Device for centering and guiding rotation of turbine engine shaft with optimized lubrication of rolling elements with lubricant discharged from SFD

Abstract

The invention relates to a device (30) for centering and guiding the rotation of a turbine engine shaft, comprising a rolling bearing (32), a bearing support (34) and an annular damping cavity (52) formed between an inner annular surface (50) of the bearing support (34) and an outer annular surface (48) of an outer ring (38) of the bearing. A drain conduit (70) formed in the outer ring (38) connects a fluid inlet (72) to the annular damping cavity (52) to a fluid outlet (74) opening through an inner annular surface (44) of the outer ring (38) and inclined towards rolling elements (40) of the annular row of the bearing to lubricate these elements with liquid lubricant discharged from the annular damping cavity (52). The position of the supply conduit (60) opening through the inner annular surface (50) of the bearing support (34) is axially offset relative to the fluid inlet (72).

Description

Technical Field

[0001] This invention relates to the field of turbine engines, particularly to turbine engines for aircraft, and more particularly to a device for centering and guiding the rotation of a turbine engine rotor shaft, the device comprising a squeeze diaphragm damping bearing, also known as an "SFD" bearing. Background Technology

[0002] As explained, for example, in the applicant’s document EP1650449B1, the SFD bearing type device for centering and guiding the rotation of a turbine engine rotor shaft is a known device for damping shaft vibration.

[0003] The attachment of such a device is shown schematically for reference. Figure 1A Reference numeral 210 indicates the rotor shaft of a turbine engine designed to propel an aircraft, such as a turbojet engine or turboprop. This rotor shaft 210 is centered and guided to rotate within rolling bearings 212. The rolling bearings comprise an outer ring 214 supported by a resiliently deformable hollow structure 216, commonly referred to as a "squirrel cage" or "flexible cage," which itself is supported by the turbine engine's stator structure to provide a degree of radial or orbital motion to the outer ring under shaft vibration, such as after imbalance.

[0004] An outer ring 214 is mounted within a cylindrical housing 218 defined by a bearing support 220 to form a squeezed film damper (SFD) around the outer ring 214. For this purpose, an annular damping cavity 222 is defined around the outer ring 214 by a cylindrical surface 221 of the bearing support 220 defining the housing 218, and is axially closed by an annular seal 224 mounted in an annular groove 226 formed in the outer cylindrical surface of the outer ring 214. In the field of aircraft turbojet engines or turboprop aircraft, particularly in areas exposed to the highest temperatures, the annular seal 224 is typically a resiliently deformable slit ring made of a high-temperature resistant metal. This type of seal is sometimes referred to as a "metal section" or "piston ring" because it is commonly used to ensure piston sealing.

[0005] The annular cavity 222 is filled with a lubricant (usually oil) which is delivered via one or more inlet orifices 228 formed by radial holes in the housing 220 and leading to an annular groove 230 formed in a cylindrical surface 221 and leading to the annular cavity 222.

[0006] Therefore, any orbital movement of the outer ring will result in compression of the lubricant film defined by the aforementioned cavity, which causes damping.

[0007] This damping capability allows for a reduction in design loads, thereby lightening the structure and reducing overall mass.

[0008] To prevent the lubricant from being overheated within this cavity, the lubricant is continuously supplied to and discharged from the cavity to ensure continuous flow. The lubricant typically discharges via one or more leakage sections formed at the annular seal that axially defines the cavity. These leakage sections are typically defined by slits in the sections forming the seal and / or by recesses formed in these sections.

[0009] Furthermore, Figure 1 of the applicant's document EP3850233A1 illustrates a bearing of the aforementioned type within the rear section of a turbojet engine, wherein the bearing establishes a load path between the downstream end of the low-pressure rotor shaft and the exhaust housing. In this example, lubrication of the bearing is provided by lubricant delivered from a radially outer region relative to the bearing via one or more conduits, for example, extending through one or more arms through the exhaust housing and ending at one or more nozzles, the nozzles leading to a housing defined downstream of and adjacent to the bearing.

[0010] Figure 1 of document EP3850233A1 illustrates the fact that available space in the environment near a bearing can be quite limited. This particularly restricts the options for lubricating the bearing from upstream and downstream, in which case, as shown in Figure 1, lubricant supply must be made from a radially outer region relative to the bearing (rather than from a conduit extending inside the shaft). However, lubrication of both opposite sides of such a bearing is often necessary to increase its mechanical resistance and reduce the thermal gradient within it, thereby extending its service life. Summary of the Invention

[0011] The present invention relates to a device for centering and guiding the rotation of a turbine engine rotor shaft of the SFD bearing type, which is suitable for situations where there is little space available for a bearing lubrication device that requires the use of lubricant delivered from a radially outer region relative to the bearing.

