FILTER CARTRIDGE FOR FILTER UNIT

Description

1. Scope of the invention

[0001] The invention relates to the field of design and manufacture of filter cartridges that can be fitted to filtering assemblies used to filter fluids circulating in engines or hydraulic equipment.

[0002] Such filter assemblies consist of a filter body, comprising a tank and a lid, inside which is placed the filter cartridge containing a filter medium, generally cylindrical in shape surrounding a tubular lumen, which may be made, for example, of paper, cardboard, felt, or another porous material, such as a synthetic non-woven fabric. The filter cartridge also includes two end flanges that define the boundaries of the filter medium.

[0003] Such filter cartridges generally cooperate with a tube, particularly a central one, attached or not to the flanges, whose outer diameter is close to the inner diameter of the tubular light surrounded by the filter medium, so as to limit the deformations of the medium under the effect of the pressure exerted inside the filter assembly.

[0004] The end flanges are formed by a first flange, which may be an upper flange, and a second flange, which may be a lower flange. The role of the flanges is to contribute to the sealing of the filter cartridge and to allow the filter cartridge to be secured to the permanent part of the filtration assembly. 2. Prior art solutions

[0005] US patent 5,770,054 describes a filter assembly in which the central tube houses a valve obturator and a return mechanism, while the filter cartridge, in its upper flange, defines a valve seat surrounding an opening. The obturator is arranged to contact the valve seat in a closed position. When the filter cartridge is replaced, the valve seat is replaced, while the obturator and return mechanism remain permanently attached to the central tube. A drawback of such a system is that the obturator in the closed area becomes contaminated and remains so even after the filter cartridge is changed. Another filter assembly of this type is described in document DE 10 2009 033263 A1.

[0006] Other filter assemblies exist where the safety valve, including the valve seat, the obturator element, and the return mechanism, is fully integrated into the filter cartridge. Such assemblies generate high maintenance costs. The filter cartridge is then not incinerable.

[0007] Another set of filtering methods is described, for example, in document US 2008 / 308486 A1. 3. Objectives of the invention

[0008] The invention therefore aims in particular to overcome all or part of these drawbacks of the prior art.

[0009] More specifically, the invention aims to provide a high-performance filtration system while limiting the cost of maintenance and replacement of the filter cartridge.

[0010] The invention also aims to provide an incinerable filter cartridge, in particular one free of metallic parts.

[0011] The invention also aims to provide a filter cartridge that is adaptable to different valve opening threshold pressures, without modification of the rest of the filter assembly.

[0012] The invention thus aims to provide a user with the possibility of choosing a type of filter cartridge, depending on the desired valve opening threshold pressure, without modifying the permanent part of the filter assembly. 4. Description of the invention

[0013] The invention meets all or part of these objectives by means of a filter cartridge exposed in the attached set of claims.

[0014] According to an aspect not forming part of the claimed invention, the disclosure relates to a filtering assembly for filtering at least one fluid circulating particularly in an engine or hydraulic equipment, comprising: a filter body, a tube inside the filter body, a removable filter cartridge housed in the filter body and comprising: ▪ a first and a second flange, ▪ a filter medium having a tubular lumen to surround the tube and extending between the first and second flanges, the first flange comprising a valve seat through which at least one orifice communicates with the tubular lumen, and ▪ a valve obturator element integral with the first flange so as to cooperate with the valve seat, the obturator element being configured to occupy at least two positions, namely a closed position, in which the obturator element obturates the valve seat and at least one open position in which the obturator element allows the passage of fluid through the valve seat, a return member, separate from the filter cartridge,configured to act by returning the shutter element to the closed position.

[0015] Thanks to the invention, the filter cartridge includes both the obturator element and the valve seat so that this set of two parts, soiled during the use of the filter assembly, is replaced with the filter cartridge.

[0016] It should be noted that the return element belongs to the permanent part of the filter assembly, as does the filter body and the central tube located inside the filter body.

[0017] Another advantage of the invention is that simply modifying the dimensions of the obturator element allows the opening pressure threshold of the valve formed by the valve seat, obturator element, and return mechanism to be adjusted according to the user's requirements, without altering the permanent part of the filter assembly. The same filter assembly can thus be modified in its performance, without having to change the permanent part, but only the removable part of the filter assembly, namely the filter cartridge.

[0018] According to the invention, inside the tubular portion and in the opening, for example circular, the obturating element is retained while being mobile in translation between a position corresponding to the closed position and a position corresponding to an open position of the valve.

