FILTER ELEMENT FOR FILTERING A FLUID FLOW

Abstract

A filter element for filtering a fluid flow, e.g., lubricating oil, is disclosed. The filter element includes a cylindrical fine filter body that forms a fine filter stage, a cylindrical main filter body that forms a main filter stage, and a cylindrical protection filter body that forms a protection filter stage. The fine filter body and the main filter body follow one another axially and enclose a cavity so that the fine filter stage and the main filter stage are arranged fluidically parallel. The protection filter body is arranged in the cavity so that the protection filter stage is fluidically arranged downstream of the fine filter stage and the main filter stage. A bypass valve is disposed on a first end plate for bypassing the fine filter stage and the main filter stage. An intermediate plate axially connects the fine filter body to the main filter body.

Claims

1. A filter element for filtering a fluid flow, comprising: a cylindrical fine filter body that forms a fine filter stage, a cylindrical main filter body that forms a main filter stage, and a cylindrical protection filter body that forms a protection filter stage, wherein the fine filter body and the main filter body follow one another axially and enclose a cavity so that the fine filter stage and the main filter stage are arranged fluidically parallel, wherein the protection filter body is arranged in the cavity so that the protection filter stage is fluidically arranged downstream of the fine filter stage and the main filter stage, a first end plate, on which at least one bypass valve for bypassing the fine filter stage and the main filter stage is disposed, an intermediate plate that axially connects the fine filter body to the main filter body, and at least two radially projecting spacer elements disposed on the intermediate plate spaced apart from one another in a circumferential direction and distributed over a circumference of the intermediate plate.

2. The filter element according to claim 1, wherein the fine filter body is configured as a ring filter body that can be radially flowed through by the fluid flow.

3. The filter element according to claim 1, wherein the main filter body is configured as a ring filter body that can be radially flowed through by the fluid flow.

4. The filter element according to claim 1, wherein the protection filter body is configured as a ring filter body that can be radially flowed through by the fluid flow.

5. The filter element according to claim 1, wherein the fine filter body, the main filter body and the protection filter body are each configured as a ring filter body which can each be radially flowed through by the fluid flow.

6. The filter element according to claim 1, wherein the fine filter body is configured for at least one of absorbing water for and adsorbing oil ageing products from the fluid flow.

7. The filter element according to claim 6, wherein the fine filter body contains a superabsorber for absorbing water.

8. The filter element according to claim 7, wherein the fine filter body contains at least one water-absorbing layer, which contains the superabsorber.

9. The filter element according to claim 8, wherein the at least one water-absorbing layer comprises a polyester fleece, the polyester fleece including two fleece layers between which the superabsorber is arranged.

10. The filter element according to claim 6, wherein the fine filter body is configured for adsorbing oil ageing products and comprises a filter layer arrangement that includes multiple filter layers each having different filter finenesses and which are arranged in the fine filter body so that the filter fineness increases in the through-flow direction of the fine filter body.

11. The filter element according to claim 10, wherein one of: the filter layer arrangement comprises at least two filter layers that include a coarse filter layer and a fine filter layer, which in the through-flow direction of the fine filter body are arranged so that first the coarse filter layer and then the fine filter layer are flowed through, and the filter layer arrangement comprises at least three filter layers that include a coarse filter layer, a medium filter layer and a fine filter layer, which in the through-flow direction of the fine filter body are arranged so that first the coarse filter layer, then the medium filter layer and then the fine filter layer are flowed through.

12. The filter element according to claim 10, wherein at least one filter layer of the filter layer arrangement is composed of a glass fibre fabric.

13. The filter element according to claim 7, wherein at least one filter layer of the filter layer arrangement contains the superabsorber or is formed through a water-absorbing layer containing the superabsorber.

14. A filter element for filtering a fluid flow, comprising: a cylindrical fine filter body that forms a fine filter stage, a cylindrical main filter body that forms a main filter stage, and a cylindrical protection filter body that forms a protection filter stage, wherein the fine filter body and the main filter body follow one another axially and enclose a cavity, so that the fine filter stage and the main filter stage are arranged fluidically parallel, wherein the protection filter body is arranged in the cavity so that the protection filter stage is fluidically arranged downstream of the fine filter stage and the main filter stage, a first end plate including at least one bypass valve for bypassing the fine filter stage and the main filter stage, an intermediate plate, structured and arranged to axially connect the fine filter body to the main filter body, wherein the fine filter body is configured for absorbing at least one of water and oil ageing products from the fluid flow.

