Aircraft turbine comprising means for lubricating the bearings

Abstract

The invention relates to a turbomachine for an aircraft, comprising: a first rotor comprising a first shaft; a second rotor (9) comprising a second shaft; a mechanical reduction device comprising a sun gear connected to the second shaft, a ring gear connected to the first shaft, and planet gears located between the sun gear and the ring gear and carried by a planet carrier attached to a stator of the turbomachine; rolling bearings for guiding the rotation of the first and second shafts; an annular groove extending around the ring gear of the reduction device and configured to recover oil used for lubricating the reduction device, the oil being ejected from the ring gear during operation by centrifugal action; and an annular bearing support attached to the stator of the turbomachine with the groove, the annular bearing support supporting at least one of the bearings, the turbomachine further comprising at least one device for delivering the oil recovered by the groove.

Description

Technical Field

[0001] This invention relates to the technical field of aircraft turbines.

[0002] More specifically, the present invention belongs to the field of aircraft turbines including counter-rotating turbines. Background Technology

[0003] The prior art is illustrated in documents EP-A1-3 575 562, US-A1-2015 / 361829, FR-A1-2 977 636 and EP-A1-3 460 199.

[0004] Typically, an aircraft turbine, from upstream to downstream in the direction of airflow, includes a fan, a low-pressure compressor, a high-pressure compressor, an annular combustion chamber, a high-pressure turbine, and a low-pressure turbine. The rotor of the low-pressure compressor is driven by the rotor of the low-pressure turbine, and the rotor of the high-pressure compressor is driven by the rotor of the high-pressure turbine.

[0005] From the perspective of engine performance and fuel consumption, maximizing the speed of the low-pressure turbine is advantageous because it allows for higher turbine efficiency. However, increasing the turbine speed means increasing the centrifugal force on the turbine, thus making turbine design very complex.

[0006] One suggestion for improving turbine efficiency without increasing turbine speed is to use a counter-rotating turbine. The low-pressure turbine is replaced by a dual-rotor turbine with a first rotor and a second rotor. The first rotor is configured to rotate in a first direction of rotation and is connected to a first turbine shaft, while the second rotor is configured to rotate in the opposite direction of rotation and is connected to a second turbine shaft. The first and second turbine shafts are centered and guided to rotate by multiple guide bearings. The first rotor has a turbine wheel portion that is inserted between the turbine wheel portions of the second rotor.

[0007] In a conventional turbine-driven fan architecture, the low-pressure turbine can have a takeoff speed of approximately 4,000 revolutions per minute (rpm), or in an architecture where the turbine drives the fan via a reduction gear, the low-pressure turbine can have a takeoff speed of approximately 10,000 rpm. Replacing the aforementioned low-pressure turbine with counter-rotating turbines whose rotors rotate at takeoff speeds of approximately 3,000 rpm and approximately 7,000 rpm respectively enables a relative speed of 10,000 (3,000 + 7,000) rpm, while maintaining an absolute speed within the lower range of the aforementioned speed range.

[0008] Therefore, the counter-rotating turbine includes a low-speed rotor and a high-speed rotor. The low-speed rotor drives the fan, and the high-speed rotor meshes with a planetary rotary reducer. The input and output parts of the planetary rotary reducer are counter-rotating (rotating ring gear, fixed planet carrier, and rotating sun gear).

[0009] The reduction gear connects the high-speed rotor to the low-speed rotor, thereby transferring power from the high-speed rotor to the low-speed rotor. This takes advantage of the high efficiency of the high-speed turbine, while transferring most of the power from the turbine to the fan, not through the reduction gear, but through the shaft.

[0010] Due to the mechanical integration of this architecture, it is complex: the mechanical reduction gear is located, for example, downstream of the turbine, radially inside the stator annular housing (referred to as the exhaust housing), or upstream of the turbine, radially inside the stator annular housing (referred to as the intermediate housing).

[0011] Furthermore, since the reduction gear releases a considerable amount of energy (approximately 100kW) during operation, it must be continuously lubricated to maintain an acceptable operating temperature. Therefore, an oil circuit is implemented to supply oil to the reduction gear. Oil drainage is a fundamental issue. In reality, the amount of oil required to operate the reduction gear is substantial, making oil drainage complex and requiring a bulky drainage device, which is difficult to implement in this environment.

