Easy-to-assemble drip-jet oil separator

Abstract

A rotating oil separator sealing device (20) comprising a first element (21) mounted to rotate about a longitudinal axis (Ax) relative to a second element (40), wherein one of the first and second elements (21, 40) comprises a first portion (24) extending radially from the longitudinal axis (Ax) and of which a first outer end (22.11, 25.1) extends at a first distance (d22.1) from the longitudinal axis (Ax), and the other of the first and second elements (21, 40) comprises a ring (40) comprising a first radial wall (41) of which a second inner end (46) delimits an inner opening (47) of which a smallest passage distance (R47) is less than the first distance (d22.1). Turbomachine comprising such a device (20) Figure for abstract: Figure 2

Description

Title of the invention: TITLE OF THE INVENTION Easy-to-assemble drip-jet oil separator Technical field

[0001] The invention relates to the field of sealing devices for bearing enclosures of rotating machines and more particularly to oil-separating sealing devices with dropper nozzles. The purpose of such an oil-separating sealing device is to prevent a transfer, between two neighboring volumes, of liquid particles - in particular lubricant - captured and centrifuged against a wall of a stator. STATE OF THE PRIOR ART

[0002] Climate change is a major concern for many legislative and regulatory bodies around the world. Indeed, various restrictions on carbon emissions have been, are being, or will be adopted by various states. In particular, an ambitious standard applies both to new types of aircraft and those in circulation requiring the implementation of technological solutions in order to make them compliant with current regulations. Civil aviation has been mobilizing for several years now to make a contribution to the fight against climate change.

[0003] Technological research efforts have already made it possible to significantly improve the environmental performance of aircraft. The Applicant takes into consideration the impact factors in all phases of design and development to obtain less energy-intensive, more environmentally friendly aeronautical components and products whose integration and use in civil aviation have moderate environmental consequences with the aim of improving the energy efficiency of aircraft.

[0004] Consequently, the Applicant is constantly working to reduce its negative climate impact by using methods and operating virtuous development and manufacturing processes and minimizing greenhouse gas emissions to the minimum possible in order to reduce the environmental footprint of its activity.

[0005] This sustained research and development work covers new generations of aircraft engines, the lightening of aircraft, particularly through the materials used and lighter on-board equipment, the development of the use of electrical technologies to ensure propulsion, and, as essential complements to technological progress, aeronautical biofuels.

[0006] To this end, the invention is the result of technological research aimed at very significantly improving the performance of aircraft and, in this sense, contributes to reducing the environmental impact of aircraft. For this purpose, the invention relates to reducing the consumption of lubricating oil and limiting the dispersion of this lubricating oil in the environment of the aircraft.

[0007] Conventionally, a bearing of a rotating element of a turbomachine is lubricated and cooled, according to the expected operating conditions, by direct projection of a jet of lubricating oil onto the rolling elements, by a centrifugal distribution of lubricating oil. The bearings and the clouds of oil that they project are confined in enclosures which must be sealed, both to control the circulation of gas between enclosures and guarantee the efficiency of the turbomachine, and to maintain the lubricating fluid (generally oil) in the dedicated circuit, the lubricating oil being able to impair the operation of other components of the turbomachine close to the enclosure or pollute the external environment.A rotating sealing device may alternatively comprise a lip seal, a brush seal, a carbon seal, or a labyrinth seal secured to a fixed element and which bears (lip seal) or is flush with a rotating shaft. To limit the quantity of oil that the seal must stop, it is known to install a drip-jet sealing device - or oil separator - near the seal. The drip-jet consists of a wall secured in rotation to the rotating shaft and which evacuates centrifugally and then by gravity to a collector the oil particles coming into contact with or touching the wall.

