Aircraft turbine engine mechanical reducer

Abstract

The invention relates to a mechanical reducer (6) for a turbine engine, in particular for an aircraft, comprising: a sun gear having an axis of rotation, a ring gear (9) extending around the sun gear and configured to be rotationally fixed around said axis, planetary gears meshing with the sun gear and the ring gear and supported by a planet carrier causing rotational movement around said axis, at least one lubricating oil distributor comprising a rotor part (14) which rotates integrally with the planet carrier and a stator part (15) which is rotationally fixed, and an annular oil deflector (26) which is integral with the ring gear, characterized in that the stator part of the distributor is integral with the deflector.

Description

Technical Field

[0001] The invention relates to the field of mechanical speed reducers for turbine engines, in particular for aircraft. Background Art

[0002] The prior art includes in particular documents WO-A1-2010 / 092263, FR-A1-2 987 416, FR-A1-3 041 054, EP-A2-2 518 279 and EP-A2-2 554 874.

[0003] The function of a mechanical reducer is to change the speed and torque ratio between the input shaft and the output shaft of a mechanical system.

[0004] New generation bypass turbine engines, especially those with high bypass ratios, include a mechanical speed reducer to drive the fan shaft. Typically, the purpose of the speed reducer is to convert the rotational speed of the shaft of the power turbine (called the fast rotational speed) to a slower rotational speed of the shaft driving the fan.

[0005] This reducer includes a central pinion called a sun gear, a ring gear and pinions called planet gears, which are engaged between the sun gear and the ring gear. The planet gears are supported by a support called a planet carrier. The sun gear, the ring gear and the planet carrier are planetary because their axes of rotation coincide with the longitudinal axis X of the turbine engine. The planet gears each have a different axis of rotation, which is evenly distributed around the planet axis on the same working diameter. These axes are parallel to the longitudinal axis X.

[0006] There are many types of speed reducer structures. In the prior art of bypass turbine engines, the speed reducer is planetary or epicyclic. In other similar applications, there is a structure called differential or "compound".

[0007] -In a planetary reducer, the planet carrier is fixed and the ring gear forms the output shaft of the device, which rotates in the opposite direction of the sun gear.

[0008] -In an epicyclic reducer, the ring gear is fixed and the planetary carrier forms the output shaft of the device,

[0009] The output shaft rotates in the same direction as the sun gear.

[0010] -In a differential reducer, no element is fixed in rotation. The ring gear is rotated along with the sun gear and the planetary gears.

[0011] The rack rotates in the opposite direction.

[0012] The reducer may include one or more meshing stages. This meshing is ensured in different ways, for example by contact, by friction or also by magnetic fields. The meshing by contact is of various types, for example meshing with spur gears or herringbone gears.

[0013] The reducer must be lubricated and the input of lubricating oil to the rotating parts of the reducer may present problems. When the reducer is of planetary type, the oil is brought to the reducer by a distributor, which comprises an integrally rotating rotor part of the planet carrier and a rotationally fixed stator part. The stator part of the distributor is in sealing engagement with the rotor part, and this sealing needs to be ensured when the stator part must move and tilt relative to the reducer during operation and follow the movement of the rotor part. In the current technology, the stator part is rotationally fixed to the stator housing of the turbine engine by a rod connection.

[0014] The present invention proposes a simple, effective and economical improvement plan for this technology. Summary of the invention

[0015] The present invention relates to a planet carrier of a mechanical reducer for a turbine engine, in particular for an aircraft, the reducer comprising:

[0016] - a sun gear having an axis of rotation,

[0017] - a ring gear extending around the sun gear and configured to be rotationally fixed about said axis,

[0018] - planetary gears meshing with the sun gear and the ring gear and supported by a planet carrier causing the planet carrier to move in rotation about said axis,

[0019] - a lubricating oil distributor comprising a rotor part which rotates integrally with the planet carrier and a stator part which is fixed in rotation, and

[0020] - at least one annular oil deflector integral with said ring gear,

[0021] Characterized in that the stator portion of the distributor is integral with the deflector.

