Filter and filter cartridge

Abstract

A filter cartridge for a filter for filtration of a fluid has a prismatic basic shape with a base face and a top face arranged parallel to each other and each having a polygonal basic shape. The prismatic basic shape is provided with a first lateral face and a second lateral face neighboring the first lateral face, wherein the first lateral face is an inflow surface and is substantially positioned perpendicular to the neighboring second lateral face. The prismatic basic shape has a third lateral face that is an outflow surface and is positioned at an angle relative to the first lateral face, wherein the angle is greater than 10° and smaller than 80°. A filter with such a filter cartridge is disclosed.

Claims

1. A filter cartridge for a filter for filtration of a gaseous fluid, the filter cartridge comprising: a prismatic basic shape comprising a base face and a top face arranged parallel to each other and each having a polygonal basic shape; wherein the parallel arranged base face and top face have a polygonal basic shape; the prismatic basic shape further comprising a first lateral face and a second lateral face neighboring the first lateral face, wherein the first lateral face is an inflow surface and is substantially positioned perpendicular to the base face and the top face; the prismatic basic shape further comprising a third lateral face that is an outflow surface and is positioned at an angle relative to the first lateral face, wherein the angle is greater than 10° and smaller than 80°; wherein the prismatic basic shape is a quadrangle and comprises a fourth lateral face positioned parallel to and opposite the second lateral face; the filter cartridge further comprising: a filter cartridge frame; a seal arranged in the area of the outflow surface and configured to separate a filter interior into a clean side and a raw side, the seal having a sealing surface extending parallel to the outflow surface; wherein the filter cartridge frame has a contact surface configured and adapted to support a support surface of a blade projecting from a housing; wherein the third lateral face and the first lateral face are spaced apart and tilted angularly relative to each other such that a distance between the third lateral face and the first lateral face decreases continuously across the prismatic basic shape from the top face to the base face of the prismatic basic shape.

2. The filter cartridge according to claim 1, wherein the seal is an axially acting seal, the sealing surface facing in a direction away from the outflow surface, the contact surface facing in the opposite direction.

3. The filter cartridge according to claim 1, further comprising a zigzag-shaped folded filter medium comprising folds.

4. The filter cartridge according to claim 3, wherein the folds comprise outer fold edges, positioned on the first lateral face, and further comprise inner fold edges, wherein the inner fold edges are positioned opposite the outer fold edges and are positioned on the third lateral face.

5. The filter cartridge according to claim 3, wherein the folds each have a depth and the depth of the folds differs among the folds that are neighboring each other.

6. The filter cartridge according to claim 3, wherein the depth of the folds at the second lateral face is different from the depth of the folds at the fourth lateral face.

7. The filter cartridge according to claim 3, wherein the depth of the folds changes continuously from the second lateral face toward the fourth lateral face.

8. The filter cartridge according to claim 3, wherein the folds comprise a first end face and a second end face, wherein the first end face of the folds is positioned on the base face and the second end face of the folds is positioned on the top face.

9. The filter cartridge according to claim 1, further comprising: a spacer structure configured to determine a spacing between the filter cartridge frame and a further downstream filter cartridge.

10. The filter cartridge according to claim 9, wherein the spacer structure is formed integrally with the seal.

11. The filter cartridge according to claim 1, further comprising: a filter body; a filter cartridge frame supporting the filter body; an edge protection disposed on the filter cartridge frame in the area of the inflow surface and circumferentially surrounding externally the filter body, wherein the edge protection connects the filter body and the filter cartridge frame detachably or non-detachably to each other.

12. A filter comprising a filter cartridge according to claim 1, wherein a main inflow direction of the filter and a main outflow direction of the filter are positioned at an angle of more than 30° relative to each other.

13. The filter according to claim 12, wherein a main inflow direction of the filter is parallel and displaced relative to a main outflow direction of the filter.

14. A filter comprising a main filter cartridge and a secondary filter cartridge, wherein at least one of the main filter cartridge and of the secondary filter cartridge is embodied according to claim 1.

15. A filter comprising: a filter housing comprising a raw-side area and a clean-side area; a main filter cartridge according to claim 1, wherein the main filter cartridge is configured to be disposed in the filter housing, wherein the main filter cartridge comprises a main filter cartridge inflow surface, a main filter cartridge outflow surface, a main filter cartridge flow direction from the main filter cartridge inflow surface to the main filter cartridge outflow surface, and a seal arranged on a sealing surface of the main filter cartridge and configured to fluid-tightly separate the raw-side area and the clean-side area of the filter housing from each other when the main filter cartridge is arranged in the filter housing; a secondary filter cartridge arranged downstream of the main filter cartridge in the main filter cartridge flow direction, wherein the secondary filter cartridge comprises a secondary filter cartridge inflow surface, a secondary filter cartridge outflow surface, and a secondary filter cartridge flow direction from the secondary filter cartridge inflow surface to the secondary filter cartridge outflow surface; wherein the sealing surface is arranged at a slant relative to the main filter cartridge flow direction of the main filter cartridge.

16. The filter according to claim 15, wherein the sealing surface and the main filter cartridge flow direction are positioned at an angle relative to each other that is between 80° and 10°.

17. The filter according to claim 15, wherein the sealing surface and the main filter cartridge outflow surface extend parallel to each other.

18. The filter according to claim 15, wherein the secondary filter cartridge inflow surface extends parallel and spaced apart at a spacing relative to the sealing surface.

19. The filter according to claim 18, wherein the spacing of the secondary filter cartridge inflow surface relative to the sealing surface is less than 2 cm.