[0012] Therefore, the present invention provides a device for centering and guiding the rotation of a turbine engine shaft, the device comprising: - A rolling bearing, comprising an inner ring, an outer ring defining the axis of the rolling bearing and having an outer annular surface, and an annular row of rolling elements disposed between the outer annular surface of the inner ring and the inner annular surface of the outer ring. - Bearing support, the inner annular surface of the bearing support surrounds the outer annular surface of the outer ring; - An annular damping cavity is formed between the inner annular surface of the bearing support and the outer annular surface of the outer ring, and is axially defined between two annular seals, each formed by a freely overlapping slit metal ring. - A supply conduit is formed in the bearing support and passes through the inner annular surface of the bearing support to the annular damping cavity to supply liquid lubricant to the annular damping cavity, thereby forming a damping film in the annular damping cavity. - A discharge duct is formed in the outer ring and connects the fluid inlet to the fluid outlet. The fluid inlet passes through an opening on the outer annular surface of the outer ring within the annular damping cavity. The fluid outlet is: - The inner annular surface of the outer ring leads to an axially offset position relative to the rolling elements of the annular row, wherein the inner annular surface of the outer ring faces the outer annular surface of the inner ring, and - The rolling elements are tilted toward the annular row to lubricate them using liquid lubricant discharged from the annular damping cavity.

[0013] The configuration of this device, particularly the configuration of the fluid outlet on the outer ring of the bearing, allows lubrication of one side of the rolling element using lubricant from the damping chamber. This eliminates the need for a dedicated lubrication device, such as one or more nozzles, while remaining compatible with lubricant supply from a radially outer region. Therefore, the device according to the invention is particularly advantageous when space is limited for arranging a dedicated lubrication device and when lubrication is required on both sides of the bearing.

[0014] Furthermore, the position of the supply conduit through the inner annular surface opening of the bearing support is axially offset relative to the position of the discharge conduit through the outer annular surface opening of the outer ring (i.e., the aforementioned fluid inlet position). This arrangement optimizes the process of forming a damping film by the liquid lubricant. This is especially true considering that the aforementioned axial offset is substantial relative to the axial extent of the annular damping cavity.

[0015] In a preferred embodiment, the positions where the supply pipe passes through the inner annular surface opening of the bearing support and the positions where the discharge pipe passes through the outer annular surface opening of the outer ring are arranged on both sides of the central axial plane of the annular damping cavity.

[0016] In a preferred embodiment, the outer annular surface of the inner ring of the rolling bearing has an annular portion that flares out toward the rolling elements of the annular row and is axially offset relative to these elements to form an acceleration ramp for liquid lubricant from the fluid outlet.

[0017] In a preferred embodiment, the supply conduit includes an annular gas distribution chamber and an annular distribution passage, the annular distribution passage leading to the annular gas distribution chamber at one end and passing through the inner annular surface of the bearing support at the opposite end to the annular damping cavity.

[0018] In a preferred embodiment, the bearing support includes two corresponding concentric annular components that are rigidly fixed to each other and have two corresponding contact surfaces that contact each other, and the annular air distribution chamber is formed by an annular groove formed in one of the contact surfaces and defined by the other of the contact surfaces.

[0019] In a preferred embodiment, the supply conduit leads to an annular distribution groove, which is formed in the inner annular surface of the bearing support and leads annularly to the annular damping cavity.

[0020] In a preferred embodiment, the discharge conduit includes: an annular exhaust chamber; at least one supply passage connected at one end to the annular exhaust chamber and forming a fluid inlet at the opposite end of the supply passage; and at least one injection passage connected at one end to the annular exhaust chamber and opening at the opposite end of the injection passage along an injection axis inclined toward the rolling element of the annular ring through the inner annular surface of the outer ring to form a fluid outlet.

[0021] In a preferred embodiment, the annular exhaust chamber is a first annular exhaust chamber, at least one injection passage is a first injection passage, the injection axis is a first injection axis, and the fluid outlet is a first fluid outlet. Furthermore, the discharge conduit includes a second annular exhaust chamber connected to the annular damping chamber, and at least one second injection passage. One end of the second injection passage is connected to the second annular exhaust chamber, and at the opposite end of the second injection passage, at a position axially opposite to the first fluid outlet on the side opposite to the rolling element of the annular row, an opening is formed along a second injection axis inclined toward the rolling element of the annular row, passing through the inner annular surface of the outer ring, to form a second fluid outlet capable of lubricating the rolling element using fluid discharged from the annular damping chamber.

[0022] In a preferred embodiment, the discharge conduit includes at least one connection passage connecting the first annular exhaust chamber to the second annular exhaust chamber, thereby providing a connection between the second annular exhaust chamber and the annular damping cavity via a supply passage, the first annular exhaust chamber, and the connection passage.

[0023] In a preferred embodiment, the fluid inlet is a first fluid inlet, and the supply passage is a first supply passage. Furthermore, the discharge conduit includes at least one second supply passage, one end of which is connected to a second annular exhaust chamber, and a second fluid inlet is formed at the opposite end of the second supply passage. The second fluid inlet passes through the outer annular surface of the outer ring and leads to the annular damping cavity at a position axially offset relative to the first fluid inlet, thereby providing connection between the second annular exhaust chamber and the annular damping cavity via the second supply passage.

