DE102016004317B4 - Filter element and filter assembly - Google Patents

Abstract

Filter element (11), in particular secondary filter element, which can be accommodated in a main filter element (3), with an engagement section (18) which is designed to engage in a corresponding counter-engagement section (28) of a filter housing (2) in order to move the filter element (11) to be positively connected to the filter housing (2), the filter element (11) having an oval cross-section (33) with a longitudinal extension of the cross-section (33) in the direction of a main axis of symmetry which is greater than a longitudinal extension of the cross-section (33) in direction a secondary axis of symmetry perpendicular to the main axis of symmetry, the filter element (11) further comprising a connection section (16) for connecting the filter element (11) to a fluid outlet (25) of the filter housing (2), wherein the connection section (16) has a circular cross-section, characterized That the circular cross-section has a diameter that is smaller than the Längenausdeh tion of the cross section (33) in the direction of the main axis of symmetry (34) and is greater than the length of the cross section (33) in the direction of the secondary axis of symmetry (36).

Description

technical field

The present invention relates to a filter element and a filter arrangement with such a filter element.

State of the art

A filter element arrangement, for example for filtering air or liquid operating media of a vehicle, can have a main filter element and a secondary filter element accommodated in the main filter element. The secondary filter element essentially serves to prevent contamination of a clean side of the filter element arrangement with raw fluid to be filtered when the main filter element is replaced.

EP 2 227 307 B1 describes such a filter arrangement, wherein both the secondary filter element and the main filter element have a cylindrical geometry with a circular cross-section. The secondary filter element accommodated in the main filter element is screwed into a filter housing of the filter arrangement.

US 2014/0 102 966 A1 describes a filter arrangement with a filter element and a support tube, each of which has an oval cross section.

US 2015/0 027 092 A1 discloses a filter element with a hollow-cylindrical inner support tube, which is designed as a grid and has a thread for connecting to a filter housing.

In DE 100 63 881 A1 describes a filter element with a filter medium that is fixed in a sealing manner on a hollow-cylindrical support body by means of weld seams.

Disclosure of Invention

It is therefore the object of the present invention to provide an improved filter element.

Accordingly, a filter element, in particular a secondary filter element, which can be accommodated in a main filter element, with the features of claim 1 is proposed. The filter element comprises an engagement section which is set up to engage in a corresponding counter-engagement section of a filter housing of the filter element in order to positively connect the filter element to the filter housing, the filter element having an oval cross section.

The filter element is designed in particular to filter fluids, such as air or other gases, liquids, in particular liquid operating materials of a vehicle, in particular a motor vehicle, such as oil, water, diesel, gasoline, kerosene or urea solution. In particular, the filter element is an air filter element. The filter element is suitable in particular for filtering the combustion air of an internal combustion engine, in particular for an agricultural machine, a truck or a construction machine. In this respect, the filter element in embodiments is an air filter element for combustion air of an internal combustion engine in a motor vehicle. The filter element can be used in motor vehicles, watercraft, rail vehicles, agricultural vehicles, construction machinery, aircraft or the like. Furthermore, the filter element can be used in immobile applications, such as in building technology.

The filter element can also be referred to as a second filter element, secondary element, secondary element or secondary filter element. The main filter element can also be referred to as a first filter element, primary filter element, primary element or main element. The filter element can preferably be arranged within the main filter element. In particular, the filter element is arranged in an installed or operating state within a volume enclosed by a filter medium of the main filter element. A filter medium of the filter element is preferably arranged opposite a downstream side of the filter medium of the main filter element in the installed or operating state. Compared to externally arranged secondary filter elements, this results in a larger filter surface and thus a lower pressure loss during flow.

An oval cross section—in particular transverse to the longitudinal axis of the filter element—is understood to mean a cross section which has a peripheral line that deviates from a circle and is in particular roundishly convex. In this case, the peripheral line preferably has a curvature without a change in sign. An ellipse or stadium shape is conceivable, for example.

