely situated outer face 10 which surrounds at the side surface. The filter head side 7 has a surrounding first recess 11 between the inner face 9 and the outer face 10, wherein the filter element side 8 likewise has a surrounding second recess 12 between the inner face 9 and the outer face 10.

[0061] The filter head sealing surface 5 and the filter element sealing surface 6 are composed at least of a surrounding inner part surface 13 and a surrounding outer part surface 14. It can be seen from the figures that the filter head side 7 abuts at least locally and in a ring around the filter head sealing surface 5, and the filter element side 8 abuts at least locally and in a ring around the filter element sealing surface 6. Here, the part surfaces 13, 14 of the filter head sealing surface 5 and the filter element sealing surface 6 rise towards the centre between the part surfaces 13, 14, so that in the axial direction towards the centre axis 18, the mutual spacing of the inner part surfaces 13 decreases from the inside outwards, and the spacing of the outer part surfaces 14 decreases from the outside inwards. It can also be seen that the inner face 9 and the outer face 10 of the seal body 4 abut neither on the filter head side nor on the filter element side, and accordingly seal only axially with respect to the centre axis 18.

[0062] Furthermore a radial seal 46 is shown, which seals the filter relative to the environment or ambient atmosphere between the filter head 3 and the filter sleeve 33. The seal 46 is a seal 46 which is sealed essentially via a force acting radially to the center axis 18.

[0063] It is also apparent from Figure 1 and Figure 2 that the facets 13, 14 cooperate with the recesses 11, 12 in such a way that, in the event of pressure loading in the direction of the force F1, F2 from the inner face 9 and / or the outer face 10, the seal body 4 is wedged between the inner facet 13 and / or the outer facet 14. The sealing fit between the facets 13, 14 and the recesses 11, 12 is strengthened by the wedging action, wherein the force action F1, F2 only occurs in the event of a pressure difference between the inner face 9 and the outer face 10. In Figure 4 the following forces are shown, which act on the sealing faces 5, 6 when the sealing device 1 is loaded on the outer face F1.

[0064] It is further apparent from Figure 1 that the sealing device 1 is designed for use in a filter, wherein the mounting of the filter element 2 at the filter head 3 takes place along a mounting axis which extends identically to the center axis 18 of the seal body 4.

[0065] The seal body 4 abuts against the circular annular filter element sealing face 6 of the filter element 2 and separates the outer space 31 outside the filter element 2 from the inner space 32 inside the filter element 2 from one another between the filter head 3 and the filter element 2.

[0066] Figure 3 It is shown that the seal body 4 has a surrounding holding groove 15 on the filter head side 7 for accommodating a holding element 16. The holding element 16 is designed to form a detachable locking connection 17 in a manner cooperating with the holding groove 15. The locking connection 17 holds the filter head side 7 against the filter head sealing face 5, wherein the holding groove 15 extends in the region of the recesses 11, 12, preferably in the bottom of the first recess 11. The holding element 16 projects between the two facets 13, 14 of the filter head sealing face 5. In particular, the holding element 16 projects along a circle relative to the filter head sealing face 5.

[0067] The second recess 12 extends at least through half the width of the filter element side 8 between the inner face 9 and the outer face 10, preferably more than two thirds thereof. The first recess 11 extends at least through half the width of the filter head side 7 between the inner face 9 and the outer face 10, preferably more than two thirds thereof.

[0068] In a circumferential partial region of the second recess 12, the seal body 4 does not abut against the filter element sealing face 6, which partial region is preferably in the region of the deepest point of the second recess 12. If visible, the seal body 4 does not abut in the region closest to the filter head sealing face 5.

[0069] It is likewise derived from Figure 3 and Figure 4 that the retaining element 16 and the retaining groove 15 are designed such that there is a sealing fit between the bottom of the retaining groove 15 and the region of the retaining element which is closest to the filter element sealing face 6, which is shown in Figure 4 . This is achieved in that the depth of the retaining groove 15 of the seal in the state in which the seal body 4 is not mounted is at least as great as the height of the retaining element 16 in the direction of the centre axis 18, preferably less than the height of the retaining element 16.

[0070] It is further shown that the locking connection 17 is formed by a one-sided expansion 19 at the retaining element 16 and a corresponding recess 20 in the seal body 4. The expansion 19 projects outwards in the radial direction with respect to the centre axis 18 of the Figure 1 shown in Figure 3 . The retaining element 16 is designed substantially L-shaped, which is shown mirror-inverted in .

