Gas filter system

Abstract

The invention relates to a gas filter system (10) having: - an outer filter element (12) with a first filter medium (20) arranged between a first end plate (16) and a second end plate (18); and - an inner filter element (14) with a second filter medium (26) arranged between a third end plate (22) and a fourth end plate (24), wherein the first end plate (16) and the third end plate (22) have an open design, and the first end plate (16) surrounds the third end plate (22); the first end plate (16) has a first seal protrusion (38) which protrudes in the axial direction; the third end plate (22) has a second seal protrusion (40) which protrudes in the axial direction; and the first seal protrusion (38) and the second seal protrusion (40) engage into each other in order to seal off the third end plate (22) and the first end plate (16) from each other. The invention additionally relates to the use of an outer filter element (12) and / or an inner filter element (14) in such a gas system (10).

Description

[0001] Gas filter system

[0002] Technical area

[0003] The invention relates to a gas filter system comprising an outer filter element and an inner filter element that are sealed against each other. The invention also relates to the use of an outer filter element and / or an inner filter element in a gas filter system.

[0004] State of the art

[0005] Such filter systems have a high degree of filtration and are used, for example, for filtering combustion air for internal combustion engines, for filtering cathode air from fuel cells, or as cabin air filters. Especially for filtering cathode air for fuel cells, filter elements with different properties are used, with one filter medium designed for particle filtration and the other filter medium enabling the adsorption of harmful gases such as nitrogen oxides.

[0006] To enable compact filtration systems despite multiple filter elements, the filter elements are typically installed in a common housing, where potential leakage flows that could bypass the filter elements must be reliably prevented. For this purpose, the filter elements are often sealed from the housing, placing significant demands on the design of the filter system. If the seals are inadequately matched, for example, due to unavoidable manufacturing tolerances, unfiltered gas can flow past the filter elements. This reduces the operational reliability of the filter system.

[0007] To prevent leakage, the filter elements are often glued to each other and / or to the housing. However, this makes replacing the filter elements during maintenance a laborious process, damaging the gas filter system.

[0008] DE 10 2018 215 603 A1 discloses a modular filter element comprising an outer filter element and an inner filter element that are sealed against each other. The inner filter element is arranged within the outer filter element.

[0009] It is an object of the invention to improve the operational reliability of a gas filter system with regard to the sealing of the filter elements against each other. Disclosure of the Invention

[0010] This object is achieved by a gas filter system having the features specified in claim 1. Furthermore, the object is achieved by a use having the features specified in claim 17. Preferred embodiments are specified in the respective subclaims and the description.

[0011] According to the invention, a gas filter system is provided. The gas filter system can be used, for example, to filter combustion air for internal combustion engines or fuel cells, or as a cabin air filter.

[0012] The gas filter system comprises an outer filter element. The outer filter element comprises a first filter medium arranged between a first end plate and a second end plate. The gas filter system also comprises an inner filter element. The inner filter element comprises a second filter medium arranged between a third end plate and a fourth end plate.

[0013] Preferably, the first filter medium and / or the second filter medium are attached to the respective end plates in a gas-tight manner, particularly preferably glued to the respective end plates or molded onto the respective filter medium. In other words, the end plates enclose and seal the respective filter medium, preferably at its end faces in the axial direction. This prevents leakage flows within the respective filter element.

[0014] The first and / or the second filter medium, preferably the outer and / or the inner filter element, can surround a longitudinal axis of the gas filter system in a ring shape. The filter media can be arranged concentrically to one another and to the longitudinal axis. The respective filter medium can, for example, be folded or wound in a star shape. The filter medium can be round or oval in cross-section. The filter medium can be cylindrical or conical in the axial direction. Directional references such as axial or radial refer here and below to the longitudinal axis of the gas filter system, unless otherwise stated. The longitudinal axes of the two filter elements preferably coincide, but can also differ from one another.In particular, the longitudinal axis of the inner filter element could be inclined relative to the longitudinal axis of the outer filter element, for example, if the inner filter element is conical and the outer filter element is cylindrical, and the end plate of the inner filter element facing away from the gas inlet or outlet is not arranged around the center of the gas filter system. The first end plate and the third end plate are open. The opening in the third end plate allows gas to enter or exit an interior space of the filter element. Furthermore, the opening in the first end plate can serve to arrange the inner filter element in the outer filter element.