[0012] Furthermore, the guide bearings for the rotation of the first and second turbine shafts must also be lubricated with lubricating oil. The delivery of lubricating oil to the guide bearings is also a major issue. In this type of configuration, the amount of oil to be delivered to the guide bearings is large. Therefore, the implementation of the delivery device in this type of environment is complex, as is the oil discharge device.

[0013] Therefore, there is a need to provide a turbine in which the oil used to lubricate the reduction gear can be easily recovered and discharged, and the bearings can be easily lubricated. Summary of the Invention

[0014] Therefore, the present invention provides a turbine for an aircraft, comprising:

[0015] - First rotor, the first rotor includes a first shaft

[0016] - A second rotor, which includes a second shaft,

[0017] - A mechanical rotary speed reduction device comprising a sun gear, a ring gear, and planetary gears. The sun gear is connected to a second shaft, the ring gear is connected to a first shaft, and the planetary gears are located between the sun gear and the ring gear and are supported by a planetary carrier, which is fixed to the stator of the turbine.

[0018] - A rolling bearing, used to guide the rotation of the first and second shafts.

[0019] - An annular groove extending around the ring gear of the reduction gear and configured to recover the oil used to lubricate the reduction gear, which is ejected from the ring gear during operation by centrifugal force.

[0020] - A ring bearing support member, which is fixed to the stator of the turbine with a groove, and which supports at least one of the bearings.

[0021] The turbine differs in that it also includes at least one means for conveying the oil recovered from the trench, the at least one means being carried by the annular support and extending to the at least one bearing for lubrication of the at least one bearing.

[0022] Therefore, the turbine includes grooves for recovering oil used to lubricate the reduction gear. According to the invention, the turbine also includes means for conveying at least a portion of the oil recovered from the grooves, extending to the bearings. Thus, the conveying means allows the oil recovered from the grooves for lubricating the reduction gear to be used for lubricating the bearings. Due to this invention, a specific oil supply for lubricating the bearings can be eliminated, thereby providing considerable cost savings.

[0023] Furthermore, since a portion of the oil used to lubricate the reduction gear is also used to lubricate the bearings, the total amount of oil to be injected and discharged is reduced. The oil to be injected and discharged is delivered via an oil circuit that passes through the arms of the turbine housing. Therefore, the size of the circuit can be reduced, facilitating its integration into the arms of the turbine housing.

[0024] The turbine according to the invention may include one or more of the following features, which may be adopted independently of each other or in combination with each other:

[0025] - The conveying device includes a scoop configured to remove oil recovered from the trench, the scoop being disposed in the annular sidewall of the trench;

[0026] - The conveying device includes at least one conduit for conveying oil taken from the scoop to the at least one bearing, the conduit extending between a first end connected to the groove and a second end extending to the bearing;

[0027] - The delivery pipe has a generally spiral shape around the longitudinal axis of the turbine.

[0028] - The conveying conduit is formed in a rib protruding from the inner annular surface of the annular support, or formed by a pipe section supported by the annular support;

[0029] - The delivery device includes at least one injection section for injecting oil into the at least one bearing, the injection section being supported by the annular support member;

[0030] - The at least one spraying part has a generally straight or angled shape;

[0031] - A first shaft is fixed to a ring gear and extends at least partially between the reduction gear and the ring support, the first shaft being guided by the at least one bearing, the at least one bearing being supported by the ring support and lubricated by the device;

[0032] - The at least one injection part is inserted axially between the at least one bearing and a dynamic annular seal mounted around the first shaft;

[0033] - The annular housing extends at least partially around the deceleration device, and the annular support and the groove are fixed to the annular housing, which includes an arm that extends radially relative to the longitudinal axis of the turbine and passes through the flow jet of the gas flux inside the turbine. Attached Figure Description

[0034] Other features and advantages will become apparent from the following description of non-limiting embodiments of the present invention, and with reference to the accompanying drawings, in which:

[0035] [ Figure 1 ] Figure 1 This is a very schematic view of the turbine half of an aircraft according to the present invention;

[0036] [ Figure 2 ] Figure 2 yes Figure 1 An enlarged schematic view of a portion of the turbine;

[0037] [ Figure 3 ] Figure 3 yes Figure 2 A magnified view of a portion;

