A gear assembly comprising two pinions and a washer interposed between the two pinions.

Abstract

This gear set includes: - a double pinion (20) with a shaft (26), and first and second pinions (28, 30); - a lubricant injection device (22) in a bore of the shaft (26); and - a washer (24) interposed between the first and second pinions (28, 30), a lubrication channel (34) of the first pinion opening on one side into the bore of the shaft (26), and on the other side onto a first face (24a) of the washer (24) circumferentially between two successive teeth of a tooth of the first pinion (28), a lubrication channel (36) of the second pinion (30) opening on one side into the bore of the shaft (26), and on the other side onto a second face (24b) of the washer (24) circumferentially between two successive teeth of a tooth of the second pinion (30). Figure for the abbreviation: Fig 3

Description

Title of the invention: Gear assembly comprising two pinions and a washer interposed between the two pinions. Technical field

[0001] The invention relates technically to gears, and in particular to the lubrication of gears.

[0002] 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. Previous techniques

[0003] It is necessary to lubricate the gears for operational reasons, in particular to avoid overheating or seizing.

[0004] Jets directed towards gear teeth are generally used to spray them with oil.

[0005] 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.

[0006] It has been proposed in document FR 3 116 319 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.

[0007] However, this solution requires significant structural modifications to the pinion. Description of the invention

[0008] 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.

[0009] The present invention relates to a gear assembly for an aircraft turbomachine comprising:

[0010] - a double pinion equipped with a shaft, and first and second pinions arranged in so that the shaft and the first and second pinions are fixed together in rotation around an axis of elongation of the shaft;

[0011] - a device for injecting a lubricant into a bore of the barrel; and

[0012] - a washer mounted on the barrel and interposed between the first and second pinions, the washer being provided with 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 of the first pinion being provided in the body and in the washer, said at least one lubrication channel of the first pinion opening on the one hand into the bore of the body, and on the other hand onto the first face of the washer circumferentially between two successive teeth of a tooth of the first pinion, at least one lubrication channel of the second pinion being provided in the body and in the washer, said at least one lubrication channel of the second pinion opening on the one hand into the bore of the body, and on the other hand onto the second face of the washer circumferentially between two successive teeth of a tooth of the second pinion.

[0013] 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.

[0014] Advantageously, the washer is mounted on the barrel so that the barrel, the washer and the first and second pinions are fixed together in rotation around the axis of extension of the barrel.

[0015] 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 channel of the second pinion to the second face of the washer.

[0016] The axial direction is parallel to the axis of elongation of the shaft. The radial direction is orthogonal to the axial direction.

[0017] 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 pinions.

[0018] Said mechanism allows the washer to be positioned angularly so that said lubrication line of the pinion concerned opens circumferentially between two successive teeth of the pinion concerned, thus avoiding any error in positioning the washer relative to the pinion concerned.

[0019] Optionally, the washer is provided 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.

[0020] Optionally, the first pinion or the shaft includes a first complementary angular positioning mechanism of 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 the shaft including a second complementary angular positioning mechanism of 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.

[0021] Said positioning mechanism may include a pin. In this case, one of the first and second pinions may include an orifice of complementary shape to the pin so that the orifice and the pin together allow the washer to be angularly positioned relative to the pinion concerned.

[0022] Said positioning mechanism may include a lug. In this case, one of the first and second pinions may include a stop such that the stop and the lug together allow the washer to be angularly positioned relative to the pinion concerned.

[0023] Said positioning mechanism may include a spline. In this case, one of the first and second pinions may include a groove such that the groove and the spline together allow the washer to be angularly positioned relative to the pinion concerned.

[0024] Said positioning mechanism may include three stops adapted to cooperate with a trilobed pinion. In this case, one of the first and second pinions may be a trilobed pinion. The external shape of the trilobed pinion 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 pinion.

[0025] Optionally, the barrel came from material with the first pinion, the second pinion being mounted on the barrel.

[0026] 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.

[0027] Optionally, the lubricant injection device includes a nozzle configured to project lubricant into the bore of the barrel.

[0028] 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.

[0029] Preferably, the lubrication channels of the first pinion are equally distributed in the circumferential direction.

[0030] Preferably, the lubrication channels of the second pinion are equally distributed in the circumferential direction.

[0031] The present invention also relates to an AGB gearbox for turbomachine comprising at least one gear set as defined above.

[0032] The present invention also relates to a mechanical reducer comprising at least one gear set as defined above.

