Assembly for turbomachine

Abstract

This document describes an assembly (2) for a turbomachine (1) comprising a turbomachine shaft (10) extending along an axis (X), a nut (42) screwed about said axis (X) onto the turbomachine shaft (10), and a nut locking device, said nut locking device comprising a coupling member (58), said coupling member (58) comprising a first rotating coupling zone (60b) cooperating with a first complementary coupling zone (48) of the nut (42), and a second rotating coupling zone (66a, 66b) cooperating with a second complementary coupling zone (12a, 12b) of the shaft (10), the coupling member (58) being capable of being moved axially relative to the nut (42) between a rotational coupling position of the nut (42) relative to the shaft (10), and a first decoupling position, said coupling device nut further comprising elastic return means (74). Figure of the abstract: Figure 2.

Description

Description Title of the invention: Turbomachine assembly Technical field The present disclosure relates to an assembly for an aircraft turbomachine, such as for example an aircraft turbojet or turboprop. Prior art [Fig. 1] describes a prior art turbomachine 1 comprising 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 1c and an exhaust nozzle 1h. The high pressure compressor 1b and the high pressure turbine 1d are connected by a high pressure shaft 2 and form with it a high pressure (HP) body. The low pressure compressor 1a and the low pressure turbine 1c are connected by a low pressure shaft 3 and form with it a low pressure (LP) body. The blower S is driven by a blower shaft 4 which is driven by the LP shaft 3 by means of a reducer 6. A turbomachine shaft may comprise a nut screwed onto said shaft and making it possible to axially immobilize an additional element on this shaft. In order to prevent such a nut from loosening, it is known to equip the turbomachine shaft with a brake or a nut coupling member. Document FR 3 007 070, in the name of the Applicant, thus discloses an assembly for a turbomachine, comprising a nut screwed onto an end portion of a tubular shaft and a member for coupling the nut to the shaft. The coupling member is formed by a split ring capable of being compressed radially. The coupling member is capable of being moved between a position for rotational coupling of the nut and the shaft, in which the coupling member is housed in a first groove of the nut, and a position for decoupling or releasing the nut relative to the shaft, in which the coupling member is housed in a second groove of the nut. The passage from one groove to another, and therefore from one position to another, is achieved by radial compression of the coupling member, axial translation towards the corresponding groove, then a release of the deformable part so that the coupling member returns to its original diameter and is housed in the corresponding groove. Handling the coupling member is tedious because access to this element is generally difficult for an operator. This document aims to provide a set allowing for more efficient handling easy coupling of the coupling organ. Summary For this purpose, the present document relates to a turbomachine assembly comprising a turbomachine shaft extending along an axis, a nut screwed around said axis onto the turbomachine shaft, and a nut braking device, said nut braking device comprising a coupling member, said coupling member comprising a first rotational coupling zone cooperating with a first complementary coupling zone of the nut, and a second rotational coupling zone cooperating with a second complementary coupling zone of the shaft, said coupling member being able to be moved axially relative to the nut between a coupling position in which the coupling member is rotationally coupled to the nut via the first coupling zone and the first complementary coupling zone and in which the nut is rotationally coupled to the shaft via the second coupling zone and the second complementary coupling zone, and a first decoupling position in which the coupling member is rotationally coupled to the nut via the first coupling zone and the first complementary coupling zone and in which the coupling member is not coupled to the shaft, said nut locking device further comprising elastic return means capable of generating an axial return force on the coupling member so as to move it axially towards its coupling position. The terms axial, radial and circumferential are defined relative to the axis of the turbomachine shaft. The coupling member thus makes it possible to couple the nut in rotation to the turbomachine shaft in the coupling position. When an operator wishes to unscrew the nut relative to the turbomachine shaft, the latter can axially move the coupling member against the forces of the elastic return means towards the first decoupling position. In this position, the coupling member and the nut remain integral in rotation but are decoupled in rotation from the turbomachine shaft. Indeed, in this first decoupling position, the second coupling zone of the coupling member is decoupled