Filter element and filter device

Abstract

a filter element comprising an element material (26) extending between at least two end caps (28, 30), wherein at least one of the two end caps (28, 30) has a receiving portion (44) for receiving the element material (26) and a connecting portion (52) for connecting to a housing portion (16), wherein both the receiving portion (44) and the connecting portion (52) have several through openings (56, 58) on their inner peripheries for the passage of a fluid, and wherein the several through openings (56, 58) are arranged offset from one another with respect to a longitudinal axis (22) of the filter element (20); wherein an offset step (54) is arranged between the receiving portion (44) and the connecting portion (52) and has a through opening (60), and wherein the through openings (56, 58, 60) of the receiving portion (44), the connecting portion (52), and the offset step (54) have the same free cross-section, passing perpendicularly to the longitudinal axis (22) of the filter element (20).

Description

[Technical Field]

[0001] The present invention relates to a filter element consisting of at least an element material extending between two end caps, at least one of which has a receiving portion for receiving the element material and a connecting portion for connecting to a housing portion, both of which have several through openings on their inner peripheries for the passage of a fluid, the several through openings being offset from one another with respect to a longitudinal axis of the filter element. [Background technology]

[0002] Patent document 1 (EP 2490784) describes a filter element for use in a related filter device, the filter element having an end cap at at least one end to form an enclosure for each end rim of the filter material, the end cap being capable of being fixed to an element holder arranged at the bottom of a filter housing to fix the position of the filter element in a functional position, the end cap being provided with a shape irregularity on a portion thereof that engages with a portion of the element holder in the related filter housing in the functional position, and the shape irregularity is provided on a portion of the element holder to engage with the shape irregularity arranged on the portion of the element holder, The filter element is disclosed as follows: when the positions of the regularities are aligned with each other, engagement between the end cap and the element holder and thus movement of the filter element to its functional position are possible, the end cap has a connector that extends into an inner filter cavity surrounded by a fluid-permeable support tube and engages with one tube connector of the element holder in the filter housing in the functional position of the filter element, the opening cross-section of the connector is adapted to the non-circular and asymmetrical outer contour of the one tube connector of the element holder, forming the geometric irregularity associated with the end cap. In this regard, the through opening on the inner periphery of the receiving part with the filter element and the through opening on the inner periphery of the connecting part for connecting to the housing part are offset from each other with respect to their respective longitudinal axes.

[0003] As a result, the filter element can only be moved into a functional position provided that the complementary features on the element holder and end cap are matched to each other to allow them to engage when properly aligned with each other, thereby ensuring that the filter device can be operated only with filter elements that are provided for each particular application and that can meet the application specifications to ensure operational safety.

[0004] The resulting defined rotational position of the filter element within the filter housing also opens up the further advantageous possibility of providing a shield on the end cap in a filter housing that has a side fluid inlet adjacent the end cap of the filter element in its functional position, the shield extending along the outside of the filter material of the filter element and covering the area of ​​the fluid inlet as impact protection when the filter element is in its functional position. The fixed rotational position ensures that the impact protection is in the flow area of ​​the filter element. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent No. 2490784 Summary of the Invention

[0006] Based on this prior art, the object of the present invention is to arrange the associated filter element in a positionally fixed, preferably exchangeable, manner in the associated filter housing while retaining the advantages of the known solutions, and to predefine the positioning of the filter element in the filter housing so that the pressure loss during the filtering operation is reduced. This problem is solved by a filter element having the features of claim 1 and a filter device having the features of claim 9.

[0007] According to the features of claim 1, the filter element has an offset step between the receiving part and the connecting part, the offset step having a through-opening, and the through-opening of the receiving part, the connecting part, and the offset step have the same free cross-section, each passing perpendicularly through the longitudinal axis of the filter element. The same free cross-sections prevent flow losses when the filtered flow is discharged from the filter element, i.e., when the unfiltered medium flow is passed from the outside to the inside through the element material of the filter element for particle cleaning.

[0008] Additionally, the offset step on the filter element allows the interior of the filter element having the filtration volume to be spatially separated from its filtered media discharge point, such that the filtered media intake and filtered media discharge are functionally at different locations on the filter element.

[0009] In connection with the filter housing of the filter device according to the features of claim 9, this allows for an eccentric mounting of the filter element as a whole in the filter housing, so that at the inlet side of the filter housing, to which the flow of unfiltered medium is supplied, an enlarged annular gap is formed between the outer periphery of the filter element and the adjacent inner periphery of the associated filter housing, while at the rear side of the filter element, i.e., the side facing away from the inlet side, this annular gap is reduced, thereby resulting in lower flow losses, i.e. a lower ΔP, than if the filter element were mounted centrally and coaxially on the longitudinal axis while maintaining the same wall distance from the filter housing. This is not equivalent to the prior art.

