Tool for assisting in coupling two turbomachine shafts and method for coupling these two shafts

Abstract

Tool for assisting in coupling two turbomachine shafts and method for coupling these two shafts One aspect of the invention relates to a tool for assisting in coupling (40) a female shaft (10) and a male shaft (20), the male shaft comprising a coupling part (32) concentrically engaged in a complementary coupling part (31) of the female shaft, said tool (40) comprising at least two longitudinal arch-shaped parts (41, 42) connected to each other by at least one spring part (43) providing elasticity to said tool so that the longitudinal arch-shaped parts (41, 42) are capable of being mounted around at least the coupling part (32) of the male shaft and of being dismantled intact. Another aspect of the invention relates to a method for implementing this device. Figure to be published with the abstract: Figure 3

Description

Description Title of the invention: Tool for assisting the coupling of two turbomachine shafts and method for coupling these two shafts technical field

[0001] The present invention relates to a tool for assisting in the coupling of two shafts, particularly aircraft turbomachinery. It also concerns a process coupling of two shafts, in which said tool is used to facilitate mating.

[0002] — The invention finds applications in the field of shaft coupling, in particular for coupling shafts of an aircraft turbomachine such as a turbine shaft and compressor shaft. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In the field of aeronautics, certain turbomachines, known as "twin-body" turbomachines ", consist of a low-pressure body and a high-pressure body. The low- Pressure and high-pressure systems each have a rotor, these rotors being arranged in coaxially with respect to each other. For this, the shafts of each of the rotors are coupled generally by means of a coupling device, for example by grooves.

[0004] Moreover, within the same body, for example the low-pressure body, the turbine low pressure includes a shaft coupled to the shaft of the low pressure compressor. The low-pressure turbine shaft and the low-pressure compressor shaft are coupled generally by means of a coupling device, for example by grooves.

[0005] — An example of two shafts coupled by means of a coupling device The grooved type is shown in Figure 1. In this example, a female shaft 10, for example a compressor shaft, and a male shaft 20, for example a shaft of turbine, extend along the same axis of rotation XX of the turbomachine.

[0006] The female shaft 10 and the male shaft 20 are coupled to each other by means of a coupling device 30. This coupling device 30 comprises a first part 31 terminating the female tree 10 and a second part 32 terminating the male tree 20, the first part 31 and the second part 32 being engaged coaxially one on the other. In the case of a gear coupling device, each of the The first and second parts comprise a plurality of 35 grooves, the grooves of one of the parts engaging the splines of the other part.

