Housing Main Part of a Filter Housing, Filter System, and Pre-Separator Module of a Filter System

Abstract

A housing main part of a filter housing has an element receiving space and an adapter chamber. A filter element is inserted into or removed from the element receiving space through a lateral mounting opening. A pre-separator module and the filter element are arranged behind each other along the main flow axis of the fluid to separate an outlet from an inlet of the filter housing. The adapter chamber accommodates the pre-separator module and/or the filter element. The adapter chamber is arranged at an axial end face of the housing main part and is open axially toward the element receiving space and, axially opposed thereto, toward the environment. The mounting opening is surrounded by a cover receiving rim that extends across the adapter chamber. A part of a connecting device within the housing main part is used to attach the pre-separator module to the housing main part.

Claims

1. A housing main part of a filter housing of a filter system, the housing main part comprising: circumferential walls defining an interior comprising an element receiving space and an adapter chamber; at least one outlet communicating with the interior, wherein a fluid to be filtered passes though the interior along a main flow axis from an inlet side of the housing main part to the at least one outlet; at least one mounting opening arranged laterally on the housing main part relative to the main flow axis and configured to be closed by a housing cover, the at least one mounting opening configured to enable insertion of at least one exchangeable filter element into the element receiving space or removal of the at least one exchangeable filter element from the element receiving space; the housing main part configured to receive at least one pre-separator module, wherein the at least one pre-separator module and the at least one exchangeable filter element are arranged behind each other along the main flow axis such that the at least one outlet and an inlet of the filter housing are separated from each other, wherein the inlet of the filter housing is at least partially formed by the at least one pre-separator module; wherein the adapter chamber is arranged at an axial end face of the housing main part axially arranged relative to the main flow axis, wherein the adapter chamber, relative to the main flow axis, is open axially toward the element receiving space and, axially opposed thereto, toward an environment; wherein the adapter chamber is configured to accommodate at least partially the least one pre-separator module; the at least one exchangeable filter element; or the least one pre-separator module and the at least one exchangeable filter element; wherein the at least one mounting opening is surrounded by at least one cover receiving rim that extends across at least a portion of the adapter chamber; wherein the housing main part comprises at or within the adapter chamber at least one part of a connecting device configured to connect the at least one pre-separator module to the housing main part.

2. The housing main part according to claim 1, wherein the adapter chamber is configured to have a form and a size such that the adapter chamber at least partially accommodates at least a pre-separator housing of the at least one pre-separator module.

3. The housing main part according to claim 1, further comprising at least one intermediate wall delimiting circumferentially the adapter chamber on a side of the housing main part where the at least one mounting opening is located, wherein the at least one intermediate wall extends into an area delimited by the at least one cover receiving rim.

4. The housing main part according to claim 1, wherein in at least one of the circumferential walls in an area delimiting the adapter chamber at least one passage is prepared for at least one discharge opening of the at least one pre-separator module, wherein media separated from the fluid by the at least one pre-separator module are discharged through the at least one discharge opening.

5. The housing main part according to claim 4, wherein the at least one passage is an optional passage.

6. The housing main part according to claim 1, wherein the at least one part of the connecting device is a first connecting flange configured to connect the at least one pre-separator module to the housing main part.

7. The housing main part according to claim 6, wherein the at least one pre-separator module comprises a second connecting flange and the first connecting flange is configured to connect to the second connecting flange.

8. The housing main part according to claim 1, wherein the adapter chamber is cylindrical and a cylinder axis of the adapter chamber extends parallel or axial relative to the main flow axis.

9. The housing main part according to claim 8, wherein the adapter chamber has an approximately square or rectangular cross-section.

10. The housing main part according to claim 8, wherein the at least one pre-separator module is cylindrical and a cylinder axis of the at least one pre-separator extends parallel or axial relative to the main flow axis.

11. The housing main part according to claim 10, wherein the at least one pre-separator module comprises a pre-separator housing and the pre-separator housing is cylindrical.