[0019] Thus, the first flange and the obturator element cooperate to allow the obturator element to perform its function of opening and closing the valve, depending on the pressure exerted by the fluid on the obturator element and, in reaction, on the force of the return mechanism exerted on the opposite side of the obturator element. It is the return mechanism that forces the obturator element into the closed position when the pressure exerted on the opposite side of the obturator element is below a predetermined pressure threshold.

[0020] In this case, the opening can, for example, be defined by a tubular section, and a protruding element of the obturator element can abut against an internal shoulder of the tubular section during assembly. This allows a limit to be set on the opening of the obturator element in its maximum open position during assembly, and retains the obturator element on the first flange and therefore on the filter cartridge. During use, this maximum opening may not be reached, as some play can be maintained between the obturator element and the protruding element. To achieve this, the obturator element can, for example, be held against the tube to create this play and prevent the obturator element from reaching its maximum open position.

[0021] The opening can, particularly in this case, be confused at least partially with the orifice passing through the valve seat and closed by the obturator element in its closed position.

[0022] It should be noted that the orifice through the valve seat may be several orifices, or a single orifice, which is closed by the sealing surface when the sealing element is in the closing position or closed position.

[0023] In another example not covered by the claimed invention, the opening is distinct from said at least one orifice passing through the valve seat and through which the fluid can pass, in the open position of the obturator element.

[0024] The obturator element may include a skirt having the obturator surface suitable for coming into contact with the valve seat, in the closed position of the obturator element.

[0025] The tube can be at least partially hollow and the return mechanism can be mounted inside the tube.

[0026] In a preferred embodiment, the return element comprises a spring, in particular a helical spring. However, the invention is not limited to a helical spring. In particular, the return element may comprise a leaf spring or an elastic material.

[0027] In a particular embodiment, the tube of the filter assembly may have a free end forming at least partially an edge extending diametrically inwards so as to retain the return member coming against said edge.

[0028] The tube may, alternatively, include, in a free end portion, a housing configured to house and retain the return mechanism, without however preventing it from fulfilling its role of returning the obturator element to the closed position.

[0029] The obturator element may include a cooperation zone with the return member, comprising a support surface for the return member and / or a guiding zone for the return member.

[0030] In summary, the obturator element comprises, according to one embodiment of the invention, a zone for securing with the first flange, a zone for obturating the valve seat and a zone for cooperating with the return member.

[0031] The filter body advantageously comprises a tank and a lid including means of cooperation between them which are sealed but removable, so as to allow the replacement of the filter cartridge.

[0032] The filtration medium may be chosen from the group consisting of: cellulose, in particular paper or cardboard, felt, a woven or non-woven porous material, synthetic or non-synthetic, and any other suitable filtration medium.

[0033] The shutter element may be made of a polymer material, in particular polyamide. Advantageously, the shutter element is made of an incinerable material. 5. List of figures

[0034] Other features and advantages of the invention will become clearer upon reading the following description of embodiments of the invention, given by way of illustrative and non-limiting examples, and the accompanying drawing in which: there figure 1 represents a schematic cross-section of a filtering assembly according to a first embodiment of the invention, the figure 2 illustrates in isolation, in schematic cross-section, the filter cartridge of the filter assembly of the figure 1 , there figure 3 is a schematic cross-sectional view of a permanent part of the filter assembly of the figure 1 , lacking the filter cartridge, the Figures 4 and 5illustrate schematically and partially, in cross-section, the filtering assembly of the figure 1 during its operation, the figure 6 schematically illustrates, in isolation and partially, in cross-section and perspective, the tube of the filter assembly of the figure 1 , there figure 7 is a view similar to the figure 6 , the return mechanism being further positioned within the tube, the figure 8 illustrates schematically and partially a filtering assembly seen in cross-section and conforming to a second embodiment not covered by the claimed invention, the figure 9 schematically and partially represents the valve portion of the filter assembly of the figure 8 , there Figure 10 represents, schematically and in perspective, viewed from below, the first flange fitted with the shutter element of the filter assembly of the figure 8 , and the figure 11represents, schematically and in perspective, viewed from above, the first flange fitted with the shutter element of the filter assembly of the figure 8 . 6. Detailed description of embodiments of the invention

[0035] We have represented on the figure 1 A filter assembly 1 for fluid circulating in an engine or hydraulic equipment. This filter assembly 1 comprises a filter body 2 having a bowl 3 and a cover 4. The filter body 2 delimits a volume 5 within which the filter assembly 1 includes a tube 6, central in this example. The filter assembly 1 also includes a filter cartridge 7 shown separately in the diagram. figure 2 .

