TURBOMACHINE TURBOCHARGER ROTOR ORIENTATION BEARING CARTRIDGE

Abstract

A slewing bearing cartridge for a variable-pitch propeller rotor (100) with (2) blades of an X-axis turbomachine, comprising: a cartridge body (1) formed around an axis (Y) orthogonal to said turbomachine axis (X) and intended to receive a blade root shaft (20); sealing means intended to be positioned between said cartridge body (1) and said blade root shaft (20), and comprising a lower seal (3) and an upper seal (4) positioned radially external to said lower seal (3), said cartridge body (1), said blade root shaft (20), and said sealing means delimiting a sealed enclosure (9) within which a lubricant circulates, said slewing bearing cartridge further comprising a first bearing (5), a second bearing (6), and a volumetric recirculation pump (7) of lubricant. Figure 2

Description

Title of the invention: ORIENTATION BEARING CARTRIDGE FOR A TURBOMACHINE BLADED PROPELLER ROTOR Field of invention

[0001] The present invention relates to the field of turbomachines and more particularly concerns turbomachines of the variable-pitch propeller or fan type, shrouded or unshrouded.

[0002] More particularly, the invention relates to the lubrication of rolling bearings used in slewing bearing cartridges.

[0003] The invention relates to all types of aircraft turbomachine, in particular turbojets and turboprops having a propeller with variable-pitch blades. State of the prior art

[0004] Variable-pitch propeller rotors of turbomachines rotating around a longitudinal axis of rotation X conventionally comprise a circle of blades distributed around the axis of rotation X.

[0005] The variable pitch blades or vanes are fixed at a guide bearing cartridge mounted around a central axis Y which is substantially orthogonal to the axis of rotation X of the aircraft engine. The rotation of the variable pitch blades is guided by rolling or plain bearings.

[0006] More particularly, each of the variable-pitch blades comprises a blade root whose support shaft is housed in an orientation bearing cartridge and which is guided by a minimum of two bearings arranged around the blade root shaft, namely a radially internal rolling bearing and a radially external rolling bearing.

[0007] The centrifugal forces exerted on the bearings during rotation of the propeller are directed along the axis of the blade root shaft, i.e. along the Y axis. Therefore, a seal must be added at each of the bearings so as to close the bearing housing on the side radially outside the bearings, and to form a sealed enclosure. This thus prevents the entry of moisture or polluting particles into the housing, and also prevents the flow of lubricant (whatever its nature) under the effect of centrifugal forces.

[0008] For their theoretical purposes, each of the rolling bearings is greased independently, with a ratio of approximately 20% between lubricant and air.

[0009] However, since the entire variable-pitch propeller rotor is subjected to centrifugal force during rotation of the turbomachine, the lubricant tends to be projected towards the radially external rolling bearing without however descending once the turbomachine is stopped.

[0010] This causes an overload of lubricant in the radially external rolling bearing, thus impairing its optimal operation.

[0011] This also causes the radially internal rolling bearing to dry out, which leads to a risk of deterioration of this radially internal rolling bearing and therefore a risk of the appearance of an excessive resistive moment, of poor guidance of the variable-pitch blade, or even a breakage of the radially internal rolling bearing and therefore an inability of the variable-pitch blade to rotate, causing deterioration of the turbomachine.

[0012] There is therefore a need to improve the lubrication of rolling bearing cartridges for variable-pitch propeller rotors of turbomachines. Statement of the invention

[0013] The invention aims to remedy at least in part the drawbacks mentioned above relating to the techniques of the prior art.

[0014] To this end, the invention relates to an orientation bearing cartridge for a propeller rotor blade of an X-axis turbomachine, comprising: - a cartridge body arranged around a Y axis orthogonal to said turbomachine axis X and intended to accommodate a blade root shaft; - sealing means intended to be positioned between said cartridge body and said blade root shaft, and comprising a lower seal and an upper seal positioned relative to the turbomachine axis X radially external to said lower seal,

[0015] said cartridge body, said blade root shaft, and said sealing means delimiting a sealed enclosure inside which a lubricant circulates,

[0016] said orientation bearing cartridge further comprising:

[0017] - a first radially internal bearing arranged in said sealed enclosure proximity of said lower seal so as to bear against said cartridge body and against said blade root shaft;

[0018] - a second radially external bearing arranged in said sealed enclosure proximity to said upper seal so as to bear against said cartridge body and against said blade root shaft.