[0015] The first end plate preferably surrounds the third end plate circumferentially. In other words, the third end plate is arranged at least partially, preferably completely, within the first end plate. Furthermore, the inner filter element can be arranged at least predominantly, preferably completely, within the outer filter element. This allows for particularly compact dimensions of the gas filter system to be achieved.

[0016] The first end plate has, in particular on a side facing away from the first filter medium, a first sealing projection protruding in the axial direction. The third end plate has, in particular on a side facing away from the second filter medium, a second sealing projection protruding in the axial direction. In other words, the sealing projections protrude beyond the respective end plate along the longitudinal axis of the gas filter system. Preferably, the first and second sealing projections protrude beyond their respective end plate in the same direction along the longitudinal axis. The sealing projections serve for sealing contact with a corresponding mating contour, for example the respective other sealing projection and / or a housing of the gas filter system. Preferably, the sealing projections are formed integrally on the respective end plates.

[0017] Alternatively, the sealing projections and the end plates covering the axial end faces of the filter media bodies can be separate components that can be connected to each other, for example, by gluing, welding, or injection molding. These multi-piece embodiments are also encompassed by the term "end plates."

[0018] The sealing projections can each have at least one section that also extends in a radial direction, in particular protrudes in a radial direction beyond the respective end plate. The first and the second sealing projection generally have different cross sections. The sealing projections are particularly preferably designed to be complementary to one another in order to enable positive engagement. The first or the second sealing projection can, for example, have a groove-shaped (U-shaped) cross section, while the respective other sealing projection has a web-shaped (I-shaped) cross section. The third end plate and the first end plate are sealed against one another. In other words, leakage flows between the first end plate and the third end plate are prevented bidirectionally. For this purpose, the first sealing projection and the second sealing projection engage with one another.

[0019] The inventive design of the gas filter system, in particular the interaction of the sealing projections of both filter elements, advantageously increases its tightness. Leakage flows can thus be reliably prevented and, at the same time, easy replacement of the filter elements is ensured, thereby increasing the operational efficiency of the gas filter system.

[0020] In a preferred embodiment of the gas filter system, the first sealing projection and the second sealing projection are in sealing contact with each other on at least two projection sealing surfaces. The projection sealing surfaces can be spatially spaced from one another. Preferably, the projection sealing surfaces have a different orientation. This allows leakage paths to be prevented even more effectively, thereby further improving the sealing effect.

[0021] A further preferred embodiment is one in which the first sealing projection and the second sealing projection are in sealing contact with one another on at least one axial projection sealing surface and at least one radial projection sealing surface. The axial projection sealing surface and the radial projection sealing surface can be adjacent to one another. This allows the sealing area to be kept particularly compact.

[0022] Particularly preferred is an embodiment of the gas filter system in which one of the sealing projections is elastic and engages over the other sealing projection, so that it is widened by the engagement of the other of the sealing projections. The elastic sealing projection can comprise polyurethane, in particular the elastic sealing projection is formed from polyurethane. The other sealing projection can be rigid, preferably from polypropylene.

[0023] In a preferred embodiment of the gas filter system, the first sealing projection and / or the second sealing projection is / are formed circumferentially on the respective end plate. The first and the second sealing projection are preferably formed circumferentially. In other words, the first and / or the second sealing projection can be formed in a ring-like manner around the longitudinal axis. This can further increase the sealing effect. For the gas filter system to function reliably, it may be necessary that only filter elements that correspond to the specifications are used. In addition, for additional functions, for example an air mass meter, the rotational installation position of a fundamentally rotationally symmetrical filter element can be important, since similar filter elements can exhibit similar deviations from an ideal due to manufacturing reasons.Mass air flow sensors, in particular, are very sensitive to such deviations; therefore, if these deviations always occur in the same way, they can be compensated.

[0024] A further development is also preferred in which the first sealing projection and the second sealing projection each have at least one radial recess and / or one radial projection. The corresponding sealing projection is therefore not designed strictly in a basic shape, for example a circular one, when viewed in the direction of the longitudinal axis, but has local deviations from the basic shape, such as the circular shape. The at least one radial recess or projection can participate in the sealing with respect to the respective other sealing projection and / or a housing. The respective other sealing projection and / or the housing is preferably designed to correspond. Thus, a radial projection on one sealing projection engages in a radial recess on the other sealing projection. The deviation from the basic shape, in particular a circular one, on the sealing projection forces installation of the filter element in a defined rotational orientation.In addition, it is ensured that only filter elements adapted to the respective gas filter system can be used.

