Filter system and filter element

Abstract

The invention relates to a filter system (100) comprising a filter element (10) wherein a recess (30) is arranged on an outer side (22) of the filter element (10). At least one coding element (32) is arranged on a circumference (24) of an end cap (18, 20) of the filter element (10). At least one coding pin (32) is arranged on an inner side (114) of the bottom housing part (112) for cooperating with the groove (30) when the filter element (10) is inserted into the housing (110). The bottom housing part (112) comprises a circular shield (116) comprising a slot (132) extending in an axial direction (L), where the slot (132) is configured to receive a coding element (32) of the filter element (10) when the filter element (10) is inserted into the housing (110). The invention also relates to a filter element (10).

Description

Technical Field

[0001] The present invention relates to a filter system comprising a housing having a fluid inlet and a fluid outlet and a filter element accommodated in the housing in an axial direction for filtering a fluid flowing from the fluid inlet to the fluid outlet, in particular for air filter applications; and to a filter element comprising a filter bellows. Background Art

[0002] WO2020 / 014141A1 discloses a filtering system, comprising a housing having a first housing end and a second housing end. The housing defines a central compartment therein. The housing comprises an alignment tab disposed on the second housing end. The alignment tab protrudes from the second housing end toward the first housing end. A filter element is positioned within the housing. The filter element comprises a first end cap, a second end cap, and a filter medium positioned between the first end cap and the second end cap and extending axially between the first end cap and the second end cap. The filter medium defines a central opening extending axially therein. An alignment notch is disposed on the second end cap, and the alignment notch protrudes from the second end cap toward the first end cap.

[0003] US9718019B2 discloses an air cleaner device, which includes an air cleaner housing and an air filter box that can be used. The air cleaner housing includes an air flow inlet device and an air flow outlet device. The air cleaner housing defines the interior of the housing and includes a housing body and an access cover. A protrusion / receiver device including first and second components is provided. One component of the protrusion / receiver device is positioned on the access cover. Another component of the protrusion / receiver device is positioned on the outer end surface of the end cap of the filter box. It can be engaged with the access cover in a defined manner. In general, the first and second components of the protrusion / receiver device are engaged to provide a cantilever support of the air filter box at the second end. The first and second components of the protrusion / receiver device are also engaged in a non-rotatable manner. Summary of the invention

[0004] It is an object of the present invention to provide a filter system having variants which can be provided cost-effectively.

[0005] A further object of the invention is to provide a filter element for such a filter system which has cost-effective provision variants.

[0006] According to one aspect of the present invention, the aforementioned object is achieved by a filter system, comprising a housing having a fluid inlet and a fluid outlet and a filter element accommodated in the housing in an axial direction for filtering a fluid flowing from the fluid inlet to the fluid outlet, the filter element comprising a filter corrugated portion having a first end face and a second end face opposite in the axial direction, wherein at least one of the end faces comprises an end cap, wherein a groove is arranged on the outer side of the first end face in at least the at least one end cap, the groove extending in the axial direction, wherein at least one coding element is arranged on the circumference of the at least one end cap, wherein at least one coding pin is arranged on the inner side of a bottom housing part of the housing, the coding pin being configured to cooperate with the groove when the filter element is inserted into the housing, wherein the bottom housing part comprises a circular shielding member arranged coaxially with the filter element, the shielding member comprising a groove extending in the axial direction, wherein the groove is configured to receive the coding element of the filter element when the filter element is inserted into the housing, wherein, with respect to each axial direction, a first angle between an angular position of the coding element of the filter element and an angular position of the groove matches a second angle between an angular position of the groove of the bottom housing part and an angular position of the coding pin.

[0007] According to another aspect of the present invention, another object is achieved by a filter element, comprising a filter corrugated portion having a first end face and a second end face opposite in an axial direction, wherein at least one of the end faces comprises an open end cap. The filter element is suitable for use in a filter system according to the first aspect of the present invention. A groove is arranged on the outer side of the first end face in at least the at least one end cap, the groove extending in an axial direction for cooperating with a coding pin of a housing of the filter system in intended use. At least one coding element is arranged at the outer circumference of the at least one end cap for cooperating with a groove of a circular shield of a bottom housing part of the filter system in intended use, wherein, with respect to each axial direction, a first angle between the angular position of the coding element of the filter element and the angular position of the groove matches a second angle between the angular position of the groove of the bottom housing part and the angular position of the coding pin of the filter system. The coding element is arranged to have a preferably predetermined spacing from the first end face in the axial direction. The coding element can particularly have a total extension range in the axial direction, which is significantly smaller than the extension range of the filter corrugated portion in the axial direction.

