FR3066792B1 - BEARING LUBRICATION DEVICE - Google Patents

Abstract

The invention relates to a bearing for rolling elements comprising a wall with a cylindrical outer surface and a cavity intended to contain a lubricating fluid, said cavity opening outwards through at least one opening allowing the lubricating fluid to be admitted into the cavity. , said bearing further comprising a device for circulating a fluid putting in fluid communication the cavity and the outside thereof to ensure the distribution of a film of fluid on the outer surface of the bearing wall, characterized in the circulation device comprises at least one hollow insert passing through the cavity and extending substantially diametrically therein, said hollow insert having an outlet orifice at the outer surface of the bearing wall and at least one intake hole in the vicinity of the bottom of the cavity opposite this outlet and thus communicating said bottom of the cavity and the outside of the landing.

Description

BEARING LUBRICATION DEVICE

GENERAL TECHNICAL FIELD AND PRIOR ART The invention generally relates to bearings, and more particularly to their lubrication. The invention is advantageously applicable for gear trains, for example epicyclic gear trains, in particular on epicyclic gear trains.

It also relates to turbomachines equipped with such gear trains or such bearings. The invention can also find its application on a rolling bearing.

An epicyclic gear train conventionally comprises, as illustrated in FIG. 1, a first sun gear 1, a satellite 2 rotatably mounted on a satellite 3, and a second sun gear 4 (or crown in this particular case). The reduction ratio (or multiplication) of rotational speeds depends on observed elements and fixed elements among planets and the satellite carrier.

The movable elements are generally assembled on the fixed elements or having a different rotational speed by interposing between them bearings 5, an example of which is shown in FIG. 2, making it possible to limit the friction between the satellite carrier 3 and the satellite 2.

This reduction in friction limits the energy losses in the mechanism and improves the overall mechanical efficiency of the gear train.

In order to further reduce friction, these bearings may be lubricated, or comprise a device 6 for circulating a lubricating fluid.

With reference to FIG. 3, a flow of lubricating fluid conventionally circulates from a cavity 7 located inside the bearing 5 towards its outer surface 8 following ducts 9 made through the wall 10 of the bearing 5.

In some cases, the circulation of the lubricating fluid is provided by a pumping system.

When the pump encounters an abnormality, the fluid circulation system is no longer supplied normally. It is necessary to ensure the lubrication of the various elements during a determined period of time, corresponding for example to an emergency stop of the gear train, the ignition of an auxiliary pumping system or the restart of the main pumping system to avoid a bearing degradation.

During this time, only the fluid present in the gear train at the time of the failure of the pumping system makes it possible to ensure the lubrication function of the bearings.

In order to maximize this amount of fluid, it is known to make palms 5 having chambers serving as an oil reservoir 11 providing emergency lubrication in the event of an anomaly in the main lubrication system.

The circulation of this fluid is ensured, in this case of operationconcerning a satellite bearing of an epicyclic gear train, by centrifugal effect.In fact, in the case where the carrier is rotating, the fluid contained in the landing of the satellite is subjected to a centrifugal force due to the eccentricity of the satellite with respect to the axis of rotation of the planet carrier.

The fluid is thus held against a wall of the chamber located on the opposite side to the axis of rotation of the carrier.

This centrifugal force allows the fluid to borrow the main pipes 9 so as to ensure the lubrication function of the bearing.

It is known to provide secondary conduits 12, which allow a lower fluid injection rate than that of the main pipe 9.

In order to increase the autonomy of the fluid reserve in the event of failure of the pumping system, it is known to adopt a certain configuration of the different pipes so as to prevent the fluid from unnecessarily borrowing the main pipe 9.

The main pipe 9 is generally made by a bores extending between the outer surface 8 of the bearing and one of the 15excentrés holes made on a partition wall 14 of the oil tank 11.

Thus, when the oil level is below the level of the 15excentré piercing having a mouth 17 of the main pipe 9, the oil can borrow only the secondary pipes 12, the oil beingprojected against the wall of the side opposite the piercing 15 by centrifugal effect.

The holes 15 made on the partition wall 14 are made by inserting the tools in the internal cavities 7 through their side opening 16, having a smaller diameter than the internal cavity 7.

