Filter element and filter comprising at least two filter elements - Patents.com

Abstract

The filter element (10) of the filter has an inner surface (20), an outer surface, a filtering mesh (22), two concentric edges, an inner edge (24) and an outer edge (26) between which the filtering mesh (22) extends, and main ribs (28) provided on at least the inner surface (20), the main ribs (28) extending substantially radially between the edges (24, 26) and distributed circumferentially to form sectors on the inner surface (20), the filter element (10) being fitted to a corresponding filter element. a filter element (26) having a first rib (28) and a second rib (40) extending between said first ribs (26, 28) and said second rib (40) and adapted to be assembled against said filter element (26), such that said inner surface (20) faces the inner surface of the corresponding filter element, said main ribs (28) define the range of motion of the sectors to circumferentially define compartments in the space between said inner surface and said corresponding filter element, said inner edges (24) having inner passages (30) each communicating with a corresponding one of the sectors, and at least one rib (28, 40) extending between said edges (24, 26) is a curved rib having a bend along its entire length.

Description

[Technical field]

[0001] The present invention relates to a filter element having a filtering mesh extending between two concentric edges, to a set of such filter elements arranged relative to one another, to a filter comprising a plurality of such filter elements stacked along an axis, and more particularly to an improvement in a filter element. [Background technology]

[0002] US Patent No. 5,399,633 describes a filter structure using annular flat filter elements, each having an inner surface, an outer surface, and a filtering mesh. FIG. 1 of the present application depicts such a filter element. The filtering mesh is annular and extends between two concentric edges, the inner edge and the outer edge, respectively. Radial ribs, regularly distributed in the circumferential direction and correspondingly extending in the axial direction on both sides of the filtering mesh between said concentric edges, act to form sectors on the inner and outer surfaces. Such filter elements are designed to be assembled with respect to each other such that their opposing inner surfaces form a space that is circumferentially partitioned by the contacting radial ribs of said inner surfaces. For each sector, passages are arranged on the inner and outer edges. By stacking pairs of a selected number of filter elements, a desired filter area is obtained for the intended application. Usually, the fluid to be filtered penetrates through the stack via passages located on the inner edge, passes through the filtering mesh, is purified, and then exits via passages formed on the outer edge.

[0003] In addition, such filters generally include a reverse flow system configured to selectively reverse the flow in some sectors of the filter element in order to clear clogging of the filtering mesh in said sectors. However, alternating between normal and reverse flow imposes shear loads on the wires of the filtering mesh that are crossed by the radial ribs, which can break from fatigue after a number of cycles. In particular, this shear load is greatest at each location where the wires of the filtering mesh are crossed substantially orthogonally by the ribs of the filter element.

[0004] Furthermore, in such known filter elements, as clearly shown in Fig. 1, some radial ribs necessarily extend substantially orthogonally to that of the main mesh direction of the filtering mesh, which in the case of Fig. 1 are 45°, 135°, 225° and 315°, so that such radial ribs substantially orthogonally traverse a number of continuous wires along said ribs from the inner edge to the outer edge.

[0005] As a result, such configurations may, over time, result in an increasing number of successive wire breaks, and while such breaks do not substantially impede the filtering function of the filter element, they may ultimately reduce the life of the filter element.

[0006] Such a phenomenon is particularly relevant in more recent filter elements which, in addition to the usual radial ribs, include stiffening ribs. In fact, in such filter elements, each sector is reinforced by additional ribs extending radially and / or in an oblique direction, as disclosed, for example, in US Pat. No. 5,399,363. As a result, due to the increased number of ribs and the increased number of directions provided by these ribs, the possibility that some of these ribs will extend substantially perpendicular to the wires of the filtering mesh is even more increased. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] European Patent Application Publication No. 1091791 [Patent Document 2] European Patent Application Publication No. 3199219 Summary of the Invention [Problem to be solved by the invention]

[0008] Therefore, there is a need for new types of filters that have improved durability. [Means for solving the problem]

[0009] The present disclosure relates to a filter element having an inner surface, an outer surface, a filtering mesh, two concentric edges, an inner edge and an outer edge respectively, between which the filtering mesh extends, and a main rib provided on at least the inner surface, the main ribs extending substantially radially between the edges and distributed circumferentially to create sectors on the inner surface, the filter element being configured to be assembled to a corresponding filter element such that the inner surface faces the inner surface of the corresponding filter element, the main ribs defining the operating range of the sectors to circumferentially form partitions in the space between the inner surface and the corresponding filter element, the inner edges having inner passages each communicating with a corresponding one of the sectors, and at least one rib extending between the edges is a curved rib having a bend over its entire length.