20. The filter according to claim 15, wherein the secondary filter cartridge has a basic shape of a parallelepiped.

21. The filter according to claim 15, wherein the main filter cartridge has a basic shape of a prism with a base face shaped as a quadrangle and a top face shaped as a quadrangle.

22. The filter according to claim 15, wherein the main filter element comprises a folded bellows with at least two different fold depths.

23. The filter according to claim 15, wherein the filter housing comprises an inflow direction, an outflow direction, an outflow area with an outflow opening, and an outflow socket configured to be attached to the outflow area, wherein the outflow area comprises a fastening surface for the outflow socket, and wherein the fastening surface is positioned at an angle of 45° relative to the main filter cartridge flow direction.

24. The filter according to claim 23, wherein the outflow socket is formed such that a deflection of a flow direction by 45° results.

25. The filter according to claim 23, wherein the outflow socket is embodied with rotational symmetry and comprises a fastening area configured to be attached to the filter housing.

26. The filter according to claim 23, wherein the outflow direction of the filter housing and the fastening surface of the outflow area are positioned at an angle of 45° relative to each other.

27. The filter according to claim 23, wherein the fastening surface of the outflow area and the secondary filter cartridge outflow surface extend parallel to each other.

28. The filter according to claim 15, wherein the main filter cartridge is insertable and removable into and from the filter housing along an insertion axis, wherein the insertion axis is positioned relative to the main filter cartridge flow direction at an angle that is between a 90° angle and the angle at which the sealing surface of the main filter cartridge and the main filter cartridge flow direction are positioned relative to each other, wherein the filter housing comprises a cover that is designed such that, in the state in which the cover closes off the filter housing, the cover exerts a force on the main filter cartridge in the direction toward the sealing surface.

29. The filter according to claim 16, wherein the filter housing comprises a housing cover, the cover comprising two wedge shaped blades that project from the cover, laterally relative to the main filter element, into the filter housing, the blades having support surfaces on their narrow sides, respectively.

30. The filter according to claim 29, wherein the blades each comprise first and second, opposite support surfaces.

31. The filter according to claim 30, wherein the support surfaces of the blades are positioned relative to each other at an angle which corresponds to the angle between inflow surface and outflow or sealing surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be explained in more detail with reference to the drawings. The terms filter cartridge and filter element are synonymously used.

(2) FIG. 1 is a perspective section illustration of an embodiment of a filter according to the invention with inserted main filter cartridge and secondary filter cartridge.

(3) FIG. 2 shows the filter of FIG. 1 without inserted secondary filter cartridge.

(4) FIG. 3 shows the filter of FIG. 1 without inserted main filter cartridge.

(5) FIG. 4 shows the filter of FIG. 1 in a cross-sectional view.

(6) FIG. 5 is a perspective external view of the filter of FIG. 1 according to the invention.

(7) FIG. 6 is a perspective view of a secondary filter cartridge according to the invention with filter body.

(8) FIG. 6a is a perspective view of an alternative secondary filter cartridge filter body according to the invention.

(9) FIG. 7 is a perspective view of the secondary filter cartridge of FIG. 6 without filter body.

(10) FIG. 8 is another perspective view of the secondary filter cartridge of FIG. 6 without filter body.

(11) FIG. 9 is a perspective section view of the filter of FIG. 6.

(12) FIG. 10 is a section view of the filter of FIG. 7.

(13) FIGS. 11 and 11B are perspective front views of a main filter cartridge according to the invention.

(14) FIG. 11a is a perspective front view of a second embodiment of a main filter cartridge according to the invention.

(15) FIG. 12 is a perspective rear view of the main filter cartridge of FIG. 11.

(16) FIG. 12a is a perspective rear view of the main filter cartridge of FIG. 11a in a support frame.

(17) FIG. 12b is a perspective rear view of the main filter cartridge of FIG. 11a without support frame.

(18) FIG. 13 is a perspective section view of the main filter cartridge of FIG. 11.

(19) FIG. 13a is a perspective section view of the main filter cartridge of FIG. 11a.

(20) FIG. 13b is a perspective section view of the support frame of the main filter cartridge of FIG. 11a.

(21) FIG. 13c is a section view of the main filter cartridge of FIG. 11a in a support frame, wherein the section is extending centrally through the main filter cartridge, parallel to the main flow direction X, perpendicular to the inflow surface, and perpendicular to the installation direction Z.

(22) FIG. 13d is a section view of the main filter cartridge of FIG. 11a in a support frame, wherein the section is extending centrally through the main filter cartridge, parallel to the main flow direction X, perpendicular to the inflow surface, and parallel to the installation direction Z.

(23) FIG. 14 is a perspective rear view of the main filter cartridge of FIG. 11 without edge protection.

(24) FIG. 15 is perspective external view of the filter of FIG. 5 showing the outlet socket in a first position.

(25) FIG. 16 is perspective external view of the filter of FIG. 5 showing the outlet socket in a second position.

(26) FIG. 17 is a side view of the filter of FIG. 5.

(27) FIG. 18 is a side view of the filter of FIG. 15.

(28) FIG. 19 is a side view of the filter of FIG. 16.

(29) The embodiments described in connection with the above Figures represent detailed embodiments and further developments are described with the aid of FIGS. 20 to 36 wherein the features are not mandatorily required but are envisioned to be added individually or in combination to an embodiment according to the following illustrated Figures.

(30) FIG. 20 is a perspective front view of the filter.

(31) FIG. 21 is a perspective rear view of the filter of FIG. 20.

(32) FIG. 22 is an exploded view of the filter of FIG. 20.