[0019] According to the invention, said orientation bearing cartridge comprises a volumetric pump for recirculating lubricant as a function of the rotation of said blade root shaft, so as to recirculate lubricant inside said sealed enclosure, the volumetric recirculation pump comprising a rotary element arranged between a suction duct opening near said second bearing and an injection duct opening near said first bearing.

[0020] Thus, the invention proposes a new and inventive approach making it possible to resolve at least in part certain of the drawbacks of the prior art.

[0021] In particular, by implementing recirculation means making it possible to recirculate lubricant towards a radially internal part of said orientation bearing cartridge, minimum lubrication of each of the rolling bearings implemented is ensured and thus rotation of the variable pitch blades is ensured so as to improve the operation of the propeller rotors.

[0022] Furthermore, by implementing a lubricant recirculation pump as a function of the rotation of said blade root shaft to carry out this recirculation, reliable and inexpensive mechanical means are implemented.

[0023] According to a particular aspect of at least one embodiment of the invention, said suction duct is hollowed out in said cartridge body and / or said injection duct is hollowed out in said cartridge body.

[0024] According to a particular aspect of at least one embodiment of the invention, said suction duct opens between the upper seal and said second bearing and / or said injection duct opens between the lower seal and said first bearing.

[0025] According to a particular aspect of at least one embodiment of the invention, the volumetric lubricant recirculation pump further comprises one-way rotation drive means so as to drive the rotary element in rotation as a function of the rotation of said blade root shaft.

[0026] According to a particular aspect of at least one embodiment of the invention, the one-way rotation drive means comprise an end having a movement transmission end piece comprising a bevel gear and intended to cooperate with a toothed crown on the blade root shaft so as to transmit a rotational movement of the blade root shaft to said one-way rotation drive means.

[0027] According to a particular aspect of at least one embodiment of the invention, the cartridge comprises lubricant retention means arranged in the vicinity of said first bearing.

[0028] According to a particular aspect of at least one embodiment of the invention, the retention means comprise a lower gutter arranged between an outlet of said injection duct and said first bearing so as to circumferentially distribute lubricant leaving said injection duct.

[0029] According to a particular aspect of at least one embodiment of the invention, the retention means comprise an upper gutter arranged radially ex inside said first bearing so as to continuously maintain lubricant in contact with said first bearing.

[0030] According to a particular aspect of at least one embodiment of the invention, said volumetric lubricant recirculation pump is of the progressive cavity volumetric pump type.

[0031] In this case, the pump can for example be of the Moineau™ type.

[0032] The invention also relates to a propeller rotor with variable pitch blades for an X-axis turbomachine, comprising a plurality of variable pitch blades rotating about a Y axis perpendicular to said X axis of the turbomachine, each of said variable pitch blades having a blade root shaft housed in an orientation bearing cartridge according to one of the aforementioned embodiments.

[0033] The invention also relates to a turbomachine for aircraft, comprising at least one propeller rotor with variable pitch blades according to the aforementioned embodiment. Presentation of the figures

[0034] The invention, as well as the various advantages that it presents, will be more easily understood in the light of the following description of an illustrative and non-limiting embodiment thereof, and of the appended drawings among which: [Fig.l] is a schematic sectional view of a turbomachine; [Fig.2] is a schematic perspective view of a propeller rotor orientation bearing cartridge according to one embodiment of the invention; [Fig.3] is a schematic perspective view of a propeller rotor orientation bearing cartridge according to a second embodiment of the invention, and [Fig.4] is a schematic perspective view of a propeller rotor orientation bearing cartridge according to a third embodiment of the invention.

[0035] Detailed description of an embodiment of the invention

[0036] It should be noted that the invention applies in particular to aircraft turbomachines, and in particular to turbomachines comprising at least one propeller with blades, or variable-pitch vanes, as shown in [Fig.l]. Preferably, and as shown here, this propeller is unducted.