[0036] Tank 3 has an internal thread 8 and lid 4 has an external thread 9 which can be screwed onto the internal thread 8 of tank 3 so as to close the filter assembly 1. The sealing of the filter assembly 1 is further ensured by at least one annular seal 10, inserted between the lid 4 and tank 3. It is therefore relatively easy to unscrew the lid 4 and the tank 3 from the filter body 2 in order to remove the filter cartridge 7 when it is used and replace it with a new filter cartridge 7.

[0037] The filter cartridge 7 comprises a first flange 11, called the upper flange, and a second flange 12, called the lower flange. The filter cartridge 7 further comprises a filter medium 13, generally cylindrical in shape, having a tubular opening 14 to surround the tube 6, as illustrated in the figure 1The filtration medium 13 extends longitudinally, along a longitudinal axis X, between the first flange 11 and the second flange 12. The first flange 11 includes a valve seat 15 through which an orifice 16 passes, communicating with the tubular lumen 14.

[0038] The second flange 12 incorporates in a housing an o-ring 22 forming the seal in the lower part of the filter cartridge 7.

[0039] As can be seen on the Figures 1 , 3 , 6 and 7 , the tube 6 has an external relief consisting, in this example, of a plurality of fins 71 inclined to retain the filtering medium 13 while allowing the passage of fluid.

[0040] Tube 6 is attached to tank 3 of filter body 2 at the lower part thereof, in particular by snap-fitting or otherwise, the seal being ensured by the presence of seals visible in these figures including seal 22, in this example.

[0041] The filter cartridge 7 further includes a valve obturator element 20 attached to the first flange 11 and suitable for cooperating with the valve seat 15. The obturator element 20 is thus configured to occupy two positions, namely a closed position in which the obturator element 20 obturates the valve seat 15 and at least one open position in which the obturator element 20 allows the passage of fluid through the valve seat 15.

[0042] The filter assembly 1 further includes a return member 21 formed in this example by a spring, separate from the filter cartridge 7, and configured to act by returning the shutter element 20 to the closed position.

[0043] It should be noted that the filter assembly 1 according to the invention comprises a permanent part including the filter body 2, the tube 6 and the return member 21, and a removable part including the filter cartridge 7 comprising the first and second flanges 11 and 12, the filter medium 13 and the obturator element 20.

[0044] Thus, according to the principle of the invention, the safety valve formed of the following three elements, namely the valve seat 15, the obturator element 20 and the return member 21, is made up partly of removable elements forming part of the filter cartridge 7, namely the valve seat 15 and the obturator element 20 and partly of permanent elements, namely the return member 21, which remains in place when the filter cartridge 7 is replaced.

[0045] An advantage of the filter assembly 1 according to the invention is that it allows the obturating area formed by the contact area between the valve seat 15 and the obturating element 20 to be completely replaced, which can become soiled during the use of the filter assembly 1. This soiled area will be completely replaced by a clean contact area when the filter cartridge 7 is replaced.

[0046] Another advantage of the invention is that the return element 21 remains permanently in the filter assembly 1 and is not replaced, thus limiting the number of component parts of the filter cartridge 7. The return element 21 may become contaminated, but this does not impair the operation of the motor.

[0047] The return element 21 may be at least partially metallic. In this case, the filter cartridge 7, lacking any metallic part, is incinerable.

[0048] In the illustrated example, the first flange 11 comprises a tubular portion 25, central in this example, at least partially hollow, extending, in the illustrated example, around an opening corresponding to the orifice 16. Inside this tubular portion 25 and within this opening, the obturator element 20 is retained while remaining free to move in translation along the longitudinal axis X between a position corresponding to the closed position and a position corresponding to the open position of the valve. The obturator element 20 comprises at least one projecting element 26, consisting of a plurality of tabs in the illustrated example, which can abut against an internal shoulder 27 extending internally around the periphery of the tubular portion 25.

[0049] The obturator element 20 further comprises a skirt 30 extending circumferentially outwards, substantially perpendicular to the axis X. The skirt 30 has the obturator surface 31 adapted to come into contact with the valve seat 15 in the closed position of the obturator element 20.

[0050] As seen on the figures 3 , 6 and 7 , the tube 6 has a free end 40 forming at least partially an edge 41 extending diametrically, as visible on the figures 6 and 7 , inwards so as to retain the return element 21, in this case the spring, which comes to rest against this edge 41 by its first end 42. It should be noted that the edge 41 consists, in this example, of the end of an upward extension formed here of four rods 72, as illustrated and partially visible on the figures 6 and 7in particular. The presence of these rods 72 gives a certain elasticity to this portion of the tube 6. However, it could be otherwise without departing from the scope of the invention.