[0010] The edges of the concentric circles are generally circular with respect to the central axis and are hereafter referred to as forming an axial direction. The main ribs are optionally regularly distributed in the circumferential direction to form sectors on said inner surface. The radial direction is the direction perpendicular to the central axis and intersects it. The axial plane is the plane that contains the central axis. The radial plane is the plane that is perpendicular to the central axis. The circumference is a circle contained in the radial plane and has its center at its central axis. The tangential or circumferential direction is the direction of a tangent to the circumference, which is perpendicular to the central axis but does not intersect it. As referred to herein, the corresponding filter element can be a filter element that is substantially similar or identical to the filter element, or a filter element that is not similar but has a complementary shape, in particular a filtering mesh that extends between concentric inner and outer edges. Such a corresponding filter element would likely have major ribs intended to contact major ribs on the inner surface of the filter element to form a compartment when the filter element and the corresponding filter element are assembled.

[0011] The main ribs are therefore substantially radially extending ribs. In particular, in the present disclosure, the direction of extension of any curved rib, or more generally of any curved portion, is defined as the direction of the chord of said curved rib, or more generally of said curved portion. Furthermore, since the outer edge is generally circular with respect to the central axis, the plane in which the outer edge extends is a radial plane.

[0012] Thanks to this filter configuration, which includes at least one curved rib, it is possible to prevent or at least reduce the tearing phenomenon mentioned above. Indeed, because the rib is curved, the number of continuous wires that are crossed orthogonally by the rib is necessarily reduced, so that the area that can be affected by a wire breakage is limited. In addition, because the rib is curved in each case, the longitudinal wires emerge regularly from the rib and combine with the transverse wires that are in danger of shearing, so that these longitudinal wires can bear part of the load that these transverse wires bear, which prevents the tear from spreading too far.

[0013] Thanks to this filter configuration, it is therefore possible to prevent or delay breakage of the wires of the filtering mesh, or at least to limit these breakages to very limited areas so that the filtering function of the filter element is not substantially hindered.

[0014] In the present disclosure, a curved rib is formed by a single curved section or by several curved sections connected by angular or singular points, in particular, this means that such a curved rib does not have any straight sections.

[0015] In some embodiments, each curved portion of such a curved rib locally has a radius of curvature that is at least 5 times larger than the pitch between two consecutive wires of the filtering mesh, preferably at least 10 times larger, but less than 100 times larger than this pitch.

[0016] In some embodiments, at least some of the main ribs, preferably most of the main ribs, or even all of the main ribs are curved ribs. Naturally, the more curved ribs and therefore the fewer straight ribs, the better the tearing phenomenon can be prevented.

[0017] In some embodiments, the main ribs include a first type of main rib that directly connects the inner edge and the outer edge, and a second type of main rib that connects the inner edge and the outer edge via eyelets that form assembly holes. As a result, it should be understood that the first type of main rib is devoid of eyelets. Such assembly holes allow several filter elements to be stacked by inserting an assembly rod into the assembly holes of each filter element. The contour of the eyelets thus forms a curved portion relative to the second type of main rib, etc. In this respect, it is preferred that the contour of such eyelets is circular.

[0018] In some embodiments, at least some of the first type of major ribs, preferably most of the first type of major ribs, or even all of the first type of major ribs are curved ribs.

[0019] In some embodiments, each of said curved main ribs of the first type comprises a single or two curved portions. Preferably, said curved main ribs of the first type comprise a single curved portion. A simple contour is preferred since it actually ensures a proper watertightness between the sectors.

[0020] In some embodiments, the at least two consecutive main ribs of a first type are curved ribs, and a recess in a first one of the two consecutive main ribs of the first type is oriented in the direction of a recess in a second one of the two consecutive main ribs of the first type.

[0021] In some embodiments, at least some of the second type of major ribs, preferably most of the second type of major ribs, or even all of the second type of major ribs are curved ribs.

[0022] In some embodiments, the curved major ribs of the second type each include an inner link connecting their eyelets to their inner edges, the inner links including a single curved portion.

[0023] In some embodiments, the inner links are substantially tangent to the contour of the eyelet, and when the filter element is made by injection, such a configuration facilitates spreading of the injection material towards the eyelet.

[0024] In some embodiments, the two consecutive main ribs of the second type are curved ribs, and the recess in an inner link of a first one of the two consecutive main ribs of the second type is oriented in the direction of the recess in an inner link of a second one of the two consecutive main ribs of the second type.

[0025] In some embodiments, the angle formed between the curved main rib and the inner edge is comprised between 60° and 85°, preferably between 75° and 85°. Such an angle range is a good compromise between the advantages of having an angle low enough to obtain a significant curvature and an angle high enough to facilitate the flow of injection material towards the rib during the manufacturing process.