[0022] In the prior art, the deflector has a single function of capturing and directing the oil sprayed radially outwards, taking into account the discharge and recirculation of the oil. In the present invention, the deflector has this function and also has another function of supporting the stator part of the distributor so as to limit the relative movement and relative tilt between the rotor part and the stator part of the distributor in operation, which makes it possible to ensure a good seal between these parts in particular.

[0023] The solution proposed below is compatible with epicyclic reducers whose ring gear is fixed in the reference frame of the engine. It is compatible with any type of gear (spur, herringbone) with any type of planetary carrier (whether integral or cage / cage), and with planetary bearings consisting of rolling elements (ball bearings, roller bearings, tapered roller bearings, etc.) or hydrodynamic bearings.

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

[0025] - the deflector comprises an annular flange for mounting to an annular flange of the gear ring,

[0026] - the gear ring comprises two gear ring halves, each gear ring half comprising a rim equipped with a gear and a mounting flange half, the mounting flange halves being fixed together and to the flange of the deflector,

[0027] the gear ring comprises two gear ring halves, each gear ring half comprising a rim equipped with gears and a mounting flange half, the sleeve being fixed to the rim of one of the gear ring halves or being formed as an integral part with one of the gear ring halves,

[0028] - the deflector comprises an outer peripheral portion extending around the toothed ring half,

[0029] - the deflector comprises an inner peripheral portion extending substantially radially relative to said axis,

[0030] - the deflector comprises an annular row of through holes,

[0031] - the deflector comprises a truncated portion, said space being formed in said truncated portion,

[0032] - said stator part of the distributor comprises:

[0033] an outer cylindrical surface comprising an oil outlet orifice and configured to engage in a sealing manner with said rotor portion of the distributor, and

[0034] - an internal oil circuit comprising an annular cavity connected on the one hand to a line extending substantially axially and connecting said cavity to said orifice and on the other hand to at least one supply channel extending substantially radially from said cavity.

[0035] The invention also relates to a turbine engine, in particular for an aircraft, comprising a mechanical reduction gear as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other features and advantages will emerge from the following description of non-limiting embodiments of the invention with reference to the accompanying drawings, in which:

[0037] Figure 1 is a schematic axial cross-sectional view of a turbine engine using the present invention,

[0038] Figure 2 This is a partial axial cross-sectional view of a mechanical reducer.

[0039] Figure 3 is another partial axial cross-sectional view of a mechanical reducer and illustrates the prior art of the present invention,

[0040] Figure 4 is another partial axial cross-sectional view of the mechanical reducer, and illustrates the present invention,

[0041] Figure 5 yes Figure 4 A perspective view of the reducer, and

[0042] Figure 6 is with Figure 4 Similar views and showing another embodiment of the present invention. DETAILED DESCRIPTION

[0043] Figure 1 A turbine engine 1 is described, which generally includes a fan S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1c, a high-pressure turbine 1d, a low-pressure turbine 1e and an exhaust pipe 1h. The high-pressure compressor 1b and the high-pressure turbine 1d are connected by a high-pressure shaft 2 and form a high-pressure (HP) body with the high-pressure shaft. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and form a low-pressure (LP) body with the low-pressure shaft.

[0044] The fan S is driven by a fan shaft 4, which is connected to the LP shaft 3 via a reducer 6. The reducer 6 is usually of planetary or epicyclic type.

[0045] The following description relates to an epicyclic reducer, in which the planet carrier and the sun gear are rotatably movable and the reducer ring gear is fixed in the engine reference frame.

[0046] The reducer 6 is located in the front part of the turbine engine. In the present application, the expressions "upstream" and "downstream" refer to the general flow of gases in the turbine engine along the extension axis of the turbine engine or the rotation axis of the rotor of the turbine engine. A fixed structure is arranged to form a casing E around the reducer 6, which schematically includes a downstream part 5b and an upstream part 5a forming the engine casing or stator 5. The casing E is closed here upstream by a seal at the height of the bearing (the bearing height allows the fan shaft 4 to pass through) and downstream by a seal at a height that allows the LP shaft 3 to pass through.

