Visual reminder system for a filter element

Abstract

One aspect of the invention relates to a filtering device (10) for a turbomachine, the device comprising: - a filter support (14); - a removable filter (18) co-operating with the filter support; - a cover (12); - an indicator pin (16); the device comprising a plate (13) that is translatably movable relative to the cover and relative to the indicator pin, the plate being translatably movable between two positions: - a first position such that the plate bears against the removable filter and the indicator pin is in a retracted position; - a second position such that the plate is remote from the cover due to the absence of the removable filter and the indicator pin is in an extended position.

Description

DESCRIPTION TITLE: VISUAL ANTI-FORGETTING SYSTEM FOR A FILTER ELEMENT TECHNICAL FIELD OF THE INVENTION

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

[0002] The present invention relates to a filtering device. The invention also relates to a method for indicating the presence of a filter and to a turbomachine. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Typically, turbomachines have oil and fuel circuits that use filter elements (or filters) to protect downstream elements in the circuits. The filtration systems for these circuits typically include a filter holder that cooperates with a removable filter (or filter cartridge).

[0004] Figure 1 is an exploded view of a filtering device according to the prior art comprising a filter 1 of cylindrical shape and comprising an axis A. Figure 2 is a sectional view along the axis A of the filter 1 of the filtering device according to the prior art. A filter support 2 cooperates with the filter 1 by a cylindrical rod 29 secured to the filter support 2 inserted in a hollow and cylindrical part 19 of the filter 1. A clogging valve 17 is movable in translation relative to the filter support 2 by means of a spring. A cup 3 of cylindrical shape is inserted in the hollow part 19 making it possible to hold the filter 1 in position.

[0005] Sometimes the filtering device is installed even though no filter has been placed in the device. Operating the turbomachine without a filter element can lead to engine malfunctions.

[0006] Solutions are known to prevent the turbomachine from being put into service without a filter.

[0007] For example, screwing a drain plug onto a filter is a known solution. The drain plug cannot be screwed on if the filter is missing. 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.

[0008] Another solution is to design two holes on the bottom of the filter housing to cause a leak in the absence of a filter. The filter has two O-rings on the inner and outer diameter of the filter to ensure a seal with the filter holder. However, this solution allows the leak to be detected only during commissioning of the turbomachine.

[0009] Thus, existing solutions do not allow for reliable mechanical guarantees of the filter's installation in a filtration system without drawbacks. SUMMARY OF THE INVENTION

[0010] The invention provides a solution to the problems mentioned above, by making it possible to detect the absence of a filter in a filtering device, in particular for a turbomachine before said turbomachine is put into service.

[0011] A first aspect of the invention relates to a filtering device comprising: a filter support; a removable filter cooperating with the filter support; a cover movable in translation relative to the filter support; a clogging valve movable in translation relative to the filter support and connected to one end of the filter support by means of a first compression spring with a first compression force F1; a magnet positioned at one end of the clogging valve; an indicator pin having a magnetic surface, being movable in translation relative to the cover and connected to the cover by means of a second compression spring with a second compression force F2, the magnetic surface being opposite the magnet, the indicator pin being movable in translation between two positions: an extended position such that the indicator pin projects from a surface of the cover;a retracted position such that the indicator pin is in contact with the magnet; the device comprises a plate secured to the sealing valve, the plate being movable in translation relative to the cover and relative to the indicator pin by; by means of third compression springs positioned between the plate and the cover, the third compression springs having a third compression force F3 greater than the first compression force F1 of the first compression spring, the plate being movable in translation between two positions: a first position such that the plate is resting on the removable filter and the indicator pin is in the retracted position; a second position such that the plate is moved away from the cover due to the absence of the removable filter and the indicator pin is in the extended position.

[0012] Thus, the indicator pin protrudes and is therefore visible if the removable filter is not mounted on the device. This makes it possible to indicate the absence of the filter and to detect the absence of the removable filter before starting the turbomachine by means of a visual indicator which is the indicator pin. The third compression springs hold the plate in the second position in the absence of the removable filter.

[0013] Advantageously, the plate comprises a first cylindrical surface cooperating with a second cylindrical surface of the filter support. Thus, the filter support makes it possible to guide the plate along the axis of the filter support.