[0026] In some embodiments, the angle formed between the first type of curved main rib and the outer edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0027] In some embodiments, at least some of the sectors, preferably most of the sectors, or even all of the sectors each comprise at least one stiffening rib connecting at least the main rib to the edge. Thanks to these stiffening ribs, the size of the filter element can be increased, the stiffening ribs can be smaller in size than the main ribs, and less material is required, so that the filtering mesh surface available for filtration is increased compared to prior art devices. Due to the increase in the available filtering mesh surface, the pressure loss is reduced. Furthermore, this configuration makes it possible to design filter elements made of materials with an inherently lower mechanical strength, but with a similar mechanical strength to filter elements without stiffening ribs. In particular, the filtering mesh has a lower resistance by itself, but is able to achieve the expected mechanical strength due to the stiffening ribs. Preferably, the surface of the stiffening rib is recessed with respect to the surface of the main rib, so that the influence of the stiffening rib on the filtered flow is reduced during the functioning of the filter.

[0028] In some embodiments, at least some of the stiffening ribs, preferably most of the stiffening ribs, or even all of the stiffening ribs are curved ribs.

[0029] In some embodiments, the stiffening ribs include a first type of stiffening rib that is not connected to any main rib of a second type, and a second type of stiffening rib that is connected to at least one main rib portion of the second type.

[0030] In some embodiments, at least one stiffening rib of the second type is connected to an eyelet of said main rib of the second type, which is preferred for most, or even all, of the stiffening ribs of the second type. If the filter element is made by injection, such a configuration facilitates spreading of the injection material towards the eyelet.

[0031] In some embodiments, both sides of each eyelet are connected in a manner by a second type of unique stiffening rib. Preferably, at least one of these stiffening ribs converges towards the eyelet from the inside. In fact, the injection of such a filter element is usually carried out from the inside towards the outside of the filter element. Preferably, at least one of these stiffening ribs contacts the contour of the eyelet. This can also facilitate the flow of the injection material during injection.

[0032] In some embodiments, at least one stiffening rib comprises several branches connected to both edges and to at least three, preferably four elements of both adjacent main ribs. Thanks to such a configuration, the filter element is further strengthened and the flow of the injection material during injection is made easier.

[0033] In some embodiments, the branches of at least one stiffening rib of the first type converge towards the branch connected to the outer edge, such an orientation reducing the effect of the stiffening ribs on the flow of the fluid being filtered during functioning of the filter.

[0034] In some embodiments, the branches of at least one stiffening rib of the second type converge towards the link connected to the inner edge, such an orientation facilitating the flow of injection material towards the outside of the filter element, and in particular towards the eyelets during injection.

[0035] In some embodiments, at least some of the stiffening ribs have a psi (Ψ)-like shape, including a central link connecting the inner and outer edges, and two converging links, each extending from a separate main rib and converging outwardly or inwardly to connect to the central link at preferably offset connection points. However, these connection points can also be common. The converging links preferably converge outwardly. Such a shape helps to facilitate outward flow of injection material during injection, while reducing the effect of the stiffening ribs on the flow of the fluid being filtered during functioning of the filter.

[0036] In some embodiments, at least some of the stiffening ribs include a central link connecting the inner and outer edges, branch links branching outwardly from the central link to connect a first main rib, and converging links converging outwardly from a second main rib to connect to the central link.

number

[0037] In some embodiments, the stiffening ribs divide the filtering mesh surface of the sector into areas of substantially similar size. In the present disclosure, substantially equal areas are areas that differ from each other by no more than 50%. In these embodiments, the stresses in the filtering mesh are therefore balanced between all regions.

[0038] In some embodiments, the ratio of the filtering mesh surface available for filtering to the total filtering mesh surface is at least 70%, preferably at least 75%. The special configuration of the stiffening ribs can increase the ratio of the filtering mesh surface available for filtering to the total filtering mesh surface to increase the efficiency of the filter element.

[0039] In some embodiments, the angle formed between the curved stiffening rib and the inner edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0040] In some embodiments, the angle formed between the curved stiffening rib and the outer edge is comprised between 60° and 85°, preferably between 75° and 85°.

[0041] In some embodiments, at least some of the main ribs, preferably most of the main ribs, or even all of the main ribs are connected to the inner edge between two consecutive inner passages.

[0042] In some embodiments, at least some of the stiffening ribs, preferably most of the stiffening ribs, or even all of the stiffening ribs are connected to the inner edge at the inner passage.

[0043] In some embodiments, the outer periphery includes exterior passages on an exterior surface thereof, such passages allowing filtered fluid to exit the filter element.

[0044] In some embodiments, at least some of the main ribs, preferably most of the main ribs, or even all of the main ribs are connected to the outer edge between two consecutive outer passages, which facilitates the flow of the filtered fluid towards the outlet passage, thus reducing the pressure loss during the functioning of the filter.