[0008] Advantageous embodiments and advantages of the invention are described in the further claims, the description, and the drawings.

[0009] According to a first aspect of the present invention, a filter system is proposed, comprising a housing having a fluid inlet and a fluid outlet and a filter element accommodated in the housing in an axial direction, for filtering a fluid flowing from the fluid inlet to the fluid outlet. The filter element comprises a filter corrugated portion having a first end face and a second end face opposite in an axial direction, wherein at least one of the end faces comprises an end cap. A groove is arranged on the outer side of the first end face in at least the at least one end cap, and the groove extends in an axial direction. At least one coding element is arranged on the circumference of the at least one end cap. At least one coding pin is arranged on the inner side of the bottom housing part of the housing, and the coding pin is configured to cooperate with the groove when the filter element is inserted into the housing. The bottom housing part comprises a circular shielding member coaxially arranged with the filter element, the shielding member comprises a groove extending in an axial direction, wherein the groove is configured to receive the coding element of the filter element when the filter element is inserted into the housing, wherein, with respect to each axial direction, the first angle between the angular position of the coding element of the filter element and the angular position of the groove matches the second angle between the angular position of the groove of the bottom housing part and the angular position of the coding pin.

[0010] Advantageously, in a hollow cylindrical filter element, the groove can be radially arranged on the outside of the end face of the filter element. Advantageously, the groove can be wedge-shaped. Advantageously, the groove can penetrate the seal and / or the end plate in the axial direction, and it is also possible to partially penetrate the filter corrugated portion. In the case of penetrating the seal, it is preferably partially penetrated so that a distance is left between the penetration portion and the sealing surface. The end cap can be equipped with a circumferential ring in the form of a crown, which is composed of a large number of individual (preferably evenly spaced individual) teeth (prong) or saw teeth. The profile of the saw teeth can be designed so that a separated coding element (such as a radially protruding cam) can be detachably or inseparably connected to the crown, for example, by a snap connection. According to the teeth installed by the coding element, there is a defined angle between the groove and the angular position of the coding element. The number of available teeth therefore leads to the number of coding variants.

[0011] Advantageously, a coding element (preferably a coding pin) is mounted on the inner side of the bottom housing part, the design and size of the coding element matching the groove in the filter element and matching the shape of the groove in the filter element. The coding pin is preferably a separate component and can be preferably mounted in a predetermined position at any angular position, for example by ultrasonic welding, to form a welding interface. Additionally, the bottom housing part has a circumferential shielding member upright in the axial direction, with a defined distance to the outer diameter of the filter element. A vertical groove is provided in the shielding member, matching the coding element of the filter element. Depending on the position of the bolt to which the coding element is attached, there is a defined angle between the coding element and the shielding member slot.

[0012] If the angles between the coding element and the groove and between the coding pin and the shield slot are the same, the filter element can be inserted into the bottom housing part. If the angles are different, installation of the filter element is no longer possible. A change in the coding angle creates new filter variants.

[0013] In contrast to the prior art, the coding, i.e. the interface between the housing of the filter system and the end cap of the filter element, is not located in the radial center, but on the outside of the filter element, and the contour of the interface is not rotationally symmetrical. A further difference is that the coding is not only incorporated in the seal and the end cap, but also in the filter body.

[0014] Advantageously, the coding comprises at least two spatially separated elements at a defined angle on the outside of the filter element.Thus, a plurality of variants of the filter system and the filter element can be coded as separate variants.

[0015] Thus, by avoiding the need for machining work, a lower overall cost for the simultaneous supply of many variants can be achieved, since no interchangeable inserts, no complete change-outs, no tool replacements are required.

[0016] Due to the interchangeable coding elements as coding element and coding pin, many different variants can be manufactured using the same tool and the same parts.

[0017] By using coding elements that differ in design, size, etc., the number of coding variants can be increased many times over.

[0018] Small numbers of filter systems can be manufactured with many possible variants without requiring extensive production work. Short delivery times for new variants for the customer are achievable because the same individual parts are always used and high stock levels are therefore not a problem for the production plant.