12. A filter system comprising: at least one filter housing comprising at least one inlet for a fluid to be filtered and at least one outlet for filtered fluid, the at least one filter housing comprising a housing main part, wherein the fluid flows through the at least one filter housing along a main flow axis; at least one pre-separator module; at least one exchangeable filter element; wherein the at least one pre-separator module and the at least one exchangeable filter element are arranged behind each other along the main flow axis in or on the at least one filter housing such that the at least inlet and the at least one outlet are separated from each other; wherein the housing main part comprises at least one mounting opening arranged laterally relative to the main flow axis; a housing cover configured to close off the at least one mounting opening; wherein the at least one mounting opening is configured to enable insertion of the at least one exchangeable filter element into an element receiving space of the housing main part or removal of the at least one exchangeable filter element from the element receiving space; wherein the housing main part comprises an adapter chamber arranged at an end face of the housing main part that is arranged axially relative to the main flow axis, wherein the adapter chamber, relative to the main flow axis, is open axially toward the element receiving space and, axially opposed thereto, toward an environment; wherein the at least one pre-separator module; the at least one exchangeable filter element; or the at least one pre-separator module and the at least one exchangeable filter element are arranged at least partially on or in the adapter chamber; wherein the at least one mounting opening is surrounded by least one cover receiving rim and wherein the at least one cover receiving rim and the housing cover extend at least across a portion of the adapter chamber.

13. The filter system according to claim 12, wherein the housing main part comprises at or within the adapter chamber at least one part of a connecting device configured to connect the at least one pre-separator module to the housing main part.

14. The filter system according to claim 12, wherein the at least one outlet is provided on the housing main part.

15. A pre-separator module for a filter system, the pre-separator module configured to be arranged in or on a housing main part of a filter housing of the filter system along a main flow axis of the fluid to be filtered upstream of at least one exchangeable filter element such that the pre-separator module separates at least one outlet of the housing main part from at least one inlet of the filter housing for the fluid to be filtered, wherein the at least one inlet of the filter housing is at least partially formed by the pre-separator module, wherein the pre-separator module comprises a narrow end face and, relative to the main flow axis, an axially oppositely positioned wider area that is wider than the narrow end face, wherein the pre-separator module is configured to be pivoted about 180° relative to the main flow axis to be arranged either with the narrow end face leading at least partially within an adapter chamber of the housing main part or, with the wider area leading, to be arranged on the adapter chamber of the housing main part.

16. The pre-separator module according to claim 15, wherein the wider area is a wide end face.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Further advantages, features, and details of the invention result from the following description in which embodiments of the invention will be explained in more detail with the aid of the drawing. A person of skill in the art will consider the features disclosed in the drawing, the description, and the claims in combination also expediently individually and combine them to other meaningful combinations.

[0079] FIG. 1 shows an isometric illustration of an air filter system of an internal combustion engine of a construction or agricultural machine according to a first embodiment, comprising a pre-separator module that is arranged in a receiving chamber of a housing main part, and comprising a main filter element which is arranged hidden in an element receiving space of the housing main part in FIG. 1.

[0080] FIG. 2 shows a longitudinal section of the air filter system of FIG. 1.

[0081] FIG. 3 is an exploded illustration of the air filter system of FIGS. 1 and 2.

[0082] FIG. 4 is an isometric illustration of the air filter system of FIGS. 1 to 3 without housing cover.

[0083] FIG. 5 is an isometric illustration of an air filter system according to a second embodiment in which a main filter element that is bigger than the main filter element of the first embodiment according to FIGS. 1 to 4, projects partially into the adapter chamber and a pre-separator module is arranged outside of the adapter chamber on the housing main part.

[0084] FIG. 6 shows a longitudinal section of the air filter system of FIG. 5.

[0085] FIG. 7 shows an isometric illustration of the air filter system of FIGS. 5 and 6 without housing cover.

[0086] In the Figures, same components are provided with same reference characters.

DETAILED DESCRIPTION

[0087] In FIGS. 1 to 4, an air filter system 10 according to a first embodiment is shown in different perspectives and section views. The air filter system 10 can be used, for example, in an air intake manifold of a construction or agricultural machine for filtering air.

[0088] The air filter system 10 comprises a filter housing 12 with an inlet 14 for air to be purified and an outlet 16 for purified air. For the air filter system 10, a pre-separator module 20, a main filter element 22, and a secondary filter element 24 are arranged behind each other between the inlet 14 and the outlet 16, relative to a main flow axis 18 of the air to be purified. The air filter system 10 is configured with three stages as a so-called inline system. This means that the three filter stages of the air filter system 10, namely the pre-separator module 20, the main filter element 22, and the secondary filter element 24, are arranged substantially linearly behind each other along the main flow axis 18.

[0089] To improve comprehension, an X-Y-Z coordinate system is illustrated in the Figures whose X axis is extending parallel to the main flow axis 18.