15. The filter element according to claim 14, further comprising at least two radially projecting spacer elements disposed on the intermediate plate spaced apart from one another in a circumferential direction and distributed over a circumference of the intermediate plate.

16. The filter element according to claim 1, wherein the at least two spacer elements include axially and radially extending ribs.

17. The filter element according to claim 1, wherein: the fine filter body has a filter fineness of 3 m+/1 m, the main filter body has a filter fineness of 10 m+/3 m, the protection filter body has a filter fineness of 50 m+/10 m.

18. The filter element according to claim 1, further comprising: a second end plate having a central outlet opening, wherein the protection filter element is arranged in a region of the second end plate so that the fluid flow can flow out of the cavity to the outlet opening only through the protection filter body.

19. The filter element according to claim 18, wherein: the protection filter body comprises an open plate and a closed end plate, and the protection filter body is radially and tightly supported via the open end plate in the region of the second end plate on the fine filter body or on the main filter body.

20. The filter body according to claim 19, wherein the protection filter body on the closed end plate comprises radially projecting support elements that are arranged distributed in the circumferential direction and spaced apart from one another, via which the protection filter body is radially supported on one of the fine filter body, the main filter body, and the intermediate plate.

21. A filter device for filtering lubricating oil, comprising: at least one filter element, the at least one filter element including: a cylindrical fine filter body that forms a fine filter stage, a cylindrical main filter body that forms a main filter stage, and a cylindrical protection filter body that forms a protection filter stage; wherein the fine filter body and the main filter body follow one another axially and enclose a cavity so that the fine filter stage and the main filter stage are arranged fluidically parallel; wherein the protection filter body is arranged in the cavity so that the protection filter stage is fluidically arranged downstream of the fine filter stage and the main filter stage; a first end plate, on which at least one bypass valve for bypassing the fine filter stage and the main filter stage is disposed; an intermediate plate that axially connects the fine filter body to the main filter body; and at least two radially projecting spacer elements disposed on the intermediate plate spaced apart from one another in a circumferential direction and distributed over a circumference of the intermediate plate; at least one substantially cylindrical filter housing, in which the at least one filter element is arranged, wherein an annular space is disposed between an inner wall of the filter housing and the at least one filter element that extends along a longitudinal centre axis of the filter housing.

22. The filter device according to claim 21, wherein the at least one filter element radially supports itself on the filter housing via the at least two radially projecting spacer elements.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0034] It shows, in each case schematically:

[0035] FIG. 1 an isometric view of a filter element according to the invention,

[0036] FIG. 2 a plan view of the filter element according to the invention,

[0037] FIG. 3 a partly sectioned lateral view of the filter element according to the invention,

[0038] FIG. 4 a greatly simplified sectional view of a filter material,

[0039] FIG. 5 a sectional view as in FIG. 4, however with another embodiment of the filter material.

DETAILED DESCRIPTION

[0040] As illustrated in FIG. 1, a filter element 1 designed cylindrically and in three stages for filtering a fluid flow, in particular for filtering lubricating oil, comprises a cylindrical fine filter body 2, which forms a fine filter stage 2, a cylindrical main filter body 3, which forms a main filter stage 3, and a cylindrical protection filter body 4, which forms a protection filter stage 4. Here, the fine filter body 2 and the main filter body 3 axially follow one another and enclose a cavity 5 only shown in FIG. 3, so that the fine filter stage 2 and the main filter stage 3 are arranged fluidically parallel. The protection filter 4 which is likewise only shown in FIG. 3 is arranged in this cavity 5 so that the protection filter stage 4 is arranged fluidically downstream of the fine filter stage 2 and the main filter stage 3. Here, the protection filter body 4 in FIGS. 1 and 3 is arranged in the region of the main filter body 3. It is likewise conceivable that the protection filter body 4 is arranged in the region of the fine filter body 2.