[0014] Advantageously, the tray comprises a first planar surface in contact with a first circumferential surface of the filter support when the tray is in the second position. The first circumferential surface acts as a stop for the tray when the latter is in the second position.

[0015] Advantageously, the third compression springs are each in contact with the cover and with a second circumferential surface of the tray. The third compression springs maintain the tray in the second position when the removable filter is absent from the device.

[0016] Advantageously, the third compression springs are positioned in cover housings located in the cover. The cover housings hold the third compression springs opposite the plate.

[0017] A second aspect of the invention relates to a method for indicating the presence of a filter in said device comprising: a step of mounting the cover; a step of pressing on the indicator pin translating the indicator pin from the extended position to the retracted position; if the removable filter is mounted on the device, then the indicator pin is held in the retracted position; if the removable filter is absent from the device, then the indicator pin translates from the retracted position to the extended position.

[0018] A third aspect of the invention relates to a turbomachine comprising said filtering device.

[0019] 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

[0020] The figures are presented for information purposes only and in no way limit the invention.

[0021] [Fig.1] is an exploded view of a filtration device according to the prior art.

[0022] [Fig.2] is a sectional view of the filtration device according to the prior art.

[0023] [Fig.3] is an exploded view of a filtration device according to the invention without a removable filter.

[0024] [Fig.4] is a perspective view of the filtration device according to the invention without a removable filter.

[0025] [Fig.5] is a sectional view along an axis B of the filtration device according to the invention without removable filter.

[0026] [Fig.6] is an enlarged view of Figure 5.

[0027] [Fig.7] is a sectional view along axis B of the filtration device according to the invention.

[0028] [Fig.8] is an enlarged view of Figure 7.

[0029] [Fig.9] is an exploded view of a cover and a tray of the filtration device according to the invention.

[0030] [Fig.10] is a sectional and perspective view of a clogging valve of the filtration device according to the invention.

[0031] [Fig.11] is a functional diagram of the filtration device according to the invention in the absence of a removable filter.

[0032] [Fig.12] is a functional diagram of the filtration device according to the invention.

[0033] [Fig.13] is a functional diagram of a method for indicating the presence of a filter in a device according to the invention. DETAILED DESCRIPTION

[0034] Unless otherwise specified, the same element appearing in different figures has a single reference.

[0035] An example of a filtering device according to the invention comprises a filter support and a clogging valve connected to the filter support by a first compression spring. The device further comprises a cover comprising an indicator pin translating in the cover and connected thereto by a second compression spring.

[0036] Figures 3 to 6 and 11 show the filtering device 10 according to the invention without a removable filter. Figures 7, 8 and 12 show the filtering device 10 according to the invention with the removable filter 18.

[0037] Figure 3 is an exploded view of the filtering device 10 comprising: the cover 12, a plate 13 of generally circular shape, three third compression springs 121 positioned between the cover 12 and the plate 13 and in contact with the cover 12 and the plate 13, the filter support 14 cooperating with the plate 13 and comprising a first hollow cylinder 149 and a platform 148 fixed to one end of the first hollow cylinder 149; the clogging valve 17 of cylindrical shape the first compression spring 141 connecting the clogging valve 17 to the filter support 14.

[0038] Figure 4 is a perspective view of the filtering device 10. The clogging valve 17 is mounted in the first hollow cylinder 149. The clogging valve 17 is movable in translation relative to the filter support 14 such that the clogging valve 17 can translate in the first hollow cylinder 149 along an axis B of the first hollow cylinder 149. The first compression spring 141 is mounted in the first hollow cylinder 149 and is in contact with the clogging valve 17. The first compression spring 141 holds the clogging valve 17 at one end of the first hollow cylinder 149.

[0039] The tray 13 and the platform 148 of the filter support 14 cooperate and fit together such that there is no possible rotational movement between the tray 13 and the platform 148 along the axis B. Indeed, the plate 13 comprises protuberances 139 cooperating with recesses 147 of the platform 148 located on the periphery of the platform 148. For example, the plate 13 comprises three protuberances 139 cooperating with three recesses 147 of the platform 148. The protuberances 139 block the rotation of the filter support 14 around the axis B.