[0019] Advantageously, after production of a market product has begun, differently coded filter elements and housings based on the same filter element and filter housing design may be provided without requiring expensive tooling changes.

[0020] The complexity of the production process does not increase with the number of filter variants.

[0021] Advantageously, the risk of assembling the wrong part for a specific variant during the production chain is lower, since the variant is not created until the last production step.

[0022] Less effort and costs are spent on development, warehousing and logistics, as each new variant may still retain the same product, associated numbers, parts list, etc., and may differ only in a different coding angle.

[0023] Advantageously, a bolt circle can be arranged in the bottom housing part, at least partially circumferentially around the axial direction, for accommodating a coding pin at the bottom housing part. Thus, the coding pin can advantageously be arranged at defined angular positions for correspondingly coding the bottom housing part.

[0024] Advantageously, at least one coding pin can be inseparably connected to the bottom housing part, in particular by welding or gluing. Additionally or alternatively, the at least one coding pin can form an integral part of the bottom housing part. In this way, the variant of the filter system is fixed, which excludes the possibility of installing an incorrect filter element in the housing of the filter system.

[0025] Advantageously, the groove of the filter element can extend at least partially into the filter corrugation. In particular, the groove in the filter corrugation can be formed by cutting the filter corrugation (in particular by laser cutting the filter corrugation) or by unfolding the pleats of the filter corrugation. Thus, a reliable coding of the filter element can be advantageously achieved. Nevertheless, the alignment of the filter element in the housing during the installation process can be facilitated.

[0026] Advantageously, at least one coding element may be inseparably connected to the end cap. Additionally or alternatively, the at least one coding element may form an integral part of at least one end cap. Advantageously, the coding element is fixed to the filter element so that it cannot become loose or lost during handling of the filter element in stock or during transport for maintenance.

[0027] Advantageously, in an embodiment of the filter system, at least part of a circumferential ring can be arranged at the at least one end cap, the circumferential ring providing a plurality of fixing elements, in particular preferably evenly spaced individual fixing elements, for accommodating the at least one coding element at the at least one end cap. In particular, the at least one coding element can be connected to the fixing elements of the circumferential ring by a snap connection. In this way, advantageously, a defined angular position of the coding element on the circumference of the filter element can be arranged to ensure a suitable decoding of the filter element.

[0028] Advantageously, at least part of the circumferential ring can form an integral part of the center tube of the filter element. Therefore, the simple production of the filter element can be achieved with low cost. Less processes are required to install the filter element. However, other options are also possible, such as a separable or inseparable connection between at least part of the circumferential ring and the center tube of the filter element or at least part of the circumferential ring and the center tube of the filter element are unconnected, separated parts.

[0029] Advantageously, at least part of the circumferential ring is moulded into at least one end cap, wherein preferably also the central tube is moulded into the same end cap.

[0030] Advantageously, at least one coding element may form an integral part of the central tube of the filter element. Thus, a simple production of the filter element may be achieved together with low costs. Fewer processes are required to install the filter element.

[0031] According to another aspect of the present invention, a filter element is proposed, comprising a filter corrugated portion having a first end face and a second end face opposite in an axial direction, wherein at least one of the end faces comprises an open end cap. The filter element is suitable for use in a filter system according to the first aspect of the present invention. A groove is arranged on the outer side of the first end face in at least the at least one end cap, and the groove extends in an axial direction for cooperating with a coding pin of a housing of the filter system in the intended use. At least one coding element is arranged at the outer circumference of the at least one end cap for cooperating with a groove of a circular shield of a bottom housing part of the filter system in the intended use, wherein, with respect to each axial direction, a first angle between the angular position of the coding element of the filter element and the angular position of the groove matches a second angle between the angular position of the groove of the bottom housing part and the angular position of the coding pin of the filter system. The coding element is arranged to have a preferably predetermined interval from the first end face in the axial direction. The coding element can particularly have a total extension range in the axial direction, and the total extension range is significantly smaller than the extension range of the filter corrugated portion in the axial direction.

[0032] In an embodiment, the coding element may be arranged on a housing surface of the filter bellows.

[0033] In an embodiment, the coding element may be arranged to have a predetermined interval from a free end portion of the first end cap in the axial direction.

[0034] In this context, an "open end cap" refers to an end body having at least one opening, in particular a central opening, which allows the fluid to be cleaned to be supplied to the filter bellows or the cleaned fluid to be supplied from the filter bellows, in particular to the inner hollow space at least partially surrounded by the filter bellows.