[0037] This aircraft engine propeller rotor 100 rotates around an axis of rotation X. The propeller comprises a circle of variable-pitch blades 2 distributed around the axis of rotation X and each of the variable-pitch blades 2 comprises a root shaft 20. The propeller rotor extends in front of a main body 400 of the engine, which may comprise a wheel 500 of variable-pitch blades straightening the air flow, a combustion chamber, and gas expansion turbines.

[0038] The variable-pitch blades 2 are fixed by their blade root to the shaft 20 at the level of a cartridge mounted around a central axis Y which is substantially orthogonal to the axis of rotation X of the aircraft engine. The rotation of the variable-pitch blades 2 is guided by bearings provided in this orientation bearing cartridge.

[0039] Throughout the description, an axial direction corresponds to the direction of the longitudinal axis X and a radial direction is a direction orthogonal to the longitudinal axis X and intersecting the longitudinal axis X. Therefore, the direction along the Y axis corresponds to a radial direction.

[0040] Similarly, the adjectives "inner" (or "internal") and outer ("or external") are used with reference to this radial direction so that the inner part of an element is, along this radial direction, closer to the longitudinal axis X than the outer part of the same element.

[0041] We now present, in relation to [Fig. 2], a first embodiment of an orientation bearing cartridge for a variable-pitch blade propeller rotor according to the invention.

[0042] As illustrated, the slewing bearing cartridge comprises: - a cartridge body 1 arranged around a Y axis orthogonal to the turbomachine axis X; - sealing means intended to be positioned between the cartridge body 1 and the blade root shaft 20.

[0043] More precisely, the sealing means comprise a lower seal 3 and an upper seal 4 positioned relative to the turbomachine axis X radially external to the lower seal 3.

[0044] In other words, and as can be seen in particular in [Fig.2], the sealing means comprise a lower seal 3 close to a bottom of the cartridge body 1, and an upper seal close to an upper surface of the cartridge body 1.

[0045] The cartridge body 1, the blade root shaft 20, and the sealing means delimit a sealed enclosure 9 inside which a lubricant circulates.

[0046] The orientation bearing cartridge further comprises:

[0047] - a first radially internal bearing 5 arranged in the sealed enclosure 9 at proximity of the lower seal 3 so as to come into contact with the cartridge body 1 and against the blade root shaft 20, and

[0048] - a second radially external bearing 6 arranged in the sealed enclosure 9 at proximity of the upper seal 4 so as to also come into contact with the cartridge body 1 and against the blade root shaft 20.

[0049] According to the invention, and as can be seen in particular in [Fig. 2], the orientation bearing cartridge comprises a volumetric pump 7 for recirculating lubricant as a function of the rotation of the blade root shaft 20, so as to recirculate lu- grinding inside the sealed enclosure 9.

[0050] More particularly, this volumetric recirculation pump 7 makes it possible to recirculate lubricant from a radially external zone of the sealed enclosure 9 to a radially internal zone of the sealed enclosure 9.

[0051] To do this, this recirculation pump 7 comprises a rotary element 72 arranged between a suction duct 70 opening near the second bearing 6 and an injection duct 71 opening near the first bearing 5.

[0052] As a result, the lubricant is sucked in from the vicinity of the second radially external bearing 6, passes through the rotary element 72, and is reinjected into the vicinity of the first bearing 5 via the injection duct 71.

[0053] More particularly, in this embodiment, the suction duct 70 opens between the upper seal 4 and the second bearing 6, and the injection duct 71 opens between the lower seal 3 and the first bearing 5.

[0054] As illustrated, the suction duct 70 is here hollowed out in the cartridge body 1. It is arranged along an oblique axis relative to the axis X of the turbomachine, with one end opening into the sealed enclosure 9 radially internally relative to the end opening onto the rotary element 72.

[0055] For its part, the injection conduit 71 is hollowed out in the cartridge body 1 and has a bent shape with a portion arranged substantially along the Y axis and opening onto the rotary element 72, and a portion arranged substantially along the X axis and opening at the level of the sealed enclosure 9.

