MECHANICAL REDUCER FOR AN AIRCRAFT TURBOMACHINE

Abstract

A mechanical gearbox (10) for a turbomachine (1), particularly an aircraft turbomachine, comprising a sun gear (11), a ring gear (14), planet gears (12) meshed with the sun gear (11) and the ring gear (14), and a lubrication circuit (C2) for the gearbox (10) comprising an oil line (28) having an oil inlet port (18) connected to an oil supply circuit (1) which includes an oil outlet port (22), the connection device (126) comprising a one-piece body (132). Figure for the abbreviation: Figure 3

Description

Title of the invention: MECHANICAL REDUCER FOR AN AIRCRAFT TURBOMACHINE Technical field of the invention

[0001] The present invention relates to a mechanical gearbox for a turbomachine, particularly for aircraft, as well as to a turbomachine comprising such a gearbox. Technical background

[0002] The state of the art includes in particular document FR-A1-3 118 646.

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

[0004] New generations of turbofan engines, particularly those with a very high bypass ratio, include a mechanical gearbox to drive the shaft of a fan. Typically, the purpose of the gearbox is to transform the high rotational speed of the power turbine shaft into a slower rotational speed for the fan-driving shaft.

[0005] Such a reduction gear comprises a central pinion, called the sun gear, a ring gear, and pinions called planet gears, which mesh between the sun gear and the ring gear. The planet gears are held by a frame called a planet carrier. The sun gear, ring gear, and planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis X of the turbomachine. The planet gears each have a different axis of revolution, equally spaced on the same operating diameter around the axis of the planetary gears. These axes are parallel to the longitudinal axis X.

[0006] Several gearbox architectures exist. In the state of the art of turbofan engines, gearboxes are of the planetary or epicyclic type. In other similar applications, there are so-called differential or compound architectures. - On a planetary reducer, the planet carrier is fixed and the ring forms the output shaft of the device which rotates in the opposite direction to the sun. - On an epicyclic reducer, the ring is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the solar. - On a differential gearbox, no element is fixed in rotation. The ring rotates in the opposite direction to the solar and satellite carrier.

[0007] Reducers can be composed of one or more meshing stages. This meshing is achieved in various ways such as by contact, by friction or by magnetic fields.

[0008] There are several types of contact meshing such as with straight, helical or chevron teeth.

[0009] One of the major challenges with these reducers is the lubrication of the various components thereof.

[0010] For this purpose, the reducer is equipped with a lubrication circuit connected to an oil supply circuit. The connection of these circuits must be designed to facilitate its assembly and disassembly, particularly during maintenance operations, but also to limit its size, especially in the axial direction.

[0011] The present invention offers a solution to this need, which is simple, effective and economical. Summary of the invention

[0012] The invention relates to a mechanical gearbox for a turbomachine, in particular for aircraft, the gearbox comprising:

[0013] - a solar array centered on a first axis,

[0014] - a corona centered on the first axis and extending around the solar element,

[0015] - satellites intercalated between the sun and the corona and centered on seconds axes parallel to the first axis and distributed around the first axis, the satellites being meshed with the sun and the corona,

[0016] - a satellite carrier for supporting satellites, and

[0017] - a lubrication circuit for the gearbox which includes an oil line comprising an oil inlet port connected to an oil supply circuit which includes an oil outlet port,

[0018] characterized in that:

[0019] - said oil inlet port is oriented radially with respect to said first axis and opens radially outwards, on one side of the reducer,

[0020] - said oil outlet port is oriented parallel to said first axis and opens axially towards said side of the reducer, and

[0021] - said oil inlet port is connected to said oil outlet port by a device connection comprising a body which is formed in one piece and which includes a first end oriented axially and engaged by male-female fit into or onto the oil outlet port, and a second end oriented radially and engaged by male-female fit into or onto the oil inlet port.

[0022] The invention thus proposes a connection device with two ends, one of which is oriented axially and the other radially. It is therefore understood that the device is of the angled type. This makes it possible to significantly reduce the size of the device and therefore of the connection between the power supply circuits. and connection. This also makes it easier to assemble and disassemble the device during maintenance operations.

[0023] The solution proposed below is compatible with a two-stage or multi-stage gearbox. It is also compatible with a planetary gearbox. It is also compatible with spur, helical, or herringbone gears.