[0008] The effectiveness of such a drop lance is directly linked to the diameter of the rotating wall and the clearance that its external diameter leaves with the internal surfaces of the stator which face it. However, this diameter is limited by the assembly / disassembly operations and in particular the fact that the rotating shaft is generally engaged in the casing by carrying out a translation of the shaft in the casing in a direction parallel to the axis of rotation of the shaft. Thus, the diameter of the wall of the drop lance is necessarily less than the minimum diameter of all the stator elements through which the shaft must pass during assembly / disassembly.

[0009] A solution for implementing a more efficient drip-jet sealing device (i.e. one with an increased diameter) requires modifying the machine casing to allow mounting of the rotating shaft by translation orthogonally to the axis of rotation of the rotating shaft. Such mounting requires extensive modification of the casing which is costly and generates other problems of sealing, bearing strength and general strength of all the otherwise axisymmetric parts surrounding the shaft. SUBJECT OF THE INVENTION

[0010] The object of the invention is to facilitate the assembly and disassembly of a rotating oil separator sealing device participating in the oil separator dropper type sealing. Statement of the invention

[0011] For this purpose, a rotating oil separator sealing device is provided comprising a first element mounted to rotate about a longitudinal axis relative to a second element. One of the first and second elements comprises a first portion extending radially from the longitudinal axis and a first outer end of which extends at a first distance from the longitudinal axis. The other of the first and second elements comprises a ring comprising a first radial wall of which a second inner end delimits an inner opening of which a smaller passage distance is less than the first distance.

[0012] This provides a particularly high-performance oil-removing sealing device which achieves a separation that is porous to gas but not porous to liquid particles - particularly lubricant - captured and centrifuged against a wall of a stator. Advantageously, the device has an overlap between the radial wall and the rotating element, which greatly improves the oil removal performance.

[0013] According to other particular, non-exclusive and optional embodiments of the invention: - the first portion is made of a material chosen so as to allow elastic deformation of the first portion leading to a deformed configuration in which the first end extends at a second distance from the longitudinal axis which is substantially equal to the smallest passage distance.

[0014] - the first portion comprises a first double row of plates and / or a first layer of first bristles. For the purposes of this application, a platelet is a short, thin sector-shaped element made of a material that is elastically deformable in the axial direction, but only slightly deformable in the radial direction. A bristle is a short, thin, slender element made of a material that is elastically deformable in the axial direction, but only slightly deformable in the radial direction;

[0015] - the first wall comprises at least a second layer of second bristles;

[0016] - the first bristles and / or the second bristles may comprise surface bristles oleophobic and oleophilic surface hairs;

[0017] - the ring may also comprise a second radial wall which defines with the first wall a groove for receiving the first portion comprising a third groove bottom wall;

[0018] - the first wall comprises a fin projecting from the first wall and extends in a direction forming an acute angle with the longitudinal axis;

[0019] - the third wall comprises a rib;

[0020] - the device may comprise a rotating brush seal of which a third radially outer end comes into contact with the ring.

[0021] The invention also applies to a turbomachine comprising a casing and a sealing device as defined above, in which a rotor of the turbomachine is connected to the first element and the second element is connected to the casing, the casing comprising a housing for receiving a bearing of the rotor.

[0022] Other characteristics and advantages of the invention will appear on reading the following description of a particular non-limiting embodiment of the invention. Brief description of the drawings

[0023] Reference will be made to the attached figures, among which:

[0024] [Fig-1] [Fig.l] is a schematic longitudinal sectional view of an engine aircraft;

[0025] [Fig.2] [Fig.2] is a schematic longitudinal sectional view of a shaft provided of a sealing device according to a first embodiment of the invention;

[0026] [Fig.3] [Fig.3] is a schematic view in longitudinal section of a shaft provided with a sealing device according to a second embodiment of the invention;

[0027] [Fig.4] [Fig.4] is a schematic longitudinal sectional view of a shaft provided of a sealing device according to a third embodiment of the invention;

[0028] [Fig.5] [Fig.5] is a schematic detail view of the sealing device of [Fig.4];

[0029] [Fig.6] [Fig.6] is a schematic view in longitudinal section of a shaft provided with a sealing device according to a fourth embodiment of the invention;

[0030] [Fig.7] [Fig.7] is a schematic longitudinal sectional view of a shaft provided of a sealing device according to a fourth embodiment of the invention.