[0035] Advantageously, in a hollow cylindrical filter element, a preferred wedge-shaped groove is radially arranged on the outside of the end face of the filter element, the groove advantageously penetrates the seal and / or the end plate in the axial direction, and may also partially penetrate the filter corrugated portion. In the case of penetrating the seal, it is preferably partially penetrated so that a distance is left between the penetration portion and the sealing surface. The end cap can be equipped with a circumferential ring in the form of a crown, which is composed of a large number of individual (preferably evenly spaced individual) teeth or saw teeth. The profile of the saw teeth can be designed so that a separated coding element (such as a radially protruding cam) can be detachably or inseparably connected to the crown, for example, by a snap connection. Depending on the teeth on which the coding element is installed, there is a defined angle between the groove and the angular position of the coding element. The number of available teeth therefore leads to the number of coding variants.

[0036] The proposed filter element can advantageously be used in a filter system as described above, ensuring a defined coding between the filter element and the housing of the filter system. Advantageously, the coding comprises two spatially separated elements at a defined angle on the outside of the filter element, as the coding element of the groove and the filter element. Thus, multiple variants of the filter system and the filter element can be coded as separated variants.

[0037] Advantageously, the groove of the filter element can extend at least partially into the filter corrugation. In particular, the groove in the filter corrugation can be formed by cutting the filter corrugation (in particular by laser cutting the filter corrugation) or by unfolding the pleats of the filter corrugation. Thus, a reliable coding of the filter element can be advantageously achieved. Nevertheless, the alignment of the filter element in the housing during the installation process can be facilitated.

[0038] Advantageously, the at least one coding element may be inseparably connected to the end cap and / or form an integral part of the at least one end cap.Advantageously, the coding element is fixed to the filter element and may not become loose or lost during handling of the filter elements in stock or during transport for maintenance.

[0039] Advantageously, at least part of the circumferential ring can be arranged at the at least one end cap, the circumferential ring providing a plurality of fixing elements, in particular preferably evenly spaced individual fixing elements, for accommodating the at least one coding element at the end cap. In particular, the at least one coding element can be connected to the fixing elements of the circumferential ring by a snap connection. In this way, advantageously, a defined angular position of the coding element on the circumference of the filter element can be arranged to ensure a suitable decoding of the filter element.

[0040] Advantageously, at least part of the circumferential ring can form an integral part of the center tube of the filter element. Therefore, the simple production of the filter element can be achieved with low cost. Less processes are required to install the filter element. However, other options are also possible, such as a separable or inseparable connection between at least part of the circumferential ring and the center tube of the filter element or at least part of the circumferential ring and the center tube of the filter element are unconnected, separated parts.

[0041] Advantageously, at least one coding element may form an integral part of the central tube of the filter element. Thus, a simple production of the filter element may be achieved together with low costs. Fewer processes are required to install the filter element. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Further advantages are derived from the following description of the drawings. Embodiments of the invention are shown in the drawings. The drawings, the description and the claims contain a number of features in combination. A person skilled in the art will also readily consider the features individually and combine them into other reasonable combinations. For example,

[0043] Figure 1 shows an isometric exploded view of a filter system according to an embodiment of the present invention;

[0044] Figure 2 Show according to Figure 1 Another isometric exploded view of the filter system;

[0045] Figure 3 An isometric view showing a filter element according to an embodiment of the present invention;

[0046] Figure 4 showing an isometric view of a coding element of a filter element;

[0047] Figure 5 Show according to Figure 1 An isometric view of the bottom housing part of the filter system;

[0048] Figure 6 An isometric view showing a coding pin of a bottom housing part of a filter system;

[0049] Figure 7 Show according to Figure 1 A side view of a filter system, wherein cross section AA is marked;

[0050] Figure 8 shows a top view of the filter system in cross section AA, wherein cross section CC is marked;

[0051] Fig. 9 showing another top view of the filter system; and

[0052] Fig.10 A side view of the filter system is shown in cross section CC. DETAILED DESCRIPTION

[0053] In the accompanying drawings, the same reference numerals are used to refer to similar elements. The accompanying drawings are only schematic representations and are not intended to depict specific parameters of the invention. In addition, the accompanying drawings are intended to depict only typical embodiments of the invention and therefore should not be considered to limit the scope of the invention.

