Meshing assembly comprising two pinions and a washer inserted between the two pinions

Abstract

The invention relates to a meshing assembly, which comprises: - a double pinion (20) provided with a shaft (26), and first and second pinions (28, 30); - a device (22) for injecting a lubricant into a bore in the shaft (26); and - a washer (24) inserted between the first and second pinions (28, 30), a lubrication duct (34) of the first pinion opening into the bore in the shaft (26) and into a first face (24a) of the washer (24) circumferentially between two successive teeth of toothing of the first pinion (28), a lubrication duct (36) of the second pinion (30) opening into the bore in the shaft (26) and into a second face (24b) of the washer (24) circumferentially between two successive teeth of toothing of the second pinion (30).

Description

[0001] DESCRIPTION

[0002] technical field

[0003] The invention relates technically to gears, and in particular to the lubrication of gears.

[0004] In particular, the invention relates to a gear set, an AGB (Acronym for "Accessory Gear Box") gearbox comprising such a gear set, a mechanical reducer comprising such a gear set, and a turbomachine comprising such an AGB gearbox or such a mechanical reducer.

[0005] Previous techniques

[0006] It is necessary to lubricate the gears for operational reasons, particularly to prevent overheating or seizing.

[0007] Jets aimed at the teeth of the gears are generally used to spray them with oil.

[0008] However, the rotation of the gears can generate an airflow that deflects the oil jet. Furthermore, this solution is sometimes difficult to implement due to space constraints.

[0009] It was proposed in document FR 3 1 16 319 to lubricate a pinion by means of channels which are cut into a ring of the pinion and which open between teeth of the pinion.

[0010] However, this solution requires significant structural modifications to the pinion.

[0011] Description of the invention

[0012] The present invention therefore aims to overcome all or part of the aforementioned disadvantages, and in particular to provide lubrication of pinion teeth and of the meshing of these pinions with each other which is suitable for compact meshings and which does not require major structural modifications of the pinions and their meshing.

[0013] The present invention relates to a gear assembly for an aircraft turbomachine comprising:

[0014] - a double pinion equipped with a shaft, and first and second pinions arranged so that the shaft and the first and second pinions are fixed together in rotation around an axis of extension of the shaft;

[0015] - a device for injecting lubricant into a bore of the barrel; and

[0016] - a washer mounted on the shaft and interposed between the first and second pinions, the washer having a first face which is in contact with the first pinion, and a second face which is opposite to the first face and which is in contact with the second pinion, at least one lubrication channel for the first pinion being provided in the shaft and in the washer, said at least one lubrication channel for the first pinion opening on one side into the bore of the shaft, and on the other side onto the first face of the washer circumferentially between two successive teeth of a tooth of the first pinion, at least one lubrication channel for the second pinion being provided in the shaft and in the washer, said at least one lubrication channel for the second pinion opening on one side into the bore of the shaft, and on the other side onto the second face of the washer circumferentially between two successive teeth of a tooth of the second pinion.

[0017] The centrifugal force linked to the rotational movement of the double pinion allows the lubricant injected into the bore of the barrel by the injection device to penetrate the lubrication channels of the first and second pinions, to be distributed directly between the teeth of the first and second pinions.

[0018] Advantageously, the washer is mounted on the shaft so that the shaft, the washer and the first and second pinions are fixed together in rotation around the axis of extension of the shaft.

[0019] Advantageously, said lubrication line of the first pinion comprises a first section formed in the barrel and extending radially from the bore of the barrel to an external surface of the barrel, a second section formed in the washer and extending radially outwards from a bore of the washer, and a third section formed in the washer and extending axially from the second section of said lubrication line of the first pinion to the first face of the washer, said lubrication line of the second pinion comprising a first section formed in the barrel and extending radially from the bore of the barrel to an external surface of the barrel, a second section formed in the washer and extending radially outwards from the bore of the washer,and a third section formed in the washer and extending axially from the second section of said lubrication line of the second pinion to the second face of the washer.

[0020] The axial direction is parallel to the axis of elongation of the shaft. The radial direction is orthogonal to the axial direction.

[0021] Advantageously, the washer is provided with at least one angular positioning mechanism for the washer relative to at least one of the first and second gears.

[0022] The said mechanism allows the washer to be positioned angularly so that the said lubrication channel of the pinion concerned opens circumferentially between two successive teeth of the pinion concerned, thus avoiding any error in the positioning of the washer relative to the pinion concerned.