[0024] The reducer according to the invention may also have one or more of the following optional features, taken alone or in combination with each other: - said power supply circuit is integrated into said satellite carrier; - said supply circuit is part of a separate oil distributor and fixed on said satellite carrier; - the body is fixed to the satellite carrier or the distributor; - the body includes at least one mounting tab for attaching to the satellite carrier or the distributor, said at least one fixing bracket having at least one opening for the passage of a fixing element such as a screw for example. - the body includes two mounting tabs on the satellite carrier or distributor, the two tabs being symmetrical with respect to a plane passing through the first axis and through said first and second end caps; - the first end is a female end; - the second end is a female end; - During assembly, the first end piece is able to slide into or onto the port entry in a radial direction with respect to said first axis.

[0025] The present invention also relates to a turbomachine, in particular for aircraft, comprising a reducer as described above. Brief description of the figures

[0026] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0027] [Fig.1] [Fig.1] is a very schematic axial cross-sectional view of an aircraft turbomachine,

[0028] [Fig.2] [Fig.2] is a very schematic axial cross-sectional view of a mechanical reducer,

[0029] [Fig.3] [Fig.3] is a schematic perspective and cross-sectional view of a connection device according to an embodiment of the invention,

[0030] [Fig.4] [Fig.4] is a schematic perspective view of the connection device of [Fig.3], and

[0031] [Fig.5] [Fig.5] is another schematic perspective view of the connection device of [Fig.3]. Detailed description of the invention

[0032] Fig. 1 shows a turbomachine 1 which includes, in a conventional manner, a blower propeller S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1e, a high-pressure turbine Id, a low-pressure turbine 1e and an exhaust nozzle Ih.

[0033] The high-pressure compressor 1b and the high-pressure turbine Id are connected by a high-pressure shaft 2 and together form a high-pressure (HP) unit. The low-pressure compressor la and the low-pressure turbine le are connected by a low-pressure shaft 3 and together form a low-pressure (LP) unit.

[0034] The blower propeller S is driven by a blower shaft 4 which is coupled to the BP shaft 3 by means of an epicyclic gear reducer 10 represented here schematically.

[0035] The reducer 10 is positioned in the front part of the turbomachine 1. A fixed structure schematically comprising, here, an upstream part 5a and a downstream part 5b is arranged to form an enclosure El surrounding the reducer 10.

[0036] This enclosure El is here closed upstream by seals at the level of a bearing allowing the passage of the blower shaft 4, and downstream by seals at the level of the passage of the BP shaft 3.

[0037] With reference to [Fig. 2], the reducer 10 comprises a ring gear 14 which is fixed by means of a ring carrier (not shown) to the fixed structure 5a, 5b with flexible means arranged to allow it to follow any movements of the blower shaft 4, for example, in certain degraded operating conditions. In a planetary configuration, the ring carrier consists of a more or less flexible part that drives the ring gear and a part held by bearings or bushings on which the blower is mounted. These fastening means are known to those skilled in the art and are not detailed here. A brief description can be found, for example, in FR-A1-2 987 416.

[0038] The reducer 10 engages on one side with the BP 3 shaft via splines which drive a planetary or solar gear pinion 11, and on the other side with the blower shaft 4 which is attached to a planet carrier 13. Conventionally, the solar 11, whose axis of rotation X coincides with that of the turbomachine 1, drives a series of planetary gears or planets 12, which are regularly distributed around the circumference of the reducer 10. The number of planets 12 is generally defined between three and seven.

[0039] The satellites 12 also rotate around the X axis of the turbomachine 1 except in the case of a planetary where they rotate only around their axes of revolution Z, by meshing with internal teeth of the ring 14, which is fixed to a stator of the turbomachine 1 by means of flanges in the case of an epicyclic or fixed to a rotor of the turbomachine in the case of a planetary.

[0040] Each of the satellites 12 rotates freely around a satellite axis / bearing 16 connected to the satellite carrier 13, using a bearing which can be smooth or with rolling elements (ball or roller bearings).

[0041] The rotation of the satellites 12 around their satellite axes 16, due to the cooperation of their pinions with the teeth of the ring 14, causes the rotation of the ring 14 around the X axis, and consequently that of the blower shaft 4 which is linked to it, at a rotational speed which is lower than that of the BP shaft 3.