(33) FIG. 23 is a section illustration of the filter according to the invention.

(34) FIG. 24 is a front view of the main filter element according to the invention.

(35) FIG. 25 is a rear view of the main filter element according to the invention.

(36) FIG. 26 is a first folding type as a schematic.

(37) FIG. 27 shows an alternative folding type as a schematic.

(38) FIG. 28 is a front view of the secondary filter element according to the invention.

(39) FIG. 29 is a rear view of the secondary filter element according to the invention.

(40) FIG. 30 shows the filter according to the invention of FIG. 20 in a second configuration.

(41) FIG. 31 shows the filter according to the invention of FIG. 20 in a third configuration.

(42) FIG. 32 is a front view of an alternative embodiment of a filter according to the invention.

(43) FIG. 33 is a rear view of the filter of FIG. 32.

(44) FIG. 34 is an exploded view of the filter of FIG. 32

(45) FIG. 35 is a section illustration of the filter of FIG. 32.

(46) FIG. 36 is a section view of an alternative main filter element and secondary filter element design of the filter of FIG. 32.

PREFERRED EMBODIMENTS OF THE INVENTION

(47) With reference to FIGS. 1 through 5, an embodiment of a filter 10 according to the invention will now be described. Such a filter 10 can be used, for example, in an air intake manifold of a construction or agricultural machine, a compressor or another device with an internal combustion engine, for filtering a fluid, in particular air. The filter 10 comprises a filter housing 12 which can be divided roughly into a raw-side area 14 and a clean-side area 16.

(48) The filter 100 is flowed through along a main inflow direction X. On an inflow side 16 the fluid to be filtered impacts on a coarse or a pre-separation module 18 which is designed in the present case as a cyclone block. In the cyclone block 18, a plurality of individual pre-separation cells 20 are connected in parallel in a so-called multi-cyclone block. The dust and/or water that has been pre-separated in the cyclone block 18 is removed through a discharge socket 22 from the filter housing 12.

(49) Downstream of the cyclone block 18, the fluid to be filtered flows into the main filter cartridge 100. The main filter cartridge 100 is embodied in the present case as a prism. An inflow surface 110 of the main filter cartridge 100 is not positioned parallel to an outflow surface 112 of the main filter cartridge 100. Instead, the inflow surface 110 and the outflow surface 112 are positioned at an angle to each. In the present case, the inflow surface 110 of the main filter cartridge 100 is smaller with regard to the desired surface area than the outflow surface 112 of the main filter cartridge 100. At the outflow side of the main filter cartridge 100, a secondary filter cartridge 200 is provided in the filter housing 12. A main inflow surface 210 of the secondary filter element 200 is oriented toward the outflow surface 112 of the main filter cartridge 100 and in particular is arranged parallel thereto. An outflow surface 212 is oriented in this embodiment parallel to the main inflow surface 210 of the secondary filter cartridge 200. Due to the slanted position of the outflow surface 112 of the main filter cartridge 100, already upon inflow of the fluid from the main filter cartridge 100, but also upon inflow from the secondary filter cartridge 200, a deflection of the main flow direction X is occurring. Due to the outflow geometry of the filter housing 12 in the outflow area 24, the flowing fluid is deflected to the outflow direction Y and guided toward an outflow socket 26. In the present case, the main outflow direction Y is substantially perpendicular to the main inflow direction X.

(50) However, other outflow directions are conceivable also. This will be explained in more detail particularly in connection with FIGS. 15 to 19.

(51) The main filter cartridge 100 comprises a main filter cartridge inflow surface 110, a main filter cartridge flow direction X1, a main filter cartridge outflow surface 112 as well as a seal 116 arranged on a sealing surface 114 for fluid-tight separation of the raw-side area 14 and of the clean-side area 16 of the filter housing 12. A secondary filter cartridge 200 with a secondary filter cartridge inflow surface 210, a secondary filter cartridge flow direction Y1, and a secondary filter cartridge outflow surface 212 is arranged downstream of the main filter cartridge 100. The sealing surface 114 of the main filter cartridge 100 is slantedly positioned relative to the main flow direction Y1 of the main filter cartridge 100. In particular, the sealing surface 114 is positioned at an angle α that is preferably between 5° and 45° (see FIG. 4), in particular the angle amounts to 24°±10° and 24°±5°. In the present embodiment, the angle α is 24° (see FIG. 4).

(52) The secondary filter cartridge inflow surface 210 extends substantially parallel and at a spacing to the sealing surface 114 of the main filter cartridge 100. The spacing is less than 2 cm; in the present embodiment, the spacing is 1 cm.

(53) FIGS. 11 to 14 show the main filter cartridge 100. The main filter cartridge 100 comprises an inflow surface 110 (first lateral face) and an outflow surface 112 (third lateral face). The arrow for the insertion direction Z points in FIG. 11 and FIG. 11B to the second lateral face (pointed to be the Z arrow) which is oppositely positioned to the smaller fourth lateral face. The top face 113A can be recognized in FIGS. 11 and 12 as the surface on which the marking for the main flow direction X1 is arranged. It is positioned parallel and congruent to the base face (113B, FIG. 11B). Base face 113B and top face 113A as well as the second and fourth lateral faces are perpendicularly oriented relative to the first lateral face (inflow surface 110). Inflow to the main filter cartridge 100 is occurring along a main inflow direction X and flow through it occurs along a main flow direction X1. The main filter cartridge 100 comprises a filter cartridge frame 118 that receives a filter body 120. The filter body 120 is in the present case designed as a folded bellows. Inflow-side fold edges 122 are positioned opposite outflow-side fold edges 124. Inflow-side fold edges 122 and outflow-side fold edges 124 are positioned parallel, substantially perpendicular to the main flow direction X1, and substantially horizontally in FIGS. 11 to 14. This orientation of the fold edges 122, 124 enables a variation of the fold depth in the direction of an insertion direction Z. Along the insertion direction Z, the main filter cartridge 100 is insertable into the filter housing 12 of the filter 10. In the present embodiment, the fold height is reduced along the insertion direction Z. This effects a tilting of the inflow surface 110 relative to the outflow surface 112.