In the present case, oval can also be understood to mean a rectangular cross section with rounded corners, an elliptical cross section or a cross section formed from a plurality of circular arcs. The cross-section is preferably closed and comprises a major axis of symmetry and a minor axis of symmetry positioned perpendicular to the major axis of symmetry. The cross section is eg built symmetrically. That is, the cross-section is symmetrical both to the main axis of symmetry and to the secondary axis of symmetry. A length extension of the cross section in the direction of the main axis of symmetry is preferably greater than a length extension of the cross section in the direction of the secondary axis of symmetry.

The fact that the secondary filter element is positively connected to the filter housing prevents the secondary filter element from being undesirably pulled out of the filter housing when the main filter element that is attached to the secondary filter element is replaced. Secondary filter elements with an oval cross section are usually accommodated in the corresponding filter housing without a positive connection. Due to the fact that the secondary filter element has an oval cross section and can be connected to the filter housing in a form-fitting manner, a secure hold in the filter housing is also ensured with such secondary filter elements. Due to the oval geometry of the filter element, a lower pressure loss can be achieved in comparison to a filter element with a circular cross-section with an enlarged filter area.

In embodiments, the filter element can be positively connected to the filter housing with the aid of a rotary movement. An angle of rotation is preferably 45° to 360°, i.e., 1/8 to 1 turn. More preferably, the angle of rotation is 90° to 180°, i.e. a quarter to half a turn.

According to the invention, the filter element also includes a connection section for connecting the filter element to a fluid outlet of the filter housing, the connection section having a circular cross section. The connection section is preferably tubular. The engaging portion is preferably provided on the terminal portion. The engagement section can be, for example, a single or multiple thread. The engagement section can also be part of a bayonet lock. A bayonet lock is a mechanical connection between two cylindrical parts that can be quickly established and released along their longitudinal axis. The parts, in this case the connection section and a fluid outlet of the filter housing, are connected by plugging them into one another and turning them in opposite directions and are also separated again in this way.

In embodiments, the filter element also includes a transition section, which forms a transition between the oval cross section of the filter element and the circular cross section of the connection section. A cross-sectional area of the cross section of the connection section is preferably equal to or larger than a cross-sectional area of the cross section of the secondary filter element.

In embodiments, the filter element further comprises a support structure provided on the outside and/or inside of a filter medium of the filter element. The support structure is preferably latticed and fluid permeable. The support structure can be molded onto the filter medium in an injection molding process. The support structure can be formed in one material with the connection section and the transition section. This ensures that the secondary filter element can be manufactured very simply and inexpensively. The support structure prevents direct contact of the main filter element with the filter medium of the secondary filter element. This prevents fiber abrasion and the formation of holes in the filter medium of the secondary filter element. The filter medium is preferably a non-woven material. In particular, the filter medium is smooth, i.e. unpleated. In contrast, a filter medium of the main filter element is preferably pleated.

In embodiments, the filter element also includes a sealing element, in particular an O-ring, for radial sealing of the filter element with respect to the filter housing. The sealing element is preferably made of an elastically deformable material, for example a rubber material or a thermoplastic elastomer. The sealing element is pressed radially between the connection section of the secondary filter element and the fluid outlet of the filter housing.

Furthermore, a filter arrangement, in particular an air filter arrangement, is proposed with a filter housing and such a filter element, the filter element being positively connected to the filter housing. The filter housing can have a removable maintenance cover through which the secondary filter element and/or the main filter element can be exchanged. The maintenance cover can be firmly connected to a receiving section of the filter housing with the aid of quick-release fasteners.

In embodiments, the engagement section is an external thread and the counter-engagement section is an internal thread or the engagement section and the counter-engagement section form a bayonet lock. The external thread is preferably provided on the connection section of the secondary filter element and the internal thread is provided on the inside at the fluid outlet of the filter housing. The threads can be single or multiple. This enables the secondary filter element to be replaced more quickly.