[0007] — During the assembly of the second part 32 of the coupling device 30 in the first part 31 of said coupling device 30. it is important that the posi- The axial alignment of the male shaft 20 relative to the female shaft 10 must be precise so that the splines of the first part engage correctly with the splines of the second part. To achieve this, a clearance must be maintained between the first part 31 and the second part 32 of the coupling device. An example of this clearance, denoted 0, is shown in Figure 2, which schematically represents the male shaft 20 and the female shaft 10 to be coupled. Generally speaking, aligning two shafts while respecting operating clearance is a delicate matter. In the field of aeronautics, aligning two shafts while respecting operating clearance is all the more difficult because the shafts are heavy and bulky and must be moved using lifting tools where it is difficult to obtain precise movement accuracy. To maintain the required operating clearance, a spacer could be used to ensure axial alignment of the two shafts while respecting a predefined interlocking distance. However, the spacer would need to remain permanently attached to the shafts because, once the shafts are coupled and secured, the spacer could not be removed without breaking. There is therefore a real need for a tool that allows for the axial positioning of two shafts relative to each other, particularly turbomachine shafts, while respecting the operating clearance required for the coupling device. Summary of the invention To address the problems mentioned above regarding the positioning of two shafts to be coupled, the applicant proposes a tool to assist in the mechanical coupling of two shafts, adapted to be positioned around the shafts before coupling and removed once the shafts have been coupled and fixed. According to a first aspect, the invention relates to a tool for assisting the coupling of a female shaft and a male shaft, the male shaft comprising a coupling part engaged concentrically in a complementary coupling part of the female shaft, said tool comprising at least two longitudinal arch-shaped pieces connected to each other by at least one spring piece ensuring elasticity of said tool so that the longitudinal arch-shaped pieces are able to be mounted around the coupling parts of the male and female shafts and to be disassembled intact. This tool allows for optimal positioning of the two shafts relative to each other, respecting the operating clearance required for coupling. It also has the advantage of being removable, so once the shafts are fixed, it can be removed without breaking. It is therefore reusable. In addition to the characteristics mentioned in the previous paragraph, The coupling aid tool according to one aspect of the invention may have one or more complementary features from among the following, considered individually or according to all technically possible combinations: the longitudinal, arch-shaped pieces are of the same length, their length being defined according to a working clearance of the parts mating of male and female trees. a first lateral end of each of the longitudinal pieces in the shape The hoops are integral with the spring piece and a second lateral end of each of the longitudinal arch-shaped pieces is free. the free ends of the longitudinal, arch-shaped pieces are spaced at a predefined distance, dependent on the elasticity generated by the spring piece. The longitudinal, arch-shaped pieces and the spring piece are manufactured in one piece. The longitudinal, arch-shaped pieces and the spring piece are manufactured by 3D printing, The spring piece has a longitudinal, semi-tubular shape. The spring part has a C, M or open square profile. It comprises four longitudinal, arch-shaped pieces connected by three spring parts. It includes, on a downstream face and / or an upstream face, means of positioning operation of fastening elements. The concepts of longitudinal or radial will be defined relative to the axis of rotation XX of the male and female shafts. According to a second aspect, the invention relates to a method for coupling a female shaft and a male shaft, the male shaft comprising a coupling part engaged concentrically in a complementary coupling part of the female shaft, characterized in that it comprises the following operations: the joining of the female tree and the male tree, installation, around the mating parts of the female and male trees, of the coupling aid tool as defined above, by spacing longitudinal pieces shaped like arches relative to each other, progression of the mating portion of the male tree inside the mating part of the female tree until the assisting tool the coupling is at its limit, and removal of the coupling aid tool by spreading the longitudinal parts tudinales in the shape of arches relative to each other. This coupling method has the advantage of allowing precise positioning, and reproducible, of two trees for the purpose of their mating. Brief description of the drawings Other advantages and features of the invention will become apparent from the following description, illustrated by the figures in which: [fig.1] Figure 1, already described, represents a schematic cross-sectional view of an example of coupled turbomachine shafts; [fig.2] Figure 2, already described, represents a schematic view of a set of functions necessary for a coupling device for two shafts to be coupled; [fig.3] Figure 3 shows a schematic cross-sectional view of an example of turbomachine shafts during coupling, when the coupling aid tool is in place; [fig.4] Figure 4 shows perspective views of an example of a coupling aid tool according to the invention; [fig.5] Figure 5 schematically represents different embodiments of the coupling aid tool according to the invention; [fig.6] Figure 6 schematically represents two trees during the mating phase and once mated; [fig.7] Figure 7 represents, according to perspective views, different stages of the method of coupling shafts of the invention with the coupling aid tool of figure 4; [fig.8] Figure 8 represents a perspective view of a variant of the coupling aid tool of figure 4. Description of the implementation methods An example of an embodiment of a tool to aid in the mechanical coupling of two shafts, configured to be easily positioned around the shafts to be coupled and easily removed once the shafts are coupled, is described in detail below, with reference to the accompanying drawings. This example illustrates the features and advantages of the invention. It should be noted, however, that the invention is not limited to this example. In the