(54) In the area of the outflow surface 110, the filter frame 118 has a sealing surface 114 along which a circumferentially extending seal 116 is provided. The seal serves for separating the raw-side area 14 from the clean-side area 16 in the filter housing 12 of the filter 10 when the main filter cartridge 100 is inserted into the filter 10. The seal 116 comprises substantially a U-shape in cross-section.

(55) For reinforcement and better mechanical connection of the seal 116 to the filter frame 118, a web 126 is provided which engages the U-shape of the seal 116. At the same time, the seal 116 can contact the filter body 120 or penetrate it so that an adhesive connection of the filter body 120 with the filter cartridge frame 118 and a fluid-tight sealing action between filter body 120 and filter cartridge frame 118 is generated at the same time.

(56) Moreover, the seal 116 comprises a spacer structure which is embodied in the present case as support knobs 128. The support knobs 128 are components of the sealing material of the seal 116. As can be seen in the cross-sectional view of FIG. 4, the support knobs 128 contact the secondary filter cartridge 200, in particular a secondary filter cartridge frame, when main filter cartridge 100 and secondary filter cartridge 200 are inserted in the filter housing 12 of the filter 10. In this state, the secondary filter cartridge 200, even for vibration excitation that can be transmitted, for example, through the filter housing 12, cannot move out of a seal seat in the filter housing 12. Also, by means of the support knobs 128 it is ensured that the secondary filter cartridge 200 after installation of the main filter cartridge 100 and closure of the cover 13 is seated in the correct position in the filter housing 12.

(57) A plurality of the support knobs 128 are positioned along the seal 116 on the side which is facing the outflow surface 112. They can be produced, for example, integrally with the seal 116 when producing the seal 116.

(58) The seal 116 is located at the outflow surface 112 of the main filter cartridge 100 and acts in a direction that is perpendicular to the outflow surface 112, i.e., substantially axially along the main flow direction X1.

(59) The main filter cartridge 100 comprises at its inflow side 110 an edge protection 130 which is extending externally circumferentially about the filter frame 118. The edge protection 130 is designed such that upon tapping of the main filter cartridge 100, for example, for cleaning, impacts against the filter frame 118 can be absorbed and at least partially compensated. In this way, breakage of the filter frame 118 or other damages of the filter cartridge 100, for example of the filter body 120, can be avoided. The edge protection 130 extends circumferentially about the inflow-side edge of the filter element 100. In this context, individual interruptions, for example, the notches 134 can be provided. The notches 134 are generated when producing the edge protection 130. In this context, the filter frame 118 together with filter body 120 is positioned in a casting mold. Webs secure the spacing between the casting mold bottom and the filter body 118 and cause the formation of the notches 134 during the casting process.

(60) Cutouts 136 are provided at the inflow-side edge 132. The cutouts 136 penetrate the sidewalls of the filter frame 118 and extend thus perpendicular to the main flow direction X1. During the already mentioned casting process, the casting material for the edge protection 130 penetrates the cutouts 136, contacts the inner walls of the filter cartridge frame 118 and in particular the filter body 120. In this way, a fluid-tight sealing action between the filter body 120 and the filter cartridge frame 118 and at the same time an adhesive connection of the two components is produced. Accordingly, the edge protection 130 is monolithically produced with the adhesive connection between the filter body 120 and the filter cartridge frame 118 and an also required sealing action between the two components. The edge protection 130 can be produced, for example, of a foamable polyurethane. However, also silicone-based material systems are conceivable.

(61) The filter cartridge 100 comprises a grip 138. The grip 138 interacts with the cover 13 of the filter 10 and ensures reliable seating of the main filter cartridge 100 in the filter housing 12 and, at the same time, exerts pressure directed axially in the direction of the main flow direction X1 on the seal 116 and ensures in this way a fixed seal seat of the main filter cartridge 100 in the filter housing 12.

(62) FIGS. 11a, 12a, 12b, and 13a to 13d show a variant 2100 of the main filter cartridge 100 in which the filter cartridge frame 2118 is detachably and reusably connected with the filter cartridge 2100. The outer shape, recognizable as a truncated wedge, corresponds to the shape of the one-part embodiment of FIGS. 11 to 14. The significant difference to the one-part embodiment is that the filter cartridge frame 2118 can be separated from the (main) filter cartridge 2100 and thus is reusable upon exchange of the filter cartridge 2100. The main filter cartridge 2100 comprises an inflow surface 2110 and an outflow surface 2112. Inflow into the main filter cartridge 2100 occurs at inflow surface 2110 and flow through it along the main flow direction X1. The main filter cartridge 2100 comprises a filter cartridge frame 2118 which receives the main filter cartridge 2100. The filter body 2120 is embodied as a folded bellows in the present case. The inflow-side fold edges 2122 are positioned opposite outflow-side fold edges 2124. Inflow-side fold edges 2122 and outflow-side fold edges 2124 are positioned parallel, substantially perpendicular to the main flow direction X1, and substantially horizontally in FIGS. 11a, 12a, 12b, and 13a to 13d. This orientation of the fold edges 2122, 2124 enables a variation of the fold depth in the direction of an insertion direction Z. Along the insertion direction Z, the main filter cartridge 2100, as an alternative to the main filter cartridge 100, is insertable into the filter housing 12 of the filter 10 (see FIGS. 1 through 5) in the same way. In the present embodiment, the fold height decreases also along the insertion direction Z. This effects tilting of the inflow surface 2110 relative to the outflow surface 2112 about angle α (FIG. 13d).