[0024] In a preferred embodiment, the supply pipe leading to the annular damping cavity is axially located between the first fluid inlet and the second fluid inlet.

[0025] In a preferred embodiment, the device includes a lubrication nozzle configured to spray liquid lubricant onto the side of the rolling element of the annular row opposite the fluid outlet.

[0026] In a preferred embodiment, the fluid outlet and / or, where applicable, the second fluid outlet, are tangentially inclined to apply rotational motion to the liquid lubricant.

[0027] In a preferred embodiment, the inner annular surface of the outer ring is a rotating cylindrical surface and extends axially beyond the rolling elements of the annular row on both sides. Attached Figure Description

[0028] The invention will be better understood by reading the following description, given by way of non-limiting example, and with reference to the accompanying drawings, and further details, advantages, and features of the invention will become apparent, as illustrated in the drawings: The already described [ Figure 1A [Illustrated axial section and perspective view of a known type of device for centering and guiding the rotation of a shaft in a turbine engine;] [ Figure 1B [This is a schematic axial cross-sectional view of an aircraft turbine engine;] [ Figure 1C [Illustration 1] is a schematic axial cross-sectional view of the rear of a known type of turbine engine at a large scale. [ Figure 2A [This is a preferred embodiment of the invention for making such...] Figure 1B A schematic axial cross-sectional view of the device that centers the shaft and guides its rotation in a turbine engine; [ Figure 2B [It belongs to] Figure 2A A partial schematic perspective view of the annular seal of the device; [ Figure 2C ] is similar to Figure 2A The view shows the device in a linear rotation configuration; [ Figure 3 ] is similar to Figure 2A The view shows a variation of the device; [ Figure 4 ] is similar to Figure 2A The view shows another variation of the device; [ Figure 5 ] is similar to Figure 2A The view shows another variation of the device; [ Figure 6 ] is similar to Figure 2A The view shows another variation of the device; [ Figure 7 ] is similar to Figure 2A The view shows another variation of the device; [ Figure 8 ] is similar to Figure 2A The view shows another variation of the device.

[0029] In the following description and accompanying drawings, the same reference numerals may refer to similar or equivalent elements. Detailed Implementation

[0030] Figure 1B A turbine engine 10 is shown, such as a dual-rotor, dual-flow engine for an aircraft. The turbine engine typically includes a fan 12 for drawing in an air flux F1, which is split downstream of the fan into a primary flux F2 flowing in a primary flux flow path (hereinafter referred to as the primary path PV) and a secondary flux F3 flowing in a secondary flux flow path (hereinafter referred to as the secondary path SV), which is arranged around the primary path PV.

[0031] For illustration, a turbofan engine typically includes a low-pressure compressor 14, a high-pressure compressor 16, a combustion chamber 18, a high-pressure turbine 20, and a low-pressure turbine 22 that collectively define the main path PV. In a known manner, the respective rotors of the high-pressure compressor and the high-pressure turbine are connected via a so-called "high-pressure shaft" 24, while the respective rotors of the low-pressure compressor and the low-pressure turbine are connected via a so-called "low-pressure shaft" 26. These rotors are rotatably mounted about the turbine engine's axis 28. For this purpose, devices 30A and 30B ensure that the high-pressure shaft 24 is centered and guided in its rotation, while devices 30C to 30E ensure that the low-pressure shaft 26 is centered and guided in its rotation. These devices 30A to 30E, each including rolling bearings, establish a load path on one side between the shafts 24 and 26 and on the other side between the turbine engine housing in a known manner.

[0032] Throughout this description, the axial direction X is the direction of axis 28. Further considering a cylindrical coordinate system centered on axis 28, where the radial direction R is orthogonal to and passes through axis 28 at all points, and the positive radial or circumferential direction C is orthogonal to both the radial direction R and axis 28 at all points. The transverse plane is a plane orthogonal to axis 28. The terms "inner" and "outer" refer to the relative proximity and relative distance of an element relative to axis 28, respectively. Finally, the "upstream" and "downstream" directions are defined by referencing the approximate flow direction FD of the gas along the axial direction X in the primary path PV and secondary path SV of the turbine engine.

[0033] Figure 1C Turbine engines (such as...) are shown at a large scale. Figure 1B The rear of the turbine engine, and in particular, allows observation of the rotor of the low-pressure turbine 22, which is formed by a blade disk 22A and an exhaust casing 29 arranged downstream of the turbine 22. The blade disk 22A and the distributor 22B are arranged alternately and connected to the low-pressure shaft 26.

[0034] Figure 1C Also shown is a device 30 for centering and guiding the rotation of the low-pressure shaft 26, which, for example, corresponds to... Figure 1B Device 30E.

[0035] The device 30 typically includes a rolling bearing 32 and a bearing support 34 rigidly connected to the exhaust housing 29.

[0036] The rolling bearing 32 includes an inner ring 36, an outer ring 38, and an annular row of rolling elements 40, such as rollers, arranged between the inner ring 36 and the outer ring 38.