[0051] The opposite end or second end 43 of the return member 21 is held inside the tube 6, as illustrated in the figure 7 In the illustrated example, four lugs 70 are present on an inner surface of the tube 6, two of which are visible on the figures 6 and 7 , allow the retention in the lower part, at the second end 43, of the return member 21.

[0052] In the illustrated example, the skirt 30 includes, in addition to the sealing surface 31 and opposite it, a contact surface 32 with the edge 41 of the tube 6.

[0053] The shutter element 20, still in this illustrated example, has a guide zone 35 for the return member 21. As illustrated, the area for attaching the shutter element 20 to the first flange 11 is located on one side of the skirt 30 corresponding to the shuttering surface 31, while the guide zone 35 for the return member 21 is located on the opposite side of the skirt 30, on the side of the contact surface 32.

[0054] The shutter element 20 also includes a bearing surface 45, visible in particular on the Figures 4 and 5 forming in this example a shoulder perpendicular to the longitudinal axis X extending around the guide area 35. This bearing surface 45 is the contact area, in this circular example, between the obturator element 20 and the return member 21.

[0055] The obturator element 20 also includes a pressure zone 44, this zone being in contact with the fluid which tends to open, by a pressure P, the valve and to place the obturator element 20 in the open position. The pressure zone 44 is illustrated in the figure 2 by a double arrow extending over the entire contact area between the fluid tending to open the valve and the obturator element 20. This pressure area 44 extends in this example, as can be seen, essentially perpendicular to the X axis along a diameter corresponding to that of the orifice 16.

[0056] In this example, the shutter element 20 thus comprises, as illustrated on the figure 2 : a zone I of attachment with the first flange 11, this attachment zone including in particular the surface of the obturator element 20 forming the pressure zone 44; a zone K of cooperation with the return member 21 including the guide zone 35 and the bearing surface 45; between these two zones, a sealing zone J including the skirt 30.

[0057] THE Figures 4 and 5 illustrate the operation, schematically, of the safety valve formed by the valve seat 15, the obturator element 20 and the return member 21.

[0058] There figure 5This illustrates the case where the safety valve is open, in the case of a cold fluid, particularly cold oil, whose viscosity is such that it cannot pass through the filter medium 13. In this case, it forces the pressure P it exerts on the pressure zone 44 of the obturator element 20 to place it in an open position, allowing the fluid to flow. At the end of the filter cartridge 7's service life, when it becomes clogged, the obturator element 20 also moves to the open position. It should be noted that in the open position illustrated in the figure 5 The contact surface 32 comes into contact with the edge 41 of the tube 6, while the bearing surface 45 comes against the upper part of the return member 21, as can be seen. The fluid passes through the open valve as illustrated in this figure.

[0059] There figure 4 illustrates the cartridge in operation, at the end of its life. Debris D is present, as illustrated on the figure 4 Around the sealing surface 31, which can create a leak L (also illustrated in this figure), the pressure P exerted on the sealing element 15 by the fluid is countered by the force exerted by the return mechanism 21, such that despite the leak L, the sealing element 20 remains in the closed position. In this configuration, the pressure P does not reach the predetermined pressure threshold required to open the valve's sealing element. As illustrated in this figure, a dirty fluid enters the filtration medium 13 externally along the arrows A; the dirty fluid is represented by dark particles M.

[0060] The filtered, clean fluid, illustrated by clear N particles, then enters tube 6 and flows downwards along arrow O.

[0061] Replacing the filter cartridge 7 allows for a clean sealing surface again, free of debris D.

[0062] It should be noted that the opening threshold pressure at which the shutter element 20 opens can be modulated by widening or narrowing the diameter R of the pressure zone 44 of the shutter element 20, visible on the figure 2 Increasing this diameter reduces the opening pressure threshold required for the valve to open. Conversely, decreasing it increases the opening pressure threshold required for the valve to open.

[0063] Furthermore, the length H along the longitudinal axis X of the shutter element 20, visible on the figure 5 The length H, between the contact surface 32 and the bearing surface 45, can be modified to modulate the threshold pressure required to open the valve, i.e., to move the obturator element 20 into an open position. The greater this length H, the higher the valve opening threshold pressure.