figures, identical elements are identified by identical references. For the sake of readability, the size scales between the represented elements are not to scale. An example of two shafts 10, 20 coupled using the coupling aid 40 according to the invention is schematically shown in Figure 3. In the example in Figure 3, the two shafts, for example a female shaft 10 and a male shaft 20, are coupled via a coupling device 30 such as that described in the prior art. In other examples, the two shafts are directly coupled to one another, the male shaft comprising, at its extremity, a coupling portion concentrically engaged in a coupling portion of the female tree. In the remainder of this description, the two trees will be considered to be coupled either by means of a coupling device 30 comprising a first portion terminating the female tree and a second portion terminating the male tree, or by their respective coupling portions. The expressions "first / second portion of the coupling device" and "coupling portion," referenced 31 and 32, will therefore be used interchangeably to refer to the extremity of a tree designed respectively to receive (female tree) or to be received (male tree) by the extremity of the other tree. The male shaft 20 has, at a predetermined distance from its axial end intended for insertion into the female shaft 10, a bearing 21 forming at least a partial projection on the circumference of said shaft. The coupling portion 31 of the female shaft 10 (the first part terminating the female shaft) has a projecting element 34 forming a stop. This projecting element 34 serves, in particular, to protect the part from scratches and to correct a face of complex geometry into a flat face suitable for forming a stop. In some embodiments, the projecting element 34 reproduces pre-grooves allowing the engagement of the splines, for example, of the coupling device 30, with the correct angular orientation. It may be, for example, annular, partially annular, or consisting of several points distributed around the circumference of the coupling portion of the female shaft.It can, for example, be a ring extending over at least part of this circumference. Alternatively, it can be formed by the external face of the first part 31 terminating the female shaft 10. The bearing 21 and the projecting element 34 act as stops to define the position of the coupling aid tool 40. Thus, as schematically shown in drawing A of Figure 4, during the coupling process of the female shaft 10 with the male shaft 20, the coupling aid tool 40—more simply called the tool—is installed around the coupling end 32 of the male shaft 20 (or the second part terminating the male shaft), or straddling the coupling part 31 of the female shaft and the coupling part 32 of the male shaft, between the projecting element 34 and the bearing 21. Of course, at the beginning of the coupling process, the male shaft 20 and the female shaft 10 are positioned almost aligned facing each other, with the bearing 21 and the projecting element 34 separated. one from the other by any distance greater than the length of the tool 40.The tool 40 can then easily be mounted around the coupling part 32 of the male shaft 20. When the coupling parts 31, 32 of the female and male shafts are inserted into each other, the distance between the bearing 21 and the protruding element 34 decreases as the coupling part 32 of the shaft progresses. The male part 20 is inserted into the coupling portion 31 of the female shaft 10 until the tool 40 is abutted against both the bearing 21 and the protruding element 34. When the tool 40 is abutted on both sides against the bearing 21 and the protruding element 34, the two coupling portions 31, 32 are considered correctly positioned and the two shafts are coupled (drawings A of Figure 4). The shafts 10, 20 can then be fixed, for example, clamped using the fasteners 50, and the tool 40 can be removed (drawing B of Figure 4). The male shaft 20 and the female shaft 10 are then fixed at a predetermined distance, corresponding to the appropriate operating clearance Δ of the coupling device 30 or coupling portions. The coupling aid 40 is a removable device that can be easily mounted around one of the shafts, for example, clipped around the male shaft in the examples of Figures 3 and 4, and can be removed just as easily, for example, unclipped, once the two shafts 10, 20 have been coupled. To this end, the tool 40 has a shape whose geometry provides elasticity, allowing it to both open for installation around the shafts, to encircle the coupling parts of said shafts when mounted, and to be removed from said shafts once the shafts are secured. This geometry is achieved by means of at least two longitudinal, arched pieces 41, 42 and one (or more) spring pieces 43 connecting the two arched pieces. The arch-shaped pieces 41, 42 are preferably identical, although differences in dimensions or symmetry may be envisaged.The length of the arched parts (i.e., the longitudinal dimension along the axis of rotation XX) corresponds to the length of the tool 40 and therefore to the distance defined between the bearing 21 and the projecting element 34 to maintain the operating clearance θ. The dimensions of the arcs of the arched parts 41, 42 are adapted to the diameters of the shafts and to the desired opening between said arched parts. An example of a first geometry is shown from different angles in the drawings of Figure 5 and in a cross-sectional view in drawing A of Figure 6. According to this first geometry, the longitudinal arch-shaped parts 41, 42 are two parts, or two portions of parts, extending longitudinally along the axis of rotation XX and forming a partial tube, open longitudinally, adapted to partially encircle the circumference of the shaft coupling parts. In other words, the two arch-shaped parts 41, 42 are in the form of two tube portions, facing each other and connected by means of a spring-shaped part 43.Thus, the first lateral end 42a, 41a of each of the arched pieces is integral with a lateral end of the spring piece 43, while their second lateral ends 42b, 41b are free and form the contours of an opening 44 through which the coupling parts of the shafts are inserted or removed from tool 40. The second lateral ends 42b, 41b are therefore spaced apart from each other by a predefined distance which may depend on the elasticity generated by the spring piece. According to this first example of geometry, the spring piece 43 has a semi-tubular shape extending longitudinally along the axis of rotation XX and connecting the two arch-shaped pieces 41, 42. In other words, the spring piece 43 has