[0031] DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0032] In a turbomachine, here a turbojet marked 1 in [Fig.l], the air is admitted into an inlet sleeve 2 to pass through a fan comprising a series of rotating blades 3 before splitting into a central primary flow which circulates in a vein called a circulation vein of a primary air flow and a secondary flow surrounding the primary flow.

[0033] The primary flow is compressed by compressor stages 4 and 5 before reaching a combustion chamber 6, after which it expands by passing through turbines 7, before being evacuated, generating thrust. The secondary flow is propelled directly by the fan to generate the main thrust.

[0034] The compressor stages 4 and 5 comprise fixed distributors regularly spaced around a shaft 8 mounted for rotation around a longitudinal axis AX in a nacelle 9 surrounding the assembly. The blades of the compressor stages 4 and 5 and of the turbines 7 are integral in rotation with the shaft 8. The shaft 8 is mounted for rotation relative to the nacelle 9 using several oil-lubricated bearings 10 which are confined in enclosures 11 at the levels of the compressors and the turbines.

[0035] In the present text, the terms "inner" or "internal" and "outer" or "external" are used with reference to the position or orientation relative to the axis of rotation of the turbine of the turbojet engine 1. In the present text, the terms "upstream" and "downstream" are used with reference to the position or orientation of an element according to the direction of air flow in the turbojet engine 1. An axial direction, a radial direction which is orthogonal to the axial direction and a circumferential direction which is orthogonal to the axial and radial directions are also defined.

[0036] With reference to [Fig.2], the enclosure 11 comprises a static casing 12 fixed by an annular flange 13. The casing 12 comprises a downstream partition 14 crossed by the shaft 8 and which is provided with a labyrinth seal 15 known per se.

[0037] The enclosure 11 also comprises a rotating oil separator sealing device 20 which comprises an inner ring 21 mounted integral with the shaft 8 and an outer ring 40 integral with the casing 12.

[0038] The ring 21 comprises a first double row of plates comprising a first series of plates 22 and a second series of plates 23 made of elastomer-fabric composite comprising a fabric reinforcement arming an elastomer matrix. The plates 22.1 to 2236 of the series of plates 22 are all identical and are, here, disc sectors with an amplitude substantially equal to ten degrees. The plates 22.1 to 22.36 constitute first portions 24 of the ring 21. The plate 22.1 extends radially from the longitudinal axis Ax and comprises a first outer end 22.11 which extends at a first distance d22.i from the longitudinal axis Ax.

[0039] The ring 40 comprises a first radial wall 41 and a second radial wall 42. The wall 42 abuts against a radial shoulder 16 of the casing 12 and is connected by a third groove bottom wall 43 to the wall 41 to define a groove 44 for receiving the series of inserts 22 and 23. The wall 41 comprises a second inner end 46 which delimits an annular inner opening 47 of which a first outer radius R4 7 is less than the distance d22.p The groove 44 has a groove depth P44 and the distance d22.1 is, here, chosen so that a penetration of the insert 22.1 into the groove 44 is substantially equal to ten percent of the depth P44 of the groove 44, preferably fifty percent.

[0040] The groove bottom wall 43 comprises a channel 48 which establishes a fluid connection between the groove 44 and a collector groove 17 of the casing 12.