[0047] Figure 2 An epicyclic reducer 6 is shown. At the inlet, the reducer 6 is connected to the LP shaft 3, for example by means of an internal spline 7a. The LP shaft 3 thus drives a planetary pinion called a sun gear 7. Typically, the axis of rotation of the sun gear 7 is coupled to the axis X of the turbine engine and the sun gear 7 drives a series of pinions called planetary gears 8, which are evenly distributed on the same diameter around the axis of rotation X. This diameter is equal to twice the working distance between the sun gear 7 and the planetary gears 8. For this type of application, the number of planetary gears 8 is generally limited to between three and seven.

[0048] All planetary gears 8 are supported by a carrier called a planet carrier 10. Each planetary gear 8 rotates about its own axis Y and meshes with a ring gear 9.

[0049] At the exit the following occurs:

[0050] ■ In this epicyclic configuration, all the planetary gears 8 drive a planet carrier 10 in rotation about the axis X of the turbine engine. The ring gear is fixed to the engine casing or stator 5 via a ring gear carrier 12 , and the planet carrier 10 is fixed to the fan shaft 4 .

[0051] ■ In another planetary configuration, all planetary gears 8 are held by a planet carrier 10 fixed to the engine housing or stator 5. Each planetary gear drives a ring gear which is connected to the fan shaft 4 via a ring gear carrier 12.

[0052] Each planet gear 8 is mounted to rotate freely by using a bearing 11, which is for example of the roller bearing type or the hydrodynamic bearing type. Each bearing 11 is mounted on one of the shafts 10a of the planet carrier 10, and all the shafts are positioned relative to each other by using one or more structural supports 10a of the planet carrier 10. The number of shafts 10b and bearings 11 is equal to the number of planet gears. For reasons of operation, installation, production, control, maintenance or replacement, the shaft 10a and the support 10a can be divided into multiple parts.

[0053] For the same reasons as above, the gears of the reducer can be divided into multiple spirals, each with a middle plane P. In this example, the operation of a reducer with multiple spirals is described in detail, where the ring gear is divided into two ring gear halves:

[0054] ■Front gear ring half 9a, which consists of a rim 9aa and a mounting flange half 9ab. The front spiral portion of the gear of the reducer is located on the rim 9aa. This upstream spiral portion meshes with the upstream spiral portion of the planetary gear 8, and the upstream spiral portion of the planetary gear meshes with the upstream spiral portion of the sun gear 7.

[0055] ■ Downstream gear ring half 9b, which consists of a rim 9ba and a mounting flange half 9bb. The downstream spiral portion of the gear of the reducer is located on the rim 9ba. The downstream spiral portion meshes with the downstream spiral portion of the planetary gear 8, and the downstream spiral portion of the planetary gear meshes with the downstream spiral portion of the sun gear 7.

[0056] If the spiral widths between the sun gear 7, the planetary gears 8 and the ring gear 9 vary due to the overlap of the gears, for the upstream spiral they are all centered on a middle plane P, and for the downstream spiral they are all located on another middle plane P. In the case of a roller bearing with two rows of rollers, each row of rolling elements is also preferably, but not necessarily, centered on two middle planes.

[0057] The mounting flange half 9ab of the upstream ring gear 9a and the mounting flange half 9bb of the downstream ring gear 9b form the mounting flange 9c of the ring gear. The ring gear 9 is fixed to the ring gear carrier by assembling the mounting flange 9c of the ring gear carrier and the mounting flange 12a of the ring gear carrier together using a mounting member with bolts, for example.

[0058] Figure 2 The arrows in describe the travel of the oil in the reducer 6. The oil reaches the reducer 6 from the stator part 5 in the distributor 13 through different components, which will not be specified in this figure because they are specific to one or more types of structures. The distributor 13 includes an injector 13a and an arm 13b. The injector 13a has the function of lubricating the gears, and the arm 13b has the function of lubricating the bearings. The oil is brought to the injector 13a to flow out through the end 13c to lubricate the gears. The oil is also brought to the arm 13b and circulated through the inlet pipe 13d of the bearing. Then, the oil circulates through the shaft in one or more buffer areas 10c and then flows out through the orifice 10d to lubricate the bearings of the planetary gears.