[0038] [ Figure 3 ] Figure 4 yes Figure 3 A perspective view of the components of the present invention shown;

[0039] [ Figure 5 ] Figure 5 yes Figure 3 Another perspective view of the elements of the present invention shown;

[0040] [ Figure 6a ] Figure 6a This is a schematic view of a first example of an embodiment of the jet section applicable to the present invention;

[0041] [ Figure 6b ] Figure 6b This is a schematic view of a second example of an embodiment of the jet section applicable to the present invention. Detailed Implementation

[0042] For example in Figure 1 The image shows an aircraft turbine 1. Turbine 1 is, for example, a counter-rotating turbine for turbine 1. Turbine 1 extends along a longitudinal axis A.

[0043] Turbine 1 includes a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, an annular combustion chamber 5, a high-pressure turbine 6, and a counter-rotating turbine 7 in the direction of airflow F from upstream to downstream.

[0044] The turbine 1 also includes multiple structural housings. For example, the turbine includes an intermediate housing 10 disposed between the low-pressure compressor 3 and the high-pressure compressor 4. The turbine 1 also includes a turbine housing 12. The turbine housing 12 is equipped with arms forming rectifier blades, and is referred to as a turbine vane frame (TVF). The turbine housing 12 is disposed between the high-pressure turbine 6 and the counter-rotating turbine 7. The turbine 1 also includes an annular housing 13, i.e., an exhaust housing. The annular housing 13 is, for example, the final turbine housing and is referred to as a turbine rear frame (TRF).

[0045] The high-pressure turbine 6 includes a rotor that drives the rotor of the high-pressure compressor 4 to rotate via a high-pressure shaft 60. The high-pressure shaft 60 is centered and guided to rotate by high-pressure bearings, such as an upstream high-pressure bearing 61 and a downstream high-pressure bearing 62. The upstream high-pressure bearing 61 is, for example, a ball bearing, and the downstream high-pressure bearing 62 is, for example, a roller bearing. The upstream high-pressure bearing 61 is mounted between the upstream end of the high-pressure shaft 60 and the intermediate housing 10.

[0046] The counter-rotating turbine 7 includes a first rotor 8 and a second rotor 9. The first rotor includes a first shaft 80 and the second rotor includes a second shaft 90.

[0047] More specifically, the first rotor 8 includes a first series of wheel portions 81 configured to rotate in a first rotational direction and connected to a first shaft 80. The second rotor 9 includes a second series of wheel portions 91 configured to rotate in the opposite direction to the first rotational direction and connected to a second shaft 90. The second series of wheel portions 91 are inserted between the first series of wheel portions 81.

[0048] Each wheel section 81, 91 includes an annular row of blades, each blade including an aerodynamic profile having a pressure side and a suction side, the pressure side and suction side meeting to form a leading edge and a trailing edge of gas in the jet stream of the counter-rotating turbine 7.

[0049] The first shaft 80 drives the rotors of the fan 2 and the low-pressure compressor 3 to rotate.

[0050] In addition, the turbine 1 includes rolling bearings for guiding the rotation of the first shaft 80 and the second shaft 90.

[0051] According to an example not shown, the second shaft 90 is centered and guided to rotate by two upstream guide rolling bearings and a downstream guide rolling bearing.

[0052] The first shaft 80 is via at least one guide bearing, for example via Figure 2 At least one downstream guide bearing 15 is visible in the middle and is centered and guided to rotate downstream.

[0053] The first shaft 80 is centered and guided to rotate upstream by two upstream guide bearings 82, 83 installed between the upstream end of the first shaft 80 and the intermediate housing 10.

[0054] In addition, turbine 1 includes a mechanical rotary speed reduction device 14. For example... Figure 2 As shown, the reduction gear 14 includes a sun gear 41, a ring gear 42, and a planetary gear 43. The sun gear is connected to a second shaft 90, the ring gear is connected to a first shaft 80, and the planetary gear is located between the sun gear 41 and the ring gear 42 and is carried by a planetary carrier 43a, which is fixed to the stator of the turbine 1.

[0055] More specifically, such as Figure 1 As shown, the first shaft 80 has a downstream end 80a and an upstream end 80b, the downstream end being attached to the upstream end of the ring gear carrier 42a of the ring gear 42, and the upstream end 80b being attached to the last stage of the first rotor 81 of the first turbine 8.

