FILTER ELEMENT ANTI-FORGETTING SYSTEM

Abstract

FILTER ELEMENT ANTI-FORGET SYSTEM One aspect of the invention relates to a secure filter support device for a turbomachine comprising a cover and a filter absence detector (4), comprising a detector body (42) mounted on the cover (2) by closing the opening, a movable piston (43), comprising a filter stop (431) for being in contact with a filter (30) in a presence position, a piston return spring (44) between the detector body (42) and the piston (43) exerting a spreading force on the piston (43) towards and down to an absence position, and a position detector (45) comprising a detection element for detecting a part having a material detectable by the detector, in particular in ferromagnetic or magnetic material (432) in a presence position and producing a filter absence signal when the detectable part (432) is distant from the position detector (45). Figure to be published with the abbreviation: Figure 3

Description

Title of the invention: ANTI-FORGETTING SYSTEM FOR A FILTER ELEMENT TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of the oil and fuel circuits of turbomachinery.

[0002] The present invention relates to a secure filter support device for a turbomachine, a filtering device, a turbomachine assembly, and an associated turbomachine. The invention also relates to a method for mounting a turbomachine assembly. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Typically, turbomachinery includes oil and fuel circuits which use filter elements (or filters) to protect the downstream components in the circuits. The filtration systems of these circuits generally include a filter support cooperating with a removable filter (or filter cartridge).

[0004] It sometimes happens that the filtration system is installed even though no filter has been placed in said system. Operating the turbomachine without a filter element can lead to engine malfunctions, including uncommanded in-flight shutdown.

[0005] Solutions are known to prevent the turbomachine from being put into service without a filter.

[0006] For example, screwing a drain plug onto a filter cartridge is a known solution. The drain plug cannot be screwed on if the filter cartridge is absent. If the drain plug is not screwed on, a significant oil or fuel leak will be quickly detected. However, this solution only allows the leak to be detected during the turbomachine's commissioning.

[0007] Document FR2928559 filed by the applicant describes a deformable pin comprising, on the one hand, a locating feature having a curved end which, in a position without a filter, protrudes from an edge of a filter support, and on the other hand, a finger extending along the bottom of the filtration system, allowing the curved end to be moved into a mounting position when a filter is installed in the system. The finger is pushed back by the filter and forces the locating feature to retract into the mounting position so that its end no longer protrudes radially, thus allowing the filtration system to be mounted. However, the pin is removable, and in the absence of the deformable pin, the filtration system can be mounted without a filter. Furthermore, it is easy for an operator to force the pin into the position of assembly for inserting the system into a turbomachine cylinder head.

[0008] Another solution described in application FR2205455 filed by the applicant includes an anti-forcing filter presence device mounted on the support, comprising a locking finger movable between an extended position and a final position when a filter is installed, such that in the extended position the locking finger protrudes radially from the support and an anti-retraction pin comprising a first blocking protrusion, the anti-retraction pin being movable between a free position and an occupied position when a filter is installed, such that in a position without a filter, the anti-retraction pin is in the free position, the locking finger in the extended position, so that the first blocking protrusion prevents the locking finger from being pushed towards the final position.

[0009] However, such a solution results in a radial space to access the locking finger protruding radially from the filter support.

[0010] Another solution is to modify the filter element by including an additional part to allow a sensor to detect the filter element. However, this solution implies changing the entire range of filter elements, increasing the price of consumables, and furthermore, it will not work if an older generation filter element (without the additional part) is inserted.

[0011] Thus, existing solutions do not allow the absence of an old generation filter element to be prevented without radially cluttering the system and without simulating the presence of a filter element in order not to prevent the absence. Summary of the invention

[0012] The invention offers a solution to the problems mentioned above, by detecting the position of a movable piston according to the presence or absence of the filter element.

[0013] A first aspect of the invention relates to a secure filter support device for a turbomachine comprising a cover having an opening along an axis, configured to be mounted with a filter element closing a housing of a filter of the filter element, characterized in that the secure filter support device comprises a filter absence detector comprising: • a detector body mounted on the cover closing the opening, • a movable piston, between a presence position and an absence position, comprising a filter stop to be in contact with the filter in the presence position, and a detectable part, • a piston return spring between the detector body and the piston exerting a displacing force on the piston towards and up to the absence position, and • a position detector mounted on the detector body, comprising a sensing element sensitive to the material of the detectable part in order to detect the detectable part when the piston is in a presence position and produce a filter absence signal when the detectable part is away from the sensing element beyond a predetermined position located between the presence position and the absence position of the piston.