(63) In the area of the outflow surface 2110, the filter cartridge 2100 has a sealing surface 114 which is provided along a circumferential seal 2116. The seal serves for separating the raw-side area 14 from the clean-side area 16 in the filter housing 12 of the filter 10 when the main filter cartridge 2100 is inserted into the filter 10. The seal 2116 substantially comprises in cross-section a pointed shape which ends in the preferred flattened sealing surface 2114 which can be pressed so as to seal axially against a seal contact surface of the filter housing 12. The seal 2116 and the sealing surface 2114 are located outside of, in particular radially outside of, the filter body envelope 2115 which is defined by the base and top faces as well as the second and fourth lateral faces. In this way, it is ensured that even for flow deflection downstream of the main filter cartridge 2100 no impairment of the flow by the seal 2116 occurs.

(64) For reinforcing and better mechanical support of the seal 2116 on the filter frame 2118, a seal holder is provided on the end of the filter cartridge frame 2118 which is facing the seal 2116 and which has preferably an L-shaped cross-section, wherein the first web projects away from the filter cartridge frame 2118 outwardly and provides a seal support surface 2113 extending parallel to the sealing surface 2114 on which the seal 2116 with its support surface 2115 that is opposite the sealing surface 2114 and at least partially surrounds the filter body 2120 can be supported. The seal support surface 2113 represents the first leg of the L-shaped cross-section. Moreover, for configuring the second leg of the L, a second web 2126 is provided which extends away from the filter cartridge frame 2118 and which surrounds the seal 2116 externally. At the same time, the seal 2116 can contact the filter body 2120 or penetrate it so that a fluid-tight sealing between filter body 2120 and the seal 2116 is generated.

(65) Moreover, in analogy to the first embodiment, the seal 2116 also has a spacer structure embodied as support knobs 2128 in the present case. The support knobs 2128 are component of the sealing material of the seal 2116. In analogy to the cross-section view of FIG. 4, the support knobs 2128 also contact the secondary filter cartridge 200, in particular a secondary filter cartridge frame, when the main filter cartridge 2100 and secondary filter cartridge 200 are inserted into the filter housing 12 of the filter 10. In this state, the secondary filter cartridge 200, even in case of vibration excitation that can be transmitted, for example, by the filter housing 12, cannot move out of its seal seat in the filter housing 12. Also, by means of the support knobs 2128 it is ensured that the secondary filter cartridge 200 after the installation of the main filter cartridge 100 and closing of the cover 13 is seated in the correct position within the filter housing 12.

(66) A plurality of support knobs 2128 are positioned along the seal 2116 on the side which is facing the outflow surface 2112. They can be produced, for example, integrally with the seal 2116 when producing the seal 2116.

(67) The seal 2116 is located on the outflow surface 2112 of the main filter cartridge 2100 and acts in a direction that is perpendicular to the outflow surface 2112, i.e., substantially axially along the main flow direction X1 and/or in accordance with the angle position of the outflow surface.

(68) The main filter cartridge 2100 comprises at its inflow side 2110 an edge protection 2130 which is surrounding externally the filter body 2120. The edge protection 2130 is designed such that, when tapping the main filter cartridge 2100, for example, for cleaning, impacts against the filter cartridge 2100 can be absorbed and at least partially compensated. Accordingly, damage of the filter cartridge 2100, for example, of the filter body 2120, can be avoided. The edge protection 2130 extends circumferentially about the inflow side edge of the filter element 2100. In this context, in analogy to the preceding embodiment, individual interruptions, for example, the notches 134 can be provided (not shown here). The notches 134 are produced when manufacturing the edge protection 2130. In this context, the filter body 2120 is positioned in a casting mold. Webs secure in this context the spacing between the casting mold bottom and the filter body 2120 and result in the notches 134 being produced during the casting process.

(69) At the inflow side edge 2132 of the edge protection, at least one cutout 2131 (preferably two, as shown) are provided, respectively, on the longitudinal sides (the edges relative to the base and top face) and engaged in particular by form fit by support webs 2133 of the filter cartridge frame 2118, in particular for stabilization of the filter cartridge frame and/or for positional securing of the filter cartridge 2100. The edge protection 2130 comprises moreover, in particular positioned in the installation direction (Z direction) between the cutouts 2131, on the longitudinal sides a laterally outwardly projecting projection 2135, respectively, which is projecting past the exterior surface of the filter body 2120, in particular the base and top faces. The projections can be guided upon insertion of the filter cartridge 2100 into the filter cartridge frame 2118 in a groove 2137 extending in the insertion direction, i.e., opposite to the flow direction X. The groove 2137 comprises, viewed in the insertion direction, shortly before the inflow-side end, i.e., a few millimeters or centimeters spaced away from the inflow-side edge of the filter cartridge frame, an elevation 2117 that reduces the depth of the groove 2137 and is in particular so high that, in the area of the elevation 2117, the groove 2137 completely or partially vanishes and forms again toward the inflow-side end of the filter cartridge frame in an inflow-side end area 2119. Upon insertion of the filter cartridge 2100 into the filter cartridge frame, this elevation 2117 must be overcome with elastic deformation of the filter cartridge 2100, in particular of the projections 2135, before the projections 2135 come to rest at the inflow-side end area 2119 of the groove 2137. In this way, a detachable form-fit connection of the filter cartridge 2100 with the filter cartridge frame 2118 can be produced.