[0037] The outer ring 38, for example, is composed of similar... Figure 1A The structure 216 is supported by an elastically deformable hollow structure 31 or "cage", the hollow structure or "cage" itself is fastened to a flange 33, the flange 33 is fixed to a bearing support 34, and more generally, to an exhaust housing 29.

[0038] An annular damping cavity 52 is formed between the inner annular surface of the bearing support 34 and the outer annular surface of the outer ring 38. This annular damping cavity 52 is designed to receive liquid lubricant to form a squeezed film damper (SFD). A lubricant conduit 35 leads to this cavity 52, and a lubricant supply conduit 37 is connected to the lubricant conduit 35.

[0039] Furthermore, lubrication of the bearing 32 is provided by a lubrication nozzle 39, which is designed to deliver lubricant from a radially outer region and be located downstream of the bearing 32, and to spray the lubricant upstream onto the downstream face of the bearing 32. This nozzle extends, for example, through one of the openings defined by the cage 31.

[0040] Figure 1C An exemplary configuration is shown in which space is particularly limited for means of lubricating the bearing (particularly its upper surface). In the example shown, this limitation stems from the fact that a "segmented radial" type JRS annular seal, as shown in Figure 1 of document EP2870323A1, is arranged around the device 30. This positioning of the JRS seal allows the contact track of the JRS seal to be lubricated without the risk of lubricant being directly sprayed onto the interface between the seal and the contact track.

[0041] The object of this invention is to enable configurations that provide a small space (e.g.) Figure 1C The bearing is optimally lubricated in the configuration shown.

[0042] This invention is generally applicable to any type of turbine engine, whether it is a single-flow or multi-flow, single-rotor or multi-rotor turbine engine.

[0043] More specifically, the present invention relates to a device for centering and guiding the rotation of a shaft within a turbine engine of this type of SFD bearing.

[0044] Figure 2A Such a device 30 is shown. This device 30 includes, in particular, a rolling bearing 32 and a bearing support 34.

[0045] The rolling bearing 32 includes an inner ring 36, an outer ring 38, and an annular row of rolling elements 40 arranged between the outer annular surface 42 of the inner ring 36 and the inner annular surface 44 of the outer ring 38. The rolling elements 40 are typically associated with an annular cage in a known manner.

[0046] The outer ring 38 is typically designed to be made of a flexible, deformable openwork structure (such as...) Figure 1C 31) Bearing structure.

[0047] In the example described below, the outer ring 38 is formed by an inner annular body 38A defining an inner annular surface 44 and an annular band 38B mounted around the inner annular body 38A by strapping. This particular feature facilitates the manufacture of the outer ring 38. However, the outer ring 38 can alternatively be produced as a single piece, for example, by means of additive manufacturing techniques.

[0048] When the rolling element 40 is a roller, the inner annular surface 44 of the outer ring 38 is a cylindrical surface that rotates along an axis 46 defined as the bearing 32 and, for example, coincides with the axis 28 of the turbine engine.

[0049] Furthermore, the outer ring 38 has an outer annular surface 48. In this case, the outer annular surface 48 is defined by an annular band 38B. Additionally, the inner annular surface 50 of the bearing support 34 surrounds the outer annular surface 48 of the outer ring 38. The two surfaces 48 and 50 are centered along the bearing axis 46.

[0050] An annular damping cavity 52 is formed between the inner annular surface 50 of the bearing support and the outer annular surface 48 of the outer ring. The annular damping cavity 52 is used to receive liquid lubricant to form a damping film or "squeezed film" and is axially defined between two annular seals 54A and 54B. The two annular seals 54A and 54B are installed in corresponding annular grooves formed in the surface 48 so that they can make 360-degree contact with the surface 50 respectively.

[0051] These seals 54A, 54B are configured to tightly or substantially tightly axially close the annular damping cavity 52, which differs from seals typically used in known extrusion film bearings, which are configured to form at least one leakage section as described above.

[0052] For this purpose, seals 54A and 54B are, for example, overlapping slit metal rings. Figure 2B As shown, this type of seal without a notch has two ends defined on both sides of the slit, wherein one end 56A forms a tenon, and the other end 56B has a slot having a shape substantially complementary to the tenon and formed on the side of the seal opposite to the annular damping cavity 52, so as to receive the tenon in the circumferential direction with a small gap (typically on the order of a tenth of a millimeter to a few millimeters), so that the seal does not have a cross-section of fluid passage directly into the annular damping cavity 52, thus maximizing the sealing performance relative to the lubricant in the annular damping cavity 52.

[0053] In addition, the device 30 includes a supply conduit 60 formed in the bearing support 34 and passing through the inner annular surface 50 of the bearing support to the annular damping cavity 52, so as to supply liquid lubricant to the annular damping cavity to form the aforementioned damping film in the annular damping cavity.

[0054] In this specification, "pipeline" should generally be understood as any channel or network of channels suitable for the flow of liquids.

[0055] The supply line 60 includes one or more inlet passages 62 for lubricant, which can be sourced from any circuit or source in the turbine engine that can be used for this purpose.