[0023] Optionally, the washer is equipped with a first angular positioning mechanism for the washer relative to the first pinion and a second angular positioning mechanism for the washer relative to the second pinion.

[0024] Optionally, the first pinion or shaft includes a first complementary angular positioning mechanism for the washer relative to the first pinion which is able to cooperate with the first angular positioning mechanism to angularly position the washer relative to the first pinion, the second pinion or shaft including a second complementary angular positioning mechanism for the washer relative to the second pinion which is able to cooperate with the second angular positioning mechanism to angularly position the washer relative to the second pinion.

[0025] The positioning mechanism may include a pin. In this case, one of the first and second gears may include an orifice with a shape complementary to the pin, such that the orifice and the pin together allow the washer to be angularly positioned relative to the gear in question.

[0026] The positioning mechanism may include a lug. In this case, one of the first and second gears may include a stop so that the stop and the lug together allow the washer to be angularly positioned relative to the gear in question.

[0027] The positioning mechanism may include a spline. In this case, one of the first and second gears may include a groove such that the groove and the spline together allow the washer to be angularly positioned relative to the gear in question.

[0028] The positioning mechanism may include three stops that are designed to cooperate with a trilobed gear. In this case, one of the first and second gears may be a trilobed gear. The external shape of the trilobed gear has three lobes which, together with the three stops of the washer positioning mechanism, allow the washer to be angularly positioned relative to the trilobed gear.

[0029] Optionally, the barrel came from the material with the first pinion, the second pinion being mounted on the barrel.

[0030] Advantageously, the gear set includes a retaining ring which is mounted on the shaft and which bears against the second pinion so that the second pinion is located between the washer and the retaining ring.

[0031] Optionally, the lubricant injection device includes a nozzle configured to project lubricant into the bore of the barrel. Advantageously, the washer is provided with a plurality of lubrication channels for the first pinion, each opening onto the first face of the washer circumferentially between two successive teeth of the teeth of the first pinion, and a plurality of lubrication channels for the second pinion, each opening onto the second face of the washer circumferentially between two successive teeth of the teeth of the second pinion.

[0032] Preferably, the lubrication channels of the first pinion are equally distributed in the circumferential direction.

[0033] Preferably, the lubrication channels of the second pinion are equally distributed in the circumferential direction.

[0034] The present invention also relates to an AGB gear housing for a turbomachine comprising at least one gear set as defined above.

[0035] The present invention also relates to a mechanical reducer comprising at least one gear set as defined above.

[0036] The present invention also relates to a turbomachine comprising an AGB gearbox as defined above and / or a mechanical reducer as defined above.

[0037] Brief description of the drawings

[0038] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0039] [Fig 1] illustrates a turbomachine according to an example of an embodiment of the invention;

[0040] [Fig 2] is a top view of a kinematic chain of an AGB gearbox or mechanical reducer of the turbomachine of figure 1;

[0041] [Fig 3] is a cross-sectional view of a gear assembly from the kinematic chain of Figure 2; [Fig 4] is a perspective view of the first face of a washer from the gear assembly of Figure 3; and

[0042] [Fig 5] is a perspective view of a second face of the washer of the meshing assembly of Figure 3.

[0043] Detailed description

[0044] Figure 1 schematically represents a turbomachine 2 which includes, axially from upstream to downstream, a blower 4, a low pressure compressor 6, a high pressure compressor 8, a combustion chamber 10, a high pressure turbine 12, and a low pressure turbine 14.

[0045] The turbomachine 2 further includes an AGB 16 gearbox which draws energy from a low-pressure shaft connected to the low-pressure compressor 6 and the low-pressure turbine 14 in order to drive equipment, for example pumps or electric generators, required for the operation of the turbomachine 2.

[0046] The turbomachine 2 also includes a mechanical reducer connected between the low-pressure shaft of the turbomachine 2 and a shaft of the blower 4 in order to transform the rotational speed of the low-pressure shaft into a slower rotational speed for the blower 4 shaft.

[0047] Such a reduction gear comprises a central pinion, called the sun gear, which is driven by the low-pressure shaft and receives torque from the low-pressure shaft; a ring gear, which transmits the output torque to the blower shaft 4; and pinions called planet gears that mesh between the sun gear and the ring gear. The planet gears are held by a frame called a planet carrier.

[0048] Such a gearbox can be of the planetary or epicyclic type for a multi-flow turbomachine, particularly one with at least a primary and a secondary flow. Differential architectures also exist in other similar applications.