[0045] In some embodiments, at least some of the stiffening ribs, preferably most of the stiffening ribs or even all of the stiffening ribs are connected to the outer edge between two consecutive outer passages, which facilitates the flow of the filtered fluid towards the outlet passage and thus reduces the pressure loss during the functioning of the filter.

[0046] In some embodiments, the stiffening ribs extending on either side of one of the primary ribs are connected to said one primary rib at different radial positions. The stress in the primary rib is thus distributed over different positions. In addition, when the two filter elements are assembled relative to each other, the stiffening ribs of each filter element are at least partially shifted relative to each other, providing more room for fluid to flow and reducing pressure loss in the filter element.

[0047] In some embodiments, the inner and / or outer edges are circular. However, in other embodiments, the inner and / or outer edges are generally circular, but have a wavy profile. In fact, if the edge diameter is very large, the curvature of a circular edge becomes negligible at the mesh scale, and therefore such a wavy profile increases the curvature of the edge at a local scale without modifying the overall structure of the filter element at a global scale.

[0048] In some embodiments, the outer edge comprises recesses at least in the contact areas where the main ribs contact the outer edge. Such recesses can be provided on the inner and / or outer surface. Such recesses can limit the accumulation of the injection material during injection in parts of the filter element that would otherwise be particularly thick. Indeed, when too much injection material accumulates in small areas during injection, hot spots appear, slowing down the cooling of this mass of injection material, and then, although their periphery has already solidified, when these parts finally cool, a shrinkage phenomenon appears, which changes the intended dimensions of the final part. Such recesses can therefore prevent or at least reduce this shrinkage phenomenon.

[0049] In some embodiments, the outer edge comprises an indentation at least in the contact area of ​​a first type where a main rib of a first type contacts the outer edge. Preferably, said indentation is provided in the extension of said main rib of a first type. Preferably, the width of said indentation is equal to or less than the width of said main rib of a first type.

[0050] In some embodiments, the eyelets of at least one of the second type of major ribs, preferably most of the second type of major ribs, or even each of the second type of major ribs contact the outer edge.

[0051] In some embodiments, the outer edge comprises an axial recess at least in the second type of contact area where the eyelet contacts the outer edge. Preferably, for a given eyelet, an axial recess is provided on both the inner and outer surface. Preferably, the width of said axial recess is comprised between 50% and 100% of the inner diameter of the assembly hole.

[0052] In some embodiments, the inner edge comprises at least one relief provided on the outer surface at the rear of at least one inner passage. Said relief can be a protrusion or a recess. Such a relief forms an obstacle that slows down the flow of the injection material during injection. This helps to balance the spreading speed of the injection material on both sides of the filtering mesh. In fact, if the injection cavity fills more quickly on one side of the filtering mesh, a pressure will appear and push the filtering mesh towards the opposite side, which may change the correct position of the filtering mesh in the final part.

[0053] In some embodiments, the inner edge comprises two reliefs at the rear of each inner passage. Preferably, one of them is a protrusion and the other a recess, the shape of which is complementary to that of the protrusion. Thanks to this configuration, the protrusion of a filter element is received in the recess of the succeeding filter element, thus forming a labyrinth that improves the tightness of their interface.

[0054] In some embodiments, the filtering mesh has a conical shape, which allows for lower pressure loss near the inner passage and stronger connection between the edge and the filtering mesh, thus allowing more flow to be filtered through the filter.

[0055] In some embodiments, the major ribs also protrude into the outer surface to form sectors on said surface.

[0056] In some embodiments, the diameter of the outer edge may be comprised between 100 mm and 600 mm.

[0057] In some embodiments, the main ribs and / or stiffening ribs can be made from a polymer, but it is of course also possible to use more conventional materials for making ribs on filter elements, such as metals, and especially aluminum.

[0058] In some embodiments, the filtering mesh does not include a support mesh.

[0059] The present disclosure also relates to a set of filter elements according to any of the above embodiments arranged relative to one another so that their respective inner surfaces face one another and the contacting major ribs of said inner surfaces define a space between said inner surfaces.

[0060] The present disclosure also relates to a filter comprising a plurality of filter elements according to any of the above embodiments, said filter elements being stacked along an axis.