[0041] In the preferred embodiment shown here, all three filter bodies, i.e. the fine filter body 2, the main filter body 3 and the protection filter body 4 are each configured as ring filter body, so that the respective annular filter body 2, 3, 4 during the operation of a filter device equipped with the filter element 1 is radially flowed through by the fluid flow to be filtered in order to solve the respective filtration object. Such ring filter bodies that can be radially flowed through are characterized by a relatively low space requirement with relatively large through-flow cross section and thus by a comparatively low counter-pressure.

[0042] The filter element 1, furthermore, comprises a first end plate 6 on which at least one bypass valve 7 for bypassing the fine filter stage 2 and the main filter stage 3 is formed. The number of the bypass valves shown in FIGS. 1 to 3 is merely intended to be exemplary. It is conceivable that on the first end plate 6 fixing lugs 8 are formed.

[0043] As illustrated in FIGS. 1 and 3, the filter element 1 comprises an intermediate plate 9, by way of which the fine filter body 2 is axially connected to the main filter body 3. On the intermediate plate 9, radially projecting spacer elements 10 which are spaced apart from one another in the circumferential direction and distributed over the circumference of the intermediate plate 9 are formed. The number of the spacer elements 10 shown in FIGS. 1 to 3 should merely be seen as being exemplary. It is conceivable that the spacer elements 10 are formed of axially and radially extending ribs 11. Spacer elements 10 having a different geometrical shape remain within the scope of the present invention.

[0044] The fine filter body 2 can have a filter fineness of 3 m+/1 m, the main filter body 3 can have a filter fineness of 10 m+/3 m and the protection filter body 4 can have a filter fineness of 50 m+/10 m. Furthermore, the fine filter body 2 can be formed for absorbing water and/or oil ageing products from the fluid flow. This will still be explained in more detail further down below in the connection with FIGS. 4 and 5.

[0045] The filter element 1 is arranged in a substantially cylindrical filter housing 12 in such a manner that between an inner wall 13 of the filter housing 12 and the filter element 1 an annular space 15 extending along a longitudinal centre axis 14 of the filter housing 12 is formed. Here, the filter element 1 is radially supported on the filter housing 12 via the spacer elements 10 formed on the intermediate plate 9. The filter housing 12, the inner wall 13 and the annular space 15 are schematically illustrated only in FIGS. 1 and 3.

[0046] According to FIGS. 1 and 3, the filter element 1 comprises a second end plate 17 in which a central outlet opening 18 is formed. The protection filter body 4 is arranged in the region of the second end plate 17 so that the fluid flow out of the cavity 5 can only flow through the protection filter body 4 to the outlet opening 18.

[0047] As illustrated in FIG. 3, the protection filter body 4 comprises an open end plate 19 and a closed end plate 20. Here, the protection filter body 4 is radially and tightly supported in the region of the second end disc 17 on the fine filter body 2 or on the main filter body 3 via its open end plate 19. It is conceivable, furthermore, that the protection filter body 4 on its closed end plate 20 comprises radially projecting support elements 21 which are arranged distributed in the circumferential direction and spaced apart from one another. Here, the protection filter body 4 is radially supported on the fine filter body 2 or on the main filter body 3 or on the intermediate blade 9 via the support elements 21.

[0048] A filter device 16 having the filter housing 12 and having at least one filter element 1 of the type described above is preferentially employed in a wind energy plant for filtering lubricating oil.

[0049] According to FIGS. 4 and 5, the main filter body 2 can comprise a filter material 22 of which in FIGS. 4 and 5 only a small part each is shown as sectional view. In an annular fine filter body 2, the filter material 22 can likewise extend annularly. Preferably, the filter material 22 is additionally pleated so that it extends star-shaped in the annular fine filter body 2.

[0050] According to an advantageous embodiment it can now be provided that the fine filter body 2 for absorbing water contains a superabsorber 23. Such a superabsorber 23 is a plastic, generally a polymer 24, which is able to absorb a multiple of its own weight of a polar liquid, i.e. in particular water. Through the absorption of the liquid or of the water, the superabsorber 23 swells up and forms a hydrogel 25. In other words, the fine filter body 2 can contain a super-absorbent, i.e. water-absorbent polymer 24 which through the absorption of water forms a hydrogel 25.