[0014] The location of the filter absence detector on the lid allows for easy adaptation to any lid, as demonstrated in the detailed description, and enables the detection, without any physical modification of the filter element, that the secure filter support device is without a filter element. Furthermore, the invention avoids simulating the presence of a filter element by using the movable piston constrained in an absence position by the return spring when the secure filter support device is without a filter element. The position detector signals the absence as soon as the detectable portion of the piston in a material detectable by the detector, for example, ferromagnetic or magnetic, is too far away to be detected as being in the presence position. Thus, the filter absence detection device is not a filter presence detection device but rather an absence detection device. This avoids permanently simulating the presence of the filter.The detector can be either mechanical, using a ferromagnetic or magnetic sensing element, or electrical, using a sensor-like sensing element, or both, comprising both a sensor and a ferromagnetic component. The signal can therefore be a visible mechanical signal, an electrical signal, or a combination of both. Furthermore, in the case of incorrect mounting of the filter element, the moving piston is positioned away from its location, which can be detected by the position detector.

[0015] In addition to the characteristics mentioned in the preceding paragraph, the secure filter support device according to one aspect of the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations:

[0016] According to one embodiment, the detection element of the position detector produces a signal at a predetermined distance from the detectable part through a separating wall of the detector body and in that the detector body includes a blind hole whose separating wall forms the bottom of the blind hole, the blind hole forming a housing accommodating at least the detection element of the position detector such that the housing is sealed with respect to the volume closed by the detector body in the cover.

[0017] According to one embodiment, the filter absence detector further comprises a transparent block mounted on the detector body to display a visual signal indicating the absence of a filter when the movable piston is not in position. This allows the maintenance operator to be visually informed of the omission.

[0018] According to one example, the transparent block is a solid bulb mounted in a removable manner on the detector body. This allows access to the position detector. For example, a nut is mounted on a thread of the detector body, sandwiching part of the bulb.

[0019] According to one embodiment, the position detector comprises a mechanical detector of the detectable part made of ferromagnetic or magnetic material comprising: • a movable rod mounted in a housing in the detector body between an unfiltered position and a magnetically armed position comprising: • a visual indicator at one end forming a visual signal of the absence of a filter in the position without a filter and • the sensing element is made of magnetic or ferromagnetic material to exert a magnetic force attracting the detectable part made of ferromagnetic or magnetic material to each other, the magnetic force being less than the separating force exerted by the piston return spring, • An internal return spring mounted between the moving rod and the detector body exerts an internal return force on the moving rod towards and back to the position without the filter. This internal return force is less than the magnetic force in the piston's absence position. Thus, once the filter is installed against the cover, and the moving piston has therefore been moved to the presence position, the detector can be armed by manually pushing the rod and held in place by the magnetic force against the piston. This ensures the presence of the filter element mounted in the cover.

[0020] According to one example, the detectable part of the piston is a permanent magnet.

[0021] According to one particular feature of this example, the rod's sensing element is a ferromagnetic part tightly mounted in a housing in the rod body. According to another particular feature, the entire rod is ferromagnetic.

[0022] According to one example (which can be combined with the previous example), the sensing element of the rod is a permanent magnet.

[0023] According to one particular feature of this example, the ferromagnetic or magnetic part of the piston is a ferromagnetic component tightly fitted into a housing in the piston body. According to another particular feature, the piston itself is a ferromagnetic component.

[0024] According to one example of the two embodiments, the visual signal corresponds to the visual indicator, and in that the visual indicator is outside the detector body, surrounded by the transparent block. This allows for a simple mechanical visual signal.

[0025] According to a particular feature of this example, the transparent block is manually removable from the detector body. This allows an operator to reset the moving rod by moving it from the unfiltered position to the magnetically armed position, held in This position is determined by magnetic force when a filter is pressed against the piston in the present position. Depending on the specific model or variant, the transparent block is a flexible bulb that can be manually deformed. This allows for resetting without disassembly.

[0026] According to one embodiment, the movable piston moves in translation along an axis parallel to the axis of the opening. This avoids radial bulk and eliminates the need for a more complex linkage that could be more easily maintained in the present position by an operator wishing to simulate the presence of a filter element. Furthermore, since the piston's translation is the same as that of the filter element's insertion against the cover, it limits the additional effort required by the operator to compress the piston return spring during filter element installation.

[0027] According to one example, the movable piston is translationally movable along the axis of the opening. This makes it possible to detect incorrect mounting of the filter element (for example, at an angle).