from the second complementary coupling zone of the shaft. It is thus possible to unscrew the nut relative to the shaft. The coupling member may be axially movable relative to the nut to a second decoupling position in which the coupling member is rotationally decoupled from the nut and rotationally decoupled from the shaft. The user can axially move the coupling member to the second position decoupling against the return force exerted by the elastic return means. In this second decoupling position, the first coupling zone and the first complementary coupling zone are decoupled from each other. Likewise, in this second decoupling position, the second coupling zone and the second complementary coupling zone are decoupled from each other. Thus, it is possible to pivot the coupling member around the X axis relative to the nut so as to be able to angularly match the second coupling zone of the coupling member and the second complementary coupling zone of the shaft. The first coupling zone of the coupling member may comprise at least one axially extending groove, the first complementary coupling zone of the nut comprising at least one axially extending groove, or vice versa. The groove of the coupling member can thus be axially engaged in the corresponding groove of the nut, so as to ensure rotational coupling of the nut and the coupling member, while allowing relative axial movement between them. The first coupling zone of the coupling member may comprise a plurality of axially extending splines, the first complementary coupling zone of the nut comprising a plurality of axially extending grooves, or vice versa. The splines and grooves may be regularly distributed around the circumference. The number of grooves can be between 1 and 20. The second coupling zone of the coupling member may comprise at least one tooth extending axially, the second complementary coupling zone of the shaft comprising at least one recess of a shape complementary to the tooth, or vice versa. The tooth of the coupling member can thus be axially engaged in the corresponding recess of the shaft, so as to ensure rotational coupling of the nut and the shaft. The second coupling zone of the coupling member may comprise several axially extending teeth, the second complementary coupling zone of the shaft comprising several recesses of shapes complementary to said teeth, or vice versa. The teeth and the recesses may be regularly distributed around the circumference. The number of teeth can be between 1 and 20. The nut can be screwed radially outward from the turbomachine shaft. The coupling member can be mounted radially inside the nut. The coupling member may be annular. The turbomachine shaft may be tubular. The nut braking device may comprise an axial stop, the elastic return means being mounted between said axial stop and the coupling member. Said axial stop may be formed by an elastic split ring mounted in a groove of the nut. Alternatively, said axial stop may be formed integrally with the nut. In such a case, said axial stop may be formed by a radial surface of the nut. The elastic return means may be formed by a spring, for example a compression spring, for example a helical compression spring. The elastic return means may be a conical, biconical, cylindrical, variable pitch or constant pitch compression spring. The elastic return means may also be formed by a deformable portion of the nut locking device. The coupling member may comprise at least one gripping zone capable of cooperating with a tool. The presence of such a zone allows an operator equipped with a tool to axially move the coupling member from the coupling position to one of the decoupling positions. Said gripping zone may be formed by a radial surface of the coupling member. Said assembly may further comprise an additional element mounted around the turbomachine shaft, said additional element comprising a first radial surface, bearing on a complementary axial stop axially secured to the shaft, said additional element comprising a second radial surface, the nut being capable of bearing axially on said second radial surface. The additional element is thus able to be held axially between the nut screwed onto the shaft and said additional axial stop. Unscrewing the nut also allows the additional element to be released axially. Said additional element may be a pinion, for example a bevel pinion. Said pinion may be rotatably coupled to the shaft. Said assembly may further comprise a bearing mounted around the shaft and axially secured to the shaft, said complementary axial stop being formed by a zone of said bearing. Said bearing may be a rolling bearing, for example a ball or roller bearing. Said rolling bearing may comprise a radially inner ring, a radially outer ring and rolling members mounted radially between said inner and outer rings. Said area of ​​the bearing forming the complementary axial stop may be the radially internal ring of the bearing. This document also relates to a turbomachine comprising an assembly of the aforementioned type. Said turbomachine can be a turbojet or a