[0051] Preferably, the fine filter body 2 for this purpose can comprise at least one water-absorbing layer 26 in the filter material 22, which contains the superabsorber 23 or the water-absorbent polymer 24. The water-absorbing layer 26 extends in particular annularly and coaxially to the remaining filter body 2. Advantageously it can now be provided that the water-absorbing layer 26 comprises a polyester fleece 27 or is formed by such, which comprises two fleece layers 28, 29, between which the superabsorber 23 or the water-absorbent polymer 24 is arranged. The polyester fleece 27 can be laminated in order to fix the two layers 28, 29 to one another and thus fix the superabsorber 23 or the water-absorbent polymer 24 between the layers 28, 29, i.e. in the polyester fleece 27.

[0052] Additionally or alternatively it can now be provided that the fine filter body 2 in the filter material 22 comprises a filter layer arrangement 30 for adsorbing of oil ageing products which comprises multiple filter layers 31, 32, 33, which have different filter finenesses and which are arranged in the fine filter body 2 so that the filter fineness increases in the through-flow direction 34 of the fine filter body 2 indicated by arrows. By way of this, the filtration effect increases in the through-flow direction 34 from filter layer 31, 32, 33 to filter layer 31, 32, 33. The filter layers 31, 32, 33 and thus the filter layer arrangement 30 extend in particular annularly and coaxially to the remaining fine filter body 2.

[0053] Practically, the filter layer arrangement 30 can comprise at least two, three or more filter layers 31, 32, 33. In the example of FIG. 4, exactly three filter layers are provided in the filter layer arrangement 30, namely a coarse filter layer 31, a medium filter layer 32 and a fine filter layer 33, which are arranged in the through-flow direction 34 of the fine filter body 2 so that first the coarse filter layer 31, then the medium filter layer 32 and finally the fine filter layer 33 are flowed through. In the embodiment shown in FIG. 5, by contrast exactly two filter layers are arranged in the filter layer arrangement 30, namely a coarse filter layer 31 and a fine filter layer 33, which in the through-flow direction 34 of the fine filter body 2 are arranged so that first the coarse filter layer 31 and thereafter the fine filter layer 33 are flowed through. As mentioned further up, the fine filter body 2 can have a filter fineness of 3 m+/1 m. With the progressive filtration effect introduced here, this filter fineness of the multi-layered fine filter body 2 is ultimately defined by the layer with the smallest filter fineness. This means in this example that the fine filter layer 33 has a filter fineness of 3 m+/1 m, while the medium filter layer 32 and the coarse filter layer 31 are coarser. For example, the medium filter layer 32 can have a filter fineness of 6 m+/2 m or more and the coarse filter layer 31 can have a filter fineness of 9 m+/3 m or more. Advantageously, the respective filter layer 31, 32, 33 of the filter layer arrangement 30 can be formed by a glass fibre fabric or glass fibre fleece. The glass fibre fabrics or glass fibre fleeces that are employed in the various filter layers 31, 32, 33 differ by different mesh widths or permeabilities or pore sizes from one another. Different fibre lengths and/or fibre thicknesses are also conceivable.

[0054] In the example of FIG. 4, the water-absorbing layer 26 is provided additionally to the filter layer arrangement 30. In FIG. 4, the water-absorbing layer 26 is arranged, regarding the through-flow direction 34, upstream of the filter layer arrangement 30. Because of this, the superabsorber 23 and during the operation the hydrogel 25 are better retained in the filter material 22.

[0055] In the embodiment shown in FIG. 5, the superabsorber 23 is integrated in the filter layer arrangement 30. For this purpose, the water-absorbing layer 26 is arranged between two of the filter layers 31, 32, 33 of the filter layer arrangement 30. In the example of FIG. 5, the water-absorbing layer 26 forms the medium layer between the coarse filter layer 31 and the fine filter layer 33. Because of this, the filter layer arrangement 30 is given an additional function, namely as water absorber.

[0056] Thus, the fine filter body 2 comprises a filter material 22 which is constructed in multiple layers so that it can comprise the aforementioned water-absorbing layer 26 and/or the aforementioned filter layer arrangement 30. In addition, further layers can be provided such as for example one or more wire layers for stabilising the filter material 22. In the example of FIGS. 4 and 5, the filter material 22 is stabilised and protected through a wire mesh layer 35 on the inflow side and through a wire mesh layer 36 on the outflow side. At least one further plastic fleece layer which is not shown can be provided for example for protecting the glass fibre layers.