[0025] In a further preferred embodiment of the gas filter system, the first and / or second sealing projections have at least one housing sealing surface for sealing engagement with a housing, preferably in the axial direction. The first and / or second sealing projections can have the at least one housing sealing surface on a side facing away from the side engaged with the other sealing projection. The corresponding sealing projection can thus be arranged between the housing and the respective other sealing projection, promoting simultaneous sealing of two possible leakage paths.

[0026] An embodiment is also preferred in which the gas filter system has a preferably closed base plate. The base plate is particularly preferably arranged on the second end plate of the outer filter element. The base plate is particularly preferably designed to be gas-tight. In other words, the base plate can seal the first filter medium at the second end plate in the axial direction. By means of a closed base plate, flow around the outer filter element can be prevented. In a preferred development of the gas filter system, the base plate has a support structure, in particular at least one support rib protruding in the axial direction, for supporting the fourth end plate of the inner filter element. In other words, the outer filter element forms a stop surface for the inner filter element. This allows the inner filter element to be positioned accurately within the outer filter element.This supports the sealing engagement of the sealing projections with each other.

[0027] In a preferred embodiment of the gas filter system, the outer filter element has a support tube radially inward. In other words, the filter medium can be stabilized radially inward by a support tube. The base plate can be formed integrally with the support tube.

[0028] Alternatively or additionally, the filter medium can be stabilized radially on the outside by a cage. For external stabilization, especially of a wound filter medium, a thread winding can also be attached to the filter element. This allows the filter element to be made more rigid, thus preventing dynamic leakage paths caused by changes in the filter element's length during operation.

[0029] A preferred embodiment of the gas filter system is one in which the outer filter element and the inner filter element are hollow-cylindrical. A hollow-cylindrical design allows for a large inflow area while simultaneously maintaining compact dimensions for each individual filter element and the entire gas filter system.

[0030] In a further preferred embodiment of the gas filter system, the outer filter element is arranged upstream of the inner filter element in a flow direction through the gas filter system. In other words, the outer filter element and the inner filter element are connected in series such that the gas filter system flows radially inward. This results in smaller pressure differences between the upstream and downstream sides of the filter elements, thus preventing the formation of leakage flows.

[0031] Preferably, one of the filter media is designed for particle filtration and consists of or comprises cellulose, while the other filter medium is designed for harmful gas adsorption and preferably comprises activated carbon. Advantageously, the filter element for particle filtration is arranged upstream of the filter element for harmful gas adsorption in the direction of flow.

[0032] Further preferred is an embodiment of the gas filter system in which it has an openable housing. The housing typically has a first housing part and a second housing part, for example a housing pot and a removable housing cover. The outer filter element and the inner filter element are preferably arranged between the first housing part and the second housing part. In other words, the inner and outer filter elements can be accommodated in the housing. The housing preferably has at least one inlet opening for gas to flow into the gas filter system and at least one outlet opening for gas to flow out of the gas filter system. The inlet opening is preferably arranged immediately upstream of the outer filter element. The outlet opening is preferably arranged immediately downstream of the inner filter element.The first housing part preferably has an end face facing the first and third end plates of the filter elements. The end face can have a housing sealing groove corresponding to the first sealing projection and / or second sealing projection, in which the first sealing projection and the second sealing projection are arranged in an interlocking manner. This allows a raw gas side of the gas filter system to be effectively sealed from a clean gas side of the gas filter system. In other words, the at least one inlet opening can fluidically communicate with the at least one outlet opening only through the inner and outer filter elements.

[0033] In a preferred embodiment of the gas filter system, the front side has an opening that is fluidically positioned upstream or downstream of the inner filter element. In other words, the inlet opening or the outlet opening can be formed on the front side of the housing.

[0034] In a preferred embodiment of the gas filter system, the first housing part has a central tube on its front side, which engages with the inner filter element. The central tube can be designed to support the second filter medium. The central tube is preferably designed in a grid-like manner. The central tube can extend along the longitudinal axis over at least one-third, preferably over at least two-thirds, and particularly preferably over the entire dimension of the inner filter element in the longitudinal direction. This allows for particularly effective support of the second filter medium.