turboprop. This document also relates to an aircraft comprising at least one turbomachine of the aforementioned type. Said aircraft may be an airplane or a rotary-wing aircraft. This document may also relate to a method of mounting such an assembly of the aforementioned type, said method comprising the steps of: a. engaging the coupling member, the elastic return means and the stop axial in the nut, b. screw the nut onto the shaft, c. axially position the coupling member in the second de- coupling and angularly align the second coupling zone of the member of coupling with the second complementary coupling zone of the shaft, and d. axially moving the coupling member to the coupling position of so that the second coupling zone of the shaft cooperates with the second complementary coupling zone. Step (a) may consist of engaging the coupling member in the nut from downstream or upstream. Step (a) may consist of engaging elastic return means and the axial stop from upstream. Step (a) may consist of engaging elastic return means in the nut firstly and engaging the axial stop in the nut secondly. Steps (a) and (b) can be interchangeable. Step (c) may consist of axially moving the coupling member using the tool capable of cooperating with the gripping zone of the coupling member. Step (d) may comprise axially moving the coupling member to the first coupling position in a first step and axially moving the coupling member to the coupling position in a second step. Step (d) may consist of axially moving the coupling member using the tool capable of cooperating with the gripping zone of the coupling member. Step (d) may consist of releasing the coupling member so that the coupling member moves axially from the second coupling position to the coupling position by the elastic return force of the elastic return means. This document may also relate to a method of dismantling such an assembly of the aforementioned type, said method comprising the steps of: axially move the coupling member from its coupling position to its first decoupling position or towards its second decoupling position, and unscrew the nut relative to the shaft. Brief description of the drawings Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: [Fig.1] is a schematic half-view in axial section of a turbomachine of the prior art, [Fig.2] is a schematic half-view in axial section of an assembly according to an embodiment of the present document, the coupling member being in the coupling position, [Fig.3] a schematic half-view in axial section of a part of the assembly of [Fig.2], the coupling member being in the first decoupling position, [Fig.4] is a view corresponding to [Fig.3], in which the coupling member is in the second decoupling position, [Fig.5] is an axial sectional and perspective view of an assembly according to step (a) of the assembly method, [Fig.6] is an axial sectional and perspective view of an assembly according to step (b) of the assembly method, [Fig.7] is an axial sectional and perspective view of an assembly according to step (c) of the assembly method, [Fig.8] is a detail view of part of the assembly in the step of [Fig.7], [Fig.9] is an axial sectional and perspective view of an assembly according to step (d) of the assembly method. Description of the embodiments Figures 2 to 4 illustrate a turbomachine assembly according to one embodiment of this document. Said assembly 2 comprises a turbomachine shaft 10, for example a tubular high-pressure compressor shaft, extending along an axis X. In the remainder of the description, the terms axial, radial and circumferential are defined relative to said axis X. Said shaft comprises an end called upstream 12, on the left in Figures 2 to 4 and a part called downstream 14, on the right in Figures 2 to 4. The upstream end 12 comprises teeth 12a regularly distributed around the circumference and delimiting between them recesses 12b. The number of teeth 12a is for example between 1 and 20. Said shaft 10 comprises a radially external thread in a zone 20 located downstream of the teeth 12a having a first diameter D1. Said shaft 10 further comprises a cylindrical zone 22 located downstream of the threaded zone 20 and having a second diameter D2 greater than the first diameter DI1. Said assembly 2 further comprises an annular pinion 24 mounted around the cylindrical zone 22 of the shaft 10 and coupled in rotation to the shaft 10. Said pinion 24 comprises a toothed zone 26 having conical teeth and said pinion 24 also comprises a shoulder 28 and a cylindrical zone 30 located downstream of the toothed zone 26. The pinion 24 further comprises a first radial annular surface 32 facing downstream and a second radial annular surface 33 facing upstream. A bearing 34 is mounted around the cylindrical zone 22 of the pinion 24. The bearing 34 is a ball bearing comprising a radially inner ring 36, a radially outer ring 38 and rolling elements, here balls 40, mounted between the inner ring 36 and outer ring 38. The upstream end of the inner ring 36 bears axially on the shoulder 28 of the pinion 24. Said assembly 2 also