[0028] According to an example of this embodiment and the preceding embodiment, the movable rod is translationally movable along the same axis as the movable piston. This allows, as with the piston, for simplification and avoidance of constraints.

[0029] According to one embodiment, the detection element of the position detector is a sensor that produces a variation in electrical signal depending on the distance from the detectable part, particularly a ferromagnetic or magnetic material, thus generating a filter absence signal beyond a predetermined variation. This allows the signal to be used to transmit the filter absence signal to a display module of a remote driver or operator of the filter support device.

[0030] According to an example of this embodiment, the sensor is integral with the body of the detector.

[0031] According to a variant of this example, combining this embodiment with the embodiment comprising the movable rod, the sensor is mounted in the movable rod. This allows for redundancy through both an electrical signal and a mechanical visual signal.

[0032] According to an example of this embodiment, the detector may include a diode mounted on a detector body connected to the sensor and an electronic unit controlling the diode to produce a visual signal of the absence of filter as a function of the variation of the electrical signal of the sensor.

[0033] According to one embodiment, the filter absence detector includes a seal mounted in compression between a cylindrical face of the detector body, surrounding it, and a cylindrical face of the cover surrounding the seal. The radial seal allows it to be sufficiently far from the outside to withstand a fire for a sufficient duration, while still providing effective sealing.

[0034] According to one embodiment, the detector body comprises a thread screwed into A threaded hole in the lid. This simplifies assembly while also contributing to the seal (less pressure on the gasket).

[0035] According to one embodiment, the cover and the detector body are one piece.

[0036] A second aspect of the invention relates to a filtering device comprising a secure filter support device as described above and a filtering element comprising a filter, the movable piston of the secure filter support device being in the presence position.

[0037] A third aspect of the invention relates to an assembly comprising different secure filter support devices according to the embodiment of the first aspect of the invention, wherein the detector body comprises a thread screwed into a tapped hole in the cover, wherein the secure filter support devices comprise the same shapes of detector body and position detector and at least one movable piston, a cover and a filter element of one secure filter support device comprises a different shape respectively of a movable piston, a cover and a filter element of another secure filter support device. This allows for parts adaptable to different shapes of cover and filter element.

[0038] A fourth aspect of the invention relates to a turbomachine comprising a casing and a filtering device according to the second aspect of the invention, the casing comprising a housing in which the filtering device is mounted.

[0039] According to one example, the housing comprises a first cylindrical wall surrounding a part of the housing containing the filtering device such that the detector body is visible outside the housing.

[0040] A fifth aspect of the invention relates to a method for mounting a turbomachine assembly according to the invention, in which the secure filter support device comprises a movable rod, the method comprising the following steps: • a step of mounting the filter against the cover of the secure filter support device, moving the movable piston into the present position, • a manual step of moving the movable rod to the magnetically armed position.

[0041] According to a first example, the method further includes a preliminary step of mounting the filter in the filter element before the step of mounting the filter against the cover of the secure filter support device.

[0042] According to a variant of this example, the method includes a step of mounting the assembly comprising the filter and the cover in the base of the filter element after the manual step of moving the movable rod to the magnetically armed position.

[0043] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0044] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0045] [Fig.1] represents a schematic diagram of a filtering device comprising a filtering element including a filter and a secure filter support device 1 according to an example of one of the embodiments.

[0046] [Fig.2] represents a cross-section of a secure filter support device according to a first example of a first embodiment of the invention.

[0047] [Fig.3] is an exploded view of the secure filter support device shown in [Fig.2],

[0048] [Fig.4] is an exploded view of a filter absence detector of an example of a secure filter support device.

[0049] [Fig.5a] represents a cross-section of the secure filter support device shown in [Fig.2] having a movable piston of the filter presence device in a presence position.

[0050] [Fig.5b] represents the cross-section of the secure filter support device shown in [Fig.2] having the movable piston of the filter presence device in an absence position.

[0051] [Fig.6a] represents a cross-section of the secure filter support device according to a second example of the first embodiment, having a movable piston of the filter presence device in a presence position.

[0052] [Fig.6b] shows a cross-section of the secure filter support device according to the second example of the first embodiment, having the movable piston of the filter presence device in an absence position

[0053] [Fig.7a] represents a cross-section of the secure filter support device according to a third example of the first embodiment, having a movable piston of the filter presence device in a presence position.

[0054] [Fig.7b] shows a cross-section of the secure filter support device according to the third example of the first embodiment, having the movable piston of the filter presence device in an absence position

[0055] [Fig.8a] represents a cross-section of the secure filter support device according to a first example of a second embodiment, having a movable piston of the filter presence device in a presence position.