[0056] exist Figure 2AIn the example shown, the supply conduit 60 also includes an annular air distribution chamber 64 and an annular distribution passage 66, which leads to the annular air distribution chamber 64 at one end and passes through the inner annular surface 50 of the bearing support 34 to the annular damping cavity 52 at the opposite end. The air chamber 64 facilitates temperature homogenization of the lubricant before it reaches the annular damping cavity 52.

[0057] To facilitate the formation of the annular gas distribution chamber 64, the bearing support 34 (or at least the annular portion of the defined inner annular surface 50 of the bearing support) can be produced by means of additive manufacturing technology.

[0058] Furthermore, the outer annular surface 48 of the outer ring 38 of the bearing advantageously includes an annular distribution groove 68, with the distribution passage 66 opening toward the annular distribution groove 68 to promote the homogenization of the lubricant as it reaches the annular damping cavity 52.

[0059] In addition, the device 30 includes a discharge pipe 70 formed in the outer ring 38, and has a fluid inlet 72 at one end and a fluid outlet 74 at the opposite end.

[0060] The fluid inlet 72 passes through the outer annular surface 48 of the outer ring and leads to the annular damping cavity 52.

[0061] Fluid outlet 74 passes through the inner annular surface 44 of the outer ring to an axially offset position relative to the rolling elements 40 of the annular row, wherein the inner annular surface 44 of the outer ring 38 (directly) faces the outer annular surface 42 of the inner ring 36. It should be understood that these two surfaces 42 and 44 are then separated from each other on each side of the rolling elements 40 of the annular row by annular spaces 75A, 75B in which the fluid outlet 74 opens and extends axially upward to the rolling elements 40 of the annular row. Furthermore, the fluid outlet 74 is inclined toward the rolling elements 40 so as to lubricate these elements using liquid lubricant discharged from the annular damping cavity 52. ​​In operation, due to the perfect or near-perfect tightness provided by the overlapping seals 54A, 54B, the pressure of this liquid is substantially equal to the supply pressure of the annular damping cavity 52 (excluding head loss). Depending on the desired damping level, this pressure is typically from a few bar to tens of bar.

[0062] The fluid outlet 74 may be formed by the end of a jet passage 76 formed in the outer ring 38 or by the respective ends of a plurality of such jet passages 76 distributed around the axis 46. The jet passage 76 or each jet passage 76 defines a respective jet axis 78 inclined toward the rolling element 40, and thus defines the aforementioned inclination of the fluid outlet 74.

[0063] Fluid outlet 74 is calibrated, i.e., the fluid passage cross-section of the fluid outlet is determined according to the desired flow rate and pressure of the lubricant injected from the fluid outlet 74, and to ensure appropriate liquid pressure within the annular damping cavity 52 according to the sought damping level. The dimensions of the fluid passage cross-section defined by the injection passage 76 or by each injection passage 76 are advantageously configured to diffuse the lubricant jet in the manner of an atomizing nozzle.

[0064] Therefore, the present invention enables efficient lubrication of the rolling element 40 by means of lubricant discharged from the annular damping cavity 52 and directly from the inner annular surface 44 of the outer ring 38. This lubrication, achieved using lubricant supplied from a radially outer region relative to the bearing 32 (unlike some known configurations where lubricant is supplied to the bearing from a radially inner region via the shaft), eliminates the need for nozzles or other bulky components, and thus offers advantages even in situations such as… Figure 1C The advantages shown can be achieved even in environments with very little available space.

[0065] In the example shown, the present invention is similar to, for example, Figure 1C The lubrication nozzles 39 shown combine to provide lubrication to the downstream side of the bearing 32, while the fluid outlet 74 provides lubrication to the upstream side of the bearing 32. Thus, this example illustrates another advantage of the invention: the ability to lubricate both sides of the bearing 32 despite limited space. This bilateral lubrication allows for improved mechanical resistance and reduced thermal gradient within the bearing, thereby extending its service life.

[0066] Furthermore, the inner annular surface 44 of the outer ring 38 preferably extends not only around the rolling elements 40 of the annular row, but also beyond the rolling elements 40 of the annular row in the axial direction and extends to both sides thereon, so that the assembly consisting of the rolling elements 40 of the annular row and the inner ring 36 can perform a certain axial movement or linear rotation. When the device 30 is located in a region with particularly high temperatures (e.g., inside a turbine), this axial movement occurs especially due to axial thermal expansion.

[0067] In fact, the fluid outlet 74 formed in the inner annular surface 44 allows for lubrication of the rolling element 40 without the need for components that could impede the axial movement of the rolling element 40 and the inner ring 36. Therefore, Figure 2A The device 30 is shown in its maximum straight-turn configuration in the upstream direction, while Figure 2C The device 30 is shown in its maximum straight-turn configuration in the downstream direction. Therefore, in Figure 2C In the middle, the rolling element 40 and the inner ring 36 of the annular row are already relative to Figure 2A Axial (rightward) movement. The nominal configuration of device 30 is defined such that the rolling elements 40 of the annular chain and the inner ring 36 relative to... Figure 2A and Figure 2C The extreme position is in the middle position.

