Search

CN-122003548-A - Device for centering and guiding rotation of a turbine engine shaft with optimized lubrication of rolling elements by means of lubricant discharged from SFD

CN122003548ACN 122003548 ACN122003548 ACN 122003548ACN-122003548-A

Abstract

The invention relates to a device (30) for centering a turbine engine shaft and guiding the rotation thereof, comprising a rolling bearing (32), a bearing support (34) and an annular damping chamber (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 discharge conduit (70) formed in the outer race (38) connects a fluid inlet (72) to the annular damping chamber (52) to a fluid outlet (74) that opens through the inner annular surface (44) of the outer race (38) and slopes toward the annular row of rolling elements (40) of the bearing to lubricate these elements with liquid lubricant discharged from the annular damping chamber (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).

Inventors

  • Olivier Formica
  • Naim Boubakir Besakh
  • Savirio Remy Di Gregorio
  • Maxim Eckstein
  • Nicholas Stolyalov Peiping

Assignees

  • 赛峰飞机发动机公司

Dates

Publication Date
20260508
Application Date
20240927
Priority Date
20230928

Claims (13)

  1. 1. An apparatus (30) for centering and guiding rotation of a turbine engine shaft, the apparatus comprising: -a rolling bearing (32) comprising an inner ring (36), an outer ring (38) defining an axis (46) of the rolling bearing and having an outer annular surface (48), and an annular row of rolling elements (40) arranged between an outer annular surface (42) of the inner ring (36) and an inner annular surface (44) of the outer ring (38); -a bearing support (34) having an inner annular surface (50) surrounding an outer annular surface (48) of the outer race (38); -an annular damping chamber (52) formed between an inner annular surface (50) of the bearing support (34) and an outer annular surface (48) of the outer ring (38) and axially defined between two annular seals (54 a,54 b), each formed by an overlapping split metal ring; -a supply conduit (60) formed in the bearing support (34) and opening out through an inner annular surface (50) of the bearing support into the annular damping chamber (52) to supply liquid lubricant to the annular damping chamber to form a damping film therein; -a discharge duct (70) formed in the outer ring (38) and connecting a fluid inlet (72) through an outer annular surface (48) of the outer ring (38) opening in the annular damping chamber (52) to a fluid outlet (74), Wherein the fluid outlet (74): -an inner annular surface (44) passing through the outer ring (38) opens into an axially offset position with respect to the annular row of rolling elements (40), and wherein the inner annular surface (44) of the outer ring (38) faces an outer annular surface (42) of the inner ring (36), and -Tilting towards the rolling elements (40) of the annular row to lubricate these elements with liquid lubricant discharged from the annular damping chamber (52); And wherein the position of the opening of the supply conduit (60) through the inner annular surface (50) of the bearing support (34) is axially offset with respect to the position of the opening of the discharge conduit (70) through the outer annular surface (48) of the outer race (38).
  2. 2. The device 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) which flares towards the annular row of rolling elements (40) and is axially offset with respect to these elements to form an acceleration ramp for the liquid lubricant from the fluid outlet (74).
  3. 3. The device according to claim 1 or 2, wherein the supply conduit (60) comprises an annular distribution chamber (64) and an annular row of distribution passages (66) leading at one end to the annular distribution chamber (64) and at the opposite end to the annular damping chamber (52) through the inner annular surface (50) of the bearing support (34).
  4. 4. A device according to claim 3, wherein the bearing support (34) comprises two respective concentric annular parts (34 a,34 b) rigidly fixed to each other and having two respective contact surfaces (92 a,92 b) in contact with each other, and wherein the annular plenum (64) is formed by an annular groove formed in one of the contact surfaces (92 a,92 b) and delimited by the other of the contact surfaces (92 a,92 b).
  5. 5. The device according to any one of claims 1 to 4, wherein the supply duct (60) opens into an annular distribution groove (90) formed in an inner annular surface (50) of the bearing support (34) and opening annularly into the annular damping chamber (52).
  6. 6. The device according to any one of claims 1 to 5, wherein the discharge conduit (70) comprises an annular exhaust chamber (80), at least one supply passage (82) connected to the annular exhaust chamber (80) at one end of the supply passage and forming the fluid inlet (72) at an opposite end of the supply passage, and at least one injection passage (76) connected to the annular exhaust chamber (80) at one end of the injection passage and opening through an inner annular surface (44) of the outer ring (38) at an opposite end of the injection passage along an injection axis (78) inclined towards the rolling elements (40) of the annular row to form the fluid outlet (74).
  7. 7. The device of 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 exhaust duct (70) comprises a second annular exhaust chamber (100) connected to the annular damping cavity (52), and at least one second injection passage (102) connected to the second annular exhaust chamber (100) at one end of the second injection passage, and at an opposite end of the second injection passage, a second injection axis (104) inclined towards the annular row of rolling elements (40) passes through an inner annular surface (44) of the outer ring (38) at a position axially located opposite the first fluid outlet (74) relative to the annular row of rolling elements (40) to form a second fluid outlet (106) capable of being lubricated using fluid discharged from the annular cavity (52).
  8. 8. The device according to claim 7, wherein the discharge conduit (70) comprises at least one connection passage (110) connecting the first annular exhaust chamber (80) to the second annular exhaust chamber (100), whereby a connection of the second annular exhaust chamber (100) with the annular damping chamber (52) is provided via the supply passage (82), the first annular exhaust chamber (80) and the connection passage (110).
  9. 9. The apparatus of claim 7, wherein the fluid inlet (72) is a first fluid inlet, the supply passage (82) is a first supply passage, and Wherein the discharge conduit (70) comprises at least one second supply passage (112) connected to the second annular exhaust chamber (100) at one end of the second supply passage and forming a second fluid inlet (114) at an opposite end of the second supply passage, the second fluid inlet opening through the outer annular surface (48) of the outer ring (38) into the annular damping chamber (52) at an axially offset position relative to the first fluid inlet (72), thereby providing a connection of the second annular exhaust chamber (100) with the annular damping chamber (52) via the second supply passage (112).
  10. 10. The device of claim 9, wherein a location where the supply conduit (60) opens into the annular damping chamber (52) is axially between the first and second fluid inlets (72,114).
  11. 11. The device of any one of claims 1 to 6, comprising a lubrication nozzle configured to spray liquid lubricant onto a side of the annular row of rolling elements (40) opposite the fluid outlet (74).
  12. 12. The device according to any one of claims 1 to 11, wherein the fluid outlet (74) and/or, where applicable, the second fluid outlet (106) is tangentially inclined to impart a rotational movement to the liquid lubricant.
  13. 13. The device according to any one of claims 1 to 12, wherein the inner annular surface (44) of the outer ring (38) is a revolving cylindrical surface and extends axially beyond the annular row of rolling elements (40) on both sides of the annular row of rolling elements.