[0041] When mounting the shaft 8 in the casing 12, the ring 40 is introduced into the casing 12 until the wall 42 comes into abutment against the shoulder 16. The shaft 8 is then introduced by translation into the casing 12 parallel to the axis Ax in a direction going from upstream to downstream (from left to right according to the representation in [Fig.2]). The shaft 8 is equipped with a bearing 10 for guiding the rotation of the shaft 8 relative to the casing 12. During the introduction of the shaft 8 into the casing 12, the end 22.11 of the plate 22.1 comes into contact with the wall 41 and undergoes an elastic deformation which brings the end 22.11 into a deformed configuration in which the end 22.11 extends to a second distance from the longitudinal axis Ax which is substantially equal to the first external radius R47. Once the plate 22.1 is in line with the groove 44, it straightens and its end 22.11 then extends into the groove 44.The other inserts 22.2 to 22.36 and 23.1 to 23.36 of the series of inserts 22 and 23 behave identically to the insert 22.1. The translation of the shaft 8 relative to the casing 12 is stopped when the bearing 10 comes into abutment against the ring 40.

[0042] The elastomer-fabric composite which makes up the series of plates 22 and 23 thus allows the series of plates 22 and 23 to pass through the opening 47 and then straighten them to extend between the walls 41 and 42, which allows an improvement in the oil filtering performance of the device 20 while facilitating its assembly. The device 20 delimits two volumes between which extends a separation porous to air but not porous to oil particles which are captured and centrifuged against the wall of the casing 9. Its assembly can be carried out by longitudinal engagement without requiring specific arrangements of the casing.

[0043] Elements identical or analogous to those previously described will bear a numerical reference identical to this in the following description of a second embodiment of the invention.

[0044] According to a second embodiment shown in [Fig.3], the ring 21 comprises a single portion 24 which comprises a sheet 25 (or row) of first bristles 26 and 27, a first outer end 25.1 of which extends at a distance d25.i from the longitudinal axis Ax. The first bristles comprise bristles 26 with an oleophobic surface and bristles 27 with an oleophilic surface which are arranged so as to avoid the creation of a continuous film of liquid in the sheet 25 of first bristles 26 and 27.

[0045] According to a third embodiment shown in Figures 4 and 5, the wall 41 comprises a first fin 49 projecting from the wall 41 to extend in a direction which forms an acute angle a49 with the longitudinal axis Ax. The wall 42 also comprises, symmetrically, a second fin 50 projecting of the wall 42 to extend in a direction which forms an acute angle a50 with the longitudinal axis Ax.

[0046] The bottom wall 43 comprises, here, a central rib 51 which is connected to the bottom wall 43 by two fillets 51.1 and 51.2. Two channels 52 and 53 connect the groove bottom 43 thus defined to the collector groove 17.

[0047] According to a fourth embodiment shown in [Fig. 6], the wall 41 comprises two layers 55 and 56 of second bristles 57. The second bristles 57 comprise bristles 58 with an oleophobic surface and bristles 59 with an oleophilic surface. Identicaly, the wall 42 comprises two layers 60 and 61 of bristles 57 which comprise bristles with an oleophobic surface and bristles with an oleophilic surface. The layers 55, 56, 60 and 61 are integral with a porous support 62 placed at the bottom of the groove 44 and ensure both capture of the oil and their routing towards the support 62. The porosity of the support 62 transfers the oil thus captured into the groove 17 via the channel 48.

[0048] The rolling bearing 10 could be replaced by a liquid fluid bearing in an enclosure with gaseous ambient fluid, the oil-separating sealing device according to the invention aims mainly to operate a drip guard / oil-separator function, but an alternative consists of making it provide a sealing function. For this, during the design, the rotating brush will be defined, in the distribution, the density, the length, and the affinity to the oil of the bristles, so as to limit the permeability while ensuring the capture and the guidance of the oil particles towards the discharge groove.

[0049] The device 20 then comprises, according to a fifth embodiment shown in [Fig.7], a rotating brush seal 70 of which a third radially external end 71 comes into contact with the second wall 42 of the ring 40.