[0056] [Fig.8b] represents a cross-section of the secure filter support device according to the first example of a second embodiment, having the movable piston of the filter presence device in an absence position. DETAILED DESCRIPTION

[0057] The invention proposes a solution that not only avoids mounting a filtering device in a turbomachine circuit, without a filter being mounted in the filtering device by informing by a signal from a detector of absence of filter which will be described later, but also to adapt to different types of filtering device.

[0058] Fig. 1 represents a schematic diagram of a filtering device for a turbomachine comprising a filtering element 3 including a filter 30 and a secure filter support device 1 including a cover 2 and a filter absence detector 4 according to an example of one of the embodiments.

[0059] The filter element 3 comprises a base 31, for example made of plastic, having an open housing for a replaceable (consumable) filter 30. The filtering device further comprises a cover 2 covering the filter 30 by closing the housing. The cover 2 comprises a cylindrical wall 219 and a radial closing wall 213 about the axis of the cylindrical wall 219, and an opening for a filter absence detector 4 extending from an inner surface of the radial closing wall 213 to be opposite the filter 30 and sandwiching the filter 30 against the base 31. The filter 30 is, for example, a fiberglass cartridge. The filter element 3 includes an inlet 32 ​​passing through the base 31 to connect the housing to an oil circuit of the turbomachine, an oil outlet 33, and an outlet channel connected between the oil outlet 33 and the outlet of the filter 30.In this example, the filter element 3 comprises an oil check valve 34 mounted in the outlet channel, a bypass valve 35 mounted between the outlet channel and the housing, an oil filter pre-clogging indicator 36 connected to a first bypass channel open to the outlet channel and a second bypass channel open to the housing. According to another example not shown, the filter element lacks an oil check valve 34 and / or a bypass valve 35 and / or an oil filter pre-clogging indicator 36 and its two bypass channels.

[0060] In this example, the cylindrical wall 219 of the cover 2 surrounds a large part of the filter 30, mounted in a cylindrical wall 319 of the base 31 with a seal 19 between these two cylindrical walls 319, 219.

[0061] The filter 30 of the filter element 3 is interchangeable, the cover 2 and the base 31 are removable from each other so that the filter can be changed, for example the cover may include a thread and the base 31 a tapping to be mounted tightly together.

[0062] The invention relates to the secure filter support device 1, examples of a first embodiment of which are shown in Figures 2 to 6b and an example of a second embodiment is shown in Figures 7a and 7b.

[0063] In both embodiments described, the secure filter support device 1 comprises the cover 2 of a turbomachine filtering device for mounting on a base (either in, as in the previous example, or around, surrounding the base). As shown in [Fig. 3], which shows an exploded view of a secure filter support device 1 whose cover 2 is fixed to a base of the filter element 3. The cover 2 differs from the prior art only in that it includes an opening along a central axis. The opening passes through the radial closing wall 213. In the examples shown of these two embodiments, the central axis of the opening is the same axis as that of the cylindrical wall 219 but could be offset from this axis while remaining parallel. In the examples shown of these two embodiments, the opening is cylindrical along the central axis but could have another shape, for example, by having a center of symmetry as its axis.

[0064] In both embodiments described, the secure filter support device 1 comprises a filter absence detector 4, including a detector body 42, for example made of plastic, attached to the cover 2 by closing the opening. In these examples shown, the detector body 42 includes at least two mounting openings parallel to the opening in the cover 2, and the radial closing wall 213 includes the same number of tapped holes opposite the mounting openings. The filter absence detector 4 further includes the same number of screws 48 screwed into one of the tapped holes, each passing through one of the mounting openings, bearing against a wall of the detector body 42 to secure the detector body 42 to the cover 2. This is only one example; other solutions for attaching the detector body 42 to the cover 2 can be implemented.Furthermore, in these examples, the filter absence detector 4 includes a radial seal by means of a compressed gasket 47 between a cylindrical face of the detector body 42, surrounding it, and a cylindrical face (delimiting the opening) of the cover 2 surrounding the gasket 47. The cylindrical face of the detector body 42 may include a tapped hole, and that of the cover 2 a thread, allowing for fixing and assisting the seal between the detector body 42 and the cover 2. According to yet another example, the cylindrical face of the detector body 42 may include collars or bases having a diameter greater than that of the cylindrical face of the cover 2 to form a tight fit with each other (in this case, screws may assist in the tight fit).