[0010] It is particularly preferred that the through openings of the receiving part and the connecting part are formed from annular hollow cylinders, the hollow cylinder of the receiving part extending concentrically with the longitudinal axis of the filter element, the longitudinal axis of the hollow cylinder of the connecting part extending parallel to the longitudinal axis of the filter element with an offset, and the offset step spans the annular cavity, the longitudinal axis of which intersects with the other two longitudinal axes of the receiving part and the connecting part at a predetermined offset angle α, preferably between 15° and 45°, more preferably 35°. In this way, both the receiving part and the connecting part, as well as the offset step between the receiving part and the connecting part, can be accommodated in an end cap of the element material in a particularly space-saving manner, and in this way the filtered flow can be discharged from the filter element.

[0011] In a further particularly preferred embodiment of the filter element according to the invention, it is provided that an end cap includes a flow diverter that starts from a receiving portion and extends a predeterminable distance along at least a portion of the outer periphery of the element material. Preferably, the flow diverter is designed in a bowl shape and covers a portion of the element material of the filter element, the predeterminable distance being selected so that the element material is protected or released when fluid flows over it from the inlet side. Due to the fixed rotational position of the filter element in the filter housing, the resulting impact protection is always located within the flow field of the filter element, preferably ensuring uniform distribution of the unfiltered medium flow in the direction of the element material.

[0012] In a particularly preferred embodiment of the filter element according to the invention, the flow divider is provided with channel-like fluid passages to improve flow guidance. In this case, the channel-like fluid passages are preferably divided into at least two groups extending in a V-shape away from the central axis of the flow divider, and the two groups are preferably wedge-shaped in this respect, allowing for uniform flow distribution of the inflowing fluid in two different directions. Because the flow divider has channel-like fluid passages, it does not form a closed shield as impact protection, so that the element material behind the channel-like fluid passages is still in fluid contact, and therefore effective particle filtration can also be achieved even in the covered area.

[0013] The combination of the filter element with an inflow protection or flow divider leads to an optimized flow rate and a more uniform flow rate distribution or flow rate through the entire filter element during filtration operation.As part of the simplified replacement procedure for replacing a used filter element with a new one, it is provided that each connection of the filter element has an annular groove on its outer periphery for receiving a standardized sealing device.

[0014] In a further particularly preferred embodiment of the filter element solution according to the invention, it is provided that one end cap in the region of the offset step, aligned parallel to the longitudinal axis of the element material, is provided with individual longitudinal ribs spaced apart from one another and surrounded by polygons as imaginary surrounding edges. The polygonal shape, referred to as imaginary surrounding edges, of the longitudinal ribs assists in the accurate positioning of the filter element in the element holder of the filter device.

[0015] The present invention also provides a filter device having a filter housing in which the above-described filter element is received, characterized in that the filter element is received asymmetrically in the filter housing by end caps so that an enlarged annular gap is formed on the filter inlet side with the unfiltered medium flow and a reduced annular gap is formed between the filter element and the filter housing on the opposite side facing away from the filter housing. This results in an asymmetrical element holder and flow guidance in the associated filter housing with an essentially cylindrical housing cavity. Preferably, the inlet side for supplying the unfiltered medium flow in the filter housing is encompassed at a predeterminable distance from the flow divider of the filter element.

[0016] In the following, the filter element according to the invention together with the associated filter device will be explained in more detail using embodiments according to the drawings, which are shown diagrammatically and not to scale. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 shows the entire filter device in longitudinal section. [Figure 2] FIG. 2 is a view of the filter device rotated 90° forward relative to the viewing direction of FIG. [Figure 3] FIG. 3 is a partial half-section of a filter element as can in principle be used in the filter device according to FIGS. [Figure 4] FIG. 4 shows a perspective view from below of a connection for receiving a filter element according to FIGS. [Figure 5] FIG. 5 shows a perspective side view of a connection for receiving a filter element according to FIGS. 1 and 3. FIG. [Figure 6] FIG. 6 shows a plan view of a connection for receiving a filter element according to FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0018] The filter housing in the form of a hollow cylinder, generally designated 10 in Figure 1, has an upper part 12, an intermediate part 14 and a bottom part 16, which are screwed together. In particular, the intermediate part 14 can be formed integrally with the bottom part 16. The filter device shown in Figure 1 is shown in its operative position, the upper end of the upper part 12 opposite the bottom part 16 being closeable by a screwable housing cover 18. A filter element, generally designated 20, is received in filter housing 10 in an exchangeable manner, with a longitudinal axis 22 of the filter element 20 extending parallel to a longitudinal axis 23 of the filter housing 10.