[0059] Figure 3 A more specific exemplary embodiment of an oil distributor 13 is shown, which comprises a rotor part 14 and a stator part 15 .

[0060] The rotor portion 14 rotates integrally with the planet carrier 10 and has a generally annular shape about the axis X. This portion 14 comprises a nozzle 14a engaging in an inlet duct 13d of the bearing 11 of the planetary gear 8 and comprising an oil outlet orifice 16 for supplying oil from the buffer zone 10c.

[0061] The rotor part 14 comprises at its inner periphery a cylindrical inner surface 14b with an oil inlet orifice 17. The rotor part 14 further comprises an annular chamber 18 connected on the one hand to a first channel 19 substantially radial to the orifice 17 and also to the orifice 16 via a second channel 20 substantially L-shaped.

[0062] The stator part 15 of the distributor 13 is integral with the turbine engine casing (not shown). In practice, this part 15 is connected to the casing by an arm that serves to avoid angular deviations of the reducer 6.

[0063] The stator part 15 has a generally annular shape around the axis X and comprises a cylindrical body engaged in the rotor part 14 and comprising a cylindrical outer surface 15a with an oil outlet orifice 21. In operation, the surfaces 14b and 15a engage together to ensure sealing between the internal oil circuits of the distributor 13.

[0064] The internal oil circuit of the stator part 15 comprises an annular cavity 22 connected on the one hand to a line 23 and on the other hand to at least one supply channel 24 extending substantially axially and connecting the cavity 22 to the orifice 21, the supply channel 24 extending substantially radially from the cavity 22. The channel 24 opens radially outwards on the outer surface of the stator part 15 to form an oil inlet orifice 25.

[0065] Figure 3 The reducer 6 further comprises an annular oil deflector 26. When the ring gear 9 is fixed, the deflector 26 is integral with the ring gear 9 and forms part of the stator of the reducer. The deflector 26 is presented in the form of a thin annular sleeve. The deflector 26 comprises a radially outer peripheral edge, which is fixed to the ring gear 9 and in particular comprises an annular flange 27 for mounting to the flange 9c of the ring gear. The deflector 26 extends around the ring gear half 9b downstream here and comprises a free radially inner peripheral edge.

[0066] In axial cross section, the deflector 26 has a generally curved shape. The deflector is configured to capture oil that is expelled radially outwards and centrifuged in operation and direct the oil to the flange 9c of the ring gear 9 where it can be discharged and recirculated.

[0067] However, as mentioned above, in order to ensure sealing between the stator 15 and rotor 14 parts of the distributor 13, any relative movement (other than the rotation of the rotor part 14 around the stator part 15) and any relative tilting of these parts must be limited or even prevented.

[0068] The present invention can overcome this problem and proposes Figure 4 and Figure 5 In the first embodiment, the deflector 26 is modified so that it has the additional function of supporting the stator part 15 of the deflector 26. The holding of the stator part 15 by the stator element of the reducer (in this case the ring gear 9) makes it possible to limit or even prevent the above-mentioned relative movement and tilting.

[0069] For this purpose, the deflector 26 extends and in the present case extends from the ring gear 9 to the stator part 15. The deflector 26 comprises a similar Figure 3 The radially outer peripheral portion 26a of the radially outer peripheral portion in the embodiment (and including the flange 27 for mounting to the ring gear 9), and additionally includes two additional parts, namely the radially inner peripheral portion 26c and the middle portion 26b (located between the portions 26a, 26c).

[0070] The intermediate portion 26 b has a generally truncated shape and comprises, in the example shown, an annular row of through holes 28 which serve to adjust the mass and flexibility of the component 26. These holes are not essential for the correct functioning of the component 26.

[0071] The inner portion 26c extends substantially radially relative to the axis X and may be fixed to the stator portion 15 by any suitable means, for example by welding or interference fit. In a variant, the deflector 26 may be formed with the stator portion 15 as a single component.