[0090] The filter housing 12 comprises an approximately parallelepipedal housing main part 26 which is preferably formed monolithically of plastic material. The housing main part 26 comprises an outlet socket which forms the outlet 16 and which projects outwardly from an outflow-associated end-face end wall relative to the main flow axis 18. An axis of the outlet socket is preferably slanted by approximately 45 degrees relative to the main flow axis 18 in the X-Z plane of the X-Y-Z coordinate system. The outflow-associated end wall of the housing main part 26 is preferably slanted correspondingly.

[0091] On a cover side which is extending substantially parallel to the main flow axis 18 and the X-Y plane of the X-Y-Z coordinate system, the housing main part 26 has a mounting opening 28 for installation and removal and for servicing of the main filter element 22 and of the secondary filter element 24. The mounting opening 28 extends preferably almost across the entire axial expansion of the housing main part 26 relative to the main flow axis 18. Further preferred, the mounting opening 28 extends laterally into the oppositely positioned sidewalls of the housing main part 26. In the operative state, the mounting opening 26, as shown in FIGS. 1 and 2, is closed off with a removable housing cover 30 of the filter housing 12.

[0092] The mounting opening 28 is surrounded continuously by a cover receiving rim 32 in circumferential direction. In the operative state, as shown in FIGS. 1 and 2, an appropriate cover rim of the housing cover 30 is in particular seal-tightly resting, circumferentially closed, on the cover receiving rim 32. The housing cover 30 is secured by means of releasable clamps 34 on the housing main part 26.

[0093] In the interior of the housing main part 26, a receiving frame 36 for the optionally employable secondary filter element 24 is arranged on the side which is facing the outlet 16. The receiving frame 36 extends preferably at a slant relative to the main flow axis 18 and is penetrated by it. On the receiving frame 36, a circumferentially continuous sealing area of the secondary filter element 24 is resting seal-tightly, preferably radially, relative to an axis of the secondary filter element 24 . The secondary filter element 24 separates a clean air side 38 of the air filter system 10 from a main element outflow side 40 of the main filter element 22. The clean air side 38 is connected to the outlet 16.

[0094] Fluidically upstream of the receiving frame 36, a flat sealing surface 42 is arranged for supporting an axial seal 44 of the main filter element 22. The sealing surface 42 extends circumferentially closed coaxially relative to and/or about the axis of the secondary filter element 24. The sealing surface 42 surrounds the receiving frame 36 and adjoins the latter preferably, in particular such that the receiving frame 36 is formed as an opening within the sealing surface 42. The sealing surface 42 is preferably flat and extends radially and circumferentially relative to the axis of the secondary filter element 24. It is facing toward the main filter element 22. The plane of the sealing surface 42 extends thus at a slant relative to the main flow axis 18.

[0095] The axial seal 44 surrounds in a circumferentially continuous way the main element outflow side 40 of the main filter element 22, relative to the main flow axis 18 which is coinciding in the instant embodiment with an element axis of the main filter element 22.

[0096] On the inlet side which is axially facing away from the outlet 16 relative to the main flow axis 18, the housing main part 26 comprises an adapter chamber 46. The adapter chamber 46 is approximately parallelepipedal in shape. In the illustrated embodiment, the pre-separator module 20 is arranged in the adapter chamber 46.

[0097] The adapter chamber 46 is surrounded in circumferential direction relative to the main flow axis 18 by opposed sidewalls 48, a bottom wall 50, and an intermediate cover wall 52 of the housing main part 26. The sidewalls 48 extend parallel to the X-Y plane of the X-Y-Z coordinate system. The bottom wall 50 and the intermediate cover wall 52 extend each parallel to the Y-Z plane.

[0098] On their side which is facing axially relative to the main flow axis 18 the outlet 16, the sidewalls 48, the bottom wall 50, and the intermediate cover wall 52 constitute a filter-associated connecting flange 54 which, relative to the main flow axis 18, is extending circumferentially and is of a stepped configuration radially inwardly. On the filter-associated connecting flange 54, an appropriate separator-associated connecting flange 56 of a pre-separator housing 58 of the pre-separator module 20 can be seal-tightly attached. The pre-separator housing 58 forms also a portion of the filter housing 12. It comprises the inlet 14.

[0099] An inner width of the adapter chamber 46 perpendicular to the main flow axis 18, i.e., in the Y-Z plane, is greater than the corresponding space requirement of the main filter element 22 transverse to the main flow axis 18 and of the pre-separator housing 58 transverse to the main flow axis 18. In this way, the pre-separator housing 58 as well as the main filter element 22 can be arranged selectively and/or each partially in the adapter chamber 46.