[0019] The filter element 20 typically includes an element material 26 extending between a top end cap 28 and a bottom end cap 30. The element material 26 serves to clean particle contamination from the fluid stream. To guide the fluid flow, the filter housing 10 or the bottom housing portion 16, respectively, includes an inlet side 32 for supplying the unfiltered media stream, the inlet side 32 being formed by a circular housing opening 34 in the bottom portion 16. Starting from the inlet side 32, the unfiltered media splits along the periphery of the filter element 20 and flows from the outside to the inside through the element material 26 before the thus-cleaned fluid stream reaches the interior 36 of the filter element 20 as filtered media. As the fluid flow continues, the filtered media located inside 36 of the filter element 20 then reaches the bottom discharge side 38 of the filter housing 10. While the top cap 28 typically includes a bypass valve 40 that allows bypass flow from the unfiltered media or raw side directly to the filtered or clean side, bypassing the element material 26 if the element material 26 becomes clogged or blocked, the bottom cap 30 includes a passage area 42 specifically designed to guide the filtered flow. This passage area 42 is permanently connected in a fluid-transmitting manner to the filtered or clean side or interior 36 of the filter element 20, respectively. In this regard, the bottom cap 30 can be divided into individual sections with different areas for different purposes. The bottom cap 20 thus includes a receptacle 44 for receiving the element material 26 in the usual manner. For this purpose, the receptacle 44 includes an annular adhesive bed 46 extending around its periphery, to which the lower end of the element material 26, free at its end face, is adhesively attached. The fluid-permeable support tubes 48, regularly arranged on the inner periphery of the hollow cylindrical element material 26, are also adhesively fixed together with the element material 26 in this region within the adhesive bed 46 of the receiving portion 44. Similarly, the upper end regions of the element material 26 and the support tubes 48 are firmly connected to the upper end cap 28 via a further adhesive bed 50, just like the lower end cap 30.

[0020] Furthermore, the bottom cap 30 comprises a connecting portion 52 for connecting the filter element 20 to the bottom housing part or bottom 16. An additional offset portion, an offset step 54, is provided between the receiving portion 44 and the connecting portion 52. Both the receiving portion 44 and the connecting portion 52, as so-called offset portions, as well as the offset step 54, are integral parts of the bottom cap 30 and are formed, in particular, from molded plastic parts. The above-mentioned receiving portion 44, the connecting portion 52, and the offset step 54 all have respective through-openings 56, 58, 60 on their inner peripheries, which merge continuously into one another. In particular, the free cross-sections of the through-openings 56, 58, 60 of the receiving portion 44, the connecting portion 52, and the offset step 54, passing in each case perpendicularly to the longitudinal axis 22 of the filter element 20, are identical.

[0021] The respective through openings 56, 58 of the receiving portion 44 or the connecting portion 52 are formed from annular hollow cylinders 62, 66 in the bottom end cap 30, with the hollow cylinder 62 of the receiving portion 44 extending concentrically with the longitudinal axis 22 of the filter element 20. However, the hollow cylinder 66 of the connecting portion 52 extends concentrically with the longitudinal axis 23 of the filter housing 10. The offset step 54 spans an annular cavity 70 with an obliquely extending boundary wall, the longitudinal axis 72 of which intersects with the two other longitudinal axes 22 and 23 that pass through the receiving portion 44 and the connecting portion 52, respectively, at a predetermined offset angle a, which in this case is approximately 35° but which can vary in an angular range of 15° to 45°.

[0022] As can be further seen, one bottom end cap 30 includes a flow diverter 74 that begins at the receiver 44 and extends a predeterminable distance along at least a portion of the outer periphery 76 of the element material 26. The element material 26 is preferably disposed within the individual filter folds, with the imaginary outer periphery (not shown) of the filter folds thus formed defining an annular gap 78 with the inner periphery of the flow diverter 74.

[0023] 4, the flow divider 74 is designed in a bowl shape, and the extent of the element material 26 is selected so that the element material 26 is protected when fluid flows over the element material 26 from the inlet side 32. To this end, as shown in FIGS. 1 and 2, the flow divider 74 extends over the annular housing opening 34 that defines the inlet side 32 with the unfiltered medium from the inside, maintaining a predeterminable distance.