[0054] Figure 1 and Figure 2 Two isometric exploded views of a filter system 100 according to an embodiment of the invention are shown in two different viewing angles. The filter system 100 may be used in particular for air filtration, for example in industrial applications.

[0055] The filter system 100 comprises a housing 110 having a fluid inlet 102 and a fluid outlet 108. Only the bottom housing part 112 is shown, where the fluid inlet 102 and the fluid outlet 108 may be located. An upper housing part for firmly closing the housing 110 is omitted. The filter system 100 also comprises a filter element 10 accommodated in the housing 110 in an axial direction L for filtering a fluid, typically air, flowing from the fluid inlet 102 to the fluid outlet 108.

[0056] Figure 3 An isometric view of a filter element 10 according to an embodiment of the invention is shown.

[0057] The filter element 10 comprises a filter bellows 12 having a first end face 14 and a second end face 16 opposite in the axial direction L. Both end faces 14, 16 comprise end caps 18, 20 for stable mounting and sealing in the housing 110. The end caps 18, 20 can be generally preferably made of foamed polyurethane (PUR) material or other sealing materials (preferably elastomers). The filter bellows 12 can generally be made of pleated filter media.

[0058] As in Figure 3 As can be seen in the figure, the groove 30 is arranged on the outer side 22 of the first end face 14 in the first end cap 18, which is an open end cap 18, and the groove 30 extends in the axial direction L. The groove 30 of the filter element 10 partially extends into the filter corrugated part 12. In particular, the groove 30 in the filter corrugated part 12 can be formed by cutting the filter corrugated part 12, in particular by laser cutting the filter corrugated part 12. Alternatively, the groove 30 can be formed by unfolding the pleats of the filter corrugated part 12.

[0059] The coding element 32 is arranged on the outer circumference 24 of the open end cap 18. The coding element 32 is arranged to have a predetermined interval from the first end face 14 in the axial direction L. The interval between the proximal end of the coding element 32 facing the first end face 14 and the first end face 14 may be, for example, in the range between 5% and 25% of the total length of the filter corrugated portion 12 in the axial direction L (particularly 7% and 15% of the total length of the filter corrugated portion 12 in the axial direction L).

[0060] For this purpose, at least part of the circumferential ring 34 is arranged at the end cap 18. The circumferential ring 34 provides a plurality of fixing elements 36, in particular preferably evenly spaced individual fixing elements 36, for accommodating the coding element 32 at the end cap 18. In particular, the coding element 32 can be connected to the fixing elements 36 of the circumferential ring 34, for example by a snap connection.

[0061] In another embodiment, at least part of the circumferential ring 34 may form an integral part of a central tube 38 of the filter element 10. The central tube 38, which supports the filter bellows 12, is located on the inner side of the filter element 10 and is located at the bottom of the filter element 10. Figure 2 and 3 Visible in.

[0062] Figure 4 An isometric view of a coding element 32 of a filter element 10 is shown. The coding element 32 is provided with an opening 42 for mounting the coding element 32 on a fixing element 36 of a circumferential ring 34. The coding element 32 may be inseparably fixed to the fixing element 36 by welding or gluing. A snap-fit ​​connection may also be possible.

[0063] The coding element 32 may be inseparably connected to the end caps 18 , 20 .

[0064] In alternative embodiments, the coding element 32 may be formed directly as an integral part of the end cap 18 .

[0065] In further alternative embodiments, the coding element 32 may directly form an integral part of the center tube 38 of the filter element 10 .

[0066] Figure 5 Show according to Figure 1 FIG. 1 is an isometric view of a bottom housing part 112 of the filter system 100 .

[0067] The coding pin 130 is arranged on the inner side 114 of the bottom housing part 112 of the housing 110. The coding pin 130 is configured for cooperating with the groove 30 when the filter element 10 is inserted into the housing 110.

[0068] A bolt circle 134 may be arranged in the bottom housing part 112 at least partially circumferentially around the axial direction L for accommodating the coding pin 130 at the bottom housing part 112 .

[0069] Figure 6 An isometric view of the coding pin 130 is shown. The coding pin 130 can advantageously be inseparably connected to the bottom housing part 112, in particular by welding or gluing.

[0070] In an alternative embodiment, the coding pin 130 may form an integral part of the bottom housing part 112 .

[0071] As in Figure 1 and 5 As can be seen in FIG. 1 , the bottom housing part 112 further comprises a circular shield 116 arranged coaxially with the filter element 10 . The shield 116 serves to protect the filter bellows 12 from particles in the fluid entering from the fluid inlet 102 , for example.