In embodiments, the filter element has a first positioning element and the filter housing has a second positioning element, with the first positioning element bearing against the second positioning element in an end position of the filter element and with a main axis of symmetry of the oval cross section of the filter element being parallel to a main axis of symmetry of an oval cross section of the filter element in the end position Filter housing is positioned. The oval cross sections are in particular each symmetrical, ie they each comprise a main axis of symmetry and a secondary axis of symmetry, the secondary axis of symmetry being shorter than the main axis of symmetry assigned to it. The major axes of symmetry are preferably positioned perpendicular to the minor axes of symmetry. With the aid of the positioning elements, the secondary filter element is preferably positioned in an end position or operating position in the filter housing when the positioning elements touch. In the end position, the oval cross-section of the secondary filter element is positioned in the oval cross-section of the filter housing in particular such that an outer contour of the oval cross-section of the secondary filter element is at a constant distance from an outer contour of the oval cross-section of the filter housing. Furthermore, in particular both the main axes of symmetry and the secondary axes of symmetry are congruent or at least parallel in the end position. A simple and reproducible positioning of the secondary filter element in the filter housing is thus ensured with the aid of the positioning elements. That is, an angular position of the secondary filter element in the filter housing is fixed in the end position with the aid of the positioning elements. Incorrect installation of the secondary filter element is therefore impossible.

In embodiments, the filter assembly further includes a main filter element received within the filter housing, the filter element being disposed within the main filter element. In particular, the main filter element is detachably attached to the filter element. Preferably, the main filter element is replaced at shorter intervals than the secondary filter element. However, the positive connection of the secondary filter element to the filter housing reliably prevents the secondary filter element from being pulled out accidentally when the main filter element is replaced.

Further possible implementations of the filter element and/or the filter arrangement also include combinations of features or method steps described above or below with regard to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the filter element and/or the filter arrangement.

Further configurations of the filter element and/or the filter arrangement are the subject of the subclaims and the exemplary embodiments of the filter element and/or the filter arrangement described below. The filter element and/or the filter arrangement are explained in more detail below on the basis of exemplary embodiments with reference to the enclosed figures.

character list

• 1 eine schematische perspektivische Teilschnittansicht einer Ausführungsform einer Filteranordnung;
• 2 eine weitere schematische perspektivische Teilschnittansicht der Filteranordnung gemäß 1;
• 3 eine schematische perspektivische Ansicht einer Ausführungsform eines ersten Filterelements und eines zweiten Filterelements für die Filteranordnung gemäß 1;
• 4 eine schematische perspektivische Ansicht einer Ausführungsform eines zweiten Filterelements für die Filteranordnung gemäß 1;
• 5 eine schematische perspektivische Ansicht einer weiteren Ausführungsform eines zweiten Filterelements für die Filteranordnung gemäß 1;
• 6 eine schematische Schnittansicht der Filteranordnung gemäß 1;
• 7 eine schematische Schnittansicht einer weiteren Ausführungsform einer Filteranordnung gemäß 1;
• 8 ein vergrößertes Detail der Schnittansichten gemäß 6 und 7;
• 9 ein vergrößertes Detail der perspektivischen Ansichten gemäß 4 und 5;
• 10 ein vergrößertes Detail der perspektivischen Ansicht gemäß 1; und
• 11 eine weitere schematische Schnittansicht der Filteranordnung gem. 1.

It shows:

• 1 a schematic perspective partial sectional view of an embodiment of a filter assembly;
• 2 a further schematic perspective partial sectional view of the filter arrangement according to FIG 1 ;
• 3 a schematic perspective view of an embodiment of a first filter element and a second filter element for the filter arrangement according to FIG 1 ;
• 4 a schematic perspective view of an embodiment of a second filter element for the filter arrangement according to FIG 1 ;
• 5 a schematic perspective view of a further embodiment of a second filter element for the filter arrangement according to FIG 1 ;
• 6 a schematic sectional view of the filter arrangement according to FIG 1 ;
• 7 a schematic sectional view of a further embodiment of a filter arrangement according to FIG 1 ;
• 8th an enlarged detail of the sectional views according to FIG 6 and 7 ;
• 9 an enlarged detail of the perspective views according to FIG 4 and 5 ;
• 10 an enlarged detail according to the perspective view 1 ; and
• 11 a further schematic sectional view of the filter assembly gem. 1 .