[0035] Furthermore, an embodiment of the gas filter system is preferred in which the housing has a closure arranged on the circumference, wherein the closure, in a closed state, effects a gas-tight clamping of the first housing part and the second housing part with the outer filter element and the inner filter element. In other words, in a closed state, the housing can have dimensions in the longitudinal direction that are smaller than the dimensions of the nested filter elements in the longitudinal direction. As a result, the filter elements or the sealing projections can be slightly compressed when the housing is closed, thereby ensuring a particularly gas-tight fit of the sealing projections against one another and / or against the housing.

[0036] The scope of the invention also includes the use of an outer filter element and / or an inner filter element in a gas filter system according to the invention, as described above and below. The outer and inner filter elements, respectively, can have the features described above and below.

[0037] Furthermore, a filter element with the corresponding features falls within the scope of the invention. One filter element has a filter medium which is arranged between two end plates. One end plate has a first sealing projection protruding in the axial direction. The first sealing projection has at least one projection sealing surface. The projection sealing surface is designed to bear sealingly against a further projection sealing surface of an axially protruding second sealing projection of an end plate of a further filter element. In one embodiment, the first sealing projection is made of a soft material, in particular foamed polyurethane, and is preferably formed integrally with the end plate. The first sealing projection is preferably arranged on the inner circumference of the end plate and advantageously has the shape of a U directed in the axial direction towards the open interior of the filter element.The free leg of the U-shaped element is arranged radially inward. This creates a receiving groove. In this way, a rigid, rib-like sealing projection of a second filter element arranged within this filter element can engage with the sealing projection, so that the two filter elements are sealed against each other. In an alternative embodiment, the filter element with the soft, groove-containing sealing projection forms the inner filter element, and the filter element with the rigid, rib-like sealing projection forms the outer filter element. In this case, the U-shaped groove is arranged on the outer circumference of the end plate, and the free leg is arranged radially outward.

[0038] Short description of the drawings

[0039] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, from the patent claims and from the figures of the drawing, which show details according to the invention. The features mentioned above and those explained in more detail can each be implemented individually or in groups in any expedient combination in variants of the invention. The features shown in the drawing are illustrated in such a way that the special features of the invention can be clearly seen. The drawing shows: Fig. 1 shows a first embodiment of a gas filter system according to the invention with an outer filter element and an inner filter element comprising a first end plate and a third end plate, respectively, the sealing projections of which engage in a sealing manner, in a schematic sectional view;

[0040] Fig. 2 shows a section of the gas filter system from Figure 1 in a schematic sectional view;

[0041] Fig. 3 shows the outer filter element of the gas filter system from Figures 1 and 2 in a schematic perspective view;

[0042] Fig. 4 shows the inner filter element of the gas filter system from Figures 1 and 2 in a schematic perspective view;

[0043] Fig. 5 shows a second embodiment of a gas filter system according to the invention in a schematic sectional view;

[0044] Fig. 6 shows a section of the gas filter system from Figure 5 in a schematic sectional view;

[0045] Fig. 7 shows the outer filter element of the gas filter system from Figures 5 and 6 in a schematic perspective view;

[0046] Fig. 8 shows the inner filter element of the gas filter system from Figures 5 and 6 in a schematic perspective view.

[0047] Embodiments of the invention

[0048] Figure 1 shows a first embodiment of a gas filter system 10 with an outer filter element 12 and an inner filter element 14.

[0049] The outer filter element 12 has a first filter medium 20 arranged between a first end plate 16 and a second end plate 18. The first filter medium 20 is preferably attached to the end plates 16, 18 in a gas-tight manner. Particularly preferably, the end plates 16, 18 are injection-molded onto the first filter medium 20.

[0050] The inner filter element 14 has a second filter medium 26 arranged between a third end plate 22 and a fourth end plate 24. The second filter medium 26 is preferably attached to the end plates 22, 24 in a gas-tight manner. Particularly preferably, the end plates 22, 24 are injection-molded onto the first filter medium 26.

[0051] The first and / or second filter medium 20, 26 is / are designed to filter gas flowing through the filter media 20, 26. Preferably, the first and / or second filter medium 20, 26 is formed from a folded or pleated filter material. This allows the permeable surface area of ​​the filter elements 12, 14 to be increased, which has a positive effect on pressure loss. Advantageously, one of the filter materials comprises activated carbon for adsorbing harmful gases.