Description

Device for centering and guiding rotation of a turbine engine shaft with optimized lubrication of rolling elements by means of lubricant discharged from SFD Technical Field The present invention relates to the field of turbine engines, in particular for aircraft, and more particularly to a device for centering and guiding the rotation of a turbine engine rotor shaft, comprising a squeeze film damping bearing, also known as "SFD" bearing. Background As explained for example in the applicant's document EP1650449B1, a bearing-type device for centering and guiding the turbine engine rotor shaft in rotation is a known device for damping shaft vibrations. Referring to fig. 1A, which schematically illustrates such an apparatus, reference numeral 210 denotes a rotor shaft of a turbine engine intended to propel an aircraft, such as an aircraft turbojet or turboprop. The rotor shaft 210 is centered in a rolling bearing 212 and guided for rotation. The rolling bearing comprises an outer ring 214 carried by an elastically deformable hollowed out structure 216, commonly referred to as a "squirrel cage" or "flexible cage", which itself is carried by the stator structure of the turbine engine, so as to provide a degree of radial or orbital movement to the outer ring under the effect of shaft vibrations, for example after unbalance. The outer race 214 is mounted in a cylindrical housing 218 defined by a bearing support 220 to form a Squeeze Film Damper (SFD) around the outer race 214. To this end, the annular damping chamber 222 is delimited 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, the annular groove 226 being formed in the outer cylindrical surface of the outer ring 214. In the field of aircraft turbojet engines or turboprop aircraft, in particular in the region exposed to the highest temperatures, the annular seal 224 is typically an elastically deformable split ring made of a refractory metal. This type of seal is sometimes referred to as a "metal segment" or "piston ring" because it is commonly used to ensure piston tightness. The annular cavity 222 is filled with a lubricant (typically oil) which is delivered via one or more inlet orifices 228, which inlet orifices 228 are formed by radial holes of the housing 220 and open into an annular groove 230, which annular groove 230 is formed in the cylindrical surface 221 and opens into the annular cavity 222. Thus, any orbiting movement of the outer race will result in compression of the lubricant film defined by the aforementioned cavity, such compression causing damping. This damping capability makes it possible to reduce the design load and thus the structure, and thus the overall mass. To avoid overheating of the lubricant in such a chamber, the lubricant is continuously fed into and discharged from the chamber, so that the lubricant can be circulated continuously. The lubricant is typically discharged via one or more leakage sections formed at an annular seal axially defining the cavity. These leakage sections are typically defined by slits forming sections of the seal and/or by notches formed in these sections. Furthermore, figure 1 of applicant's document EP3850233A1 shows a bearing of the above-mentioned type in the rear part 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 part. In this example, lubrication of the bearing is provided by lubricant delivered from a radially outer region relative to the bearing, by one or more conduits extending through one or more arms of the exhaust casing portion and ending with one or more nozzles leading into a housing defined downstream of and adjacent to the bearing. Figure 1 of document EP3850233A1 shows the fact that the space available in the environment in the vicinity of the bearing can be considerably limited. This limits in particular the choice of lubrication of the bearing from upstream and downstream, in which case the lubricant supply must be made from a radially outer region with respect to the bearing (rather than from a duct extending inside the shaft), as in this figure 1. However, it is often desirable to lubricate both opposite sides of such bearings to increase the mechanical resistance of the bearing and reduce thermal gradients in the bearing, thereby extending the useful life of the bearing. Disclosure of Invention 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 cases where the space available for the bearing lubrication device is small, which bearing lubrication device needs to be operated with lubricant delivered from a radially outer region with respect to the bearing. To this end, the present invention provides an apparatus for centering and guiding ro