[0064] It should also be noted that after the filter cartridge 7 is mounted in the permanent part of the filter assembly 1, the shutter element 20 never reaches, in this example, the maximum opening position illustrated on the figure 2 when the filter cartridge 7 is not yet mounted on the rest of the filter assembly 1. Indeed, once the filter cartridge 7 is mounted, the dimensions of the elements are chosen so as to leave a gap between the inner shoulder 27 of the first flange 11 and the protruding element 26, due to the retention formed by the edge 41 against the contact surface 32.

[0065] We have represented on the figures 8 to 11 a second example of an embodiment not covered by the claimed invention.

[0066] In this embodiment, the tube 6 has, in a free end part 50, a housing 51 configured to house and retain the return member 21. This housing 51 has a bottom wall 52, perpendicular to the X axis, cutting the tube 6 in its length.

[0067] In this example as well, the first flange 11 has a plurality of openings 55 and 60. One of these openings, 55, central, allows the retention of the shutter element 20 while leaving it mobile in translation between a position corresponding to the closed position and a position corresponding to an open position.

[0068] Furthermore, around this opening 55, are arranged a plurality of openings 60 visible in particular on the figure 11 In the illustrated example, there are three openings, forming the fluid passage when the obturator element 20 is in the open position. These openings 60 are formed peripherally around the opening 55.

[0069] In this example as well, the skirt 30 has on one side the sealing surface 31 and, on the opposite side, the contact surface 45 with the return member 21.

[0070] It should be noted that in this embodiment, the opening 55 in the first flange 11 allowing the retention of the obturator element 20 is distinct from the orifices 60 allowing the passage of fluid in the absence of obturator, i.e. in the open position.

[0071] Throughout the description, the expressions "containing a" or "comprising a" should be understood as synonymous with the expressions "containing at least one" and "comprising at least one" respectively, unless otherwise specified.

Claims

1. Filter cartridge (7) being able to equip a filter assembly (1) to filter at least one fluid (F), the filter cartridge (7) being configured to be removably housed in a filter body (2) of the filter assembly (1), the filter cartridge (7) comprising: • a first and a second flange (11; 12), • a filter medium (13) having a tubular light (14) being able to surround a tube (6) located inside the filter body (2), the tube (6) having a free end (40) forming at least partially one edge (41) extending diametrically towards the inside, the filter medium (13) extending between the first and the second flange (11; 12), the first flange (11) comprising a valve seat (15) passed through by at least one orifice (16) communicating with the tubular light (14) and a tubular portion (25) extending around an opening corresponding to said at least one first orifice (16) and having an internal shoulder (27) extending internally over the perimeter of the tubular portion (25), and • a valve blocking element (20) secured to the first flange (11), so as to engage with the valve seat (15), the blocking element (20) being configured to occupy at least two positions, namely a closing position, in which the blocking element (20) blocks the valve seat (15), and at least one opening position, in which the blocking element (20) enables the passage of fluid (F) through the valve seat (15), the blocking element (20) comprising: • a blocking surface (31), capable of coming into contact with the valve seat (15), in the closing position of the blocking element (20), • a zone for securing to the first flange (11) provided with a side of the blocking element (20) corresponding to the blocking surface (31), • a contact surface (32) opposite the blocking surface (31), the contact surface (32) intended to come into contact with the edge (41) of the tube (6) when the filter cartridge (7) is housed inside the filter body (2) and the valve blocking element (20) is in the at least one opening position, and • a guide zone (35) located on the side of the contact surface (32), said guide zone being configured to guide a return member (21), the blocking element (20) being able to be returned into the closing position by the return member (21), distinct from the removable filter cartridge (7), the return member (21) being retained by a first end of the return member (21) abutting against the edge (41) of the tube (6), inside the tubular portion (25) and in the opening (16), the blocking element (20) is retained, while being movable in translation between a position corresponding to the closing position and a position corresponding to the at least one opening position, where the opening (16; 55) is delimited by the tubular portion (25), and in which the zone for securing to the first flange (11) comprises a projecting element (26), consisting of a plurality of strips which abut against the inner shoulder (27) of the tubular portion (25) in a maximum opening position.

2. Filter cartridge according to claim 1, wherein the blocking element (20) comprises a skirt (30) having the blocking surface (31).

3. Filter cartridge according to any one of the preceding claims, wherein that the filter medium (13) is chosen from the group consisting of: cellulose, in particular paper or cardboard, felt, a woven or non-woven material, and a synthetic or non-synthetic porous material.

4. Filter cartridge according to any one of the preceding claims, wherein the blocking element (20) comprises a polymer material, in particular, polyamide.

5. Filter cartridge according to any one of the preceding claims, with no metal parts, so as to provide an incinerable filter cartridge.