[0052] According to the embodiment shown, the outer filter element 12 and the inner filter element 14 can be formed as hollow cylinders around a longitudinal axis 28. Typically, the inner filter element 14 is arranged within the outer filter element 12. In this case, the filter elements 12, 14 are typically flowed through in a radial direction, preferably radially inward. The outer filter element 12 can form a radially outer inflow side 30 and a radially inner outflow side 32. The inner filter element 14 can form a radially outer inflow side 34 and a radially inner outflow side 36.

[0053] During typical operation of the gas filter system 10, a gas (not shown in detail) initially flows through the outer filter element 12 at the inflow side 30, which gas is guided through the first filter medium 20 and then discharged via the outflow side 32. Subsequently, the gas pre-filtered by the first filter medium is guided through the second filter medium 26 via the inflow side 34 and discharged via the outflow side 36 of the second filter medium 26. In other words, the gas filter system 10 can be flowed radially. The first filter medium 20 and the second filter medium 26 are fluidically connected in series.

[0054] The outer filter element 12 surrounds the inner filter element 14 circumferentially. In other words, the first filter medium 12 preferably completely covers the inflow side 34 of the second filter medium 26. This allows pressure losses to be kept particularly low.

[0055] As shown here by way of example, the first filter element 12 and the second filter element 14 can be arranged coaxially with one another. Preferably, the first and second filter elements 12, 14 are arranged coaxially with the longitudinal axis 28.

[0056] The first end plate 16 has a first sealing projection 38 that protrudes beyond the first end plate 16 in an axial direction or along the longitudinal axis 28. The third end plate 22 has a second sealing projection 40 that protrudes beyond the third end plate 22 in an axial direction or along the longitudinal axis 28. The first sealing projection 38 and / or the second sealing projection 40 can each be arranged on the side of the end plate 16, 22 opposite the respective filter medium 20, 26 of the same filter element 12, 14. Preferably, the first and / or the second sealing projection 38, 40 is formed integrally with the respective end plate 16, 22. The first sealing projection 38 and the second sealing projection 40 engage with one another in order to form a gas-tight seal between the adjacent filter elements 12, 14 and the end plates 16, 22.

[0057] According to the embodiment shown, the outer filter element 12 can have a base plate 42. The base plate 42 can have a support structure 44—here in the form of a plurality of support ribs 46. The support structure 44 is preferably designed to support the fourth end plate 24 of the inner filter element 14.

[0058] Furthermore, the outer filter element 12 can have a support tube 48. The support tube 48 can be designed to support the first filter medium 20 against a flow-induced pressure force. The support tube 48 is preferably designed in a grid-like manner, which allows the flow resistance to be kept low.

[0059] Preferably, the base plate 42 and / or the support tube 48 are arranged on the second end plate 18, in particular partially embedded therein. This allows the outer filter element 12 to be designed as a particularly gas-tight unit.

[0060] Particularly preferably, the support tube 48 is formed integrally with the base plate 42. This allows the number of individual parts to be reduced, thereby simplifying the assembly of the gas filter system 10.

[0061] In an alternative embodiment (not shown), the outer filter element 12 does not have a base plate. The annular end plate 18 then surrounds an opening to the interior of the filter element 12. This makes it possible to first mount the outer filter element 12 and then push the inner filter element 14 through the opening in the base of the outer filter element 12. This allows the flexible first sealing projection 38 to be positioned in the housing sealing groove provided for it—described later—and then the rib-like second sealing projection 40 to be securely inserted into the first sealing projection 38.

[0062] The gas filter system 10 can have a housing 50 with a first housing part 52 and a second housing part 54. The first housing part 52 can be detachably arranged on the second housing part 54, preferably by means of a closure 56. As shown, the closure 56 can be designed as a tension lock in order to press the filter elements 12, 14 arranged between the first housing part 52 and the second housing part 54 gas-tight against the housing parts 52, 54 when the housing 50 is closed. As shown in Fig. 1, the gas filter system 10 can have a central tube 58. The central tube 58 can be arranged on the first housing part 52. The central tube 58 is preferably fastened to the first housing part 52. The central tube 58 can extend over at least part of the axial extent, preferably over the entire axial extent, of the second filter medium 26.As a result, the second filter medium 26 can be supported in the radial direction, for example in the event of flow-related forces.