[0072] In the example shown, with the stator portion 15 joining into the rotor portion 14 from downstream and its inlet orifice 25 situated downstream of the ring gear 6 , the connection of the deflector 26 to this stator portion 15 may be situated just upstream of this orifice 25 .

[0073] exist Figure 6 In the embodiment of the present invention, the deflector 26 of the prior art is retained, and an additional deflector 26 ′ is equipped with the speed reducer 6 .

[0074] The deflector 26' comprises parts 26b', 26c', which are similar to Figure 4 and Figure 5The peripheral edge of the deflector 26' is not fixed to the flange of the gear ring here, but is directly connected to the rim 9ba of one of the gear ring halves, here the downstream gear ring half 9b. The deflector 26' can be fixed to the rim 9ba by welding or can be formed as a single part with the rim, as in the example shown.

[0075] The free inner peripheral edge of the deflector 26 surrounds the outer periphery of the deflector 26 ′ and is spaced apart from the deflector 26 ′ by a low radial gap 29 .

[0076] The solution proposed by the invention therefore consists in integrating two functions in one and the same component, which makes the structural design simpler. Furthermore, the deflector is a more effective means than the aforementioned arms of the prior art to avoid angular deviations of the reducer.

Claims

1. A mechanical reducer (6) of a turbine engine (1), the mechanical reducer comprising: - a sun gear (7) having an axis of rotation (X), a ring gear (9) extending around the sun gear (7) and configured to be rotationally fixed about the axis (X), - planetary gears (8) meshing with the sun gear (7) and the ring gear (9) and supported by a planet carrier causing the planet carrier to move in rotation about the axis (X), - a lubricating oil distributor (13) comprising an integrally rotating rotor part (14) and a stator part (15) of the planet carrier, and - at least one annular oil deflector, said at least one annular oil deflector being integral with said ring gear (9), Characterized in that the stator part (15) of the lubricating oil distributor (13) is integrated with the annular oil deflector.

2. The mechanical reducer (6) according to claim 1, wherein: The annular oil deflector (26) comprises an annular flange (27) for mounting to an annular flange (9c) of the ring gear (9).

3. The mechanical reducer (6) according to claim 2, wherein: The gear ring (9) comprises two gear ring halves, each gear ring half comprising a rim equipped with gears and a mounting flange half, the mounting flange halves being fixed together and to a flange (27) of the annular oil deflector (26).

4. The mechanical reducer (6) according to claim 1, wherein: The gear ring (9) comprises two gear ring halves, each gear ring half comprising a rim equipped with gears and a mounting flange half, the annular oil deflector (26) being fixed to the rim of one of the gear ring halves or being formed as an integral part with one of the gear ring halves.

5. The mechanical reducer (6) according to claim 3 or 4, wherein: The annular oil deflector (26) includes an outer peripheral portion (26a) extending around the gear ring half (9b).

6. The mechanical reducer (6) according to any one of claims 1 to 4, wherein: The annular oil deflector (26) comprises an inner peripheral portion (26c) extending substantially radially relative to the axis (X).

7. The mechanical reducer (6) according to any one of claims 1 to 4, wherein: The annular oil deflector (26) comprises an annular row of through holes (28).

8. The mechanical reducer (6) according to claim 7, wherein: The annular oil deflector (26) includes a truncated portion (26b) in which the through hole (28) is formed.

9. The mechanical reducer (6) according to any one of claims 1 to 4, wherein: The stator part (15) of the lubricating oil distributor (13) comprises: an outer cylindrical surface (15a) comprising an oil outlet orifice (21) and configured to engage in a sealing manner with the rotor portion (14) of the lubricating oil distributor (13), and - an internal oil circuit comprising an annular cavity (22) connected on the one hand to a pipeline (23) extending substantially axially and connecting the annular cavity to the oil outlet orifice (21), and on the other hand to at least one supply channel (24) extending substantially radially from the annular cavity (22).

10. Turbine engine (1) comprising a mechanical reducer (6) according to one of claims 1 to 9.

11. Turbine engine (1) according to claim 10, being a turbine engine of an aircraft.

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