[0056] The turbine housing 12 and the annular housing 13 include a central hub and an outer ring surrounding the hub and connected to it by a series of arms 13a. The arms 13a are generally radial or inclined relative to the longitudinal axis A of the turbine 1 and pass through the turbine's jet flow. The central hub of the annular housing 13 extends around at least a portion of the reduction gear 14.

[0057] Downstream bearing 15 is located downstream of reduction gear 14. Downstream bearing 15 is supported by an annular bearing support 16, which is attached to the stator of turbine 1, for example, to an annular housing 13. First shaft 80 extends at least partially between reduction gear 14 and support 16.

[0058] Furthermore, an annular dynamic seal 23 is mounted around the first shaft 80. The dynamic seal 23 is, for example, a joint radial segment (JRS). The dynamic seal 23 is, for example, made of carbon. The dynamic seal 23 is, for example, received in a groove 231, which is provided in a flange 232 of a fixed structure connected to the stator of the turbine 1, for example, connected to the annular housing 13 and the support member 16.

[0059] During operation, the reduction gear 14 is lubricated, and the oil that has been used to lubricate the reduction gear must be recovered and discharged for recirculation to prevent the oil from accumulating in the reduction gear 14 and turning into coke under high temperature.

[0060] For this purpose, the turbine 1 includes an annular groove 17 that extends around the annular gear 42 of the reduction gear 14 and is configured to recover oil used to lubricate the reduction gear 14, which is centrifugally ejected from the annular gear 42 during operation, such as... Figure 2 As shown by the circular arrow in the image.

[0061] Specifically, the oil is centrifuged and terminates at the ring gear 42 of the reduction gear 14. For example... Figure 3 As shown, channels 42b can be positioned on the outer periphery of the ring gear 42 to centrifugally inject oil into grooves 17 extending opposite to these channels 42b. Channels 42b are oriented radially, for example, relative to the longitudinal axis A of the turbine 1.

[0062] The groove 17 and the annular bearing support 16 are fixed to the stator of the turbine 1, for example, to the annular housing 13.

[0063] like Figure 4 and Figure 5 As shown, the groove 17 has an annular sidewall 17c. The groove 17 also has an inner annular surface 17d and an outer annular surface 17e.

[0064] The groove 17 is formed, for example, by an assembly of a first annular wall 17a and a second annular wall 17b, which are coaxially mounted together. The first annular wall 17a is formed, for example, by a support member 16.

[0065] Each of walls 17a and 17b includes an annular discharge rib 174 that projects radially toward the interior.

[0066] The annular discharge ribs 174 define an oil recovery space E between the annular discharge ribs in the axial direction. This space E is defined radially by the inner annular surface 17d.

[0067] Furthermore, advantageously, the outer annular surface 17e is coated with an annular heat-insulating coating 24. Thus, the annular coating 24 is arranged radially between the annular housing 13 and the groove 17. The annular bushing 24 is separated from the annular housing 13, for example, by an annular free space for air circulation and ventilation.

[0068] The second wall 17b includes an upstream end 171 and a downstream end 172. The upstream end 171 of the second wall 17b is axially engaged in an annular groove 18a of a member 18, which is secured to an upstream flange 13b of an annular housing 13 by a retaining flange 18b. The upstream flange 13b of the annular housing 13 is located substantially in line with the arm 13a of the annular housing 13. Preferably, an annular seal is arranged in the groove 13a and axially abuts the upstream end 171 of the second wall 17b.

[0069] The downstream end 172 of the second wall 17b includes a flange that is fixed to the downstream flange 13c of the annular housing 13, which is located in a position substantially in line with the arm 13a.

[0070] The first wall 17a includes a flange that is fixed to the downstream flange 13c of the annular housing 13.

[0071] The fixed flange forms a cylindrical edge 173 facing upstream to mate with the second wall 17b.

[0072] The trench 17 includes an opening (not shown) that ensures passage of oil to a discharge conduit (not shown). The conduit passes through arm 13a of the annular housing 13. Advantageously, the trench 17 includes an oil recovery chamber (not shown) located in its lower portion. The recovery chamber provides part of the oil calming, i.e., degassing or degassing, to reduce the number of air bubbles in the oil. Thus, the oil passes through the opening communicating with the recovery chamber, for example, via a conduit that passes through arm 13a of the annular housing 13, before being discharged.