In the figures, elements that are the same or have the same function have been provided with the same reference symbols unless otherwise stated.

embodiment(s) of the invention

1 shows a schematic perspective partial sectional view of an embodiment of a filter assembly 1. 2 shows a further schematic perspective partial sectional view of the filter arrangement 1. 6 and 7 each show schematic sectional views of different embodiments of the filter assembly 1, which differ only in their dimensions.

The filter arrangement 1 comprises a filter housing 2 and a first filter element 3 arranged in the filter housing 2. The filter housing 2 can also be referred to as a housing, receptacle or filter receptacle. The first filter element 3 is also in the 2 , 3 and 6 until 8th shown. The filter arrangement 1 is preferably used in motor vehicles, trucks, construction vehicles, watercraft, rail vehicles, agricultural machines or vehicles or aircraft. The first filter element 3 is particularly suitable for filtering the combustion air of an internal combustion engine. The first filter element 3 is preferably an air filter.

The first filter element 3, which can also be referred to as a primary filter element, primary element, main filter element or main element, comprises a filter medium 4 which surrounds a support tube or center tube 5. For example, the filter medium 4 can be wound onto the central pipe 5 . The central tube 5 is preferably in the form of a lattice and is therefore fluid-permeable. The filter medium 4 is preferably pleated. The filter medium 4 is, for example, a filter fabric, a filter fabric or a filter fleece. In particular, the filter medium 4 can be produced in a spunbonded or meltblown process. Furthermore, the filter medium 4 can be felted or needled. The filter medium 4 can have natural fibers, such as cellulose or cotton, or synthetic fibers, for example made of polyester, polyvinyl sulfite or polytetrafluoroethylene. During processing, the fibers can be oriented in, obliquely and/or cross-machine direction.

The first filter element 3 has a first end disk 6 and a second end disk 7 . The end plates 6, 7 are preferably made of a plastic material. For example, the end plates 6, 7 can be designed as inexpensive plastic injection molded components. The end plates 6, 7 can be made of a polyurethane material, for example. The end plates 6, 7 can be cast onto the filter medium 4. The filter medium 4 is arranged between the end plates 6, 7. A sealing device 9 for sealing the first filter element 3 with respect to the filter housing 2 is provided on a front side 8 of the first end disk 6 facing away from the filter medium 4 . The sealing device 9 is set up to seal the first filter element 3, in particular radially and/or axially, with respect to the filter housing 2.

The filter medium 4 can be fused, glued or welded to the end plates 6, 7. The second end plate 7 is plate-shaped and impermeable to fluids. A receiving opening 10 is provided in the first end plate 6 . During operation of the filter arrangement 1, fluid L to be cleaned flows from a raw side RO of the first filter element 3 through the filter medium 4 as filtered fluid L into a cavity surrounded by the central pipe 5 onto a clean side RL of the first filter element 3.

The first filter element 3 has an oval cross section in a longitudinal direction LR thereof. Starting from the first end disk 6, the cross section can decrease in the direction of the second end disk 7, so that the first filter element 3 tapers conically. However, the first filter element 3 preferably has an oval or elliptical cross section. That is, the first filter element 3 is cylindrical with an oval base surface. In the present case, oval can be understood to mean a rectangular cross section with rounded corners, an elliptical cross section or a cross section formed from a plurality of circular arcs. The cross section is symmetrical.