[0100] The sidewalls 58 and the bottom wall 50 each comprise an optional passage 60. The passages 60 each have the shape of an approximately parabolic cutout. The passages 60 each are open on their sides that are axially facing away from the outlet 16 relative to the main flow axis 18. Optionally, a corresponding dust discharge socket 62 of the pre-separator module 20 can be guided through the passages 60.

[0101] In the conventional operating orientation of the air filter system 10, as shown in FIGS. 1 and 4, the dust discharge socket 62 is positioned spatially at the bottom on the pre-separator module 20. In this way, water and dust particles separated by the pre-separator module 20 can sink downwardly, following the force of gravity, and be discharged thereat. In the illustrated embodiment, the dust discharge socket 62 in an exemplary fashion passes through the passage 60 in the bottom wall 50. The air filter system 10 can however also be operated in an orientation that is different from that which is being shown. In this case, the pre-separator module 20 can be modified such that the dust discharge socket 62 extends outwardly at a different side and passes through one of the other optional passages 60.

[0102] On the side which is facing the outlet 16 relative to the main flow axis 18, the adapter chamber 46 is open toward the interior of the housing main part 26. Also, the adapter chamber 46 is open at the side which is facing away from the outlet 16 relative to the main flow axis 18 so that the pre-separator module 20 can be inserted there.

[0103] The mounting opening 28 and the cover receiving rim 32 extend on the inlet side of the filter housing 12 across the adapter chamber 46 and the intermediate cover wall 52. In this way, the adapter chamber 46 is freely accessible through the mounting opening 28 when the housing cover 30 is removed, as shown in FIG. 4.

[0104] Between the adapter chamber 46 and the sealing surface 42, the housing main part 26 has an element receiving space 64 for the main filter element 22. The element receiving space 64 is accessible from the exterior through the mounting opening 28. The mounting opening 28 and the cover receiving rim 32 extend across the entire expansion of the element receiving space 64 on the cover side of the housing main part 26. The element receiving space 64 is open toward the adapter chamber 46.

[0105] The main filter element 22 comprises a folded bellows 66. The folded bellows 66 is comprised of a zigzag-shaped folded filter medium, for example, filter paper. The fold edges are located at the main element outflow side 40 and at a main element inflow side 68 which is axially opposed relative to the main flow axis 18. The fold edges extend parallel to each other and extend perpendicular to the main flow axis 18, i.e., in the direction of a Y axis of the X-Y-Z coordinate system. The folds extend parallel to the main flow axis 18, i.e., parallel to the X axis of the X-Y-Z coordinate system.

[0106] The fold height is defined as a spacing between neighboring inflow-associated fold edges and outflow-associated fold edges. Viewed perpendicular to the main flow axis 18 in Z direction, the fold height is reduced in a stepwise fashion from the side, which is facing the mounting opening 28 in the mounted state, toward the bottom side. The folded bellows 66 and thus the main filter element 22 has an approximately prismatic shape as a whole. The expansion of the main filter element 22 in the direction of the main flow axis 18, i.e., the element axis, decreases, viewed perpendicular to the main flow axis 18, from the mounting opening 28 toward the bottom of the housing main part 26 in accordance with the dimensions of the element receiving space 64.

[0107] The main element inflow side 68 extends perpendicular to the main flow axis 18. In cross section perpendicular to the main flow axis 18, the main filter element 22 is rectangular. The folded bellows 66 has perpendicular to the main flow axis 18 a rectangular cross section. The circumferential sidewalls of the folded bellows 66 extend in pairs parallel to each other and parallel to the main flow axis 18. In this context, the wide sides extend parallel to the X-Z plane and the narrow sides parallel to the X-Y plane. The main element outflow side 40 of the main filter element 22 extends at a slant to the main element inflow side 68 and at a slant to the element axis, i.e., to the main flow axis 18.

[0108] The filter bellows 66 is circumferentially surrounded by an element frame 70 which is coaxial relative to the element axis and which comprises the outer shape of the filter bellows 66. On its upper circumferential side which is facing the mounting opening 28, the element frame 70 is provided externally with a grip 72 by which the main filter element 22 can be gripped and removed from the filter housing 12 and installed in the latter.

[0109] The axial seal 44 is attached to the outflow-associated rim of the element frame 70. The main filter element 22 ends, viewed from the outlet 16 in the direction of the main flow axis 18, before the adapter chamber 46.