[0071] The seal body 4 shown also has a hardness of between 60 Shore A and 80 Shore A, preferably 70 Shore A.

[0072] Figure 4 It is shown that the partial faces 13, 14 of the filter head sealing face 5 and the filter element sealing face 6 form an inner angle a of less than 180°, preferably between 130° and 170°, with respect to one another in the radial direction with respect to the centre axis 18. Furthermore, the filter head side 5 of the seal body 4 has two circular ring-shaped circumferential sealing faces 23, 24 between which the retaining groove 15 extends into the seal body 4. The two sealing faces 23, 24 have an outer angle a1 of less than 180°, preferably between 125° and 175°, with respect to one another in the radial direction with respect to the centre axis 18.

[0073] Since the seal body 4 is shown in Figure 4 in the extruded state, it is apparent that the second recess 12 in the direction of the centre axis 18 in the unmounted state has a depth which is greater than the extension of the partial faces 13, 14 towards the centre between the two partial faces 13, 14 in the direction towards the filter head 3. The shown extrusion of the seal body 4 is achieved, for example, if the height of the partial faces 13, 14 is less than 70% of the depth of the second recess 12.

[0074] From the inner face 9 and the outer face 10 of the seal it is visible that the seal 4 is an axially acting seal, which seals essentially only via axial forces.

[0075] Figure 5 A respective filter element 2 is shown, which is shown here as a filter cartridge. The filter element 2 has a filter element sealing face 6, which is recessed with respect to an end side 21 of the filter element 2. In other words, the end side 21 is formed by a surrounding flange 22, which protrudes with respect to the filter element sealing face 6.

[0076] The filter element 2 shown is a replaceable filter element 2, which can be used for separating particles and / or gases and / or liquids. In particular, it can be a filter cartridge, which can be designed for use in a filter, in particular a compressed air filter. Here, the filter can be equipped with a plurality of filter stages.

[0077] The filter element 2 shown comprises a substantially tubular main body 27 with an annular end side 21, which faces also the filter head 3 shown in Figure 1 and Figure 7 . Furthermore, the filter element 2 has a lower side 28, which is spaced apart from the end side 21 and which faces away from the filter head 3. Furthermore, the filter element 2 has a circumferential face 29, which extends along the central axis 18, in particular the rotational axis. As can be seen: The circumferential face 29 connects the end side 21 and the lower side 28 to one another. Furthermore, a plurality of, preferably three, in particular preferably four, retaining arms 30 are shown in the region of the end side 21, which extend radially with respect to the central axis 18. There is a circular annular filter element sealing face 6 at the end side 21. The retaining arms 30 protrude with respect to the filter element sealing face 6 and / or with respect to the end side 21.

[0078] The retaining arms 30 are substantially L-shaped. Furthermore, the retaining arms 30 protrude in an axial direction and in a radial direction outwardly with respect to the filter element sealing face 6 and / or the end side 21, wherein the retaining arms 30 protrude radially outwardly from the circumferential face 29.

[0079] It is also derived from Figure 5 that the retaining arms 30 are fixedly connected to the filter element sealing face 6, preferably are integrally manufactured with the filter element sealing face 6.

[0080] It is also derived that the holding arms 30 each have a support surface 47 which is directed counter to the direction of the filter element sealing surface 6. The support surface 47 is convexly curved. The convex curvature of the support surface 47 here extends in the radial direction with respect to the center axis 18, wherein the support surface 47 is connected to the free end of the holding arm 30, preferably to the end surface 49, and has a length in the radial direction of at least 2 mm and at most 8 mm. A length of between 3 and 6 mm is particularly advantageous. This dimensioning allows the filter element 2 to be removed simply and at the same time provides sufficient support surface 47 as a bearing for the receiving device 36.

[0081] The holding arms 30 have an end surface 49 at the exposed end of the holding arm 30 which is directed in the radial direction away from the circumferential surface 29 and thus away from the center axis 18. Here, the spacing between the center of the filter element sealing surface 6 and the end surface 49 in the radial direction with respect to the center axis 18 is between 12 and 18 mm. Particularly advantageously, the spacing between the end surface 49 and the center of the filter element sealing surface 6 is between 14 and 16 mm. The spacing between the filter element sealing surface 6 and the starting point of the support surface 47 in the axial direction is between 0 and 4 mm, preferably between 1 and 2 mm.