A second filter element 11 can be accommodated in the first filter element 3 . The second filter element 11 can be referred to as a secondary filter element, secondary element, secondary filter element or secondary element. The first filter element 3 and the second filter element 11 are arranged such that during operation of the filter arrangement 1 the fluid L to be cleaned flows first through the first filter element 3 and then through the second filter element 11 . The second filter element 11 is preferably accommodated in the accommodation opening 10 . The second filter element 11 preferably also has an oval cross section. The first filter element 3 can include the second filter element 11 . The second filter element 11 has a filter medium 12 and a first end plate 13 . The first end plate 13 can be made from an elastically deformable plastic material, for example from a foamed polyurethane material. The filter medium 12 can be a filter fleece. The second filter element 11 also includes a second end disk or transition section 14 .

The filter medium 12 is positioned between the first end disk 13 and the transition section 14 . The filter medium 12 can be supported on the inside by a support tube. The filter media 12 is preferably smooth, i.e., unpleated.

The second filter element 11 can, as in 2 and 5 until 8th shown, have a support structure 15 provided on the outside of the filter medium 12 . The support structure 15 is lattice-shaped and fluid-permeable. Alternatively, as in 4 shown, the support structure 15 can also be dispensed with. The support structure 15 is made of a plastic material. The support structure 15 can be molded onto the filter medium 12 in a plastic injection molding process. In particular, the support structure 15 can be formed in one piece with the transition section 14 . That is, the support structure 15 can be molded onto the filter medium 12 together with the transition section 14 in a plastic injection molding process. Because the support structure 15 is attached to the outside of the filter medium 12, fiber abrasion on the filter medium 12 is prevented when the first filter element 3 is pushed onto the second filter element 11 and/or when it is pulled off the second filter element 11. In other words, the central pipe 5 only contacts the support structure 15 and not the filter medium 12. This reliably prevents damage and in particular the formation of holes in the filter medium 12.

The second filter element 11 includes a tubular connection section 16. The connection section 16 has a circular cross section. The connection section 16 is preferably formed in one piece with the transition section 14 and the support structure 15 , with the transition section 14 being arranged between the support structure 15 and the connection section 16 . The transition section 14 forms a transition between the oval cross section of an interior 17 of the second filter element 11 and the circular cross section of the connection section 16, with a cross-sectional area of the interior 17 preferably being the same size as a cross-sectional area of the connection section 16.

An engagement portion 18 is provided on the terminal portion 16 . The engagement section 18 can also be referred to as engagement geometry, engagement contour, connection geometry or connection contour. The engaging portion 18 is, as in 1 until 10 shown, an external thread provided on the connection section 16 . Alternatively, the engagement section 18 can also be part of a bayonet lock. In particular, the engagement section 18 can be a single-start or multi-start thread. A sealing element 19 is also provided on the connection section 16 and is slipped over the connection section 16 . The sealing element 19 is preferably made of an elastic plastic material, in particular a thermoplastic elastomer, or a rubber material. The sealing element 19 can be an O-ring. The sealing element 19 is preferably arranged between the transition section 14 and the engagement section 18 . The sealing element 19 is preferably provided at a transition between the connection section 16 and the transition section 14 . The connection section 16 forms a fluid outflow opening 20 of the second filter element 11.

The filter housing 2 includes a receiving section 21 for receiving the first filter element 3 and the second filter element 11. The receiving section 21 is preferably made of a plastic material. Alternatively, the receiving section 21 can be made of sheet metal, in particular sheet steel. For example, the receiving section 21 can be designed as a cost-effective plastic injection-molded component. Furthermore, the filter housing 2 has a maintenance cover 22 that can be removed from the receiving section 21 . The first filter element 3 and the second filter element 11 can be removed from the receiving section 21 via the maintenance cover 22 . The maintenance cover 22 can be connected to the receiving section 21 with the aid of quick-release fasteners 23 . A sealing device can be provided between the maintenance cover 22 and the receiving section 21 .