[0049] With reference to figures 2 and 3, the AGB gearbox or reducer includes a kinematic chain 18, here composed of two meshing stages distributed on first, second and third axes 18a, 18b, 18c.

[0050] The kinematic chain 18, and more specifically the second axis 18b, includes a gear set comprising a double pinion 20, a lubricant injection device 22 and a washer 24.

[0051] The double pinion 20 is fitted with a shaft 26, and first and second pinions 28, 30, the first pinion 28 being formed from the shaft 26. The washer 24 and the second pinion 30 are mounted on the shaft 26 so that the washer 24 is interposed between the first and second pinions 28, 30. The shaft 26 extends through the bore of the washer 24 and the bore of the second pinion 30.

[0052] The barrel 26, the washer 24 and the first and second pinions 28, 30 are fixed together in rotation around an axis of extension of the barrel 26.

[0053] In particular, the gear set includes a retaining ring 32 which is mounted on the shaft 26, for example by means of a screw thread, and which bears against the second pinion 30 so that the second pinion 30 is located between the washer 24 and the retaining ring 32. The retaining ring 32 makes it possible to lock the relative positioning of the shaft 26, the washer 24 and the first and second pinions 28, 30 so that the shaft 26, the washer 24 and the first and second pinions 28, 30 are rotationally fixed around an axis of extension of the shaft 26.

[0054] The first pinion 28 meshes with a pinion of the third axis 18c of the kinematic chain 18. The second pinion 30 meshes with a pinion of the first axis 18a of the kinematic chain 18.

[0055] The lubricant injection device 22, for example a nozzle, is suitable for projecting lubricant, for example oil, into a bore of the shaft 26. The bore of the shaft 26 is blind. In particular, the bore opens on the nozzle side and not on the opposite side. Thus, the bore of the shaft 26 forms a cavity that can retain the lubricant before distributing it to the first and second gears 28, 30. The washer 24 has a first face 24a which is in contact with the first gear 28, and a second face 24b which is in contact with the second gear 30.

[0056] As more clearly illustrated in Figure 4, a plurality of lubrication channels 34 for the first pinion 28 are provided in the shaft 26 and in the washer 24. Each lubrication channel 34 for the first pinion 28 opens, on the one hand, into the bore of the shaft 26, and on the other hand, onto the first face 24a of the washer 24 circumferentially between two successive teeth of a tooth profile of the first pinion 28. More precisely, each lubrication channel 34 for the first pinion 28 comprises a first section provided in the shaft 26 and extending radially from the bore of the shaft 26 to an external surface of the shaft 26, a second section provided in the washer 24 and extending radially outwards from a bore of the washer 24, and a third section provided in the washer 24 and extending axially from the second section of the relevant lubrication line 34 of the first pinion 28 to the first face 24a of the washer 24.

[0057] The lubrication channels 34 of the first pinion 28 are here equally distributed along the circumferential direction of the shaft 26. The lubrication channels 34 of the first pinion 28 allow the lubricant present in the bore of the shaft 26 to be distributed to the teeth of the first pinion 28.

[0058] The axial direction is parallel to the elongation axis of the shaft 26. The radial direction is orthogonal to the axial direction.

[0059] As illustrated more visibly in figure 5, a plurality of lubrication channels 36 of the second pinion 30 are provided in the barrel 26 and in the washer 24. Each lubrication channel 36 of the second pinion 30 opens on one side into the bore of the barrel 26, and on the other side into the second face 24b of the washer 24 circumferentially between two successive teeth of a tooth of the second pinion 30.More specifically, each lubrication channel 36 of the second pinion 30 comprises a first section formed in the barrel 26 and extending radially from the bore of the barrel 26 to an external surface of the barrel 26, a second section formed in the washer 24 and extending radially outwards from the bore of the washer 24, and a third section formed in the washer 24 and extending axially from the second section of the relevant lubrication channel 36 of the second pinion 30 to the second face 24b of the washer 24.

[0060] The lubrication channels 36 of the second pinion 30 are here equally distributed along the circumferential direction of the barrel 26. The lubrication channels 36 of the second pinion 30 allow the lubricant present in the bore of the barrel 26 to be distributed to the teeth of the second pinion 30.

[0061] The washer 24 further includes a mechanism for angularly positioning the washer 24 relative to the first and second pinions 28, 30 (not shown) so as to ensure that the lubrication channels 34, 36 of the first and second pinions 28, 30 open circumferentially between the teeth of the teeth of the first and second pinions 28, 30.