It is therefore impracticable in these embodiments to maximize the fluid reserve by drilling through the partition wall at the lowest level of the internal cavity 7.

There is, however, a need to increase the reserve of fluid available in the event of a breakdown of the lubricating fluid pumping system.

GENERAL PRESENTATION OF THE INVENTION

An object of the invention is to increase the fluid reserve in the pallet in case of failure of the pumping system.

Another aim is to simplify the internal structure of the bearing, and indirectly its manufacturing process and its cost.

Another goal is to lighten the landing.

Another goal is to improve the performance of the lubrication system.

According to one aspect, the invention provides a bearing comprising a wall with a cylindrical outer surface and a cavity intended to contain a lubricating fluid, said cavity opening outwards through at least one opening allowing the lubricating fluid to be admitted into the cavity, said bearing further comprising a device for circulating a fluid putting in fluid communication the cavity and the outside thereof to ensure the distribution of a film of fluid on the outer surface of the bearing paroid, characterized in that the device of circulation comprises at least one hollow insert extending through the cavity and extending substantially diametrically therethrough, said hollow insert having an outlet opening at the outer surface of the bearing wall and at least one inlet hole at the near the bottom of the cavity opposite said outlet port and thereby communicating said bottom of the cavity and the outside of the link. The insertion of at least one hollow insert into the bearing cavity makes it possible to increase the fluid reserve in the event of failure while decreasing the bearing mass and simplifying its manufacturing process.

Indeed, the presence of a hollow insert makes it possible to eliminate the separation partition present in the prior art.

This suppression allows, with equal external dimensions of the bearing, larger internal cavities and thus an increase in the reserve of fluid.

The structure is also lightened.

Also, the use of an insert makes it possible to fetch the fluid at the vicinity of the bottom of the bearing, without it being necessary to make holes from an inlet opening.

The amount of fluid present in the cavity that serves as a reserve incase of failure (amount of fluid beyond the level of the intake hole) is increased.

In addition, during the manufacture of the bearing, the cavity can be made from a single inlet opening, which simplifies the manufacture.

Such a device is advantageously supplemented by the following different features taken alone or in combination: the cavity comprises a single inlet opening; - The bearing is a plain bearing; - The wall of the bearing has at least one bore which is a secondary channel by which fluid is discharged to the outside including in configurations where the intake hole of the insert is no longer supplied; - The bore opens at the outer surface of the bearing in an area opposite the inlet hole of the insert; - The bearing comprises at least two inserts distributed in the length of the cavity; - The insert is held by shrinking on the bearing wall; - The bearing wall comprises an inner blind bore in which is received the end of the insert opposite the outlet, and a through bore which is diametrically opposed to the blind hole and is coaxial therewith; - The insert comprises a stop portion engaged in theborborborgne, a centering portion extending in the perforagetraversant, the stop portion and the centering portion having a wall thickness greater than the wall thickness laportion insert extending between said stop portion and said centering portion.

In another aspect, the invention also provides a manufacturing method for making such a bearing, wherein, when the bearing is a single inlet opening, the internal surfaces of the cavity are machined from the single side opening.

In another aspect, the invention provides an epicyclic gear comprising such a satellite bearing.

According to another aspect, the invention proposes a turbomachine comprising such an epicyclic gear train.

PRESENTATION OF THE FIGURES Other features and advantages of the invention will become apparent from the description which follows, which is purely illustrative and nonlimiting, and should be read with reference to the appended figures in which: FIG. 1 is a 3D isometric representation of FIG. a conventional epicyclic train; FIG. 2 is a schematic representation of a profile view of the implementation of a bearing on a porte-satellite; FIG. 3 is a diagrammatic representation of a sectional view of a bearing of the prior art; FIG. 4 is a sectional sectional view of an embodiment of a bearing equipped with inserts according to the invention; - Figure 5 is a schematic representation of a profile view of a profile of an insert; - Figure 6 is a sectional sectional view of another embodiment of a bearing equipped with inserts according to the invention.

DESCRIPTION OF ONE OR MORE MODES OF IMPLEMENTATION AND REALIZATION

The embodiments described below relate to the case of an X-axis bearing 5, shown in FIG. 4. However, the example given is not intended to be limiting, since the bearing could have various geometrical specifications.