[0072] In an embodiment, the shield 116 includes a slot 132 extending in the axial direction L. The slot 132 is configured to receive the coding element 32 of the filter element 10 when the filter element 10 is inserted into the housing 110 .

[0073] Figure 7 Show according to Figure 1 1 is a side view of the filter system 100 , wherein the cross section AA is marked.

[0074] exist Figure 7 In the side view in FIG. 1 , the filter element 10 is mounted in a predetermined position in the bottom housing part 112. In this view, the distance 118 between the shield 116 and the diameter 26 of the filter element 10 is marked.

[0075] Figure 8 The filter system 100 is shown in Figure 7 A top view of cross section AA, wherein cross section CC is marked.

[0076] In the top view, when the filter element 10 is in the predetermined position in the bottom housing part 112, the cooperation between the coding element 32 at the filter element 10 and the groove 132 of the shield 116 of the bottom housing part 112 as well as the coding pin 130 of the bottom housing part 112 and the groove 30 in the filter element 10 is clearly visible.

[0077] The collaboration focuses on Fig. 9, which shows another top view of the filter system 100. It can be seen that, with respect to each axial direction L, a first angle 40 between the angular position of the coding element 32 and the angular position of the groove 30 of the filter element 10 matches a second angle 140 between the angular position of the groove 132 and the angular position of the coding pin 130 of the bottom housing part 112. This matching is a necessary condition for the filter element 10 with defined groove 30 and coding element 32 to be inserted in the correct position into the bottom housing part 112 with defined coding pin 130 and groove 132.

[0078] If the angle 40 between the coding element 32 and the groove 30 and the angle between the coding pin 130 and the shielding slot 132 are the same, the filter element 10 can be inserted into the bottom housing part 112. If the angles 40, 140 are different, the installation of the filter element 10 is no longer possible. The change of the coding angles 40, 140 produces new filter variants.

[0079] In the exemplary embodiment shown, an angle 40 , 140 of 78° is selected between the coding element 32 and the groove 30 and between the coding pin 130 and the shield slot 132 .

[0080] Fig.10 The filter system 100 is shown in Figure 8 In this view, the installation of the filter element 10 at the bottom of the bottom housing part 112 is visible when the filter element 10 is in its final position in the housing 110 for the intended use of the filter system 100, when the housing 110 is closed by the upper housing part (not shown).

[0081] Reference numeral 10 filter element

[0082] 12 filter corrugated portion 14 end surface

[0083] 16 End face

[0084] 18 End Cap

[0085] 20 End cap

[0086] 22 Outer side

[0087] 24 Circumference

[0088] 26 diameter

[0089] 30 grooves

[0090] 32 coding elements

[0091] 34 rings

[0092] 36Fixing elements

[0093] 38 center tube

[0094] 40 First Angle

[0095] 42 Opening

[0096] 100 filter system 102 fluid inlet

[0097] 108 Fluid outlet

[0098] 110 Shell

[0099] 112 Bottom shell part 114 inner side

[0100] 116 circular shield 118 distance

[0101] 130 coding pin

[0102] 132 slots

[0103] 134 bolt circle 140 second angle L axial direction

Claims

1. A filter system (100), comprising a housing (110) having a fluid inlet (102) and a fluid outlet (108), and a filter element (10) received in the housing (110) along an axial direction (L), for filtering a fluid flowing from the fluid inlet (102) to the fluid outlet (108), The filter element (10) comprises a filter bellows (12) having a first end face (14) and a second end face (16) opposite in an axial direction (L), wherein: At least one of the end surfaces (14, 16) includes an end cap (18, 20), The groove (30) is arranged on the outer side (22) of the first end surface (14) of at least one of the end caps (18, 20), and the groove (30) extends in an axial direction (L). wherein at least one coding element (32) is arranged on a circumference (24) of the at least one end cap (18, 20), wherein at least one coding pin (32) is arranged on the inner side (114) of the bottom housing part (112) of the housing (110), the coding pin (130) being configured to cooperate with the groove (30) when the filter element (10) is inserted into the housing (110), wherein the bottom housing part (112) comprises a circular shield (116) arranged coaxially with the filter element (10), the shield (116) comprising a groove (132) extending in an axial direction (L), wherein the groove (132) is configured to receive a coding element (32) of the filter element (10) when the filter element (10) is inserted into the housing (110), Therein, with respect to each axial direction (L), a first angle (40) between the angular position of the coding element (32) of the filter element (10) and the angular position of the groove (30) matches a second angle (140) between the angular position of the groove (132) of the bottom housing part (112) and the angular position of the coding pin (130).