a cross-section substantially in the shape of a C, each lateral end 43i, 43j of which is integral with the first lateral end 41a, 42a of one of the arch-shaped pieces 41, 42. Thus, as can be seen in the cross-sectional view (A) of Figure 6, the tool 40, according to the first geometry, has a cross-section in the shape of an open double circle. This geometry allows the tool 40 to be radially elastic but longitudinally rigid. The tool 40 can therefore be easily mounted around a shaft, or removed from the shaft, by moving its second lateral ends 42b, 41b apart. In some variants, the spring piece 43 has the same length as the arched pieces 41, 42. In other variants, the spring piece 43 has a shorter length than the arched pieces 41, 42, the difference in length of the spring piece allowing the elasticity of the tool 40 to be varied considerably. Other examples of geometries are shown, according to schematic cross-sectional views, in Figure 6. In Example B of Figure 6, the tool 40 comprises two arch-shaped parts 41, 42 substantially identical to those described previously for Example A and a spring part 43 having a cross-section substantially in the shape of a rounded M comprising two legs 43a, 43b attached to the first lateral ends 4a, 42a of the arch-shaped parts 41, 42 and, between the two legs 43a, 43b, a central undulation 43c (for example a U-shaped hollow) providing radial elasticity to the tool. In example C of figure 6, the tool 40 comprises two arch-shaped pieces 41, 42 substantially identical to those described previously for example A and a spring piece 43 having a cross-section substantially in the shape of an open square, two opposite sides 43d, 43e of which are integral with the first lateral ends 41a, 42a of the arch-shaped pieces 41, 42 and a third side 43f connects sides 43d and 43e. In Example D of Figure 6, the tool 40 comprises four arch-shaped parts 41 and three spring parts 43, each spring part 43 connecting two arch-shaped parts 41 or 42. The arch-shaped parts 41 or 42 may have shorter arcs than those of the arch-shaped parts described previously for Example A. The spring parts 43 may have an identical shape, but possibly reduced transverse dimensions (i.e., the di- dimensions perpendicular to the longitudinal dimension), compared to those of the spring parts described for examples A, B or C in Figure 6. In this example, the plurality of spring parts offers greater elasticity to the tool 40, which can make it possible to increase the circumferential surface area of ​​the tool and / or decrease the size of the opening 44. Of course, the number of arch-shaped parts and spring parts can be adjusted according to the shafts and the desired elasticity. Regardless of the embodiment, the arched parts 41, 42 are integral with the spring part 43. To achieve this, the various parts can be assembled using any known assembly method, such as welding or brazing. The various parts can also be manufactured as a single unit, for example by machining or bending, particularly when the tool is made of sheet metal or metal. They can also be manufactured as a single unit by 3D printing when the tool is made of plastic (for example, PLA for FDM 3D printing), 3D printing having the advantage of enabling rapid and inexpensive manufacturing. A person skilled in the art will understand that, regardless of the method of implementation of the tool, the shapes and dimensions of the various parts of the tool 40 can be modified and adapted to the dimensions of the coupling parts of the shafts to be coupled and / or to the opening and elasticity required to allow the mounting and dismounting of said tool 40 on the shafts. In some embodiments, the tool 40 may include means for positioning the shaft fastening elements. These positioning means may be distributed over one or more rows, on one or both faces of the tool 40 perpendicular to the axis of rotation XX. For example, as shown in Figure 7, the tool 40 may include lugs 60 distributed on its downstream face 45. Lugs could also be distributed on the upstream face 46 of said tool 40, in addition to or instead of those on the downstream face 45. These lugs 60 may, for example, be blades projecting from the downstream face 45, each provided with a through hole 61, adapted to receive a fastening element such as a screw. The positioning means can alternatively be clips or any other element allowing to temporarily hold fixing elements in order to prefix one and / or the other tree. Figure 8 shows, in four drawings, the assembly and disassembly steps of the tool 40. Step A in Figure 8 depicts the mounting of the male shaft 20 onto the female shaft 10 (or vice versa) so that the two shafts are substantially aligned with each other. This mounting step may also include the partial insertion of the coupling portion 32 of the male shaft into the first coupling portion 31 of the female shaft. Step B in Figure 8 shows the installation of the tool 40 around the coupling portion 32 of the male shaft 20. The tool 40 is mounted around the shaft 20 by pressing said tool against said shaft so that the arched parts 41, 42 move apart to allow passage of the shaft. Those skilled in the art will understand that, depending on the shape of the coupling portion 31 of the female shaft, the tool 40 can be mounted only around the coupling portion 32 of the male shaft or straddling the coupling portion 31 of the female shaft and the coupling portion 32 of the male shaft. Step C of Figure 8 shows the step during which the tool 40 is mounted and encircles the coupling parts 31, 32. During this step, the coupling parts 31, 32 are inserted into each other until the tool 40 is against both the bearing 21 and the protruding element 34.When the tool 40 is against the stop on both sides (against the bearing 21 and against the projecting element 34), the shafts 10 and 20 are correctly positioned relative to each other and the operating clearance of the coupling parts is maintained. The shafts 10 and 20 can then be fixed. Step D in Figure 8 shows the operation of removing the tool 40. The tool 40 is disassembled, that is to say, removed by separating the arched parts 41, 42 from each other and moving the tool 40 away from the shafts. Because of its elasticity, tool 40, once removed, is intact and can be reused later for coupling other shafts. Although described through a number of examples, variants and modes of realization, the tool for assisting the coupling of two trees according to the invention includes various variants, modifications and improvements which will be obvious to a person skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention.