[0068] The outer annular surface 42 of the inner ring 36 of the bearing preferably has an annular portion 79 that is flared toward the rolling elements 40 of the annular row and axially offset relative to these elements on the same side as the fluid outlet 74, so as to form an acceleration ramp for the liquid lubricant from the fluid outlet 74. Due to the rotation of the inner ring 36 and the centrifugal force generated when the lubricant comes into contact with the aforementioned annular portion 79 of the surface 42, the lubricant reaching the annular portion 79 will indeed be accelerated toward the rolling elements 40. This flared annular portion 79 is particularly useful when the device is in a linear rotation configuration, which results in a relative axial distance between the fluid outlet 74 and the rolling elements 40 of the annular row, such that the fluid outlet 74 is axially located at the annular portion 79.

[0069] The injection axis 78 is preferably within the angle defined between the two half-lines L1 and L2, each originating from the center of the inlet of the injection passage 76, such that: when the device is in the maximum straight-turn configuration in the downstream direction, the first half-line L1 passes through the point at the base of the flared annular portion 79 of the outer annular surface 42 of the inner ring 36. Figure 2C ); and when the device is in its maximum straight-turn configuration in the upstream direction, the second half-line L2 passes through the radial outer end of the rolling element 40 of the annular row ( Figure 2A Therefore, regardless of the axial position of the rolling elements 40 of the annular row between the two extreme straight-line turning positions, these elements 40 receive lubricant directly or after centrifugal separation on the flared annular portion 79.

[0070] Furthermore, the fluid outlet 74 is advantageously tangentially inclined to apply rotational motion to the liquid lubricant. In this case, it should be understood that the discharge passage or the discharge axis 78 of each discharge passage is not included in any plane containing the bearing axis 46, and thus such an axis 78 extends in a direction that includes not only a component in the axial direction X but also a component in the circumferential direction C.

[0071] Furthermore, the position where the supply conduit 60 passes through the opening of the inner annular surface 50 of the bearing support 34 is axially offset relative to the position where the discharge conduit 70 passes through the opening of the outer annular surface 48 of the outer ring 38. These two positions are preferably arranged on either side of the intermediate axial plane M of the cavity 52, and ideally near the two opposite axial ends of the cavity 52 defined by seals 54A and 54B, respectively. Therefore, the trajectory followed by the liquid within the cavity 52 to reach the discharge conduit 70 can be maximized, which tends to promote uniformity of liquid pressure within the cavity 52, thus allowing for optimization of the damping capacity of the SFD.

[0072] exist Figure 2A In the example shown, the discharge conduit 70 includes: an annular exhaust chamber 80; at least one supply passage 82, which is connected at one end to the annular exhaust chamber 80 and forms the aforementioned fluid inlet 72 at the opposite end; and injection passages 76 or each injection passage 76, which is connected at one end to the annular exhaust chamber 80 and forms the aforementioned fluid outlet 74 at the opposite end. The annular exhaust chamber 80 enables the homogenization of lubricant temperature before lubricant is injected toward the rolling element through the injection passages 76 or each injection passage 76.

[0073] The annular exhaust chamber 80 is defined, for example, by an annular groove formed in the outer annular surface 84A of the inner annular body 38A and the inner annular surface 84B of the annular belt 38B. Therefore, the exhaust chamber can be easily manufactured by machining the outer annular surface 84A of the inner annular body 38A before assembling the inner annular body 38A and the annular belt 38B.

[0074] exist Figures 2A to 2C The rolling element 40 of the device 30 seen in the image is a roller.

[0075] Figure 3 The diagram shows that the rolling element 40 is a variation of a ball.

[0076] exist Figure 4 In the variant shown, the supply conduit 60 leads to an annular distribution groove 90, which is formed in the inner annular surface 50 of the bearing support 34 and annularly connects to the annular damping cavity 52. ​​In this case, the annular distribution groove 90 functions similarly to the annular air distribution chamber 64 and the annular distribution groove 68 described above. Unlike the air chamber 64, the annular distribution groove 90 can be produced by machining the inner annular surface 50 of the bearing support 34, providing an option to easily manufacture the bearing support 34 using techniques other than additive manufacturing.

[0077] exist Figure 5 In another variant shown, the annular exhaust chamber 80 is defined by an annular groove formed in the inner annular surface 84B of the annular belt 38B and the outer annular surface 84A of the inner annular body 38A. Therefore, the exhaust chamber can be easily manufactured by machining the inner annular surface 84B of the annular belt 38B before assembling the annular belt 38B with the inner annular body 38A.

[0078] exist Figure 6In another variation shown, the bearing support 34 is formed by two corresponding concentric annular components 34A and 34B, which are rigidly fixed to each other and have two corresponding contact surfaces 92A and 92B that contact each other. Furthermore, the annular filling chamber 64 is formed by an annular groove formed in one of the contact surfaces and defined by the other contact surface. This particular feature facilitates the manufacture of the bearing support 34.