[0063] In one embodiment, the housing 50 can have at least one filter element receptacle 60. Preferably, the housing 50 has a filter element receptacle 60 on each of the first housing part 52 and the second housing part 54. The filter element receptacle 60 can be designed as a radially inwardly offset wall that grips the outer filter element 12 on its radial outer side. This allows the filter elements 12, 14 of the gas filter system 10 to be prepositioned, simplifying assembly.

[0064] Fig. 2 shows a section of the gas filter system 10 from Fig. 1 in a detailed view.

[0065] The first housing part 52 has an end face 62 facing the outer filter element 12 and the inner filter element 14, or the first end plate 16 and the third end plate 22. The end face 62 forms a housing sealing groove 64. The second sealing projection 40 and the first sealing projection 38, which engages the second sealing projection 40, are arranged in the housing sealing groove 64. This allows a raw gas side 66 of the gas filter system 10 to be sealed from a clean gas side 68 of the gas filter system 10.

[0066] The first sealing projection 38 can comprise an elastic material, in particular PUR. Preferably, the first sealing projection 38 is formed from the elastic material, as shown. The second sealing projection 40 can comprise a rigid material, in particular polyamide or polypropylene. Preferably, the second sealing projection 40 is formed from the rigid material, as shown.

[0067] As shown, the first sealing projection 38 can abut against the housing sealing groove 64 with an axial housing sealing surface 70, a radially inner housing sealing surface 72, and a radially outer housing sealing surface 74. This allows a particularly high sealing effect to be achieved.

[0068] Further, as shown, the first sealing projection 38 and the second sealing projection 40 can engage with each other such that the first sealing projection 38 surrounds the second sealing projection 40. In other words, the first sealing projection 38 can bear against at least one axial projection sealing surface 76, a radially inner projection sealing surface 78, and a radially outer projection sealing surface 80 on the second sealing projection 40.

[0069] During assembly of the gas filter system 10, in the illustrated embodiment, the first sealing projection 38 can be pressed against the end face 62 or the housing sealing groove 64 by the second sealing projection 40. Sealing the raw gas side 66 against the clean gas side 68 using two filter elements 12, 14 can thus be achieved particularly easily in a single sealing area 82. The complex structural design and precise manufacturing of a separate sealing area for each filter element 12, 14 can be eliminated.

[0070] In an alternative embodiment (not shown) of the upper end faces in the illustration, the outer filter element 12 has the rigid rib-like sealing projection, and the inner filter element 14 has the corresponding soft groove-like sealing projection. This allows the inner filter element 14 to be mounted first in the housing part 52, and the outer filter element 12 to be pushed on afterward, so that its sealing projection protrudes into the sealing projection of the inner filter element 14.

[0071] Fig. 3 shows the outer filter element 12 from Figs. 1, 2 in a perspective view.

[0072] The first sealing projection 38 is formed circumferentially on the first end plate 16. As shown, the first sealing projection 38 can have a radial recess 84. The radial recess 84 can be understood as a radially inwardly directed deviation of the otherwise rotationally symmetrical first sealing projection 38. The recess 84 can enable a rotationally secure arrangement of the first filter element 12 on the housing 50 (see Figs. 1, 2), thereby ensuring precise positioning.

[0073] Fig. 4 shows the inner filter element 14 from Figs. 1, 2 in a perspective view.

[0074] The second sealing projection 40 is formed circumferentially on the third end plate 22. As shown, the second sealing projection 40 can have a radial recess 86. The radial recess 86 is formed corresponding to the radial recess 84 of the outer filter element 12 (see Fig. 3).

[0075] Fig. 5 shows a second embodiment of a gas filter system 10. The illustrated gas filter system 10 differs from the gas filter system 10 of Figure 1 essentially in the design of the first end plate 16 and the third end plate 22. Apart from the deviations described below, the second embodiment corresponds to the first embodiment; in this respect, reference is made to the above description.

[0076] As shown, the first end plate 16 can form a first sealing projection 38, and the third end plate 22 can form a second sealing projection 40. The first sealing projection 38 engages with the second sealing projection 40. According to the embodiment shown, the second sealing projection 40 can sealingly abut the housing 50 or the first housing part 52. Furthermore, the second sealing projection 40 of the inner filter element 14 can encompass the first sealing projection 38 of the outer filter element 12.