[0056] According to an embodiment not illustrated, the volumetric lubricant recirculation pump could be of the progressive cavity volumetric pump type.

[0057] As illustrated in this [Fig.2], the volumetric lubricant recirculation pump 7 of this embodiment is arranged radially in the vicinity of the outside of the turbomachine. So that the lubricant recirculation pump recirculates the lubricant as a function of the rotation of the blade root shaft, the lubricant recirculation pump further comprises one-way rotation drive means 75 so as to drive the rotary element 72 in rotation as a function of the rotation of the blade root shaft 20.

[0058] These one-way rotation drive means 75 comprise an end having a movement transmission end piece 750 intended to come into contact with the blade root shaft 20 so as to transmit a rotational movement of the blade root shaft 20 to the one-way rotation drive means 75. The transmission end piece 750 is in this embodiment a bevel gear system.

[0059] More particularly, in this embodiment, the movement transmission end piece comprising a bevel gear is intended to cooperate with a toothed crown 73 formed projecting from the blade root shaft 20, and to lock against this toothed crown so that a rotation of the blade root shaft 20 is transmitted to the one-way rotation drive means 75 by means of this toothed crown 73 which transmits the movement to the end 750.

[0060] As illustrated in [Fig.2], the bearing cartridge comprises lubricant retention means arranged in the vicinity of the first bearing 5.

[0061] More particularly, here, the retention means comprise a lower gutter 74a and an upper gutter 74b located on either side of the first bearing 5.

[0062] These lower and upper gutters here have a curved shape with a top oriented towards the second bearing 6, so as to be able to form a lubricant retention gutter against the centrifugal effect applied during rotation of the rotor.

[0063] The lower gutter 74a is arranged between an outlet of the injection duct 71 and the first bearing 5 so as to circumferentially distribute the lubricant leaving the injection duct 71.

[0064] For its part, the upper gutter 74b is arranged radially outside the first bearing 5 so as to continuously maintain lubricant in contact with the first bearing 5.

[0065] An embodiment could also be provided in which the retention means would comprise only one gutter.

[0066] We now present, in relation to [Fig. 3], a second embodiment of an orientation bearing cartridge for a variable-pitch blade propeller rotor according to the invention.

[0067] As illustrated in this [Fig.3], the volumetric lubricant recirculation pump 7' of this embodiment is arranged radially inside relative to the volumetric lubricant recirculation pump of the first embodiment.

[0068] This recirculation volumetric pump 7' also comprises a rotary element 72 arranged between a suction duct 70 opening near the second bearing 6 and an injection duct 71 opening near the first bearing 5.

[0069] Therefore, in this embodiment also, the lubricant is sucked in from the vicinity of the second radially external bearing 6, passes through the rotary element 72, and is reinjected in the vicinity of the first bearing 5 via the injection duct 71.

[0070] As illustrated, in this embodiment, the suction duct 70 opens between the upper seal and the second bearing 6, and the injection duct 71 opens between the lower seal and the first bearing 5.

[0071] The recirculation volumetric pump 7' of this embodiment further comprises one-way rotation drive means 75' so as to drive the rotary element 72 in rotation as a function of the rotation of the blade root shaft 20.

[0072] These one-way rotation drive means 75' comprise one end having a motion transmission end piece 750' intended to come into contact with the blade root shaft 20 so as to transmit a rotational movement of the blade root shaft 20 to the one-way rotational drive means 75'. The transmission end piece 750' is in this embodiment a bevel gear system.

[0073] Here, the one-way drive means are arranged radially inside relative to the one-way drive means of the first embodiment. As a result, these one-way rotation drive means have a drive shaft 751' running along the injection duct 71 so as to cooperate with the rotary element 72.

[0074] In a similar manner to the first embodiment, the movement transmission end piece comprising a bevel gear is intended to cooperate with a toothed ring 73' formed projecting from the blade root shaft 20, and to lock against this toothed ring so that a rotation of the blade root shaft 20 is transmitted to the one-way rotation drive means 75' by means of this toothed ring 73' which transmits the movement to the end 750'.