[0065] In both embodiments described, the filter absence detector 4 further comprises a movable piston 43, between a presence position and an absence position, including a filter stop 431 for contacting the filter 30 in the presence position. The movable piston 43 further comprises a detectable portion 432 by the position detector; in the examples shown, the detectable portion 432 is a ferromagnetic or magnetic portion. According to another example not shown, the detectable portion 432 is made of plastic and the position detector is an inductive sensor. In these examples shown, the movable piston 43 comprises In this instance, a centering pin 430 replaces that of a prior art cover to center the filter 30; however, if the filter does not have a central centering hole, the piston may lack one. This centering pin 430, in some examples, forms the filter stop 431. According to another example, the detector body 42 includes one or more centering pins. The detectable part 432 may be either a permanent magnet in the magnetic case or a ferromagnetic part, for example, an iron component. The movable piston 43 may include a body 433 made of a lightweight material such as a composite or a plastic, and this detectable part 432 is fixed to the body 433, for example, by being press-fitted into a hole in the body 433 opposite the centering pin 432.

[0066] In both embodiments described, the filter absence detector 4 further includes a piston return spring 44 mounted in compression between the detector body 42 and the piston 43, exerting a displacing force on the piston 43 towards and to the absence position. Thus, when a filter 30 is mounted in the housing of the filter element 3 and the cover 2 covers the filter 30, closing its housing, the filter 30 is sandwiched between the base 31 and the filter stop 431 of the movable piston 43 in the presence position, compressing the piston return spring 44. If the filter 30 has not been inserted, the piston return spring 44 is less compressed and exerts a sufficient force on the movable piston 43 in the absence position (it will be seen later why gravity is not sufficient here).

[0067] In both embodiments described, the filter absence detector 4 further includes a position detector 45 mounted on the detector body 42. The position detector 45 includes a detection element 452 sensitive to ferromagnetism or magnetism to detect the detectable part 432, here ferromagnetic or magnetic, when the piston 43 is in a presence position and to produce a filter absence signal when the detectable part 432 is distant from the detection element 45 beyond a predetermined position located between the presence position and the absence position of the piston.

[0068] In these examples shown, the detector body 42 includes a hole, preferably blind to avoid sealing problems, forming a housing for the position detector 45 to allow detection of the detectable part 432, here in this case made of ferromagnetic or magnetic material, of the movable piston 43. In particular, in these examples shown, the body 433 of the movable piston 43 includes a hollow cylindrical portion 435 housing the detectable part 432 fixed in the bottom and further surrounds a portion of the detector body 42 as well as the detection element 452 such that, in the present position, the detection element 452 is closer to the detectable part 432 than in the absent position. In these examples shown, the hollow cylindrical portion 435 guides the piston 43 during its translation along the central axis by surrounding the detection element 452 from the position of absence to the position of presence. Of course this could be reversed, that is to say that the detector body 42 includes a hollow cylindrical part having at the bottom its detection element 452 for example by surrounding a solid cylinder of the piston 43. In this latter case, the detector body 42 is made of a material which is not magnetic, for example plastic.

[0069] Examples of the first embodiment are described below.

[0070] In the first embodiment, the detector body 42 and the position detector 45 are identical in all the examples described. As can be seen in [Fig. 4], which shows the filter absence detector 4 in exploded view, the position detector 45 comprises a mechanical detector of the detectable part 432, including a movable rod 450 mounted in an opening in the detector body 42 between a position without a filter and a magnetically armed position. The movable rod 450 includes the detection element 452, and in particular, as explained previously, in these examples, this element is housed in the recess of the cylindrical part 453.In this embodiment, the sensing element 452 is made of a magnetic or ferromagnetic material to exert a magnetic force attracting the detectable part 432 to each other, the magnetic force being less than the retraction force exerted by the piston return spring 44. In other words, either the sensing element 452 and the detectable part 432 are each permanent magnets oriented to attract each other (one North pole opposite the South pole), or one of the two is a permanent magnet and the other is a ferromagnetic part. In other words, in this embodiment, either the sensing element 452 or the detectable part 432 is a ferromagnetic magnet. In the examples shown, the detectable part 432 is a permanent magnet and the sensing element 452 is a ferromagnetic part 452 fixed in a body 453 of the movable rod 450 as seen in [Fig. 4]. .

[0071] The movable rod 450 further includes at the other end a visual indicator 451 at a first end forming a visual signal of the absence of filter signal in the position without filter.