The bearing 5 has an internal cavity 7, an outer surface 8 and an inner surface 17, a wall 10 and an inlet opening 16 at one of its ends.

In some embodiments, an O-ring 18 is provided on each of the ends of the bearing 5 so as to increase the bearing load 5 and to facilitate assembly thereof.

The grooves 18 make it possible to limit the deformation of the surface used of the bearing 5, this useful surface being the external surface 8.

In case of significant effort that can cause deformation of the pallet, the deformation is performed at the groove 18, the surface of the pallet 5 thus remaining cylindrical.

This behavior also makes it possible not to transmit the misalignments to the toothing, when a misalignment of the axes occurs between the carrier-satellite and the satellite for example.

During normal operation, a lubrication fluid put in pressure by a pumping system circulates in the internal cavity 7 passing through the inlet opening 16.

This lubricating fluid is directed towards the outer surface 8 from the inner cavity 7 through outlet openings 33 of inserts 19 making the main cabling 9.

In the embodiment shown in FIG. 5, the inserts 19present a cylindrical body 22 with a variable diameter, and comprise a coaxial piercing 23 to the body 22 or longitudinal and an orthogonal piercing 24 to the body 22 or transverse.

The longitudinal bore 23 opens into the transverse bore 24, the transverse bore 24 passing through the insert 19 diametrically and thereby providing a fluid inlet hole 32.

Extra thicknesses can be made at the portions of the inserts 19 in contact with the bearing 5, in particular a centering portion25 and a stop portion 26, a central portion 27 extending between the centering portion 25 and the stop portion 26. .

The centering and stop portions 26 have a wall thickness greater than the central portion 27.

To facilitate their mounting in the bearing 5, the inserts 19 have chamfers 28 at the diameter change zones.

The longitudinal bore 23 may have at its end a conical mouth 29 for making a thread for the purpose of cooperating with a tool during a disassembly step of the insert 19, when the insert 19 is damaged or an accident occurred during the assembly involves dismantling the insert 19, thereby preserving the bearing 5.

In an embodiment shown in FIG. 6, bores are made in the wall of the bearing 5 so as to form secondary ducts 12.

These secondary lines 12 allow a circulation of the lubrication fluid from the cavity 7 to the outer surface 8 of the bearing 5when the pumping system is faulty.

In some embodiments, the secondary pipes 12 have a smaller section than the section of the main pipes 9.

The secondary lines 12 are generally located in a region diametrically opposite to the intake holes.

In this way, when the amount of fluid present in the cavity is reduced by the effect of a failure of the pumping system, the fluid no longer borrows the main pipes 9 when the fluid level no longer reaches the level of the holes. 'admission.

It therefore borrows only the secondary lines 12 which have a reduced diameter and therefore limit the flow of fluid to allow to maintain a degraded operation as long as possible.

The relative positioning of the secondary ducts 12 with respect to the intake holes thus makes it possible to maximize the fluid reserve 11. The use of inserts 19 to produce the main ducts 9 also makes it possible to simplify the internal structure of the bearing 5.

Indeed, it is no longer necessary to realize the main pipes 9 in the partition wall, which can be removed. Therefore, the manufacturing process is lightened, allowing all internal surfaces to be realized from a single lateral opening 16 of the bearing 5.

The removal of the central wall 14 also makes it possible to reduce the weight of the bearing 5 in addition to offering a significant gain in volume allowing the fluid reserve 11 to be increased.

The transverse drilling 24 does not need to be performed in the central wall, it can be positioned closer to the inner surface 17 of the cavity, thus maximizing the oil reserve in case of damage in the pumping system.

This structural change also makes it possible to carry out several main ducts 9 so as to offer a better distribution of the lubricating fluid on the outer surface 8 of the bearing 5.

Indeed, a pipe made in a wall would involve deréaliser several walls in the cavity 7, which would reduce the fluid reserve and increase the mass of the bearing.

In the illustrated embodiment, the bearing 5 comprises two parallel inserts19 between them radially implanted in the bearing 5, thus allowing a better distribution of the lubricating fluid on the outer surface 8.

Solutions comprising a single insert 19 or more than two inserts 19 may be envisaged, arranged according to a different geometry of the illustrated entometry.