[0040] As shown in Figure 5 and Figure 6, the plate 13 comprises a second hollow cylinder 138 having an axis coaxial with the axis B.

[0041] The clogging valve 17 is movable in translation along the axis B relative to the plate 13. The clogging valve 17 comprises a magnet 171 located at one of its ends. The clogging valve 17 is cylindrical in shape and the cylindrical magnet 171 is positioned in the second hollow cylinder 138 of the plate 13.

[0042] Concerning the elements of the cover 12, the indicator pin 16 is mounted in a cavity 129 of cylindrical shape of the cover 12. The indicator pin 16 is of cylindrical shape and has an axis coaxial with the axis B. The indicator pin 16 is movable in translation relative to the cover 12. The second compression spring 161 is positioned around the indicator pin 16 and inside the cavity 129 and exerts a second compression force F2 along the axis B towards a direction opposite to the sealing valve 17.

[0043] The indicator pin 16 comprises a magnetic surface 162 facing the magnet 171 of the sealing valve 17. The magnet 171 exerts an attractive electromagnetic force on the magnetic surface 162 of the indicator pin 16 in such a way that the indicator pin 16 is attracted towards the magnet 171. The electromagnetic force of the magnet 171 is in the opposite direction to the second compression force F2 of the second compression spring 161. The indicator pin 16 also comprises a shoulder 169 acting as a stop and allowing the indicator pin 16 not to come out of the cavity 129 of the cover 12. The shoulder 169 abuts on a stop surface 168 of the cover 12

[0044] Thus, the indicator pin 16 is movable in translation along the axis B between two positions: An extended position (shown in Figures 5, 6 and 11) such that the indicator pin 16 protrudes from a surface of the cover 128. A retracted position (shown in Figures 7, 8 and 12) such that the magnetic surface 162 is in contact with the magnet 171. In the retracted position, the indicator pin 16 does not protrude from the surface of the cover 128.

[0045] When the indicator pin 16 is in the extended position, the shoulder 129 comes into abutment on the abutment surface 168 of the cover 12.

[0046] As shown in Figure 6, the plate 13 comprises a first planar surface 132 in contact with a first circumferential surface 143 of the platform 148.

[0047] As shown in Figure 6, the third compression springs 121 are positioned between the plate 13 and the cover 12 to exert a third compression force F3 thereon. The device 10 comprises in the example considered three third compression springs 121 (only one of the third compression springs 121 is shown in the sectional view of Figure 6) distributed over the periphery of the plate 13. There could be more or less than three third compression springs 121 without departing from the scope of the present invention. Each third compression spring 121 is in contact with a second circumferential surface 133 of the plate 13 located close to the radial edges of the plate 13 relative to the axis B. The second circumferential surface 133 is parallel to the first flat surface 132 but is not in the same plane as the first flat surface 132.The third compression springs 121 are also in contact with the cover 12 and each positioned respectively in a cover housing 127. The cover 12 comprises three cover housings 127 (only one housing is shown in FIG. 6) to accommodate each of the third compression springs 121. Each cover housing 127 is opposite the second circumferential surface 133 of the plate 13. The cover housings 127 make it possible to ensure the positioning of the third compression springs 121. The third compression springs 121 cannot therefore move radially relative to the axis B.

[0048] The plate 13 is movable in translation between two positions: A first position such that the plate 13 is resting on the removable filter 18 (shown in figures 7, 8 and 12) and the indicator pin 16 is in the retracted position; A second position such that the tray 13 is moved away from the removable filter 18 (shown in Figures 5, 6 and 11) and the indicator pin 16 is in the extended position.

[0049] Figure 7 and Figure 8 show the device 10 when the plate 13 is in the first position. The removable filter 18 is in contact with a second flat surface 134 (visible in Figure 8) of the cover 13. The removable filter 18 exerts pressure (illustrated by the two arrows positioned on the filter) on the second flat surface 134 compressing the third compression springs 121. The second flat surface 134 is parallel to the second circumferential surface 133 of the plate 13. In the first position, a third flat surface 135 of the plate 13 comes into abutment on the cover 12 which thus blocks the position of the plate 13.