(70) In analogy to the first embodiment, the filter cartridge frame 2118 has also a grip 2138. The grip 2138 interacts preferably with the cover 13 of the filter 10 and ensures a reliable seat of the main filter cartridge 100 in the filter housing 12 and exerts at the same time a pressure on the seal 116 directed axially in the direction of the main flow direction X1 and ensures in this way the fixed seal seat of the main filter cartridge 100 in the filter housing 12.

(71) However, in both embodiments it is preferred that blades that extend from the cover 13, laterally of the main filter element 2100, 100, into the filter housing 12 and are preferably wedge-shaped, exert a force in the direction of the sealing surface 114, 2114 on the main filter element 2100, 1200 in the closed state. This can be realized preferably in that the blades at their narrow sides each have a support surface. The blades are supported in this context preferably with a first support surface on the filter housing and are resting with a second support surface opposite the first one on a contact surface 2121 of the main filter element 100 or of the support frame 2118 and press thereby the seal 116, 2116 of the main filter element 100, 2100 against the sealing surface of the housing 12. In case of the first embodiment, the force is transmitted in this context by the support frame 118 directly to the seal 116 as a result of the form fit connection. In case of the second embodiment, the support force is transmitted from the blade against the contact surface 2121 and is in this way introduced into the support frame 2118 which, in turn, is supported on the seal support surface 2113 on the seal 2116, in particular its support surface 2115, and in this way introduces the force into the seal 2116 where then the compression of the sealing surface 2114 with the corresponding contact surface of the housing 12 is realized.

(72) The FIGS. 6 to 10 show an embodiment of a secondary filter cartridge 200. The secondary filter cartridge 200 comprises a main inflow surface 210, an outflow surface 212 as well as a main flow direction Y1. Moreover, the secondary filter cartridge 200 comprises a filter body 214 which is supported by a filter cartridge frame 216. At the inflow side, the filter cartridge frame 216 with a frame area 218 circumferentially surrounding the filter body 214 is substantially flush with the filter body 214. The frame area 218 can serve, for example, as an abutment for the support knobs 128 of the main filter cartridge 100 in the inserted state of both filter cartridges 100, 200.

(73) In the present embodiment, the filter body 214 is substantially parallelepipedal, however, other basic shapes like, for example, a prism are conceivable. At the outflow side, i.e., in the area of the outflow surface 212, the filter cartridge frame 216 is provided with a grate structure 220. The grate structure 220 covers the outflow surface 212 at least partially. In case of a high differential pressure between the inflow side 210 and the outflow side 212, the grate structure 220 prevents an undesirable bending or even falling out of the filter body 214.

(74) At a narrow side of the parallelepipedal filter body 214, the filter cartridge frame 216 is provided with a grip depression 222. In order to provide for comfortable gripping in the grip depression 222 by the hand of a person who wants to exchange the secondary filter cartridge 200, the frame area 218 in the area of the grip depression 222 is widened to a grip stay 224. The width of the grip stay 224 is selected such in this context that a direct inflow of a fluid exiting from the main filter cartridge outflow side 112 toward the filter body 214 is possible in particular at the side which is facing the grip depression 222. This is easily apparent in particular also in the cross-sectional view of FIG. 4. Also, from the uppermost edge 113 of the main filter element outflow surface 112, exiting fluid can flow directly to the filter body 214 of the secondary filter cartridge 200. In this context, the fluid can enter in particular through the auxiliary inflow surface 211 into the filter body 214.

(75) In this embodiment, the filter body 214 is designed as a filter bellows. The fold edges extend in this context parallel to the longitudinal axis of the secondary filter cartridge 200 so that the end faces of the folds form the auxiliary inflow surface 211. The fold edges of the folds form the main inflow surface 210 and the outflow surface 212. By the combination of grip depression 222 and filter bellows 214 with inflow laterally via the auxiliary inflow surface 211, the pressure losses at the secondary filter cartridge 200 can be reduced because the secondary filter cartridge 200 is matched significantly better to the flow guidance from the main filter cartridge 100 to the outflow socket in the filter housing 12. At the same time, the grate structure 220 at the outflow side 212 improves collapse resistance of the secondary filter cartridge 200. Moreover, by means of the integrated grip at the grip depression 222, an easy removal of the filter cartridge 200 is possible.

(76) The secondary filter cartridge 200 comprises a filter frame 216 which provides a groove 226 extending circumferentially about the outflow-side rim of the filter body 214. At the same time, a web 228 is provided on the side of the filter cartridge frame 216 which is facing the grip depression 222. The groove 226 serves as a casting mold for a circumferentially extending adhesive connection and sealing action of the filter body 214 with the filter cartridge frame 216. The sealing action and adhesive connection are effected by a sealing material 230 (see FIG. 9). The sealing material 230 can be, for example, a foaming polyurethane. However, also silicone-based material systems are conceivable.

(77) The groove 226 and additionally the web 228 ensure good mechanical coupling of the sealing material 230 on the filter cartridge frame 216. This configuration has moreover the advantage that after introduction of the sealing material 230 into the groove 226 and insertion of the filter body 214 into the filter cartridge frame 216 and a subsequent foaming and hardening, no further processing steps such as, for example, cutting to size of the sealing material 230, are required. Excess material can be absorbed partially by the filter body 214 or can reach the intermediate area between filter body 214 and filter cartridge frame 216 without this being disadvantageous.