[0082] The filter element 2 is designed such that essentially only an axial force acts on the filter element sealing surface 6. The holding arms 30 form a bearing 50 for the axial force, which is formed by Figure 1 the pressing of the sealing body 4 shown in the middle against the filter element sealing surface 6.

[0083] It is particularly advantageous if the holding arms 30 are flexible in the axial direction and thus form a compensation element between the sealing body 4 which Figure 6 is pressed against the filter element sealing surface 6 and the receiving device 36 shown. The receiving device 36 receives the holding arms 30.

[0084] The filter element 2 has a centering chamfer 48 at the transition between the holding arm 30 and the circumferential surface 29, which has an angle of between 70° and 5° with respect to the center axis 18 and extends from the circumferential surface in the direction of the holding arm 30. It is particularly advantageous if the angle between the circumferential surface 29 and the centering chamfer 48 is between 20° and 40°. The centering chamfer 48 connects the circumferential surface 29 and the support surface 47 to one another, wherein the centering chamfer 48 serves for the centering of the filter element 2 in the surrounding filter sleeve 33.

[0085] Figure 6A substantially tubular filter sleeve 33 with a filter element 2 is shown, wherein the filter sleeve 33 has an open filter sleeve end side 34 facing the filter head 3 and a filter sleeve outer side 35 running along the lateral surface. The filter sleeve 33 surrounds the filter element 2 and separates the interior of the filter from the environment. The filter sleeve end side 34 has a receiving device 36 for holding the arm 30, wherein the filter element 2 is in contact with the filter sleeve 33 only via the holding arm 30 arranged in the receiving device 36, and the filter element is hanging in the filter sleeve 23 with other parts hanging free.

[0086] The receiving device 36 is formed at least by a continuous axial cutout 38, which begins at the filter sleeve end side 34 and runs radially with respect to the center axis 18, wherein the receiving device 36 receives the holding arm 30. The end of the cutout 38 forms a seat 50, which is concavely shaped to the convex support surface 47 of the holding arm 30, wherein the seat 50 absorbs the pressing forces formed by the pressing of the sealing body 4.

[0087] Two of the receiving devices 36 are designed to receive a locking device 51 for receiving the holding arm 30 and for receiving Figure 8 the holding peg 37 shown in the middle. The holding peg 37 is attached at the filter head 3 and points radially with respect to the center axis 18. The receiving locking device 51 is designed such that the holding peg 37 cooperates with the receiving locking device 51 in the form of a bayonet connection.

[0088] In addition to the axial cutout 38, the receiving locking device 51 has a fixed expansion 39, wherein the fixed expansion 39 is formed by a further cutout, which extends away from the axial cutout 38 and runs substantially in the circumferential direction around a portion of the filter sleeve 33. The fixed expansion 39 also has a locking undercut 40, which is formed by a recess on the filter head side in the end region of the fixed expansion 39.

[0089] Figure 7 The filter head 3 is shown from below, wherein the filter sleeve 33 and the filter element 2 are not shown. The filter head 3 has a filter head sealing surface 5, Figures 1 to 3 the sealing body 4 shown is pressed against. It follows from the figure: A holding arm recess 41 is provided, which is recessed with respect to the filter head sealing surface 5, wherein the holding arm 30 extends into the holding arm recess 41 in the installed state.

[0090] The filter head 3 also has a hollow-cylindrical filter sleeve end-side recess 42 which extends from the filter head sealing face 5 and substantially axially symmetrically with respect to the centre axis 18 into the filter head 3 and in the installed state accommodates the filter sleeve end side 34, wherein the filter sleeve end-side recess 42 is outside the filter head sealing face 5 in the radial direction with respect to the centre axis 18.

[0091] The filter head 3 also has two retaining peg holes 43 which extend radially with respect to the centre axis 18, which are preferably opposite one another, wherein the retaining peg holes 43 accommodate retaining pegs 37 which preferably cooperate in the form of a bayonet connection with Figure 6 the accommodation means 36 in the filter sleeve 33 in the filter head 3, wherein preferably a metal-on-metal conical seal 44 is provided between the retaining pegs 37 and the filter head 3.