The filter housing 2 or the receiving section 21 has a fluid inlet 24 for the inlet of the fluid L to be filtered into the filter housing 2 and a fluid outlet 25 for outlet of the fluid L filtered with the aid of the filter elements 3 , 11 from the filter housing 2 . The fluid inlet 24 and the fluid outlet 25 are preferably tubular and can have a circular cross section. The fluid L to be filtered enters the fluid inlet 24 in an inflow direction E. The fluid L emerges from the fluid outlet 25 in an outflow direction A, preferably parallel to the longitudinal direction LR of the first filter element 3 . The inflow direction E is oriented perpendicular to the outflow direction A. An engagement area 26 is provided in the filter housing 2 and in particular in the receiving section 21, in which the sealing device 9 of the first filter element 3 engages. The engagement area 26 can completely surround the fluid outlet 25 .

A particle discharge opening 27 can be provided on the maintenance cover 22 . The particle discharge opening 27 is preferably tubular. Particles previously separated from the fluid L can be discharged from the filter housing 2 via the particle discharge opening 27 . The particle discharge opening 27 can have a valve.

The filter housing 2 includes a counter-engagement portion 28 that corresponds to the engagement portion 18 of the second filter element 11. The counter-engagement section 28 is preferably provided on the inside of the fluid outlet 25 . The engagement section 18 is designed to positively engage in the counter-engagement section 28 so that the second filter element 11 can be positively connected to the filter housing 2 and in particular to the receiving section 21 . The counter-engagement section 28 can also be referred to as a counter-engagement geometry, counter-engagement contour, connection geometry or connection contour. The counter-engagement section 28 is an internal thread provided on the inside of the fluid outlet 25 . Alternatively, the counter-engagement section 28 can also be part of a bayonet lock. That is, a rotary coupling is provided between the second filter element 11 and the filter housing 2 . In particular, the counter-engagement section 28 can be a single-start or multi-start thread.

When the second filter element 11 is screwed into the filter housing 2 , the sealing element 19 is positioned between a shoulder 29 that completely surrounds the connection section 16 and the counter-engagement section 28 . The sealing element 19 is then pressed radially between the connection section 16 and the fluid outlet 25 . That is, the sealing element 19 seals the second filter element 11 radially with respect to the filter housing 2 .

On the second filter element 11 and in particular on the shoulder 29, as in 9 and 10 shown, a first positioning element 30 is provided. A second positioning element 31 corresponding to the first positioning element 30 is arranged on the filter housing 2 and in particular on the fluid outlet 25 . When the second filter element 11 is screwed into the filter housing 2, it makes contact with the first positioning element 30, as shown in FIG 10 shown, the second positioning element 31. As a result, the rotatability of the second filter element 11 relative to the filter housing 2 is restricted. That is, with the aid of the positioning elements 30, 31 it is ensured that the second filter element 11 can be arranged in only one predetermined position relative to the filter housing 2.

The filter housing 2 has, as in 11 shown only very schematically, has an oval cross section 32 and the second filter element 11 has an oval cross section 33 .

The cross sections 32, 33 are shown in greatly simplified form as ellipses. The oval cross sections 32, 33 are each symmetrical, i.e. they each include a main axis of symmetry 34, 35 and a secondary axis of symmetry 36, 37, with the secondary axis of symmetry 36, 37 being shorter than the main axis of symmetry 34, 35 assigned to it. The main axes of symmetry 34, 35 are arranged perpendicular to the secondary axes of symmetry 36, 37. With the aid of the positioning elements 30, 31, the second filter element 11 is positioned in an end position or operating position in the filter housing 2 when the positioning elements 30, 31 touch. In the end position, the oval cross section 33 of the second filter element 11 is positioned in the oval cross section 32 of the filter housing 2 such that an outer contour 38 of the oval cross section 33 of the second filter element 11 is circumferentially spaced from an outer contour 39 of the oval cross section 32 of the filter housing 2 at a constant distance . Furthermore, both the main axes of symmetry 34, 35 and the secondary axes of symmetry 36, 37 are congruent or at least parallel in the end position.