[0024] As particularly shown in Figures 4 and 5, the flow divider 74 is provided with channel-like fluid passages 80 for improved flow guidance. In this process, the channel-like fluid passages 80 are divided into at least two groups 82, 84 extending away from a vertical central axis 86 of the flow divider 74 in a V-shape, preferably wedge-shaped, allowing for uniform flow distribution of the incoming fluid in two different directions, i.e., in the direction of one group 82 and the other group 84. As shown in Figure 5, a V-shaped central region 88 can be configured starting from the central axis 86 below where there are no channel-like fluid passages 80, so that a solid shield can be formed in this V-shaped region as impact protection. Several channel-like fluid passages 80 are each formed by strip- or rod-shaped channels in the shield of the flow divider 74, and the elongated fluid passages 80 are introduced into the recesses of these channels in the manner of continuous longitudinal grooves, so that the fluid at a predetermined pressure entering the filter housing 10 is conducted starting from the inlet side 32 through the individual channel-like fluid passages 80 in the form of orifices, and this fluid impinges, radially, on the element material 26 via the annular gaps 78, so that a uniform flow to the individual filter folds is thus ensured without the occurrence of pressure peaks that could damage the element material 26.

[0025] 1, 3, 4 and 5, the connection part 52 has an annular groove 90 on the outer periphery of its lower end region for receiving a sealing device 92 in the form of an O-seal ring. In an embodiment not shown in detail, such a sealing device 92 could also be formed from an injection-molded sealing rim, resulting in an elastomer-free seal. However, according to the illustration in FIG. 1, via the respective sealing device 92, the filter element 20 is guided in a replaceable and sealed manner in the lower leg region, i.e., its lower end cap 30 is sealed in the bottom part 16 of the filter housing 10. To ensure replacement of a soiled filter element 20 with a new one, only the upper part 12 in the form of the housing cover 18 needs to be unscrewed from the middle part 14 of the filter housing 10; the filter element 20 can be manually pulled out as a whole from above to obtain the filter element located outside the filter housing 10, as shown in FIG. 3; the bypass valve 40 is omitted from the corresponding filter element 20, and the upper end cap 28 is configured to be closed. The new elements can then be inserted in reverse order and the device put back into operation.

[0026] As can be seen in particular from Figures 4 to 6, the bottom end cap 30, which is designed as a molded plastic part, has individual longitudinal ribs 94 of different structural lengths that project downward below the receiving portion 44 and are surrounded by a virtual surrounding edge 96, as shown by the dashed line in Figure 6, by a polygon. In this process, the surrounding edge 96 is at least partially continuous with the peripheral edge 98 of the bottom end cap 30, and the aforementioned longitudinal ribs 94 particularly reinforce the transition area between the receiving portion 44 and the connecting portion 52 in the form of the offset step 54, which the longitudinal ribs 94 themselves surround. The individual longitudinal ribs 94 are in this case combined into four different groups "top, bottom, right and left" as shown in FIG. 6, the right and left groups having longitudinal ribs 94 of the same design, otherwise extending parallel to one another and arranged perpendicularly, with the longitudinal ribs 94 spaced apart from one another within a group being in imaginary extensions perpendicular to adjacent groups, and the imaginary extensions thereof being the same as well.

[0027] In addition to reinforcing the bottom end cap 30, the longitudinal rib structure also allows for precise positioning of the filter element 20 within the filter housing 10 by positioning the flow diverter 74 in a defined, adjacent manner opposite the inlet side 32 with the housing opening 34.

[0028] 1 , the filter element 20 can be accommodated in the filter housing 10 with an offset a. That is, the longitudinal axis 22 of the filter element 20 is offset by an angle a with respect to the longitudinal axis 23 of the filter housing 10, so that an enlarged gap-shaped annular space 100 is formed on the inlet side 32 with unfiltered media flow, and on the opposite side, a reduced gap-shaped annular space 102 is created between the filter element 20 and the filter housing 10, resulting in the filter element 20 as a whole being accommodated in the filter housing 10 in an asymmetrical installation. This necessarily results in an increased distance between the flow diverter 74 and the inlet side 32 in the filter housing 10.

[0029] In the solution according to the invention, a standard filter element with an asymmetrical bottom end cap 30 can be inserted into a standard filter housing 10 in combination with an injected inflow protection in the form of a flow diverter 74. As already mentioned, the insertion ribs in the form of longitudinal ribs 94 on the bottom end cap 30 are configured in the form of a so-called O-ring cap as a polygon, so that the filter element 20 as a whole can always be mounted in a precise position within the filter housing 10, ensuring that the flow diverter 74 is always accurately positioned at the filter inlet in the form of the annular housing opening 34 forming the inlet side 32 of the device. The offset positioning of the filter element 20 shown outside the housing center, i.e., outside the longitudinal axis 23 of the filter housing 10, results in an enlarged gap-shaped annular space 100 between the unfiltered media inlet 34 and the filter element 20, thereby reducing Δp due to lower flow losses.