[0042] Figure 2 shows the oil supply to the gearbox 10 and its path within it. Arrows on Figure 2 show the path followed by the oil from, in this example, an oil supply circuit Cl connected to the fixed structure of the turbomachine 1, to a lubrication circuit C2 for the gearbox 10.

[0043] In the example shown, the lubrication circuit C2 includes an oil distributor 24 for supplying oil to the satellite shafts 16 and oil jets, for example. The lubrication circuit C2 further includes an oil inlet port 18, which is axially oriented and opens onto one side of the gearbox 10.

[0044] The supply circuit Cl includes a conduit 20 which is axially oriented and passes through the planet carrier 13. It is therefore understood that the rest of the circuit Cl is located on the side of the reducer 10, opposite the oil inlet port 18 and that the conduit 20 must therefore pass axially through the reducer 10 for its connection to the oil inlet port 18.

[0045] The conduit 20 includes at its axial end located on the side of the oil inlet port 18, an oil outlet port 22 which is connected to the oil inlet port 18 by a connecting device 26.

[0046] The present invention proposes an improvement to this type of connection device which allows easy assembly and disassembly of the device and which has a small axial footprint unlike that illustrated in [Fig.2].

[0047] Figures 3 to 5 show an example of an embodiment of a reducer 10 and a connecting device 126 according to the invention.

[0048] In the following description, the emphasis is primarily on the characteristics of the connecting device 126, as the characteristics of the reducer 10 are not truly limiting. Therefore, the reducer 10 of the invention can be considered similar or identical to that described above, although the preceding description is not exhaustive.

[0049] In general, the reducer 10 comprises:

[0050] - a solar 11 centered on the X-axis,

[0051] - a crown 14 centered on the X-axis and extending around the solar element 11, and

[0052] - satellites 12 intercalated between the solar 11 and the corona 14 and centered on the Z axes parallel to the X axis and distributed around the X axis.

[0053] The satellites 12 are meshed with the solar 11 and the corona 14.

[0054] The reducer 10 further includes a satellite carrier 13 for supporting the satellites 12. The satellite carrier 13 is of the planetary type here, as it is fixed in rotation around the X axis.

[0055] The reducer 10 further includes the lubrication circuit C2 which includes an oil line 28 having the oil inlet port 18 connected to the supply circuit Cl which includes the oil outlet port 22.

[0056] The lubrication circuit C2 may be part of or may include an oil distributor 24 as illustrated in [Fig.2], this distributor 24 being attached and fixed on the planet carrier 13. The channel 28 and the inlet port 18 then form part of the distributor 24.

[0057] Alternatively, the lubrication circuit C2 could be integrated into the planet carrier 13. The pipe 28 and the inlet port 18 would then be part of the planet carrier 13.

[0058] A first distinctive feature of the invention is related to the fact that:

[0059] - the oil inlet port 18 is oriented radially with respect to the X axis (unlike the one illustrated in [Fig. 2] which is axially oriented) and the oil inlet port 18 opens radially outwards, on one side of the reducer 10, and

[0060] - the oil outlet port 22 is oriented parallel to the X axis (as illustrated in the [Fig.2]) and opens axially towards the same side of the reducer 10, on the left in the drawing of [Fig.2].

[0061] The input port 18 is connected to the output port 22 by a connecting device 126 according to the invention.

[0062] The connection device 126 comprises a body 132 which is formed in one piece and which includes a first end 128 oriented axially and engaged by male-female insertion in or on the oil outlet port 22, and a second end 130 oriented radially and engaged by male-female insertion in or on the oil inlet port 18.

[0063] In the example shown, the first end 128 is a female end and the second end 130 is a female end. Other configurations are of course possible; both ends 128 and 130 could be male, or end 128 could be male and end 130 could be female, or end 128 could be female and end 130 could be male.

[0064] The body 132 is here fixed on the satellite carrier 13 or on the distributor 24. For this, the body 132 may include at least one tab 134, 136 for fixing on the satellite carrier 13 or on the distributor 24.

[0065] As illustrated in the drawings, the body 132 preferably includes two mounting tabs 134, 136 on the satellite carrier 13 or the distributor 24. The tabs 134, 136 are here formed in one piece with the rest of the body 132.

[0066] Moreover, as illustrated in the drawings, the legs 134, 36 can be symmetrical with respect to a plane PI passing through the X axis and through the first and second end pieces 128, 130. This plane PI is for example the cutting plane of [Fig.3].