Claims

Demands

1. Tool for assisting the mating (40) of a female tree (10) ct of a tree male (20), the male tree including a mating part (32) engaged concentrically in a complete coupling part- commentary (31) of the female tree, said tool (40) comprising at least two longitudinal, arch-shaped pieces (41, 42) connected to one another the other by at least one spring piece (43) ensuring elasticity said tool so that the longitudinal parts are arched (41, 42) be suitable for mounting around at least the coupling part (32) of the male shaft and to be disassembled intact.

2. Tool according to claim 1, characterized in that the longitudinal parts arch-shaped tudinales (41, 42) are of the same length, their length being defined according to an operating clearance (8) of the mating parts of the male and female trees.

3. Tool according to claim 1 or 2, characterized in that a first lateral end (41a, 42a) of each of the longitudinal pieces in the arched shape is integral with the spring piece (43) and that a second lateral end (41b, 42b) of each of the longitudinal pieces in The shape of the arches is free.

4. Tool according to claim 3, characterized in that the free ends (41b, 42b) longitudinal pieces in the shape of arches are spaced of a predefined distance, dependent on the elasticity generated by the part spring (43).

5. Tool according to any one of claims 1 to 4, characterized in that that the longitudinal, arch-shaped pieces and the spring piece are manufactured in one piece.

6. Tool according to claim 5, characterized in that the longitudinal parts The arch-shaped tubular components and the spring piece are manufactured by im- 3D pressure.

7. Tool according to any one of claims 1 to 6, characterized in that that the spring piece (43) has a longitudinal, semi-tubular shape.

8. Tool according to claim 7, characterized in that the spring piece (43) has a C-shaped, M-shaped, or open square profile.

9. Tool according to any one of claims 1 to 8, characterized in that that it comprises four longitudinal pieces in the shape of arches (41 or 42) connected by three spring pieces (43).

10. A tool according to any one of claims 1 to 9, characterized in that that it includes, on a downstream face and / or an upstream face, means (60) positioning of fastening elements.

11. Method for mating a female tree (10) and a male tree (20), the male tree comprising an engaged mating part (32) concentrically in a complementary coupling part (31) of the female tree, characterized in that it includes the operations following: docking of the female tree (10) and the male tree (20), installation, around the coupling parts of the trees female and male, of the mating aid tool (40) according to any one of claims 1 to 10, by way of exception longitudinal pieces in the shape of arches (41, 42) one compared to the other, progression of the mating part (32) of the male tree to the interior of the mating part (31) of the female tree until the coupling aid tool reaches its stop, and removal of the coupling aid tool (40) by spreading longitudinal pieces in the shape of arches relative to each other to the other.