[0062] In the example shown, the washer includes six lubrication channels for the first gear and four lubrication channels for the second gear. Alternatively, the washer may include between one and the number of teeth on the first gear's teeth lubrication channels for the first gear, and between one and the number of teeth on the second gear's teeth lubrication channels for the second gear.

[0063] In the example shown, the diameter of the second gear is larger than the diameter of the first gear, so the lubrication channels of the second gear open radially outside the lubrication channels of the first gear. Alternatively, the diameter of the second gear could be smaller than or equal to the diameter of the first gear, in which case the lubrication channels of the second gear could open radially inside the lubrication channels of the first gear or at the same radial distance.

[0064] In the example shown, the first pinion and the shaft are made from solid material, while the washer and the second pinion are added to the shaft. Alternatively, the second pinion and the shaft could be made from solid material, while the first pinion and the washer could be added to the shaft. As a further alternative, the first and second pinions could be added to the shaft.

Claims

DEMANDS 1. Gear assembly for an aircraft turbomachine comprising a double pinion (20) provided with a shaft (26), and first and second pinions (28, 30) arranged so that the shaft (26) and the first and second pinions (28, 30) are rotationally fixed about an axis of extension of the shaft (26), characterized in that it further comprises: - a device for injecting a lubricant (22) into a bore of the barrel (26); and - a washer (24) mounted on the shaft (26) and interposed between the first and second gears (28, 30), the washer (24) having a first face (24a) which is in contact with the first gear (28), and a second face (24b) which is opposite the first face (24a) and which is in contact with the second gear (30), at least one lubrication channel (34) for the first gear being provided in the shaft (26) and in the washer (24), said at least one lubrication channel (34) for the first gear (28) opening on one side into the bore of the shaft (26), and on the other side onto the first face (24a) of the washer (24) circumferentially between two successive teeth of a toothed section of the first gear (28), at least one lubrication channel (36) for the second gear (30) being provided in the shaft (26) and in the washer (24), said at least one lubrication channel (36) of the second pinion (30) opening on one side into the bore of the barrel (26),and on the other hand, on the second face (24b) of the washer (24) circumferentially between two successive teeth of a tooth of the second pinion (30).

2. A gear assembly according to claim 1, wherein said lubrication conduit (34) of the first pinion (28) comprises a first section formed in the barrel (26) and extending radially from the bore of the barrel (26) to an external surface of the barrel (26), a second section formed in the washer (24) and extending radially outwards from a bore of the washer (24), and a third section formed in the washer (24) and extending axially from the second section of said conduit. lubrication (34) of the first pinion (28) to the first face (24a) of the washer (24), said lubrication line (36) of the second pinion (30) comprising a first section formed in the barrel (26) and extending radially from the bore of the barrel (26) to an external surface of the barrel (26), a second section formed in the washer (24) and extending radially outwards from the bore of the washer (24), and a third section formed in the washer (24) and extending axially from the second section of said lubrication line (36) of the second pinion (30) to the second face (24b) of the washer (24).

3. Gear assembly according to claim 1 or 2, wherein the washer (24) is provided with at least one angular positioning mechanism for the washer (24) relative to at least one of the first and second pinions (28, 30).

4. Gear assembly according to any one of claims 1 to 3, wherein the shaft (26) is formed from the material with the first pinion (28), the second pinion (30) being mounted on the shaft (26).

5. Gear assembly according to any one of claims 1 to 4, comprising a retaining ring (32) which is mounted on the shaft (26) and which bears against the second pinion (30) so that the second pinion (30) is located between the washer (24) and the retaining ring (32).

6. Gear assembly according to any one of claims 1 to 5, wherein the lubricant injection device (22) includes a nozzle configured to project lubricant into the bore of the barrel (26).

7. Gear assembly according to any one of claims 1 to 6, wherein the washer (24) is provided with a plurality of lubrication channels (34) of the first pinion (28) each opening onto the first face (24a) of the washer (24) circumferentially between two successive teeth of the teeth of the first pinion (28), and a plurality of lubrication channels (36) of the second pinion (30) which each open onto the second face (24b) of the washer (24) circumferentially between two successive teeth of the teeth of the second pinion (30).

8. Gearbox AGB (16) for turbomachine comprising at least one gear set according to any one of claims 1 to 7.

9. Mechanical reducer for a turbomachine comprising at least one gear set according to any one of claims 1 to 7.

10. Turbomachine (2) comprising an AGB gear case (16) according to claim 8 and / or a mechanical reducer according to claim 9.

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