[0072] In these examples, as seen in [Fig. 5b], [Fig. 6b], and [Fig. 7b], which show a cross-section of the secure filter support device 1 according to different embodiments, in which the movable piston 43 is in the absence position and the rod 450 is in the unfiltered position, the visual indicator 451 protrudes from the detector body 42 in this unfiltered position. Conversely, as seen in Figures 2, 5a, 6a, and 7a, which show a cross-section of the secure filter support device 1 in which the movable piston 43 is in the presence position and the rod 450 is in the magnetically armed position, the visual indicator 451 is inside the detector body 42. In this case, in the magnetically armed position, the outer end of the visual indicator 451 is flush with a surface of the external radial face of the detector body 42 opposite the internal face inside the cover 2.

[0073] The mechanical position detector 45, comprising the detection element 452 of the detectable part 432, further includes an internal return spring 454 mounted between a shoulder of the body 453 of the movable rod 450 and the detector body 42, exerting an internal return force on the movable rod 450 towards the position without the filter. In this case, the internal return spring 454 is a helical spring surrounding the body 453. This internal return force is less than the magnetic force in the position when the piston is not in use.

[0074] Thus, as can be seen in Figures 2, 5a, 6a, and 7a, the permanent magnet, which is the detectable part 432, is sufficiently close to the detecting element 452 for its magnetic force to be sufficient to keep the internal return spring 454 in a compressed state in the magnetized armed position. However, as can be seen in Figures 5b, 6b, and 7b, as soon as the cover 2 is removed from the filter element 3, the piston return spring 44 exerts a force greater than the magnetic force, causing the piston to move away from its resting position. This movement causes the movable rod 450 to come to a stop against a stop on the detector body 42, which, remaining static by the stop, causes an increase in the distance between the detectable part 432 (here the ferromagnetic magnet) of the movable piston 43 and the detection element 452 (here a ferromagnetic rod inserted in the body 453 of the movable rod).The further the permanent magnet (here the magnetic part 432) moves away from the part (here the detection element 452), the more the magnetic force exerted to attract them decreases, allowing the internal return spring 454 to have sufficient force (greater than this decreasing magnetic force) to push the movable rod 450 towards the position without the filter.

[0075] In these examples represented in the first embodiment, the filter absence detector 4 further includes a transparent block 46 mounted on the detector body 42 to make the visual indicator 451 appear, forming a visual signal of the filter absence signal in the absence position of the movable piston 43. In these examples, the filter absence signal in the absence position is the visual signal; for example, the visual indicator 451 includes a red band or a yellow triangle with an exclamation mark of the type "waming".

[0076] As can be seen in [Fig. 4], the transparent block 46 is a bulb that can be manually removed from the detector body 42. The filter absence detector 4 further includes a nut 460 screwed onto the detector body 42, surrounding the transparent block 46. The transparent block 46 is thus sandwiched against the detector body 42, which has a thread corresponding to the tapping of the nut 460.

[0077] The filter absence detector 4 optionally includes, in addition to a seal 49 and a thrust washer 495 also mounted in sandwich between the transparent block 46 and the detector body 42. The rod 450, in particular the body 453 includes a shoulder extending radially from the visual indicator 451 and comes into contact against the thrust washer 495 in the position without filter.

[0078] In the various examples shown, the covers 2 and the piston 43 are the only elements with different shapes. The detector body 42, the piston return spring 44, and the position detector 45 are identical. In particular, the nut 460, the transparent block 46, the seal 49, the thrust washer 49, the screws 48, and the seal 47 are all identical in shape in the different examples.

[0079] Indeed, only the covers 2 and the piston 43 are in contact with the filter element 3 and therefore must adapt to the different basic shapes 31 of the different types of filter element 3 as well as to the different filters 30.

[0080] Indeed, the cover 2 of the first example in [Fig.2], [Fig.3] and in Figures 5a and 5b comprises a cylindrical wall 219 including an external shoulder 2191 to butt against a radial face of the cylindrical wall 319 of the base 31 as well as an external groove or channel to see the seal 19, and finally an external thread 2190 to screw into an internal thread in the cylindrical wall 219. Here the term external refers to the external cylindrical face of the cylindrical wall with respect to the central axis and the term internal refers to the internal cylindrical face of the cylindrical wall 319 of the base 31 with respect to the central axis.

[0081] The cover 2 of the second example in [Fig.6a] and 6b (similar to that shown in [Fig.4]), includes a cylindrical wall 219 to surround a cylindrical wall 319 of the base 31 (referenced and visible only in Figures 1, 2), for example by a tight fit or a thread and tap (a gasket 19 can also be fitted between the two walls).

[0082] The cover 2 of the third example in [Fig.7a] and in [Fig.7b] includes a cylindrical wall 219 (partially shown) completely surrounding the filter (replacing the wall 319 of [Fig.l]).