[0092] Figure 8 A multi-stage filter 45 having a plurality of filter stages is shown, wherein the filter stages additionally or alternatively comprise the above-described features for the sealing device 1 and / or the filter element 2. Here, the multi-stage filter 45 also comprises filter elements 2 having different filter properties.

[0093] In such a multi-stage filter 45, the sealing device 1 for sealing between the filter element 2 and the filter head 3 and / or the accommodation means 36 of the filter sleeve 33 and / or the retaining arms 30 of the filter element 2 can be substantially identically configured to one another according to the above-described features. Furthermore, at least one of the filter elements 2 can be loaded from the outside with a greater pressure than from the inside, wherein at least one of the filter elements 2 is loaded with pressure in the opposite direction.

Claims

1. Filter element (2) for use in a compressed air filter, the filter element (2) comprising a tubular main body (27) having an annular end side (21) facing towards a filter head (3), a lower side (28) facing away from the filter head (3) spaced apart from the end side (21), a circumferential face (29) extending along a central axis (18), the circumferential face (29) interconnecting the end side (21) and the lower side (28), - wherein four retaining arms (30) extending radially with respect to the central axis (18) are provided in the region of the end side (21), - wherein an annular filter element sealing face (6) is provided at the end side (21), wherein the retaining arms (30) project with respect to the filter element sealing face (6) and the retaining arms (30) project with respect to the filter element sealing face (6) both in axial direction and in radial direction outwards and the retaining arms (30) project radially outwards at the circumferential face (29), characterized in that the retaining arms (30) project with respect to the end side (21) both in axial direction and in radial direction outwards, that the filter element sealing face (6) comprises two partial faces which form an inner angle of less than 180° with respect to the radial direction of the central axis (18) with respect to each other, that the inner angle is between 130° and 170° and that the inner angle can ensure a wedging action. - wherein, The filter element (2) is a replaceable filter element. The filter element (2) is used for separating particles and / or gases and / or liquids. The filter element (2) is a filter cartridge. The filter element (2) is part of a filter (45) having a plurality of filter stages.

2. Filter element (2) according to claim 1, characterized in that The central axis (18) is an axis of rotation.

3. The filter element (2) according to claim 1, characterized in that An annular filter element sealing face (6) is provided at the end side (21).

4. The filter element (2) according to claim 1, characterized in that The retaining arms (30) are fixedly connected to the filter element sealing face (6).

5. The filter element (2) according to claim 1, characterized in that The retaining arms (30) are integral with the filter element sealing face (6).

6. The filter element (2) according to claim 1, characterized in that The retaining arms (30) each have a support face (47) facing away from the filter element sealing face (6).

7. The filter element (2) according to claim 1, characterized in that The support face (47) is convexly arched and / or the spacing between the filter element sealing face (6) and the support face (47) in axial direction is between 0 mm and 4 mm.

8. The filter element (2) according to any one of claims 1 to 7, characterized in that The support face (47) is convexly arched and / or the spacing between the filter element sealing face (6) and the support face (47) in axial direction is between 1 mm and 2 mm.

9. Filter element (2) according to claim 8, characterized in that The retaining arms (30) each have an end face (49) at an exposed end of the respective retaining arm (30) pointing away from the circumferential face (29) in radial direction.

10. The filter element (2) according to any one of claims 1 to 7, characterized in that The spacing between the center of the filter element sealing face (6) and the end face (49) in radial direction is between 12 mm and 18 mm.

11. Filter element (2) according to claim 10, characterized in that ​ 12. Filter element (2) according to claim 10, characterized in that ​ 13. The filter element (2) according to any one of claims 1 to 7, characterized in that ​ 14. Filter element (2) according to claim 13, characterized in that ​ 15. Filter element (2) according to claim 14, characterized in that The distance from the center of the filter element sealing face (6) is between 14 and 16 mm.

16. The filter element (2) according to any one of claims 1 to 7, characterized in that The filter element (2) is designed such that only an axial force acts on the filter element sealing face (6).

17. Filter element (2) according to claim 16, characterized in that The holding arm (30) forms a bearing (50) against the axial force.

18. The filter element (2) according to claim 16, characterized in that The axial force is generated by an extrusion seal (4) which bears against the filter element sealing face (6).

19. Filter element (2) according to claim 18, characterized in that The holding arm (30) is flexible in the axial direction and forms a compensation element between the seal (4) against the filter element sealing face (6) and a receiving device (36) which receives the holding arm (30).

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