2. The filter system according to claim 1, wherein: A bolt circle (134) is arranged in the bottom housing part (112), at least partially circumferentially around the axial direction (L), for receiving a coding pin (130) at the bottom housing part (112).

3. The filter system according to claim 1 or 2, wherein: The at least one coding pin (130) is inseparably connected to the bottom housing part (112), in particular by welding or gluing, and / or the at least one coding pin (130) forms an integral part of the bottom housing part (112).

4. The filter system according to any one of the preceding claims, wherein: The groove (30) of the filter element (10) extends at least partially into the filter bellows (12), in particular wherein: The grooves (30) in the filter bellows (12) are formed by cutting the filter bellows (12), in particular by laser cutting the filter bellows (12), or by unfolding the folds of the filter bellows (12).

5. The filter system according to any one of the preceding claims, wherein: At least one coding element (32) is inseparably connected to the end cap (18, 20) and / or forms an integral part of at least one end cap (18, 20).

6. The filter system according to any one of the preceding claims, wherein: At least part of a circumferential ring (34) is arranged at at least one end cap (18, 20), the circumferential ring (34) providing a plurality of fixing elements (36), in particular preferably evenly spaced individual fixing elements (36), for accommodating the at least one coding element (32) at the at least one end cap (18, 20), in particular wherein the at least one coding element (32) is connected to the fixing elements (36) of the circumferential ring (34) by a snap connection.

7. The filter system according to claim 6, wherein: At least part of the circumferential ring (34) forms an integral part of a central tube (38) of the filter element (10).

8. The filter system according to any one of the preceding claims, wherein: At least one coding element (32) forms an integral part of a central tube (38) or at least part of a circumferential ring (34) of the filter element (10).

9. A filter element (10) for a filter system according to any one of the preceding claims, comprising a filter bellows (12) having a first end face (14) and a second end face (16) opposite in an axial direction (L), wherein: At least one of the end surfaces (14, 16) includes an open end cap (18, 20), wherein at least one groove (30) is arranged on the outer side (22) of the first end face (14) of at least one of the end caps (18, 20), the groove (30) extending in an axial direction (L) for cooperating with a coding pin (130) of a housing (110) of a filter system (100) in intended use, wherein at least one coding element (32) is arranged at an outer circumference (24) of the at least one end cap (18, 20) for cooperating with a groove (132) of a circular shield (116) of a bottom housing part (112) of a filter system (100) in intended use, wherein the coding element (32) is arranged at a spacing from the first end face (14) in an axial direction (L), And wherein, with respect to each axial direction (L), a first angle (40) between the angular position of the coding element (32) of the filter element (10) and the angular position of the groove (30) matches a second angle (140) between the angular position of the groove (132) of the bottom housing part (112) and the angular position of the coding pin (130) of the filter system (100).

10. The filter element according to claim 9, wherein The groove (30) of the filter element (10) extends at least partially into the filter bellows (12), in particular wherein: The grooves (30) in the filter bellows (12) are formed by cutting the filter bellows (12), in particular by laser cutting the filter bellows (12), or by unfolding the folds of the filter bellows (12).

11. The filter element according to any one of claims 9 to 10, wherein At least one coding element (32) is inseparably connected to the end cap (18, 20) and / or forms an integral part of at least one end cap (18, 20).

12. The filter element according to any one of claims 9 to 11, wherein At least part of a circumferential ring (34) is arranged at at least one end cap (18, 20), the circumferential ring (34) providing a plurality of fixing elements (36), in particular preferably evenly spaced individual fixing elements (36), for accommodating the at least one coding element (32) at the end cap (18, 20), in particular wherein the at least one coding element (32) is connected to the fixing elements (36) of the circumferential ring (34) by a snap connection.

13. The filter element of claim 12, wherein: At least part of the circumferential ring (34) forms an integral part of a central tube (38) of the filter element (10).

14. The filter element according to any one of claims 9 to 13, wherein At least one coding element (32) forms an integral part of a central tube (38) or at least part of a circumferential ring (34) of the filter element (10).

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