[0061] The above features and advantages, as well as others, will become apparent from the following detailed description of exemplary embodiments of the illustrated filter elements and filters, which description refers to the accompanying drawings, in which:

[0062] The invention and its advantages will be better understood on reading the following detailed description of embodiments of the invention given as non-limiting examples, this description making reference to the accompanying drawings, in which: [Brief description of the drawings]

[0063] [Figure 1] FIG. 1 shows a prior art filter element. [Diagram 2] 1 is a perspective view of an inner surface of an example filter element; [Diagram 3] FIG. 3 is a front view of the inner surface of the filter element of FIG. 2. [Figure 4] 3 is a perspective view of the exterior surface of the filter element of FIG. 2. [Diagram 5] FIG. 3 is a front view of the exterior surface of the filter element of FIG. 2. [Figure 6] FIG. 2 is a partial perspective view of a filter comprising two filter elements stacked on top of one another. [Figure 7] FIG. 7 is an enlarged view of Frame VII in FIG. [Figure 8] FIG. 4 is an enlarged view of Frame VIII in FIG. [Figure 9] FIG. 5 is an enlarged view of frame IX in FIG. [Figure 10] FIG. 2 is an exploded perspective view of a stack of filter elements. [Figure 11] FIG. 1 is a perspective view of a filter comprising multiple filter elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] An embodiment of a filter 100 comprising a filter element 10 will be described with reference to FIGS.

[0065] The filter element 10 according to the embodiment shown in Figures 2 to 5 has an inner surface 20, an outer surface 21, a filtering mesh 22 and two concentric circular edges, respectively an inner edge 24 and an outer edge 26, between which said filtering mesh 22 extends. The concentric circular edges 24, 26 are circular with respect to a central axis X, hereafter referred to as defining the axial direction. The inner edge 24 extends mainly in a plane perpendicular to the axial direction X, i.e. a radial plane. The outer edge 26 extends mainly in a plane perpendicular to the axial direction X, i.e. a radial plane.

[0066] In this embodiment, the diameter of the outer rim 26 is about 260 mm. Of course, other diameters are possible, including, for example, diameters ranging from about 100 mm to about 600 mm.

[0067] The filter element 10 includes major ribs 28 on at least the inner surface 20. In this embodiment, as shown in Figure 2, the major ribs 28 are correspondingly also provided on the outer surface 21. Thus, when three similar filter elements 10 are stacked, the two faces of the filter element in the middle of the stack, the inner faces of the two other filter elements, and the major ribs on each of these faces interact to form compartments.

[0068] The main ribs 28 extend radially between the inner edge 24 and the outer edge 26. The main ribs 28 are regularly distributed in the circumferential direction to form sectors on said inner surface 20, as shown in Figure 1. In this embodiment, the main ribs 28 also form sectors on said outer surface 21, as shown in Figure 2.

[0069] The inner edge 24 has inner passages 30 each communicating with a corresponding one of the sectors. The inner passages 30 are provided as notches or cutouts in the inner edge 24. The inner passages 30 are provided between successive main ribs 28. The inner passages 30 are provided in the inner surface 20. An abutment portion 31 is left on the inner edge 24 between each inner passage 30.

[0070] As shown in Fig. 2, the outer edge 26 has outer passages 32 each communicating with a corresponding one of the sectors. The outer passages 32 are provided as indentations or cutouts in the outer edge 26. At least one, and in this example preferably two, outer passages 32 are provided between successive main ribs 28. The passages 32 are provided in the outer surface 21. An abutment portion 33 is left on the outer edge 26 between each outer passage 32.

[0071] Some of the main ribs 28 connect the inner edge 24 directly to the outer edge 26 and are referred to as a first type of main ribs 28a. Other main ribs 28 connect the inner edge 24 to the outer edge 26 via eyelets 34 and are referred to as a second type of main ribs 28b.

[0072] The eyelets 34 are circular and form holes 36 for passing an assembly rod through them. The eyelets 34 are also configured to form male and female bushings for indexing the two filter elements 10 relative to each other.

[0073] In the non-limiting example shown, all of the major ribs 28 are curved along their entire length, i.e., from the inner edge 24 to the outer edge 26 .

[0074] In this particular example, as best seen in Figure 7, each main rib 28a of the first type comprises a single curved portion 51 extending from the inner edge 24 to the outer edge 26. The curved portion 51 therefore diverges from its chord 52.

[0075] However, it should be understood that other configurations are possible, for example such a rib could have an S-shape, i.e. it could comprise two curved portions connected by a bend point.

[0076] In this example, the first type of major ribs 28a are arranged in pairs, with the ribs of a given pair being symmetrical with respect to each other.

[0077] The areas where the first type of main ribs 28a contact the outer edge 26 are called first type contact areas 29a. Each first type contact area 29a comprises, at the junction between its outer surface and its exterior surface, a notch 71 formed in the outer edge 26. This notch 71 is provided in the extension of the rib 28a and has a width substantially equal to the width of the rib 28a.