The secondary ducts 12 can be located in a different plane of the main ducts 9. Despite the slight decrease in the fluid reserve 11 that this arrangement implies, a secondary duct opening 12 slightly eccentric at the inner surface 17 of the bearing 5 allows to avoid that impurities morelourdes that the fluid do not come foul the secondary conduits 12.

The distribution of the inserts 19 forming the main pipes 9 and holes forming the secondary pipes 12 is chosen to best distribute the oil pressure along the length of the outer surface8, avoiding excessive flow at the ends of the deck 5. to prevent the fluid from flowing directly to the outside, which would reduce the effect of lubrication.

The inserts 19 are assembled to the bearing 5 in perforations 20 made through the wall 10 of the bearing, these holes 20 being extended by blind holes 21 coaxial with the through holes 20, the blind holes 21 being formed on the inner surface 17 of the bearing5.

The stop portion 26 of the inserts 19 is thus located in the bore holes 21, the centering portion 25 extending in the piercing holes 20.

In some embodiments, the inserts 19 are mounted in the blind holes 21 and the through holes 20 by hooping.

One embodiment proposes a hot shrinking, the material withdrawal of the cold bearing 5 ensuring the clamping force realizingassembly between the insert 19 and the bearing 5.

However, it is possible to use other assembly methods, such as brazing, gluing, threaded assembly, or all technical solution to obtain a fixed connection between the inserts 19 and the bearing 5.

The method of assembly by hot shrinking involves significant depressions levels in the inserts 19. The thickness of the wall of the insert19 at the stop portion 26 and at the level of the centering portion25 is therefore dimensioned to limit the internal pressure levels in the inserts 19 due to the hooping pressure.

Claims (11)

CLAIMS * Bearing (5) having a wall (10) with an outer surface (8) and a cylindrical cavity (7) for containing a lubricating fluid, said cavity (7) opening out through at least one opening (16) allowing the admission of the lubricating fluid into the cavity (7), said bearing further comprising a circulation device (6) for a fluid fluidly communicating the cavity (7) and the outside of the bearing to ensure the distribution of a film of fluid on the outer surface (8) of the wall (10) dupalier, characterized in that the circulation device (6) comprises at least a hollow insert (19) through the cavity (7) extending substantially diametrically to the interior thereof, said hollow insert (19) having an outlet (33) at the outer surface (8) of the bearing wall (10) and at least one inlet hole (32) in the vicinity of the bottom the cavity (7) opposite this outlet orifice (33) and thus encommunicating cation said bottom of the cavity (7) and the outside of the bearing, and in that the wall (10) of the bearing comprises at least one secondary pipe (12) through which fluid is discharged to the outside including inconfigurations wherein the inlet hole (32) of the insert (19) is no longer fed. Bearing according to claim 1, characterized in that the cavity (7) has a single inlet opening (16). 3. Bearing according to one of the preceding claims, characterized in that saidpalier (5) is a plain bearing. 4. Bearing according to one of the preceding claims, characterized in that the secondary lacanalisation (12) opens at the outer surface (8) of the bearing in an area opposite the inlet hole (32) of the insert (19). ). 5. Bearing according to one of the preceding claims, charac- terized in that lepàhencomporte at least two inserts (19) distributed in the longevity length (7). 6. Bearing according to one of the preceding claims, characterized in thatinsert (19) is held by shrinking on the wall (10) of the bearing. 7. Bearing according to one of the preceding claims, characterized in that the wall (10) of the bearing has an internal blind bore (21) in which is received the end of the insert (19) opposite the outlet orifice ( 33), and a through hole (20) which is diametrically opposed to saidboringborage (21) and is coaxial therewith. 8. Bearing according to the preceding claim, characterized in that the insert (19) comprises a stop portion (26) engaged in the blind hole (21), a centering portion (25) extending in the through bore (20), the stop portion (26) and the centering portion (25) having a wall thickness greater than the wall thickness of the portion of the insert extending between said stop portion (26) and said centering portion (25). 9. Manufacturing process for producing a device according to one of Claims 2 to 8, characterized in that all the internal surfaces of the cavity (7) are made from the single lateral opening (16). 10. Epicyclic train comprising at least one bearing (5) according to one of claims 1 to 8. 11. A turbomachine comprising an epicyclic train according to claim 10.