[0079] Therefore, in Figure 6 In the example shown, the bearing support 34 is formed by an outer annular body 34A and an annular belt 34B, which is mounted inside the outer annular body 34A by binding and defining the inner annular surface 50 of the bearing support 34. Furthermore, the annular air distribution chamber 64 is formed by an annular groove, which is produced by machining the inner annular surface 92A of the body 34A, and is further defined by the outer annular surface 92B of the annular belt 34B.

[0080] In this case, the distribution path 66 is formed by passing through the annular band 34B.

[0081] exist Figure 7 and Figure 8 In the variant shown, for clarity, the annular exhaust chamber 80 is referred to as the first annular exhaust chamber, the injection passage 76 or each injection passage 76 is referred to as the first injection passage, the injection axis 78 or each injection axis 78 is referred to as the first injection axis, and the fluid outlet 74 is referred to as the first fluid outlet.

[0082] In these variations, the discharge conduit 70 further includes a second annular exhaust chamber 100 connected to the annular damping cavity 52, and at least one second injection passage 102. The at least one second injection passage 102 is connected at one end to the second annular exhaust chamber 100 and, at its opposite end, passes through an opening in the inner annular surface 44 of the outer ring 38 at a position axially positioned relative to the rolling elements 40 of the annular row on the side opposite to the first fluid outlet 74, along a second injection axis 104 inclined toward the rolling elements 40 of the annular row, to form a second fluid outlet 106. The second fluid outlet 106 is capable of lubricating the rolling elements 40 using fluid discharged from the annular damping cavity 52. ​​Therefore, lubricant from the annular damping cavity 52 can be used to provide lubrication to both opposite sides of the bearing without using any lubrication nozzles. Thus, this variation is particularly suitable for configurations with very limited available space.

[0083] In these variations, the outer annular surface 42 of the inner ring 36 of the bearing preferably has an annular portion 108 that is flared toward the rolling elements 40 of the annular row and axially offset relative to these elements on the same side as the second fluid outlet 106 to form an acceleration ramp for the liquid lubricant from the second fluid outlet 106.

[0084] exist Figure 7 In the example, the discharge conduit 70 also includes at least one connection passage 110 connecting the first annular exhaust chamber 80 to the second annular exhaust chamber 100, whereby the connection between the second annular exhaust chamber 100 and the annular damping cavity 52 is provided via a supply passage 82 (or each supply passage 82) and a connection passage 110 (or each connection passage 110) of the first annular exhaust chamber 80. In this case, as described above, the trajectory of the liquid flowing from the supply conduit 60 to the discharge conduit 70 can be further maximized.

[0085] exist Figure 8 In the example, for clarity, fluid inlet 72 is referred to as the first fluid inlet, and supply passage 82 or each supply passage 82 is referred to as the first supply passage. Furthermore, the discharge conduit 70 includes at least one second supply passage 112 connected at one end to the second annular exhaust chamber 100, and forming a second fluid inlet 114 at the opposite end. This second fluid inlet 114 extends through the outer annular surface 48 of the outer ring to the annular damping cavity 52 at an axially offset position relative to the first fluid inlet 72, thereby providing connection between the second annular exhaust chamber 100 and the annular damping cavity 52 via the second supply passage 112 or each of the second supply passages 112.

[0086] Advantageously, the supply conduit 60 is axially positioned between the first fluid inlet 72 and the second fluid inlet 114, for example, between the first fluid inlet 72 and the second fluid inlet 114, to limit the head loss difference experienced by the lubricant before diffusion by the first fluid outlet 74 and the second fluid outlet 106, and again to maximize the trajectory followed by the liquid flowing from the supply conduit 60 to the discharge conduit 70. Here, these two specific features again ensure optimal damping of the SFD.

Claims

1. A device (30) for centering and guiding the rotation of a turbine engine shaft, said device comprising: - Rolling bearing (32), the rolling bearing includes an inner ring (36), an outer ring (38) defining the axis (46) of the rolling bearing and having an outer annular surface (48), and an annular row of rolling elements (40) arranged between the outer annular surface (42) of the inner ring (36) and the inner annular surface (44) of the outer ring (38). - Bearing support (34), the inner annular surface (50) of the bearing support surrounds the outer annular surface (48) of the outer ring (38). - An annular damping cavity (52) is formed between the inner annular surface (50) of the bearing support (34) and the outer annular surface (48) of the outer ring (38), and is axially defined between two annular seals (54A, 54B), each of which is formed by a freely overlapping slit metal ring. - A supply conduit (60) is formed in the bearing support (34) and passes through the inner annular surface (50) of the bearing support to the annular damping cavity (52) to supply liquid lubricant to the annular damping cavity, thereby forming a damping film in the annular damping cavity; - A discharge pipe (70) is formed in the outer ring (38) and connects a fluid inlet (72) to a fluid outlet (74), the fluid inlet opening through an outer annular surface (48) of the outer ring (38) in the annular damping cavity (52). Wherein, the fluid outlet (74): - The inner annular surface (44) of the outer ring (38) leads to an axially offset position relative to the rolling element (40) of the annular row, wherein the inner annular surface (44) of the outer ring (38) faces the outer annular surface (42) of the inner ring (36), and - Inclined toward the rolling elements (40) of the annular row to lubricate these elements using liquid lubricant discharged from the annular damping cavity (52); Furthermore, the position where the supply pipe (60) passes through the opening of the inner annular surface (50) of the bearing support (34) is axially offset relative to the position where the discharge pipe (70) passes through the opening of the outer annular surface (48) of the outer ring (38).