[0078] As explained above, each second type main rib 28b includes an eyelet 34. More specifically, in each second type main rib 28b, the eyelet 34 contacts the outer edge 26, thus forming a second type contact area 29b. Additionally, each second type main rib 28b includes an inner link 38 connecting the inner edge 24 to the eyelet 34.

[0079] The inside link 38 includes a single curved portion 53 that extends from the inner edge 24 to the eyelet 34. The curved portion 53 therefore diverges from its chord 54.

[0080] This contour of the eyelet 34 therefore forms a second curved portion 55 connecting the first curved portion 53 to the outer edge 26, and therefore the second type of main rib 28b is also a curved rib within the meaning of the present disclosure.

[0081] In this example, the second type of major ribs 28b are arranged in pairs, the ribs of a given pair being symmetrical with respect to each other.

[0082] In addition, in each contact area 29b of the second type, two axial recesses 72, 73 are provided correspondingly on the inner surface 20 and on the outer surface 21. In particular, the axial recess 73 on the outer surface 21 is provided in the abutment portion 33 of the outer edge 26. The width of these axial recesses 72, 73 is substantially equal to the inner diameter of the hole 36.

[0083] In the non-limiting example shown, each filter element 10 has four eyelets 34 with bushings divided into 12 sectors and regularly spaced circumferentially. Such a filter element 10 therefore has eight main ribs 28a of the first type and four main ribs 28b of the second type. Depending in particular on its diametric dimension, a filter element can have fewer or more sectors. For example, a filter element with an outer diameter of 100 to 150 mm can have 8 to 12 sectors, a filter element with an outer diameter of about 300 mm can have 16 sectors and a filter element with an outer diameter of 500 to 600 mm can have 20 to 24 sectors.

[0084] The filter elements 10 can be manufactured by molding around the filtering mesh 22. In other words, they can be manufactured by injection molding or the like, the filtering mesh 22 forming an insert in the molding. The molded parts can be made of metal (e.g. aluminum alloy) or plastic material, in particular polymer. The main ribs 28 and the inner edge 24, as well as the outer edge 26, can be coated with an elastomer to avoid leakage between the filter elements 10.

[0085] Furthermore, as shown in figure 9, the outer surface 21 of the inner edge 24 is provided at the rear of the inner passages 30 with reliefs 74 each extending along the circumferential direction of the inner edge 24. In this example, two identical reliefs, which are recesses 74, are provided at the rear of each inner passage 30. However, in another example, the first relief can be a recess, while the second relief can be a protrusion with a shape complementary to that of the recesses.

[0086] During filter operation, the fluid to be filtered, e.g., oil or water, can enter filter 100 through inner passages 30 at inner edge 24 of filter element 10, pass across filtering mesh 22 from inner surface 20 to outer surface 21, whereby the liquid is filtered and exits filter element 10 through outer passages 32 at outer edge 26. The opposite flow direction is possible as well.

[0087] In addition, each one of the sectors comprises at least one stiffening rib 40 connecting at least the main rib 28 to at least the circular edges 24, 26. In this example, each stiffening rib 40 comprises several branches to connect with both adjacent main ribs 28 and with both circular edges 24, 26. Each stiffening rib 40 is connected to the inner edge 24 substantially in the middle of the inner passage 30 and to the outer edge 26 between two consecutive outer passages 32.

[0088] The stiffening ribs 40 are provided on both sides of the filtering mesh 22, i.e., on both the inner surface 20 and the outer surface 21. The stiffening ribs 40 have an axial thickness less than that of the main ribs 28, and therefore both sides of the stiffening ribs 40 are recessed relative to the surfaces of the main ribs 28.

[0089] Some stiffening ribs 40 are connected to at least the second type of main ribs 28b and are referred to as second type stiffening ribs 40b, 40b'. Other stiffening ribs 40 that are not connected to the second type of main ribs 28b are referred to as first type stiffening ribs 40a.

[0090] These stiffening ribs 40 can have different shapes, but are preferably curved over their entire length, which means that all branches of these stiffening ribs are curved. The branches can be connected to each other by angle points or by singular points, preferably by inflection points.

[0091] In this example, all of the first type of stiffening ribs 40a share the same configuration, having a psi-like shape. Specifically, such ribs comprise a central link 41 connecting the inner edge 24 and the outer edge 26, and two converging links 42, 43 that converge outwardly, each extending in an oblique direction from another adjacent main rib 28a and connecting with the central link 41 at its outer half. Preferably, the connection point 42a of the first converging link 42 is slightly offset outwardly with respect to the connection point 43a of the second converging link 43.

[0092] Here, the central link 41 comprises two curved sections connected by a bend point. Similarly, each of the convergent links 42, 43 comprises two curved sections connected by a bend point.