[0050] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0051] In particular, - although here the first portion is a composite fabric plate with a fabric matrix and glass fibers, the invention also applies to other types of materials for the first portion, such as for example polymer fibers, ceramic, carbon, metal, an elastomer with a carbon or silicon chain, or even a highly elastic metal; - although here the first wall comprises two rows of bristles, the invention also applies to a different number of rows of bristles such as for example one sheet or more than two; - I the inner ring is mounted integrally to the shaft, using a connection by shrinking, gluing or screwing; although here the first portion is a composite elastomer plate comprising a fabric reinforcement arming an elastomer matrix, the invention also applies to other types of materials for the first portion, such as for example polymer fibers, ceramic, carbon, metal, a carbon or silicon chain elastomer, or even a highly elastic metal. The plates can be made of metal of a thickness and an alloy ensuring a large amplitude of elastic deformation; although here the interior opening is circular with a first radius, the invention also applies to other types of interior openings such as, for example, square, triangular or polygonal openings. The smallest passage distance corresponds to the distance considered in a radial plane and which separates the axis from the portion of the first wall closest to the axis; although here the row of inserts is a double row, the invention also applies to rows of inserts comprising more than two series of inserts, such as for example a triple or quadruple row of inserts; although here the series of plates comprise thirty-six plates in the form of sectors of amplitude substantially equal to ten degrees, the invention also applies to other types of series of plates such as for example series which would comprise plates whose amplitude would be between five and twenty-five degrees according to the diameters of the shaft and the enclosure, their number being adjusted to substantially cover - apart from the spaces between plates - a total sector of three hundred and sixty degrees.

Claims

Claims

1. A rotary oil separator sealing device (20) comprising a first element (21) mounted to rotate about a longitudinal axis (Ax) relative to a second element (40), wherein one of the first and second elements (21, 40) comprises a first portion (24) extending radially from the longitudinal axis (Ax) and of which a first outer end (22.11, 25.1) extends at a first distance (d22.1) from the longitudinal axis (Ax), and the other of the first and second elements (21, 40) comprises a ring (40) comprising a first radial wall (41) of which a second inner end (46) delimits an inner opening (47) of which a smallest passage distance (R47) is less than the first distance (d22.1), wherein the first portion (24) is made of a material chosen so as to allow elastic deformation of the first portion (24) leading to a deformed configuration in which the first end (22.11, 25.1) extends to a second distance from the longitudinal axis (Ax) which is substantially equal to the smallest passage distance (R47).

2. .Rotating oil separator sealing device (20) according to claim 1, in which the first portion (24) comprises a first double row of plates (22, 23) and / or a first layer (25) of first bristles (26, 27).

3. A rotating oil separator sealing device (20) according to claim 3, wherein the first wall (41) comprises at least one second layer (55, 56, 60, 61) of second bristles (58, 59).

4. A rotating oil separator sealing device according to claim 3 or 4, wherein the first bristles (26, 27) and / or the second bristles (58, 59) comprise bristles with an oleophobic surface and bristles with an oleophilic surface.

5. Rotary oil separator sealing device (20) according to any one of the preceding claims, in which the ring (40) also comprises a second radial wall (42) which defines with the first wall (41) a groove (44) for receiving the first portion (24) comprising a third wall (43) at the bottom of the groove (44).

6. A rotating oil separator sealing device (20) according to any preceding claim, wherein the first wall (41) comprises a fin (49) projecting from the first wall (41) and extending inside the groove in a direction forming an acute angle (a49) with the longitudinal axis (Ax).

7. A rotating oil separator sealing device (20) according to claim 5, wherein the third wall (43) comprises a rib (51).

8. Rotating oil separator sealing device (20) according to any one of the preceding claims, comprising a rotating brush seal (70) of which a third radially external end (71) comes into contact with the ring (40).

9. Turbomachine (1) comprising a casing (12) and a rotating oil separator sealing device (20) according to any one of the preceding claims, in which a rotor (8) of the turbomachine (1) is connected to the first element (21) and the second element (40) is connected to the casing (12), the casing (12) comprising a housing for receiving a bearing (10) of the rotor (8).

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