[0083] The same applies to the movable piston 43, whose centering pin 430 can change depending on the type of filter 30. In particular, in the first example ([Fig.2], [Fig.3], on [Fig.5a] and [Fig.5b]), the centering pin 430 (referenced [Fig.5a]) includes an orifice with a rectangular cross-section forming a housing in the centering pin 430 to receive a tab of the filter 30 and a seal 300 of the filter 30 is compressed axially against the filter stop 431 with a radial surface, while in the second and third examples the centering pin includes a cylindrical orifice and in the third example the seal 300 is pressed against a conical surface of the centering pin 430 forming the filter stop 43.

[0084] This allows for an identical set of parts for different types filter element 3. The different shapes of cover 2 all include the same shape of opening to receive the same shape of detector body. Thus, an assembly comprising different secure filter support devices 1 may include the same shapes of detector body 42 and position detector 45 and at least one movable piston 43, a cover 2 and a filter element 3 of a secure filter support device 1, each of which has a different shape respectively from a movable piston 43, a cover 2 and a filter element 3 of another secure filter support device 1.

[0085] The method for assembling a filtering device comprising is described below. the filter element 3 and the secure filter support device according to the first embodiment. The method comprises: • a step of mounting the filter 30 against the cover 2, by moving the movable piston 43 into the position where the filter 30 is in contact, • a manual step of moving the mobile rod 450 to the magnetically armed position (here by pressing on the visual indicator of the rod).

[0086] The method further includes either a preliminary step of mounting the filter 30 in the filter element 3 before mounting the filter 30 against the cover 2 of the secure filter support device 1 or a step of mounting the assembly including the filter 30 and the cover 2 in the base 31 of the filter element 3 after the manual step of moving the movable rod 450 to the magnetically armed position.

[0087] In this case the process includes a step of unscrewing the nut 460 and removing the transparent block 46 before the manual step of moving the movable rod 450 and furthermore after this manual step, a step of screwing the nut 460 to the detector body 42 by sandwiching the transparent block 46.

[0088] An example of a second embodiment of a secure filter support device 1 is described below, shown in cross-section in which the movable piston 43 is in a position of presence in [Fig.8a] and is in a position of absence in [Fig.8b].

[0089] The sensing element 452' of the position detector 45' is a sensor that produces a variation in the electrical signal according to the distance from the detectable part 432, thereby generating a filter absence signal beyond a predetermined variation. The sensing element 452' thus produces a signal variation, and the position detector 45' includes an electronic unit that generates a filter absence signal, for example, a visual signal using a diode, based on the variation in the electrical signal produced by the sensor. In this example, the detectable part 432 is a permanent magnet, and the sensing element 452' is a magnetic sensor, for example, a Hall effect proximity sensor. The position detector 45' includes, in this instance, two terminals 453 connected to a power supply to power the detection element 452'.

[0090] According to another example, the detectable part 432 is metallic and the sensing element 452' is an inductive detector.

[0091] As can be seen in this example, the position detector 45' is static (fixed) to the detector body 42. In this case, a nut 460' fixed to the detector body 42, for example by welding or overmolding, allows the position detector 45', which includes a corresponding thread, to be fixed to the detector body 42.

[0092] In this example, the detector body 42 includes an internal stud 425 forming a housing to receive a part of the position detector 45' of which the detection element 452'

[0093] In this example, the internal stud 425 is open allowing the sensing element 452' to be opposite the detectable part 432 of the movable stud 43. A seal is mounted in the housing between the internal stud 425 and the position detector 45'.

[0094] According to another example, the internal pad 425 includes a wall (preferably very thin to improve the sensitivity of the detection element 452') forming the bottom of the housing (this makes it possible to seal between the position detector 45' and the detector body 42).

[0095] Optionally, in this example of this embodiment, the position detector 45' includes a diode 451' mounted on one of the two terminals 453 connected to a power supply such that when the detectable part 432 is detected by the detection element 452', the diode 451' is sufficiently powered to produce a visual signal of the absence of filter signal.

[0096] According to this example, the position detector 45' includes at least one of its two terminals 453 connected to an electronic unit of the aerodyne including the turbomachine allowing to inform that a filter is missing on a display module of a pilot or an operator.

[0097] According to another embodiment not shown, the position detector 45 comprises the position detector 45 of the first embodiment, mounted with a sensor of the type of that of the second embodiment in the movable rod to further inform the pilot that a filter is missing. In one example, a position sensor is mounted on the detector body 42 to determine the position of the movable rod 450.