comprises a nut 42 extending along the axis X. Said nut 42 comprises, from upstream to downstream, an upstream end 44, a groove 46, a grooved zone 48, a tapped zone 50 and a downstream end 54 formed by a radial surface 54a. The tapped zone 50 is screwed onto the threaded zone 20 of the shaft 10. The radial surface 54a of the downstream end 54 of the nut 42 bears axially on the second radial surface 33 of the pinion 24. A split ring 56 is mounted in the groove 46 of the nut 42. Said split ring 56 is intended to form an axial stop. Said assembly 2 further comprises an annular coupling member 58 extending around the axis X. The upstream end 60 of the coupling member 58 comprises an upstream radial surface 60a and a radially external groove 60b cooperating with the grooved zone 48 of the nut 42, in the position illustrated in [Fig.2], so as to ensure rotational coupling of the coupling member 58 and the nut 42. The downstream end 66 of the coupling member 58 comprises a tooth 66a and a recess 66b. In the position illustrated in [Fig. 2], the tooth 66a of the coupling member 58 is engaged in one of the recesses 12b of the shaft 10. Conversely, the teeth 12a of the shaft 10 are engaged in the recess 66b of the coupling member 58. Said upstream end 60 of the coupling member 58 further comprises a radial shoulder 72 extending inwards. An elastic return member 74 is mounted axially between the split ring 56 and the upstream radial surface 60a of the upstream end 60 of the coupling member 58. The elastic member 74 is a compression spring, for example a helical compression spring. [Fig. 2] shows a coupling position in which the nut 42 is rotationally coupled to the shaft 10 via the spline 60b and the grooved area 48 of the coupling member 58 and the nut 42, on the one hand, and via the tooth 66a and recesses 12b of the coupling member 58 and the shaft 10, on the other hand. [Fig. 3] represents a first decoupling position in which the user axially moves the decoupling member 58 upstream, against the return force exerted by the elastic return member 74. For this, the user can use a tool 76 comprising an upstream end 76a capable of cooperating with the radial shoulder 72. In this position, the coupling member 58 is rotationally coupled to the nut 42 by means of the groove 60b and the grooved zone 48 of the coupling member 58 and the nut 42. In this position also, the coupling member 58 is decoupled from the shaft 10. The nut 42 is thus decoupled from the shaft 10 in the first decoupling position illustrated in [Fig. 3]. It is then possible to unscrew the nut 42 relative to the shaft 10. [Fig. 4] represents a second decoupling position in which the user axially moves the decoupling member 58 upstream, for example using the aforementioned tool 76, against the return force exerted by the elastic return member 74 beyond the grooved zone 68 of the nut 42. In this position, the coupling member 58 is rotationally decoupled from the nut 42 and is also decoupled from the shaft 10. The nut 42 is thus decoupled from the shaft 10 in the second decoupling position illustrated in [Fig. 4]. It is then possible to angularly orient the teeth of the coupling member 58 relative to the recesses 12b of the shaft 10. The user can then release the coupling member 58 which is moved axially downstream, into the coupling position of [Fig. 2], under the effect of the elastic return force exerted by the member 74. Figures 5 to 9 illustrate one embodiment of a method of mounting the aforementioned assembly. In particular, [Fig. 5] represents a first step of said assembly method in which the coupling member 58, the elastic return means 74 and the split ring 56 are engaged in the nut 42 from upstream. The coupling member 58 is coupled in rotation to the nut 42 by means of the groove 60b cooperating with the grooved zone 48 of the nut 42. The coupling member 58 is thus positioned in the first coupling position. In this configuration also, the downstream end of the elastic return means 74 is in axial support on the coupling member 58 and the upstream end of the elastic return means is in axial support on the split ring 56. [Fig.6] represents a second step of said assembly method in which the tapped zone 50 of the nut 42 cooperates with the threaded zone 20 of the shaft 10. The nut 42 is thus screwed onto the shaft 10. [Fig.7] and 8 represent a third step of the assembly method in which the coupling member 58 is moved axially from downstream to upstream, towards its second decoupling position, by compressing the elastic member 74. The coupling member coupling 58 and the shaft 10 are positioned angularly so that the tooth 66a of the coupling member 58 and one of the recesses 12a of the shaft 10 are opposite each other. [Fig. 9] shows a fourth step of the assembly method in which the coupling member 58 is moved axially from upstream to downstream, towards its coupling position. In this position, the tooth 66a of the coupling member 58 engages in one of the recesses 12b of the shaft 10, and the teeth 12a of the shaft 10 engage in the recess 66b of the coupling member 58.