The fact that the second filter element 11 is positively connected to the filter housing 2 ensures that the second filter element 11 is not pulled out of the fluid outlet 25 when the first filter element 3 is pulled off the same. This prevents contamination of the clean side RE with fluid L to be filtered. Due to the support structure 15, damage to the second filter element 11 and in particular to the filter medium 12 is also ruled out when the first filter element 3 is replaced. With the help of the positioning elements 30, 31, a simple and reproducible positioning of the second filter element 11 in the filter housing 2 is ensured. That is, an angular position of the second filter element 11 in the filter housing 2 is fixed with the aid of the positioning elements 30, 31 in the end position.

Reference List

1

filter arrangement

2

filter housing

3

filter element

4

filter medium

5

center pipe

6

end plate

7

end plate

8th

front

9

sealing device

10

intake opening

11

filter element

12

filter medium

13

end plate

14

transition section

15

support structure

16

connector section

17

inner space

18

engagement section

19

sealing element

20

fluid outflow opening

21

recording section

22

maintenance cover

23

quick release

24

fluid inlet

25

fluid outlet

26

intervention area

27

particle exit opening

28

counter engagement section

29

Unit volume

30

positioning element

31

positioning element

32

cross-section

33

cross-section

34

main axis of symmetry

35

main axis of symmetry

36

minor axis of symmetry

37

minor axis of symmetry

38

outer contour

39

outer contour

A

outflow direction

E

inflow direction

L

Fluid

LR

longitudinal direction

RL

clean side

RO

raw side

Claims (9)

Filter element (11), in particular secondary filter element, which can be accommodated in a main filter element (3), with an engagement section (18) which is designed to engage in a corresponding counter-engagement section (28) of a filter housing (2) in order to move the filter element (11) to be positively connected to the filter housing (2), the filter element (11) having an oval cross-section (33) with a longitudinal extension of the cross-section (33) in the direction of a main axis of symmetry which is greater than a longitudinal extension of the cross-section (33) in direction a secondary axis of symmetry perpendicular to the main axis of symmetry, the filter element (11) further comprising a connection section (16) for connecting the filter element (11) to a fluid outlet (25) of the filter housing (2), wherein the connection section (16) has a circular cross-section, characterized that the circular cross-section has a diameter that is smaller than the length dimension opening of the cross section (33) in the direction of the main axis of symmetry (34) and is greater than the length of the cross section (33) in the direction of the secondary axis of symmetry (36). filter element after claim 1 , wherein the filter element (11) can be positively connected to the filter housing (2) with the aid of a rotary movement filter element after claim 2 , further comprising a transition section (14) which forms a transition between the oval cross section (33) of the filter element (11) and the circular cross section of the connection section (16). Filter element according to one of Claims 1 - 3 , further comprising a support structure (15) provided on the outside and/or inside of a filter medium (12) of the filter element (11). Filter element according to one of Claims 1 - 4 , further comprising a sealing element (19), in particular an O-ring, for radial sealing of the filter element (11) relative to the filter housing (2). Filter arrangement (1), in particular air filter arrangement, with a filter housing (2) and a filter element (11) according to one of Claims 1 - 5 , wherein the filter element (11) is positively connected to the filter housing (2). filter arrangement claim 6 , wherein the engagement portion (18) is an external thread and the counter-engagement portion (28) is an internal thread or wherein the engagement portion (18) and the counter-engagement portion (28) form a bayonet lock. filter arrangement claim 6 or 7 , wherein the filter element (11) has a first positioning element (30) and the filter housing (2) has a second positioning element (31), the first positioning element (30) bearing against the second positioning element (31) in an end position of the filter element (11). and wherein in the end position a main axis of symmetry (34) of the oval cross-section (33) of the filter element (11) is positioned parallel to a main axis of symmetry (35) of an oval cross-section (32) of the filter housing (2). Filter arrangement according to one of Claims 6 - 8th , further comprising a main filter element (3) which is accommodated in the filter housing (2), the filter element (11) being arranged inside the main filter element (3).

Images