[0093] In this example, the second type of stiffening ribs 40b, 40b' can have two different configurations. Their half, identified by the reference 40b, has a psi-Ψ configuration similar to that described above for the first type of stiffening rib 40a, and therefore they each include a central link 41 and two converging links 42, 43. In such a case, the first converging link 42, which is preferably the link connected to the second type of main rib 28b, is connected to the eyelet 34 of said main rib 28b, preferably tangentially to the contour of the eyelet 34.

[0094] The other half, or second type, of stiffening rib, identified by reference 40b', is Aleph (

number

[0095] Here, the central link 44 comprises two curved sections connected by a bend point. As for the branching and converging links 45, 46, they may comprise one or two curved sections.

[0096] In this example, each main rib 28b of the second type has a stiffening rib 40b of psi-Ψ configuration on one side and an aleph (

number

[0097] As shown in Figures 2 to 5, the stiffening ribs 40 divide the filtering mesh surface of the sectors into substantially equal areas.

[0098] As shown in Fig. 6, the filter elements 10 are configured to be assembled relative to one another with their respective inner faces 20 facing one another to form spaces between them. Said spaces are bounded in the circumferential direction by the contacting main ribs 28 of said inner faces. On the other hand, the main ribs 28 provided on the outer face 21 do not have to be in contact with one another. The delimitation of sectors on the side of the filtering mesh 22 to which the liquid not to be filtered is led makes it possible to remove blockages of the filtering mesh 22 by backflow, as is known per se in the art.

[0099] Filter 100 is made by assembling together at least two filter elements 10 as shown in Figure 6. To obtain a filter of the desired filtering capacity, it is sufficient to stack and assemble together as many individual filters 100 as desired, similar to the filter shown in Figure 6.

[0100] The stiffening ribs 40 extending on either side of one of the main ribs 28 are connected to said one main rib 28 at another position in the radial direction. Thanks to this feature, when two filter elements 10 are assembled together with their respective inner surfaces 20 facing each other, the stiffening ribs 40 of each filter element 10 do not completely face each other in the axial direction. That is, when two filter elements 10 are assembled together with their respective inner surfaces 20 facing each other, the stiffening ribs 40 of the facing sectors of each filter element 10 are shifted relative to each other in a radial plane. Thus, the stiffening ribs of adjacent filter elements can have at least a portion that does not overlap in the axial direction, which facilitates the flow of fluid.

[0101] 10 shows a stack 102 comprising a plurality of filter elements 10 stacked along an axis X. The filter elements 10 are assembled in pairs, as previously described, with each identical, similar or complementary filter element 10. In each pair, the filter elements 10 are positioned relative to one another so that their respective inner surfaces 20 face one another and the contacting major ribs 28 of said respective inner surfaces 20 define spaces between said inner surfaces 20.

[0102] The assembly rods 104 are inserted into the holes 36 of the filter elements 10, thereby ensuring alignment and axial correspondence of the filter elements 10.

[0103] The filter 100 is shown in a perspective view in Figure 11. The filter 100 comprises a housing 110 in which a stack 102 of filter elements is arranged. The filter 100 thus comprises a plurality of filter elements 10, said filter elements being stacked along an axis X.

[0104] The filter 100 includes two inlet portions 112 and two outlet portions 114. The filter 100 may include one or more inlet portions 112 and / or one or more outlet portions 114. In this embodiment, the inlet portions 112 are fluidly connected to the passages 30 of the inner edge 24 of the filter element 10, while the outlet portions 114 are fluidly connected to the passages 32 of the outer edge 26. However, the flow direction within the housing 110 and stack 102 may be reversed.

[0105] The stack of filter elements 102 is secured to a housing 110 in a conventional manner.

[0106] Although the present invention has been described with reference to specific exemplary embodiments, modifications can be made to these examples without departing from the overall scope of the invention as defined by the claims. In particular, individual features of the various illustrated / described embodiments can also be combined in further embodiments. Thus, the description and drawings should be considered in an illustrative sense, and not in a limiting sense. [Explanation of symbols]

[0107] 10 Filter Elements 20. Inside 21 Exterior 22 Filtering Mesh 24 Inner edge 26 Outer edge 28 Main Rib 28a First type of main rib 28b Second type of main rib 29a First type of contact area 29b Second type of contact area 30 Inner passage 31 Contact part 32 Outside passage 33 Contact part 34 Eyelet 36 holes 38 Inner Link 40 Stiffening rib 40a First type stiffening rib 40b Second type stiffening rib 40b' Second type stiffening rib 41 Central Link 42 First Converging Link 42a Connection point 43 Second Converging Link 43a Connection point 44 Central Link 45 Branch Link 46 Converging Links 51 Curved Part 52 strings 53 First curved portion 54 strings 55 Second curved section 72 Axial recess 73 Axial recess 74 Relief 71 Notch 100 Filters 102 Stack 104 Assembly Rod 110 Housing 112 Inlet section 114 Outlet section X central axis