[0098] The invention also relates to a turbomachine comprising a housing and a filtering device including the secure filter support device according to one of the examples described, the housing including a housing in which the filtering device is mounted.

Claims

Claims

1. Secure filter support device (1) for a turbomachine comprising a cover (2) comprising an opening along an axis, configured to be mounted with a filter element (3) closing a housing of a filter (30) of the filter element (3), characterized in that the secure filter support device (1) comprises a filter absence detector (4) comprising: - a detector body (42) mounted on the cover (2) closing the opening, - a movable piston (43), between a presence position and an absence position, comprising a filter stop (431) to be in contact with the filter (30) in the presence position, and a detectable part (432), - a piston return spring (44) between the detector body (42) and the piston (43) exerting a separation force on the piston (43) towards and up to the absence position, and - a position detector (45, 45') mounted on the detector body (42),comprising a sensing element (452, 452') sensitive to the material of the detectable portion for detecting the detectable portion (432) when the piston (43) is in a presence position and producing a filter absence signal when the detectable portion (432) is distant from the sensing element (45) beyond a predetermined position located between the presence position and the absence position of the piston (43).,

2. Secure filter support device (1) according to the preceding claim, characterized in that the filter absence detector (4) further comprises a transparent block (46) mounted on the detector body (42) to display a visual signal of the filter absence signal in the absence position of the movable piston (43).

3. Secure filter support device (1) according to claim 1 or 2, characterized in that the position detector (45) comprises a mechanical detector of the detectable part (432) made of ferromagnetic or magnetic material comprising: - a movable rod (450) mounted in a housing of the detector body (42) between a filter-free position and a magnetized armed position comprising: • a visual indicator (451) at a first end forming a visual signal of the filter-free signal in the filter-free position and • the detection element (452) is made of magnetic or ferromagnetic material to exert a magnetic force attracting the detectable part (432) of ferromagnetic or magnetic material to each other, the magnetic force being less than the separation force exerted by the piston return spring (44), - an internal return spring (454) mounted between the movable rod (450) and the detector body (42) exerting an internal return force on the movable rod (450) to and as far as the filter-free position, said internal return force being less than the magnetic force in the piston-free position.

4. Secure filter holder device (1) according to claims 2 and 3, characterized in that the visual signal corresponds to the visual indicator (451) and in that the visual indicator (451) is outside the detector body (42) surrounded by the transparent block (46).

5. A secure filter support device (1) according to claim 4 wherein the transparent block (46) is manually removable from the detector body (42).

6. Secure filter support device (1) according to one of the preceding claims, in which the movable piston (43) is movable in translation along an axis parallel to the axis of the opening.

7. Secure filter support device (1) according to claim 6 and one of claims 3 to 5 in which the movable rod (450) is movable in translation along the same axis as the movable piston (43).

8. Secure filter support device (1) according to one of the preceding claims, characterized in that the detection element (452') of the position detector (45') is a sensor producing a variation in electrical signal according to the distance from the detectable part (432), in particular made of ferromagnetic or magnetic material, making it possible to produce a filter-free signal beyond a predetermined variation.

9. Secure filter support device (1) according to the preceding claim, characterized in that the sensor is integral with the detector body (42).

10. Secure filter support device (1) according to one of the preceding claims, in which the filter absence detector (4) comprises a seal (47) mounted compressed between a cylindrical face of the detector body (42) surrounding it and a cylindrical face of the cover (2) surrounding the seal (47).

11. A secure filter support device (1) according to one of the preceding claims, wherein the detector body (42) comprises a thread screwed into a thread of the cover (2).

12. Filtering device comprising a secure filter support device (1) according to one of the preceding claims and a filter element (3) comprising a filter (30) mounted against the movable piston (43) in the presence position.

13. An assembly comprising different secure filter holder devices (1) according to claim 11, wherein the secure filter holder devices (1) comprise the same shapes of detector body (42) and position detector (45) and at least one movable piston (43), a cover (2) and a filter element (3) of one secure filter holder device (1) comprises a different shape respectively of a movable piston (43), a cover (2) and a filter element (3) of another secure filter holder device (1).

14. A turbomachine comprising a casing and a filtering device according to claim 12, the casing comprising a housing in which the filtering device is mounted.

15. A method of mounting a filtering device according to claim 12, wherein the secure filter support device (1) is according to claim 3, comprising the following steps: - a step of mounting the filter (30) against the cover (2) of the secure filter support device (1) by moving the movable piston (43) into the presence position, - a manual step of moving the movable rod (450) to the magnetized armed position.

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