Claims

Claims

1. Assembly (2) for turbomachine (1) comprising a turbine shaft (10) machine extending along an axis (X), a nut (42) screwed around of said axis (X) on the turbomachine shaft (10), and a device for nut locking device, said nut locking device comprising a coupling member (58), said coupling member (58) comprising a first zone of rotating coupling (60b) cooperating with a first zone of complementary coupling (48) of the nut (42), and a second zone of rotating coupling (66a, 66b) cooperating with a second zone of complementary coupling (12a, 12b) of the shaft (10), the coupling member (58) being able to be moved axially by relative to the nut (42) between a coupling position in which the coupling member (58) is rotationally coupled to the nut (42) by through the first coupling zone (60b) and the first complementary coupling zone (48) and in which the nut (42) is rotatably coupled to the shaft (10) via the second zone coupling (66a, 66b) and the second coupling zone comple- mentary (12a, 12b), and a first decoupling position in which the coupling member (58) is rotationally coupled to the nut (42) via the first coupling zone (60b) and the first coupling zone complementary (48) and in which the coupling member (58) is not not coupled to the shaft (10), said nut coupling device further comprising means of elastic recall (74) capable of generating an axial recall force on the coupling member (58) so as to move it axially towards its coupling position.

2. Assembly (2) according to the preceding claim, in which the member of coupling (58) is capable of being axially displaced relative to the nut (42) to a second decoupling position in which the member of coupling (58) is rotationally decoupled to the nut (42) and is rotationally decoupled rotation of the shaft (10).

3. Assembly (2) according to one of the preceding claims, in which the first coupling zone (60b) of the coupling member (58) comprises at least one axially extending groove, the first zone of complementary coupling (48) of the nut (42) comprising at least one groove extending axially, or vice versa.

4. Assembly (2) according to one of the preceding claims, in which the second coupling zone (66a, 66b) of the coupling member (58) comprises at least one axially extending tooth, the second zone of complementary coupling (12a, 12b) of the shaft (10) comprising at at least one recess of complementary shape to the tooth, or in- payment.

5. Assembly (2) according to one of the preceding claims, in which the nut locking device comprises an axial stop (56), the elastic return means (74) being mounted between said axial stop (56) and the coupling member (58).

6. Assembly (2) according to one of the preceding claims, in which the coupling member (58) comprises at least one gripping zone (72) capable of cooperating with a tool (76).

7. Assembly (2) according to one of the preceding claims, said assembly further comprising an additional element (24) mounted around the shaft (10) of a turbomachine, said additional element (24) comprising a first radial surface (32), bearing on an axial stop com- additional element axially secured to the shaft (10), said ad- additional (24) having a second radial surface (33), the nut (42) being able to come into axial support on said second radial surface (33).

8. Assembly (2) according to the preceding claim, said assembly further comprising a bearing (34) mounted around the shaft (10) and axially secured to the shaft (10), said complementary axial stop being formed by a zone of said bearing (34).

9. Turbomachine (1) comprising an assembly (2) according to one of the claims- previous instructions.

10. Aircraft comprising at least one turbomachine (1) according to claim- previous instruction.

11. Method of mounting an assembly according to one of claims 1 to 8, comprising the steps of: a. engage the coupling member (58) the return means elastics (74) and the axial stop (56) in the nut (42), b. screw the nut (42) onto the shaft (10), c. axially position the coupling member (58) in the second decoupling position and angularly align the second coupling zone (66a, 66b) of the coupling member (58) with the second complementary coupling zone (12a, 12b) of the shaft (10), and axially moving the coupling member (58) towards the coupling position so that the second coupling zone (66a, 66b) of the shaft (10) cooperates with the second complementary coupling zone (12a, 12b).