[0050] The filter support 14 cooperates with the removable filter 18 via the first hollow cylinder 149 inserted into a hollow and cylindrical part 189 of the removable filter 18.

[0051] The device 10 comprises a cylindrical cup 3 inserted into the hollow portion 189. The cup 3 is in cylinder-to-cylinder contact with the removable filter 18. The removable filter 18 is held in position via the cup 3. One end of the first hollow cylinder 149 is in cylinder-to-cylinder contact with the cup 3. For example, the cup 3 is screwed onto the filter support 14.

[0052] The removable filter 18 and the cup 3 are contained in a cylindrical tank 4. The filter support 14 is in cylinder-to-cylinder contact with the tank 4. The cover is in cylinder-to-cylinder contact with the tank 4.

[0053] In the first position, the sealing valve 17 is in contact with the indicator pin 16. Thus, the magnet 171 exerts an electromagnetic force on the magnetic surface 162 of the indicator pin 16 such that the magnetic surface 162 is in contact with the magnet 171. In this first position, the indicator pin 16 is in the retracted position such that it does not protrude from the surface of the cover 128.

[0054] In the presence of the removable filter 18, when passing from the second position to the first position, the clogging valve 17 translates along the axis B in the direction of the indicator pin 16 by means of the first compression spring 141 which has a first compression force F1. Thus, the device 10 makes it possible to detect the presence of the removable filter 18 by the presence of a visual indicator which is the indicator pin 16.

[0055] In the absence of the removable filter 18, when moving from the first position to the second position, the clogging valve 17 translates towards a direction opposite to the indicator pin 16 under the effect of the third compression force F3 of the third compression springs 121. The magnet 171 then moves away from the magnetic surface 162 so that the distance between the magnet 171 and the magnetic surface 162 is too great to allow the magnet 171 to hold the indicator pin in the retracted position. Then, the second compression force F2 of the second compression spring 161 will drive the indicator pin 16 in the direction opposite to the clogging valve 17. The indicator pin 16 will then be in the extended position revealing the absence of the removable filter 18 in the device 10.

[0056] The device 10 can be mounted in an oil or fuel circuit of a turbomachine. The device 10 also has a function of detecting clogging of the removable filter 18. Indeed, if the removable filter 18 is clogged, then the pressure increases in the device 10 during the commissioning of the turbomachine created by a fluid, for example oil or fuel, circulating in the device. As shown in FIG. 7, the fluid cannot be evacuated by passing through the removable filter 18, the fluid will then concentrate in the zone 5 of the filter support 14 and create a pressure on the clogging valve 17 causing the clogging valve 17 to translate along the axis B in the opposite direction to the indicator pin 16. At this moment, the magnet 171 is no longer positioned inside the second hollow cylinder 138 of the plate 13.When the distance between the magnet 171 and the magnetic surface 162 is sufficiently large following the translation of the clogging valve 17 then the magnet 171 no longer exerts a magnetic force on the magnetic surface 162 thus releasing the indicator pin 16 in the extended position following the second compression force F2. Thus, the indicator pin 16 is in the extended position if the removable filter 18 is absent from the device 10 or if the removable filter 18 is clogged. This function of detecting clogging of the removable filter 18 is possible only during commissioning of the turbomachine.

[0057] Thus, the device 10 according to the invention makes it possible to add to the function of detecting clogging of the removable filter 18 already present in the prior art, a function of detecting the removable filter 18 before the turbomachine according to the invention is put into service. This invention avoids making significant modifications and expensive of the prior art device to add the detection function of the removable filter 18.

[0058] With reference to Figure 10, the sealing valve 17 comprises in its center a bore 172 receiving the first compression spring 141.

[0059] Figure 12 is a functional representation of the filter device 10 in the first position with the removable filter 18 mounted on the filter holder 14.