[0077] Fig. 6 shows a section of the gas filter system 10 from Fig. 5 in a detailed view.

[0078] The second sealing projection 40 and the first sealing projection 38, which engages with the second sealing projection 40, are arranged in the housing sealing groove 64 formed on the end face 62 of the first housing part 52. The raw gas side 66 of the gas filter system 10 can thus be sealed from the clean gas side 68 of the gas filter system 10.

[0079] According to the second embodiment, the first sealing projection 38 can comprise an elastic material, in particular PUR, or can be formed from the elastic material. The second sealing projection 40 can also comprise an elastic material, in particular PUR, or can be formed from the elastic material. For example, one of the sealing projections 38, 40 can be designed to widen the other sealing projection 40, 38. Here, the first sealing projection 38 has a trapezoidal or wedge-shaped cross-section, whereby when the first sealing projection 38 is arranged on or in the second sealing projection 40, the latter is widened radially. This allows the second sealing projection 40 to be pressed against the housing sealing groove 64, thereby improving the sealing effect. Furthermore, the contact force between the first sealing projection 38 and the second sealing projection 40 can be increased, which further improves the sealing effect.

[0080] As shown, when the second sealing projection 40 is widened, the axial housing sealing surface 70, the radially inner housing sealing surface 72, and the radially outer housing sealing surface 74 can be formed between the second sealing projection 40 and the housing sealing groove 64. Between the first sealing projection 38 and the second sealing projection 40, the axial projection sealing surface 76, the radially inner projection sealing surface 78, and the radially outer projection sealing surface 80 can be formed when the second sealing projection 40 is widened. Sealing the raw gas side 66 against the clean gas side 68 using two filter elements 12, 14 can thus also be achieved particularly easily in a single sealing area 82 in the second embodiment.

[0081] Fig. 7 shows the outer filter element 12 from Figures 5 and 6 in a perspective view.

[0082] The outer filter element 12 according to the second embodiment of the gas filter system 10 shown in Figures 5 and 6 has a radial projection 88 formed on the first sealing projection 38. The radial projection 88 can be understood as a radially outwardly directed deviation of the otherwise rotationally symmetrical first sealing projection 38. The projection 88 can enable a rotationally secure arrangement of the first filter element 12 on the housing 50 (see Figures 5, 6), thereby ensuring precise positioning.

[0083] Fig. 8 shows the inner filter element 14 from Figures 5 and 6 in a perspective view.

[0084] The second sealing projection 40 may have a radial projection 90, as shown. The radial projection 90 is configured to correspond to the radial projection 88 of the outer filter element 12 (see Fig. 7), so that the position of the inner filter element 14 relative to the outer filter element 12 or to the housing 50 is also fixed.

[0085] List of reference symbols

[0086] Gas filter system 10;

[0087] Outer filter element 12;

[0088] Inner filter element 14;

[0089] First end plate 16;

[0090] Second end plate 18;

[0091] First filter medium 20;

[0092] Third end plate 22;

[0093] Fourth end plate 24;

[0094] Second filter medium 26;

[0095] Longitudinal axis 28;

[0096] Inflow side 30 of the outer filter element 12;

[0097] Downstream side 32 of the outer filter element 12;

[0098] Inflow side 34 of the inner filter element 14;

[0099] Downstream side 36 of the inner filter element 14;

[0100] First sealing projection 38;

[0101] Second sealing projection 40;

[0102] Base plate 42;

[0103] Support structure 44;

[0104] Support rib 46;

[0105] Support tube 48;

[0106] Housing 50;

[0107] First housing part 52;

[0108] Second housing part 54;

[0109] Closure 56;

[0110] Center tube 58;

[0111] Filter element holder 60;

[0112] Front side 62;

[0113] Housing sealing groove 64;

[0114] Raw gas side 66;

[0115] Clean gas side 68;

[0116] Axial housing sealing surface 70;

[0117] Radial inner housing sealing surface 72;

[0118] Radial outer housing sealing surface 74;

[0119] Axial projection sealing surface 76;

[0120] Radial inner projection sealing surface 78;

[0121] Radial outer projection sealing surface 80;

[0122] Sealing area 82;

[0123] Radial recess 84 of the outer filter element 12;

[0124] Radial recess 86 of the inner filter element 14;

[0125] Radial projection 88 of the outer filter element 12;

[0126] Radial projection 90 of the inner filter element 14.