[0030] The combination of the element 20 with the inflow protection, i.e., the flow divider 74, results in flow optimization, leading to a more homogeneous flow distribution or flow throughout the filter element 20 along its longitudinal axis 22. Furthermore, the element 20 is protected in the fluid inlet area. Furthermore, by using a special mat structure in combination with the new asymmetric cap 30, it is possible to increase the fluid pressure load on the filter element and thus make the filter element smaller while maintaining the same filter performance compared to standard symmetric designs. To ensure that the filter element 20 shown in FIG. 1 is also received in an asymmetric position in the filter housing 10 in the region of its upper end cap 28, the end cap 28 can have a segment-shaped widened portion 104, which can be designed as a shaped sheet metal part with an upwardly protruding rim and supported on the inner circumference of the middle part 14 of the filter housing 10, so that the filter element 20 is functionally received in the filter housing 10 via its two end caps 28, 30.

Claims

1. A filter element comprising an element material (26) extending between at least two end caps (28, 30), at least one of the two end caps (28, 30) having a receiving portion (44) for receiving the element material (26) and a connecting portion (52) for connecting to a housing portion (16), both the receiving portion (44) and the connecting portion (52) having several through openings (56, 58) on their inner peripheries for the passage of a fluid, the several through openings (56, 58) being arranged offset from one another with respect to a longitudinal axis (22) of the filter element (20), a filter element having an offset step (54) disposed between the receiving portion (44) and the connecting portion (52) and having a through opening (60), the through openings (56, 58, 60) of the receiving portion (44), the connecting portion (52) and the offset step (54) each having the same free cross section passing perpendicularly to the longitudinal axis (22) of the filter element (20).

2. 2. The filter element according to claim 1, wherein the through openings (56, 58) of the receiving part (44) and the connecting part (52), respectively, are formed from annular hollow cylinders (62, 66), the hollow cylinder (62) of the receiving part (44) extending concentrically with the longitudinal axis (22) of the filter element (20), the hollow cylinder (66) of the connecting part (52) extending concentrically with the longitudinal axis (23) of the filter housing (10) parallel to the longitudinal axis (22) of the filter element (20) and offset (a), the offset step (54) spanning an annular cavity (70), the longitudinal axis (72) of which intersects with the other two longitudinal axes (22, 23) at a predetermined offset angle α, preferably between 15° and 45°, particularly preferably 35°.

3. 3. The filter element of claim 1, wherein the one end cap (30) comprises a flow divider (74) beginning at the receiving portion (44) and extending a predeterminable distance along at least a portion of the outer periphery (76) of the element material (26).

4. 4. The filter element according to claim 1, wherein the flow divider (74) is designed in a bowl shape and covers a part of the element material (26), and the predeterminable distance is selected so that the element material (26) is protected when a fluid flows onto the element material (26) from the inlet side (32).

5. 5. A filter element according to any one of claims 1 to 4, characterized in that the flow divider (74) is provided with flow-like fluid passages (80) for improved flow guidance.

6. 6. The filter element of claim 1, wherein the flow-through fluid passages are divided into at least two groups (82, 84) extending in a V-shape away from a central axis (86) of the flow divider (74), the two groups being preferably wedge-shaped to allow uniform flow distribution of the incoming fluid in two mutually different directions.

7. A filter element according to any one of the preceding claims, characterized in that the connection part (52) comprises an annular groove (90) on its outer periphery for receiving a sealing device (92).

8. 8. The filter element according to claim 1, wherein one end cap (30) in the region of the offset step (54) aligned parallel to the longitudinal axis (22) of the filter element (20) comprises individual, spaced apart longitudinal ribs (94) surrounded by a polygon as an imaginary enclosing end (96).

9. A filter device having a filter housing in which the filter element according to any one of claims 1 to 7 is received, 1. A filter device comprising: a filter element (20) asymmetrically received in the filter housing (10) by an end cap (30) such that an enlarged space (100) is formed on the inlet side (32) having an unfiltered medium flow; and a reduced annular space (102) is formed between the filter element (20) and the filter housing (10) on the opposite side facing away from the inlet side (32).

10. 10. The filter device according to claim 9, wherein the inlet side (32) of the filter housing (10) is covered by the flow divider (74) of the filter element (20) at a predeterminable distance for supplying the unfiltered medium flow.

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