2. The apparatus according to claim 1, characterized in that, The outer annular surface (42) of the inner ring (36) of the rolling bearing (32) has an annular portion (79) that is flared toward the rolling elements (40) of the annular row and axially offset relative to these elements to form an acceleration ramp for liquid lubricant from the fluid outlet (74).

3. The apparatus according to claim 1 or 2, wherein, The supply conduit (60) includes an annular air distribution chamber (64) and an annular distribution passage (66), the annular distribution passage leading to the annular air distribution chamber (64) at one end and passing through the inner annular surface (50) of the bearing support (34) at the opposite end to the annular damping cavity (52).

4. The apparatus according to claim 3, wherein, The bearing support (34) includes two corresponding concentric annular components (34A, 34B), which are rigidly fixed to each other and have two corresponding contact surfaces (92A, 92B) in contact with each other. The annular air distribution chamber (64) is formed by an annular groove formed in one of the contact surfaces (92A, 92B) and defined by the other of the contact surfaces (92A, 92B).

5. The apparatus according to any one of claims 1 to 4, wherein, The supply conduit (60) leads to an annular distribution groove (90), which is formed in the inner annular surface (50) of the bearing support (34) and leads annularly to the annular damping cavity (52).

6. The apparatus according to any one of claims 1 to 5, wherein, The discharge conduit (70) includes: an annular exhaust chamber (80); at least one supply passage (82) connected to the annular exhaust chamber (80) at one end and forming the fluid inlet (72) at the opposite end of the supply passage; and at least one injection passage (76) connected to the annular exhaust chamber (80) at one end and opening at the opposite end of the injection passage along an injection axis (78) inclined toward the rolling element (40) of the annular ring (38) through the inner annular surface (44) of the outer ring (38) to form the fluid outlet (74).

7. The apparatus according to claim 6, wherein, The annular exhaust chamber (80) is a first annular exhaust chamber, the at least one injection passage (76) is a first injection passage, the injection axis (78) is a first injection axis, the fluid outlet (74) is a first fluid outlet, and wherein the discharge pipe (70) includes a second annular exhaust chamber (100) connected to the annular damping cavity (52) and at least one second injection passage (102), the at least one second injection passage being connected to the second annular exhaust chamber (100) at one end of the second injection passage, and at the opposite end of the second injection passage, at a position axially located relative to the rolling element (40) of the annular row on the side opposite to the first fluid outlet (74), an opening is formed along a second injection axis (104) inclined toward the rolling element (40) of the annular row through the inner annular surface (44) of the outer ring (38) to form a second fluid outlet (106) capable of lubricating the rolling element (40) with fluid discharged from the annular damping cavity (52).

8. The apparatus according to claim 7, wherein, The discharge duct (70) includes at least one connection passage (110) that connects the first annular exhaust chamber (80) to the second annular exhaust chamber (100), thereby providing a connection between the second annular exhaust chamber (100) and the annular damping cavity (52) via the supply passage (82), the first annular exhaust chamber (80) and the connection passage (110).

9. The apparatus according to claim 7, wherein, The fluid inlet (72) is a first fluid inlet, and the supply passage (82) is a first supply passage, and The discharge pipe (70) includes at least one second supply passage (112) connected at one end to the second annular exhaust chamber (100) and forming a second fluid inlet (114) at the opposite end of the second supply passage. The second fluid inlet passes through the outer annular surface (48) of the outer ring (38) and leads to the annular damping cavity (52) at an axial offset position relative to the first fluid inlet (72), thereby providing a connection between the second annular exhaust chamber (100) and the annular damping cavity (52) via the second supply passage (112).

10. The apparatus according to claim 9, wherein, The supply conduit (60) leading to the annular damping cavity (52) is axially located between the first fluid inlet and the second fluid inlet (72, 114).

11. The apparatus according to any one of claims 1 to 6, the apparatus comprising a lubrication nozzle configured to spray liquid lubricant onto the side of the rolling element (40) of the annular row opposite to the fluid outlet (74).

12. The apparatus according to any one of claims 1 to 11, wherein, The fluid outlet (74) and / or, where applicable, the second fluid outlet (106), are tangentially inclined to apply rotational motion to the liquid lubricant.

13. The apparatus according to any one of claims 1 to 12, wherein, The inner annular surface (44) of the outer ring (38) is a rotating cylindrical surface and extends axially beyond the rolling elements (40) of the annular row on both sides.

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