[0073] In order to reduce the total amount of oil to be transported and the amount of oil to be discharged through arm 13a, thereby reducing the volume of the duct passing through arm 13a, according to the invention, the turbine further includes at least one device 19 for transporting oil recovered by trench 17, the at least one device being carried by an annular support 16 and extending to at least one guide bearing (e.g., extending to downstream guide bearing 15) for lubrication of at least one guide bearing.

[0074] like Figure 4 As shown, the device 19 includes, for example, a scoop 20 for drawing out oil, at least one pipe 21 for conveying oil, and at least one spraying part 22 for spraying oil onto a guide bearing (e.g., downstream guide bearing 15) when the first shaft 80 rotates. Figure 2 ).

[0075] The scoop 20 is configured to remove the oil collected by the groove 17. The scoop 20 is disposed in the annular sidewall 17c of the groove 17, for example, in the annular sidewall of the first wall 17a.

[0076] The scoop 20 is in fluid communication with the pipe 21. The pipe 21 is used to deliver the oil taken out by the scoop 20 to the guide bearing, such as the downstream guide bearing 15.

[0077] For example, such as Figure 5 As shown, the conduit 21 has a helical shape around the longitudinal axis A of the turbine 1. The helical shape of the conduit 21 allows for limiting the pressure loss of the oil extracted by the scoop 20 during delivery to the guide bearing. The conduit 21 extends between a first end 21a connected to the groove 17 and a second end 21b extending to the downstream bearing 15. The second end 21b is connected to the injection section 22. More specifically, the first end 21a is connected to the first wall 17a of the groove 17, the second end 21b is connected to the injection section 22, and the conduit 21 extends along the support 16 between the first end 21a and the second end 21b.

[0078] exist Figure 5 In the example shown, the conduit 21 is formed in a protruding rib on the inner annular surface 17d of the support 16. For example, the conduit 21 is formed in a rib 174 of the first wall 17a of the groove 17 and extends into the support 16.

[0079] According to another example not shown, the pipe 21 is formed by a pipe section supported by the support member 16.

[0080] The injection section 22 is used to distribute oil delivered by the pipe 21 to the bearing 15. The injection section 22 is supported, for example, by a support member 16. The injection section 22 is fixed to the downstream end of the support member 16. The injection section 22 is inserted axially between the bearing 15 and the dynamic seal 23. To limit the oil sprayed onto the dynamic seal 23, a vortex can be arranged against the dynamic seal 23.

[0081] More specifically, the spray section 22 includes a cylindrical body 22a and a spray nozzle 22b.

[0082] according to Figure 6a In the first exemplary embodiment shown, the injection section 22 has a generally straight shape. Therefore, the cylindrical body 22a and the injection nozzle 22b extend along the same axis perpendicular to the axis of the turbine 1. Figure 6b In another embodiment shown, the injection section 22 has a generally angled shape. Therefore, the injection nozzle 22b extends radially relative to the cylindrical body 22a, such that the injection nozzle 22b extends parallel to the longitudinal axis A of the turbine 1. In this example, the injection nozzle 22b is oriented toward the bearing 15. This configuration allows for maximizing the amount of oil distributed to the bearing 15, particularly in cases where pressure loss during oil delivery in the pipe 21 results in excessively low pressure in the injection section 22.

[0083] Therefore, the present invention incorporates a groove 17 that allows for the recovery of oil used to lubricate the reduction gear 14, thereby limiting the risk of coke formation in the reduction gear 14. A portion of this oil is delivered via device 19 to a guide bearing (e.g., to a downstream guide bearing 15 when the first shaft 80 rotates) for lubrication. Specifically, a portion of the delivered oil is first removed from the groove 17 by a scoop 20 connected to a conduit 21, allowing the oil to be delivered to a jetting section 23, which distributes the removed oil to the downstream guide bearing 15. As a result, less oil remains in the groove 17 and is discharged. Consequently, the size of the conduit extending from the groove 17 into the arm 13a of the annular housing 13 can be configured to discharge a smaller amount of oil. This results in a smaller conduit that can be integrated into the annular housing 13. Furthermore, the cost associated with lubricating the reduction gear 14 and bearings is reduced because the total amount of oil introduced is reduced by reusing some of the oil used to lubricate the reduction gear 14.