[0110] The secondary filter element 24 is designed as an approximately rectangular flat filter element. It comprises a filter bellows which is surrounded by a circumferential radial seal. The radial seal is resting radially seal-tightly on the receiving frame 36.

[0111] The pre-separator module 20 is designed herein as a cyclone block. In the cyclone block, a plurality of individual pre-separator cells 74, which may also be referred to as cyclone cells, are connected fluidically in parallel in a so-called multi-cyclone block. Dust or water that has been pre-separated in the cyclone block is removed through the dust discharge socket 62 from the pre-separator housing 58.

[0112] The separator-associated connecting flange 56 of the pre-separator module 20 is realized at an immersion tube plate 76. The immersion tube plate 76 is arranged on an end face rim of a separator housing frame 78 of the pre-separator housing 58 that is facing the filter-associated connecting flange 54. The immersion tube plate 76 comprises immersion tubes of the respective pre-separator cells 74. The remaining parts of the pre-separator cells 74 are monolithically connected within the separator housing frame 78 with the latter. The separator housing frame 78 is rectangular and box-shaped and is open at the two end faces. It is arranged coaxially to the main flow axis 18. The immersion tube plate 76 with the separator-associated connecting flange 56 is approximately flush with the separator housing frame 78 in radial outward direction relative to the flow axis 18.

[0113] Optionally, the separator housing frame 78 can be connected with an immersion tube plate, not illustrated in the Figures, whose separator-associated connecting flange projects past the separator housing frame 78 radially in outward direction. Correspondingly, the sidewalls 48, the bottom wall 50, and a cover wall, for example, the intermediate cover wall 52, can be provided with a corresponding outer filter-associated connecting flange, not shown in the Figures, outside of the adapter chamber 46 at the end face of the housing main part 26 which is facing away from the outlet 16 relative to the main flow axis 18. The pre-separator module 20 can be attached with the larger separator-associated connecting flange to the corresponding larger filter-associated connecting flange outside of the adapter chamber 46 on the housing main part 26. In this case, the optional passages 60 are not required. They can be closed off with appropriate cover plates. The adapter chamber 46 is then available, for example, for receiving a portion of a main filter element that, in comparison to the illustrated main filter element 22, is longer in the direction of the main flow axis 18.

[0114] The housing cover 30 can be removed, perpendicular to the main flow axis 18, from the housing main part 26. It has two blade-shaped pressure-applying structures 80 arranged in pairs on the housing cover 30 of which one is shown in FIG. 3. The pressure-applying structures 80 at the outflow side are matched in their shape respectively to the slant of the axial seal 44 of the main filter element 22. At the inflow side, the sides of the pressure-applying structures 80 provided thereat extend perpendicular to the main flow axis 18 in direction of the Z axis.

[0115] On a side which is axially opposed to the sealing surface 42 relative to the main flow axis 18, the sidewalls of the housing main part 26 each have an inwardly oriented guide step 82 for guiding and for supporting one of the pressure-applying structures 80, respectively. In the closed state of the housing cover 30, the pressure-applying structures 80 exert a force onto the main filter element 22 which is substantially oriented parallel to the axis of the axial seal 44, in the present case to the element axis of the secondary filter element 24. In this way, relative to the axis of the axial seal 44, an axially oriented pressing force is produced on the axial seal 44 which generates a particularly high sealing action.

[0116] For producing the air filter system 10, the housing main part 26, the housing cover 30, the pre-separator module 20, the main filter element 22, and the secondary filter element 24 are each separately pre-manufactured. For this purpose, the housing main part 26, the housing cover 30, the separator housing frame 78 with the appropriate parts of the pre-separator cells 74, and the immersion tube plate 76 with the immersion tubes are formed from plastic material in appropriate forming tools, respectively.

[0117] The immersion tube plate 76 is connected with the separator housing frame 78 in such a way that the immersion tubes each project into the corresponding remaining parts of the pre-separator cells 74.

[0118] For assembly, the pre-separator module 20, with the immersion tube plate 76 leading, is introduced axially relative to the main flow axis 18 through the open side of the adapter chamber 46 into the latter. In this context, the dust discharge socket 62 is oriented toward the bottom wall 50 of the housing main part 26 and is passed through the appropriate lower passage 60. The separator-associated connecting flange 56 is seal-tightly attached by means of screws to the filter-associated connecting flange 54. For this purpose, the separator housing frame 78 has on its exterior side appropriate depressions through which the corresponding screwing tools can be inserted.