(78) The depth of the groove 226 extends substantially along the main flow direction Y1 of the secondary filter cartridge 200. The outflow-side grate structure 222 can be formed as one part together with the filter cartridge frame 216.

(79) At its inflow-side circumference, the filter cartridge frame 216 has a seal receiving groove 232. In this seal receiving groove 232, a seal 234 can be inserted that is, for example, manufactured of cellular rubber. The seal 234 is thus acting radially, i.e., perpendicular to the main flow direction Y1 of the secondary filter cartridge 200.

(80) FIGS. 15 to 19 show the filter 10 with different orientations of the outflow socket 26. The filter housing 12 of the filter 10 comprises in the outflow area 24 a fastening area 25. The fastening area 25 is positioned relative to the main inflow direction X of the filter housing 12 at an angle of approximately 45°. An outflow socket 26 can be attached to the fastening area 25. The outflow socket 26 is shaped such that a fluid flowing through the outflow socket 26 is subjected to a deflection of 45°. The outflow socket 46, prior to final attachment on the fastening surface 25, is rotatably attachable. Accordingly, at a very late point in time in the manufacture of the filter 10 the final deflection direction or outflow direction Y of the filter 10 can then be determined. In the geometry shown in this embodiment, an inline flow (FIG. 15, FIG. 18), a deflection by 90° (FIG. 17) as well as intermediate angle ranges are possible. In the angle ranges that are between the extreme angles, an additional a lateral deflection occurs.

(81) The embodiments that have been described above in connection with FIGS. 1 to 19 represent detail embodiments and further developments of the embodiments which are described in the following with the aid of FIGS. 20 to 36 wherein the features which have been added by the further developments are advantageous but not mandatorily required and also can be added individually to an embodiment according to the following illustrated Figures.

(82) With reference to FIGS. 20 to 23, a first embodiment of a filter 1010 according to the invention will be described. The filter can be used in particular in the air intake manifold of construction or agricultural machines, compressors or other devices with internal combustion engines for filtering a fluid, in particular air. The filter 1010 comprises a filter housing 1011 that can be divided roughly into a raw-side area 1012 and a clean side area 1013. In the clean-side area 1012 a main filter element 1020 is insertable into the filter housing 1011. The main filter element 1020 comprises a main filter element inflow surface 1021 as well as a main filter element outflow surface 1022 and is flowed through along the main filter element flow direction X1. The main filter element flow direction X1 coincides in the here described embodiment substantially with the inflow direction X0 of the filter housing 1011. However, also other constellations are conceivable in which the main filter element flow direction X1 and the inflow direction X0 of the filter housing 1010 are positioned at an angle to each other. Upstream of the main filter element 1020, a coarse or pre-separation module is provided that is embodied in the present case as a cyclone block 1040. In the cyclone block 1040, a plurality of individual pre-separation cells 1041 are connected in parallel in a so-called multi-cyclone block. In the cyclone block 1040 the pre-separated dust and/or water is discharged through dust discharge socket 1024 from the housing.

(83) Downstream of the main filter element 1020 a secondary filter element 1030 is arranged. The secondary element inflow surface 1031 of the secondary filter element 1030 is facing the main filter element outflow surface 1022, the outflow surface 1032 of the secondary filter element 1030 is oriented in the direction of an outflow opening 1017 of the filter housing 1011. The secondary filter element 1030 is arranged in the area 1013 of the filter housing 1011 which, relative to the main filter element 1020, is a clean side and provides protection from penetration of contaminants into the intake system downstream of the filter, in particular in case of exchange of the main filter element 1020.

(84) The main filter element 1020, shown in FIG. 24 as a separate component, comprises at its outflow surface 1022 a sealing surface 1026 on which a seal 1024 for fluid-tight separation of the raw-side area 1012 and the clean side area 1013 of the filter housing 1011 is provided. The sealing surface 1026 is positioned at a slant to the main flow direction X1 of the main filter element 1020. The selected angle α is 60° in this embodiment. The angle value represents only an exemplary embodiment. According to the invention, the angle α can be varied between 10 and 80°. Particularly preferred, the angle range is between 70 and 30°.

(85) The seal 1024 of the sealing surface 1026 is resting against an appropriate housing structure 1028 and is forced by a cover 1040 of the housing 1011 against the seal seat which is formed by the housing structure 1028. The cover 1014 that closes off the housing can be removed perpendicularly to the main flow direction X1 of the main filter element 1020 from the housing and has a blade-shaped pressing structure 1050, 1051 arranged in pairs on the cover 1014. It is matched in its shape to the slant of the sealing surface 1026 and, in the closed state, exerts a force on the main filter element 1020 which is substantially perpendicular to the main flow direction X1. Due to the slanted position of the sealing surface 1026, the force which is extending perpendicular to the main flow direction X1 is deflected at least partially into a force that is extending in the main flow direction X1 and leads thus to a reliable compression of the main filter element 1020 with the housing 1011. In particular, in this way an axial pressing force, i.e., extending in the main flow direction X1, is generated that provides a particularly great sealing effect. At the same time, a particularly good contact of the seal 1026 at the corresponding housing structure is achieved because upon compression by the housing cover the seal glides somewhat and in this way unevenness is molded well into the sealing compound.