[0084] Furthermore, the present invention has been described with respect to a turbine 1 in which the reduction gear 14 is located downstream of the turbine 1 and surrounded by an annular housing 13. The invention is also applicable to a turbine 1 in which the reduction gear 14 is located upstream of the turbine 1 and surrounded by an intermediate housing 10. According to this embodiment, the groove 17 and the support 16 are attached to the intermediate housing 10. The same advantages are obtained from this embodiment.

Claims

1. A turbine (1) for an aircraft, comprising: - First rotor (8), the first rotor includes a first shaft (80). - Second rotor (9), the second rotor includes a second shaft (90). - A mechanical deceleration device (14) comprising a sun gear (41), a ring gear (42), and a planetary gear (43), wherein the sun gear is connected to a second shaft (90), the ring gear is connected to a first shaft (80), and the planetary gear is located between the sun gear (41) and the ring gear (42) and is supported by a planetary carrier (43a) which is fixed to the stator of the turbine (1). - A rolling bearing for guiding the rotation of the first shaft (80) and the second shaft (90), - An annular groove (17) extending around the annular gear (42) of the mechanical rotary reducer (14) and configured to recover oil used for lubricating the mechanical rotary reducer (14), which is ejected from the annular gear (42) by centrifugal force during operation, and - An annular bearing support (16), which is fixed to the stator of the turbine (1) with the annular groove (17) and supports at least one of the rolling bearings (15). The turbine is characterized in that it further includes: - At least one conveying device (19) for conveying the oil recovered by the annular groove (17), the at least one conveying device being carried by the annular bearing support (16) and extending to the at least one bearing (15) for lubricating the at least one bearing. The conveying device (19) includes at least one conveying pipe (21) for conveying oil taken out by the scoop (20) to the at least one bearing (15), the conveying pipe (21) extending between a first end (21a) connected to the annular groove (17) and a second end (21b) extending to the bearing (15).

2. The turbine (1) according to claim 1, characterized in that, The conveying device (19) includes a scoop (20) configured to remove oil recovered by the annular groove (17), the scoop (20) being disposed in the annular sidewall (17c) of the annular groove (17).

3. The turbine (1) according to claim 1 or 2, characterized in that, The delivery pipe (21) has a generally spiral shape around the longitudinal axis (A) of the turbine (1).

4. The turbine (1) according to claim 1 or 2, characterized in that, The conveying pipeline (21): - Formed in the rib (174) protruding from the inner annular surface (17d) of the annular bearing support (16), or - A tube portion supported by the annular bearing support (16) is formed.

5. The turbine (1) according to claim 1 or 2, characterized in that, The delivery device (19) includes at least one injection section (22) for injecting oil into the at least one bearing (15), the injection section (22) being carried by the annular bearing support (16).

6. The turbine (1) according to claim 5, characterized in that, The at least one spray section (22) has a generally straight or angled shape.

7. The turbine (1) according to claim 1 or 2, characterized in that, The first shaft (80) is fixed to the ring gear (42) and extends at least partially between the mechanical rotary deceleration device (14) and the ring bearing support (16). The first shaft (80) is guided by the at least one bearing (15), which is supported by the ring bearing support (16) and lubricated by the conveying device (19).

8. The turbine (1) according to claim 6, characterized in that, The first shaft (80) is fixed to the ring gear (42) and extends at least partially between the mechanical rotary deceleration device (14) and the ring bearing support (16). The first shaft (80) is guided by the at least one bearing (15), which is supported by the ring bearing support (16) and lubricated by the conveying device (19). The at least one jet (22) is axially inserted between the at least one bearing (15) and a dynamic annular seal (23) mounted around the first shaft (80).

9. The turbine (1) according to claim 1 or 2, characterized in that, The turbine also includes an annular housing (13) that extends at least partially around the mechanical rotary deceleration device (14), and the annular bearing support (16) and the annular groove (17) are fixed to the annular housing. The annular housing (13) includes an arm (13a) that extends radially relative to the longitudinal axis (A) of the turbine (1) and passes through the flow jet of gas flux inside the turbine (1).

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