[0119] Subsequently, the secondary filter element 24 is inserted through the mounting opening 28 into the element receiving space 64 and is placed into the receiving frame 36.

[0120] The main filter element 22 is introduced, with its narrow side leading, through the mounting opening 28 substantially perpendicular to the main flow axis 18 into the element receiving space 64 such that the slanted main element outflow side 40 is facing the secondary filter element 24. In the mounted state, the axial seal 44 is resting on the sealing surface 42.

[0121] Subsequently, the housing cover 30, with the pressure-applying structures 80 leading, is placed onto the mounting opening 28 perpendicular to the main flow axis 18. The pressure-applying structures 80 slide along the circumferential sides of the main filter element 22, the guide steps 82, and a collar of the element frame 70 on the rear of the axial seal 44. The main filter element 22 is pressed with the axial seal 44 axially against the sealing surface 42.

[0122] Finally, the housing cover 30 is secured by means of the clamps 34 on the housing main part 26.

[0123] In FIGS. 5 to 7, an air filter system 10 according to a second embodiment is illustrated. Those elements which are similar to those of the first embodiment of FIGS. 1 to 4 are provided with the same reference characters. In contrast to the first embodiment, in the second embodiment the pre-separator module 20 is not arranged within but outside of the adapter chamber 46. The dust discharge socket 62 is located also outside of the adapter chamber 46 so that corresponding passages in the bottom wall 50 or the sidewalls 48 are not required.

[0124] The filter-associated connecting flange 54 is located on the edges, facing away axially from the outlet 16 relative to the main flow axis 18, of the sidewalls 48, of the bottom wall 50, and of the appropriate cover wall of the housing main part 26. An intermediate cover wall is not provided in the second embodiment.

[0125] The immersion tube plate 76 projects with the separator-associated connecting rim 56 past the separator housing frame 78 radially in outward direction relative to the main flow axis 18.

[0126] The main filter element 22 has a greater axial expansion relative to the main flow axis 18 than the main filter element of the first embodiment so that it does not fit completely into the element receiving space 64. It projects with its main element inflow side 68 into the adapter chamber 46.

[0127] In the second embodiment of FIGS. 5 to 7, when using a smaller main filter element, the pre-separator module 20, in analogy to the first embodiment, can also be arranged in the adapter chamber 46. In this case, for example, a smaller immersion tube plate without connecting flange can be used. Instead, at the inlet side of the separator housing frame a separator-associated connecting flange can be arranged which projects past the separator housing frame in radial direction outwardly relative to the main flow axis 18. The separator-associated connecting flange can be realized, for example, in the form of a frame or an end plate which can be attached to the separator housing frame. The separator housing frame can alternatively be realized monolithically together with an appropriate separator-associated connecting flange.

[0128] The pre-separator module 20 can also be rotated relative to the main flow axis by 180° and can be inserted in reverse into the adapter chamber 46. In this context, it may be required that the pre-separator cells 74 in the pre-separator housing 58 must also be rotated by 180° so that their flow direction matches the air flow direction.

[0129] The passages 60 for the dust discharge socket 62 can be prepared in the bottom wall 50 and the sidewalls 48 as stamped elements, as indicated in dashed lines in FIG. 5. When the pre-separator module 20 is to be arranged within the adapter chamber 46, the corresponding passage 60 can be optionally broken out or cut out along the stamped line. In the illustrated embodiment, the optional passages 60 in the sidewalls 48 and the bottom wall 50 are not opened because the dust discharge socket 62 is located outside of the adapter chamber 46. When from the beginning there is no intention of arranging the pre-separator module 20 within the adapter chamber 46, the housing main part 26 can also be designed without correspondingly prepared optional passages.

[0130] In all described embodiments, in particular those shown in FIGS. 1 through 7, the same housing cover 30 can be employed. In this way, only one appropriate forming tool is required for realizing the housing cover 30.

[0131] The housing main part, the pre-separator housing, in particular the separator housing frame, and the immersion tube plates or optionally end plates or end frames can be modularly combined with each other, in particular as a function of the size of the employed main filter element.

[0132] The housing main parts 26, the separator housing frames 78, and the immersion tube plate 76 of the first embodiment and of the second embodiment may each be produced simply by means of exchange of an appropriate interchangeable insert of the respective forming tool with otherwise identical tools.