(86) The main filter element 1020 may comprise a folded bellows as a basic construction. For obtaining the desired sealing surface slant, the fold height or fold depth along a direction perpendicular to the main flow axis X1 can be reduced stepwise. With such a configuration, the fold edges are the inflow side. The end faces of the folds must be glued at least partially for such a configuration, either across the entire surface area or every other end face, so that raw side and clean side remain separated. In the section illustration of FIG. 23, in the described embodiment the fold edges extend perpendicular to the drawing plane, the end face of the folds is positioned in the drawing plane. This means that the main flow direction X1 extends parallel to the planes that are formed by the end faces of the fold edges and perpendicular to the each fold edge.

(87) Alternatively, in a folded bellows according to the invention, the orientation of the individual folds can also be such that the end face of the folds is extending substantially perpendicular to the drawing plane of FIG. 23, i.e., the cover 1014 extends parallel to the end face of the folds of the main filter element 1020. The main filter element inflow surface 1021 is then formed by fold edges that are extending perpendicular to the main flow direction X1. The fold edges extend in FIG. 20 perpendicular from top to bottom. The main filter element outflow surface 1022 is also formed by fold edges which extend along the slant according to the angle α. For such a folding, the fold height varies over the course of the fold edge.

(88) FIGS. 24 and 25 represent the main filter element 1020 as a removed element. The FIGS. 26 and 27 illustrate the aforementioned alternative folding types as schematics. In the schematics, an end face of the folds is identified with reference numeral 1023 and a fold edge with the reference numeral 1025, respectively.

(89) The secondary element 1030 which is illustrated in FIGS. 28 and 29 as a removed element can be designed as a straight folded flat elements in the present embodiment.

(90) With reference to FIGS. 23, 30, and 31, the filter 1010 will now be described with regard to the outflow situation in more detail. The filter housing 1011 comprises in the clean-side area 1013 an outflow area 1015. The outflow area 1015 is provided with the fastening surface 1016. The fastening surface 1016 is positioned relative to the inflow direction X0 of the filter housing as well as relative to the main flow direction X1 of the main filter element 1020 at an angle of 45°. An outflow socket 1018 is fastened to the fastening surface 1016. The geometry of the outflow socket 1018 is selected such that the fastening area 1019 provided for attachment on the fastening surface 1016 is also slantedly positioned by 45° relative to the outflow direction determined by the outflow socket 1018. Also, the fastening area 1019 of the outflow socket 1018 is designed to be of rotational symmetry, i.e., it forms a circular disk in which a penetration for the outflow opening 1017 of the housing 1011 is provided. As a result of the rotational symmetry, the outflow socket 1018 can be rotated prior to final attachment of the fastening area 1019 on the fastening surface 1016 of the outflow area 1015 and, in this way, the outflow direction Y0 of the filter housing 1011 can be determined. Depending on the orientation of the outflow socket 1018, the angle between the inflow direction X0 and the outflow direction Y0 can be varied between 0° (inline flow) and 90° (right angle outflow). In FIGS. 20 and 23 a deflection of the inflow direction X0 by 90° to the outflow direction Y0 is shown. In FIG. 30, an inline flow direction is shown, i.e., the inflow direction X0 and the outflow direction Y0 are parallel to each other. FIG. 31 shows an intermediate angle of approximately 45° between inflow direction X0 and outflow direction Y0.

(91) In FIGS. 32 to 36, an alternative embodiment of the filter 1010 with regard to the fastening surface 1016 of the outflow area 1015 is shown. In FIG. 36, additionally the geometry of main filter element and secondary filter element is changed in this alternative embodiment.

(92) In FIGS. 32 to 35, the filter element 1010 is however changed such that a fastening surface 1116 is provided which is located on a lateral cylinder surface. The axis of such a lateral cylinder surface is positioned perpendicular to the drawing plane, i.e., also perpendicular to the main flow direction X1 of the main filter element 1020. In accordance with the fastening surface 1116 which, viewed from the exterior, is convex, an outflow socket 1118 is provided which has a corresponding concavely shaped fastening area 1119. Depending on the fastening location of the outflow socket 1118 on the convex fastening surface 1116, the outflow direction Y0 of the filter housing 1011 can be varied.

(93) FIG. 36 shows an embodiment in which the filter housing 1011 is substantially comparable to the embodiment of FIGS. 32 to 35 but the filter element geometry is changed. For avoiding repetitions, the description of features which have been identified in the Figures with same reference characters is omitted.

(94) The filter 1110 of FIG. 36 comprises a main filter element 1120 that has a substantially planar inflow surface 1121 and an outflow surface 1122 that is convexly shaped when viewed from the exterior of the filter element. The outflow surface 1122 in the present invention is substantially a lateral cylinder surface but can also be provided, depending on the application situation, with other curvatures, also with non-uniform curvatures. In accordance with the curvature of the outflow surface 1122, a secondary element 1130 is provided that comprises an also curved inflow surface 1131 and a curved outflow surface 1132. The secondary filter element 1130 can have two differently curved inflow and outflow surfaces. In the present embodiment, the outflow surface 1132 is matched to the curvature of the fastening area 1116. This embodiment represents an embodiment that is particularly optimized with regard to installation space.

(95) The attachment of the outflow socket 1018, 1118 can be realized, for example, by fusing. Depending on the application situation, the outflow opening 1017 in the outflow area 1015 can be introduced prior to attachment of the outflow socket 1016, 1116 in a flexible way, for example, by stamping.

(96) The secondary filter element 1130 can be realized, for example, as a curved flat bellows. In manufacture, a conventional flat element could be used that during assembly is then introduced into a correspondingly curved plastic frame and shaped.

(97) In each of the illustrated variants, the secondary filter element can comprise an integrated grip for removal of the secondary filter element.