Claims

1. 1. A filter element (10) having an inner surface (20), an outer surface (21), a filtering mesh (22), concentrically arranged inner and outer edges (24) and (26) between which the filtering mesh (22) extends, and a main rib (28) on at least the inner surface (20), the main ribs (28) extend generally radially between the inner edge (24) and the outer edge (26) and are configured to be circumferentially distributed to form sectors on the inner surface (20); the filter element (10) is configured to be assembled to a corresponding filter element such that the inner surface (20) faces the inner surface of the corresponding filter element; the major ribs (28) defining the sectors act to circumferentially define compartments in the space between the inner surface and the corresponding filter element; the inner edge (24) having an inner passage (30) communicating with each of the sectors; A filter element (10) wherein at least one rib (28, 40) extending between said inner edge (24) and said outer edge (26) is a curved rib that is curved along an entire length of said rib.

2. 2. The filter element of claim 1, wherein at least some of the main ribs (28), preferably most or all of the main ribs (28) are curved ribs.

3. 3. The filter element of claim 1, wherein the main ribs (28) include a first type of main rib (28a) directly connecting the inner edge (24) and the outer edge (26) and a second type of main rib (28b) connecting the inner edge (24) and the outer edge (26) through eyelets (34) forming assembly holes (36).

4. at least some of the main ribs (28a) of the first type, preferably most or all of the main ribs (28a) of the first type, are curved ribs; 4. The filter element of claim 3, wherein each of the first type of curved major ribs (28a) comprises a single curved portion.

5. at least some of the second type of main ribs (28b), preferably most of the second type of main ribs (28b) or all of the second type of main ribs (28b) are curved ribs; each of the second type of curved main ribs (28b) includes an inner link (38) connecting the eyelet (34) of the main rib to the inner edge (24), the inner link (38) including a single curved portion; The filter element of claim 3 or 4, wherein the inner link (38) is substantially tangent to the contour of the eyelet (34).

6. at least some of said sectors, preferably most or all of said sectors, each comprise at least one stiffening rib (40) connecting at least a main rib (28) to said inner edge (24) or said outer edge (26); A filter element according to any one of claims 1 to 5, wherein at least some of said stiffening ribs (40), preferably most of said stiffening ribs (40) or all of said stiffening ribs (40) are curved ribs.

7. the stiffening ribs (40) include a first type of stiffening rib (40a) that is not connected to any of the second type of main ribs (28b) and a second type of stiffening rib (40b, 40b') that is connected to at least one of the second type of main ribs (28b); A filter element according to claims 3 and 6, wherein at least one said second type of stiffening rib (40b, 40b') is connected to an eyelet (34) of said second type of main rib (28b).

8. 8. A filter element according to claim 6 or 7, wherein at least some of the stiffening ribs (40a, 40b) have a psi (Ψ)-like shape, preferably at offset connection points (42a, 43a), the psi (Ψ)-like shape including a central link (41) connecting the inner edge (24) and the outer edge (26) and two converging links (42, 43) extending from another main rib (28) and converging outwards or inwards to connect to the central link (41).

9. At least some of the stiffening ribs (40b') are [0010] ) shape, and the aleph ( [0025] 9. The filter element of claim 6, wherein the axially extending (A)-axially extending (B) shape includes a central link (44) connecting the inner edge (24) and the outer edge (26), branch links (45) branching outwardly from the central link (44) to connect to first major ribs (28), and converging links (46) converging outwardly from second major ribs (28) to join the central link (44).

10. A filter element according to any one of claims 6 to 9, wherein said stiffening ribs (40) divide the filtering mesh surface of said sectors into areas of approximately equal size.

11. 11. A filter element according to any one of the preceding claims, wherein the outer edge (26) is provided with recesses (71, 72, 73) at least in the contact areas (29a, 29b) where the main ribs (28) contact the outer edge (26).

12. 12. The filter element according to any one of claims 1 to 11, wherein the inner edge (24) comprises at least one relief (74) provided on the outer surface (21) at the rear of at least one inner passage (30).

13. The filter element according to any one of the preceding claims, wherein the main ribs (28) and / or the stiffening ribs (40) are made of a polymer.

14. 14. A set of filter elements according to any one of claims 1 to 13, wherein the filter elements are arranged relative to one another such that the inner surfaces of the filter elements face one another and such that the main ribs (28) in contact with each other of the inner surfaces (20) divide a space between the inner surfaces (20).

15. A filter (100) comprising a plurality of filter elements according to any one of claims 1 to 13, said filter elements (10) being stacked along an axis (X).

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