[0060] A method 300, illustrated by FIG. 13, for indicating the presence of the removable filter 18 in the device 10 comprises: a step 301 of mounting the cover 12 on the device 10; a step 302 of pressing the indicator pin 16 translating the indicator pin 16 from the extended position to the retracted position; for example, the indicator pin 16 can be pressed on the part projecting from the surface of the cover 128 by an operator. if, 303, the removable filter 18 is mounted on the device 10, then the indicator pin 16 is held in the retracted position 311. The magnetic surface 162 of the indicator pin 16 is in contact with the magnet 171 of the clogging valve 17. The magnet 171 holds the indicator pin 16 in the retracted position thus revealing the presence of the removable filter 18 in the device 10; if, 303, the removable filter 18 is absent from the device 10, then the indicator pin 16 translates from the retracted position to the extended position 312.The magnetic surface 162 is not in contact with the magnet 171 in the absence of the removable filter 18 because the plate 13 is in the second position. The indicator pin 16 is not held in the retracted position. The indicator pin 16, by means of the second compression force F2 of the second compression spring 161, will then return to the extended position, thus revealing the absence of the removable filter 18 in the device 10.

[0061] After the assembly step 301, the indicator pin 16 is necessarily in the extended position due to the second compression force F2 of the second compression spring 161.

[0062] Thus, the indication method 300 makes it possible to easily and quickly detect the presence of the removable filter 18 in the device 10 before the turbomachine is put into service by simply pressing the indicator pin 16 when the latter is in the extended position. If, after the pressure step 302, the indicator pin 16 does not return to the extended position then the removable filter 18 is present in the device 10. Otherwise, the removable filter 18 is absent from the device 10.

Claims

DEMANDS

1. A filtering device (10) for a turbomachine comprising: - a filter support (14); - a removable filter (18) cooperating with the filter support (14); - a cover (12) movable in translation relative to the filter support (14); - a clogging valve (17) movable in translation relative to the filter support (14) and connected to one end of the filter support (14) by means of a first compression spring (141) with a first compression force F1; characterized in that the device comprises: - a magnet (171) positioned at one end of the sealing valve (17); - an indicator pin (16) having a magnetic surface (162), being movable in translation relative to the cover (12) and connected to the cover (12) by means of a second compression spring (161) with a second compression force F2, the magnetic surface (162) being opposite the magnet (171), the indicator pin (16) being movable in translation between two positions: o an extended position such that the indicator pin (16) protrudes from a surface of the cover (128); o a retracted position such that the indicator pin (16) is in contact with the magnet (171);the device (10) includes a plate (13) integral with the clogging valve (17), the plate (13) being movable in translation relative to the cover (12) and relative to the indicator pin (16) by means of third compression springs (121) positioned between the plate (13) and the cover (12), the third compression springs (121) having a third compression force F3 greater than the first compression force F1 of the first compression spring (141), the plate (13) being movable in translation between two positions:; - a first position such that the plate (13) is resting on the removable filter (18) and the indicator pin (16) is in the retracted position; a second position such that the tray (13) is away from the cover (12) due to the absence of the removable filter (18) and the indicator pin (16) is in the out position.

2. Device according to the preceding claim characterized in that the tray (13) comprises a first cylindrical surface (131) cooperating with a second cylindrical surface (142) of the filter support (14).

3. Device according to any one of the preceding claims characterized in that the tray (13) comprises a first flat surface (132) in contact with a first circumferential surface (143) of the filter support (14) when the tray (13) is in the second position.

4. Device according to any one of the preceding claims characterized in that the third compression springs (121) are each in contact with the cover (12) and with a second circumferential surface (133) of the tray (13).

5. Device according to any one of the preceding claims characterized in that the third compression springs (121) are positioned in lid housings (127) located in the lid (12).

6. A method for indicating the presence of a filter in a device according to any one of the preceding claims, characterized in that it comprises: - an assembly step (301) of the cover (12); - a pressure step (302) on the indicator pin (16) translating the indicator pin (16) from the extended position to the retracted position; - if (303) the removable filter (18) is mounted on the device (10), then the indicator pin (16) is held in the retracted position (311); - if (303) the removable filter (18) is absent from the device (10), then the indicator pin (16) translates from the retracted position to the extended position (312).

7. Turbomachine comprising a filtering device (10) according to any one of claims 1 to 5.

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