[0075] We now present, in relation to [Fig. 4], a third embodiment of an orientation bearing cartridge for a variable-pitch blade propeller rotor according to the invention.

[0076] The orientation bearing cartridge of this third embodiment is similar to the orientation bearing cartridge of the second embodiment except for the injection conduit 71' which is here hollowed out in the cartridge body 1 and has a bent shape with a portion arranged substantially along the Y axis and opening onto the rotary element 72, and a portion arranged at an angle inclined relative to the X axis and opening at the level of the sealed enclosure 9.

Claims

Claims

1. Orientation bearing cartridge for a propeller rotor (100) with variable-pitch blades (2) of a turbomachine with an axis (X), comprising: a cartridge body (1) arranged around an axis (Y) orthogonal to said turbomachine axis (X) and intended to accommodate a blade root shaft (20);sealing means intended to be positioned between said cartridge body (1) and said blade root shaft (20), and comprising a lower seal (3) and an upper seal (4) positioned relative to the turbomachine axis (X) radially external to said lower seal (3), said cartridge body (1), said blade root shaft (20), and said sealing means delimiting a sealed enclosure (9) inside which a lubricant circulates, said orientation bearing cartridge further comprising: - a first radially internal bearing (5) arranged in said sealed enclosure (9) near said lower seal (3) so as to bear against said cartridge body (1) and against said blade root shaft (20);- a second radially external bearing (6) arranged in said sealed enclosure (9) near said upper seal (4) so ​​as to bear against said cartridge body (1) and against said blade root shaft (20), characterized in that said orientation bearing cartridge comprises a volumetric recirculation pump (7) for lubricant as a function of the rotation of said blade root shaft (20), so as to recirculate lubricant inside said sealed enclosure (9), the volumetric recirculation pump comprising a rotary element (72) arranged between a suction duct (70) opening near said second bearing (6) and an injection duct (71) opening near said first bearing (5).;

2. An orientation bearing cartridge according to claim 1, characterized in that said suction duct (70) is hollowed out in said cartridge body (1) and / or said injection duct (71) is hollowed out in said cartridge body (1).

3. An orientation bearing cartridge according to claim 2, characterized in that said suction duct (70) opens between the seal upper seal (4) and said second bearing (6) and / or said injection duct (71) opens between the lower seal (3) and said first bearing (5).

4. Slewing bearing cartridge according to one of the preceding claims, characterized in that the volumetric lubricant recirculation pump (7) further comprises one-way rotation drive means (75) so as to drive the rotary element (72) in rotation as a function of the rotation of said blade root shaft (20).

5. Orientation bearing cartridge according to claim 4, characterized in that the one-way rotation drive means (75) comprise an end having a movement transmission end piece (750) comprising a bevel gear and intended to cooperate with a toothed crown (73) arranged on said blade root shaft (20) so as to transmit a rotational movement of said blade root shaft (20) to said one-way rotation drive means (75).

6. Orientation bearing cartridge according to one of the preceding claims, characterized in that it comprises lubricant retention means arranged in the vicinity of said first bearing (5).

7. Orientation bearing cartridge according to the preceding claim, characterized in that the retention means comprise a lower gutter (74a) arranged between an outlet of said injection duct (71) and said first bearing (5) so as to circumferentially distribute lubricant leaving said injection duct (71).

8. Orientation bearing cartridge according to one of claims 6 or 7, characterized in that the retention means comprise an upper gutter (74b) arranged radially outside said first bearing (5) so as to continuously maintain lubricant in contact with said first bearing (5).

9. Orientation bearing cartridge according to one of the preceding claims, characterized in that said volumetric lubricant recirculation pump (7) is of the progressive cavity volumetric pump type.

10. Propeller rotor (100) with variable-pitch blades for a turbomachine with an axis (X), comprising a plurality of variable-pitch blades rotating about an axis (Y) perpendicular to said axis (X) of the turbomachine, each of said variable-pitch blades (2) having a blade root shaft (20) housed in an orientation bearing cartridge according to one of claims 1 to 9.

11. Turbomachine for aircraft, comprising at least one propeller rotor (100) with variable pitch vanes (2) according to claim 10.

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