[0067] Each of the mounting tabs 134, 136 has at least one orifice 138 for the passage of a fastening element such as a screw, which is screwed for example into a tapped hole in the satellite carrier 13 or the distributor 24.

[0068] The second nozzle 130 has a tubular shape and is mounted by sliding in the inlet port 18 along an engagement axis oriented radially with respect to the X axis.

[0069] For this purpose, the inlet port 18 may include an internal cylindrical surface 18a having a predetermined length to allow this sliding.

[0070] The second end piece 130 may have at its free axial end an annular groove 140 for housing a sealing gasket, of the type O-ring for example, so as to ensure a seal in the connection with the inlet port 18.

[0071] Regarding the assembly sequence of the device 126, the body 132 is positioned so that the axes of the nozzle 130 and the inlet port 18 are aligned. The nozzle 130 is then slid into the inlet port 18 by moving the body 132 radially towards the X-axis. The pipe 20 is then moved axially for connection to the device 126. The pipe 20 is then moved axially until its outlet port 22 engages in the first nozzle 128 of the body 132. The position of the body 132 is then adjusted so that the orifices 138 are aligned with the holes of the distributor 24 or the planet carrier 13, for the purpose of screwing in the fasteners. This adjustment is made possible in particular by the sliding capacity of the tip 130 in the inlet port 18, and also that of the tip 128 in the outlet port 22.

[0072] In general, the invention optimizes the dimensions of a gearbox, thereby limiting the axial size of the parts at its interface. It facilitates the assembly of oil circuits by simplifying their connection, which notably eliminates the need for ball joints, drastically reducing the risk of damage to the fittings.

Claims

Demands

1. A mechanical gearbox (10) for a turbomachine (1), in particular an aircraft turbomachine, the gearbox (10) comprising: - a sun gear (11) centered on a first axis (X), - a ring gear (14) centered on the first axis (X) and extending around the sun gear (11), - planet gears (12) interposed between the sun gear and the ring gear (14) and centered on second axes (Z) parallel to the first axis (X) and distributed around the first axis (X), the planet gears (12) being meshed with the sun gear (11) and the ring gear (14), - a planet carrier (13) for supporting the planet gears (12), and - a lubrication circuit (C2) for the gearbox (10) comprising an oil line (28) having an oil inlet port (18) connected to an oil supply circuit (1) comprising an outlet port (22) of oil, characterized in that: - said oil inlet port (18) is oriented radially with respect to said first axis (X) and opens radially outwards,on one side of the reducer (10), - said oil outlet port (22) is oriented parallel to said first axis (X) and opens axially towards said side of the reducer (10), and - said oil inlet port (18) is connected to said oil outlet port (22) by a connecting device (126) comprising a body (132) which is formed in one piece and which includes a first end (128) oriented axially and engaged by male-female insertion into or onto the oil outlet port (22), and a second end (130) oriented radially and engaged by male-female insertion into or onto the oil inlet port (18).

2. Reducer (10) according to claim 1, wherein said power supply circuit (C2) is integrated into said satellite carrier (13).

3. Reducer (10) according to claim 1, wherein said supply circuit (C2) is part of an oil distributor (24) attached and fixed on said planet carrier (13).

4. Reducer (10) according to claim 3 or 4, wherein the body (132) is fixed on the planet carrier (13) or the distributor (24).

5. Reducer (10) according to claim 4, wherein the body (132) comprises at least one fixing lug (134, 136) on the planet carrier (13) or the distributor (24), said at least one fixing lug (134, 136) having at least one passage hole for a fixing element (138) of the screw type for example.

6. Reducer (10) according to claim 5, wherein the body (132) comprises two mounting lugs (134, 136) on the planet carrier (13) or the distributor (24), the two lugs (134, 136) being symmetrical with respect to a plane (PI) passing through the first axis (X) and through said first and second end caps (128, 130).

7. Reducer (10) according to any one of the preceding claims, wherein the first end (128) is a female end.

8. Reducer (10) according to any one of the preceding claims, wherein the second end (130) is a female end.

9. Reducer (10) according to any one of claims 1 to 10, wherein, during assembly, the first end (128) is able to slide in or on the inlet port (18) in a radial direction with respect to said first axis (X).

10. Turbomachine (1), in particular aircraft turbomachine, comprising a reduction gear (10) according to any one of the preceding claims.

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