Claims

Claims A filter system (10) comprising an outer filter element (12) with a first filter medium (20) arranged between a first end plate (16) and a second end plate (18); an inner filter element (14) with a second filter medium (26) arranged between a third end plate (22) and a fourth end plate (24); wherein the first end plate (16) and the third end plate (22) are open; wherein the first end plate (16) surrounds the third end plate (22); wherein the first end plate (16) has a first sealing projection (38) projecting in the axial direction; wherein the third end plate (22) has a second sealing projection (40) projecting in the axial direction; and wherein the first sealing projection (38) and the second sealing projection (40) engage with one another to seal the third end plate (22) and the first end plate (16) from one another.The gas filter system (40) according to claim 1, wherein the first sealing projection (38) and the second sealing projection (40) bear against one another in a sealing manner on at least two projection sealing surfaces (76, 78, 80). The gas filter system (10) according to claim 2, wherein the first sealing projection (38) and the second sealing projection (40) bear against one another in a sealing manner on at least one axial projection sealing surface (76) and at least one radial projection sealing surface (78, 80). The gas filter system (10) according to one of the preceding claims, wherein one of the sealing projections (38, 40) is elastic and engages over the other sealing projection (40, 38) such that it is widened by the engagement of the other of the sealing projections (40, 38). Gas filter system (40) according to one of the preceding claims, wherein the first sealing projection (38) and / or the second sealing projection (40) is formed circumferentially on the respective end plate (16, 22).Gas filter system (10) according to claim 5, wherein the first sealing projection (38) and the second sealing projection (40) each have at least one radial recess (84, 86) and / or one radial projection (88, 90).

7. Gas filter system (10) according to one of the preceding claims, wherein the first and / or the second sealing projection (38, 40) have at least one housing sealing surface (70, 72, 74) for sealing engagement with a housing (50), preferably in the axial direction.

8. Gas filter system (10) according to one of the preceding claims, further comprising a, preferably closed, base plate (42), wherein the base plate (42) is arranged on the second end plate (18) of the outer filter element (12).

9. Gas filter system (10) according to claim 8, wherein the base plate (42) has a support structure (44), in particular at least one support rib (46) projecting in the axial direction, for supporting the fourth end plate (24) of the inner filter element (14).

10. Gas filter system (10) according to one of the preceding claims, wherein the outer filter element (12) has a support tube (48) radially inward.

11. Gas filter system (10) according to one of the preceding claims, wherein the outer filter element (12) and the inner filter element (14) are hollow cylindrical.

12. Gas filter system (10) according to one of the preceding claims, wherein the outer filter element (12) is arranged upstream of the inner filter element (14) in a flow direction of the gas filter system (10).

13. Gas filter system (10) according to one of the preceding claims, comprising an openable housing (50) with a first housing part (52) and a second housing part (54); wherein the outer filter element (12) and the inner filter element (14) are arranged between the first housing part (52) and the second housing part (54); wherein the first housing part (52) has an end face (62) facing the first and third end plates (16, 22) of the filter elements (12, 14); wherein the end face (62) has a housing sealing groove (64) corresponding to the first sealing projection (38) and / or second sealing projection (40); wherein the first sealing projection (38) and the second sealing projection (40) are arranged in an interlocking manner in the housing sealing groove (64) in order to seal a raw gas side (66) of the gas filter system (10) from a clean gas side (68) of the gas filter system (10).

14. The gas filter system (10) according to claim 13, wherein the end face (62) has an opening that is fluidically arranged upstream or downstream of the inner filter element (14).

15. The gas filter system (10) according to claim 13 or 14, wherein the first housing part (52) has a central tube (58) on the end face (62) that engages the inner filter element (14).

16. Gas filter system (10) according to one of claims 13 to 15, wherein the housing (50) has a circumferentially arranged closure (56), wherein the closure (56), in a closed state, effects a gas-tight clamping of the first housing part (52) and the second housing part (54) with the outer filter element (12) and the inner filter element (14).

17. Use of an outer filter element (12) and / or an inner filter element (14) in a gas filter system (10) according to one of the preceding claims.

Images