[0033] The present invention also relates to a turbomachine comprising an AGB gearbox as defined above and / or a mechanical reducer as defined above. Brief description of the drawings

[0034] 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:

[0035] [Fig-1] illustrates a turbomachine according to an example of an embodiment of the invention;

[0036] [Fig.2] is a top view of a kinematic chain of a gear case AGB or a mechanical reducer of the turbomachine of the [Fig.l];

[0037] [Fig.3] is a cross-sectional view of a gear set of the kinematic chain of the [Fig.2];

[0038] [Fig.4] is a perspective view of a first face of a washer of the assembly of the engagement of the [Fig.3]; and

[0039] [Fig.5] is a perspective view of a second face of the washer of the assembly of the engagement of the [Fig.3]. Detailed description

[0040] Figure 1 schematically represents a turbomachine 2 which comprises, 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.

[0041] The turbomachine 2 further includes a gearbox AGB 16 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, necessary for the operation of the turbomachine 2.

[0042] The turbomachine 2 also includes a mechanical reducer connected between the low-pressure shaft of the turbomachine 2 and a blower shaft 4 in order to transform the rotational speed of the low-pressure shaft into a slower rotational speed for the blower shaft 4.

[0043] Such a reducer 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.

[0044] Such a reducer can be of the planetary or epicyclic type for a multi-flow turbomachine 2, in particular a turbomachine 2 having at least one primary and one secondary flow. In other similar applications, there are also so-called differential architectures.

[0045] With reference to figures 2 and 3, the AGB gearbox or reducer comprises a kinematic chain 18, here composed of two meshing stages distributed on first, second and third axes 18a, 18b, 18c.

[0046] 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.

[0047] The double pinion 20 is provided 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.

[0048] 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.

[0049] In particular, the meshing assembly 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 such 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 as that 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.

[0050] 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.

[0051] The lubricant injection device 22, for example a nozzle, is adapted to project lubricant, for example oil, into a bore of the barrel 26. The bore of the barrel 26 is blind. In particular, the bore opens on the nozzle side and not on the opposite side. Thus, the bore of the barrel 26 forms a cavity that can retain the lubricant before distributing it to the first and second gears 28, 30.

[0052] The washer 24 has a first face 24a which is in contact with the first pinion 28, and a second face 24b which is in contact with the second pinion 30.

[0053] As more clearly illustrated in [Fig. 4], a plurality of lubrication channels 34 for the first pinion 28 are provided in the barrel 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 barrel 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 barrel 26 and extending radially from the bore of the barrel 26 to an external surface of the barrel 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.

[0054] The lubrication channels 34 of the first pinion 28 are here equally distributed along the circumferential direction of the barrel 26. The lubrication channels 34 of the first pinion 28 allow the lubricant present in the bore of the barrel 26 to be distributed to the teeth of the first pinion 28.

[0055] The axial direction is parallel to the elongation axis of the shaft 26. The radial direction is orthogonal to the axial direction.

[0056] As more clearly illustrated in [Fig. 5], a plurality of lubrication channels 36 for the second pinion 30 are provided in the barrel 26 and in the washer 24. Each lubrication channel 36 for the second pinion 30 opens, on the one hand, into the bore of the barrel 26, and on the other hand, onto the second face 24b of the washer 24 circumferentially between two successive teeth of a tooth profile of the second pinion 30. More precisely, each lubrication channel 36 for the second pinion 30 comprises a first section provided 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 line 36 of the second pinion 30 to the second face 24b of the washer 24.

[0057] 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.

[0058] The washer 24 further includes an angular positioning mechanism for 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.

[0059] In the example shown, the washer comprises six lubrication channels for the first gear and four lubrication channels for the second gear. Alternatively, the washer may comprise 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.

[0060] In the example shown, the diameter of the second gear is greater 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 less 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.

[0061] In the example shown, the first pinion and the shaft are made from solid material, while the washer and the second pinion are attached 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 attached to the shaft. In a further variation, the first and second pinions could be attached to the shaft.

Claims

1.

2. Demands Gear assembly for an aircraft turbomachine comprising a double pinion (20) equipped with a shaft (26), and first and second pinions (28, 30) arranged such 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). A gear assembly according to claim 1, wherein said lubrication channel (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 lubrication channel (34) of the first pinion (28) to the first face (24a) of the washer (24), said lubrication channel (36) of the second pinion (30) comprising a first a 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 made of 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. A gear set 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) each opening onto the second face (24b) of the washer (24) circumferentially between two successive teeth of the teeth of the second pinion (30).

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

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

10. 1 d. / . Turbomachine (2) comprising an AGB gearbox (16) according to claim 8 and / or a mechanical reducer according to claim 9.

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