Torque transmission tool, and associated method

Abstract

This tool (23) for transmitting mechanical torque to a screw (20), in particular a balancing screw, of a turbomachine (2) having a through opening (22) opposite the screw (20), the screw (20) being mounted on a ferrule (16) of the turbomachine (2), comprises first and second coaxial parts (24, 26) free in translation and rotation relative to each other, the tool (23) being able to extend through the through opening (22) and come into contact with the screw (20), a first end of the first part (24) being configured to transmit the mechanical torque to the screw (20), a first end of the second part (26) being configured to be fixed to the screw (20). Figure for the abbreviation: Fig 3

Description

Title of the invention: Torque transmission tool, and associated method. Technical field

[0001] The invention has as its technical field the assembly and disassembly of turbomachine screws for aircraft, in particular balancing screws of a test turbomachine.

[0002] In particular, the present invention relates to a tool and a method for transmitting torque. Previous techniques

[0003] During test campaigns on a test turbomachine, it may be necessary to adjust the balance of the turbomachine many times, for example to correct an imbalance of the turbomachine.

[0004] This balancing is generally ensured by a ferrule equipped with a plurality of balancing screws of different masses.

[0005] Adjusting the balance generally requires removing a cover from the turbomachine to allow a technician to access the balancing screws and replace some of them with balancing screws from other masses.

[0006] This operation requires significant setup time and lengthens the test campaigns.

[0007] When changing one of these balancing screws, it sometimes happens that it slips from the hands of an operator, further slowing down the balancing adjustment operation. Description of the invention

[0008] The present invention therefore aims to overcome all or part of the aforementioned disadvantages and, in particular, to provide a torque transmission tool facilitating the screwing and unscrewing of turbomachine screws, and saving time during the balancing operation of a test turbomachine.

[0009] The present invention relates to a tool for transmitting mechanical torque to a screw, in particular a balancing screw, of a turbomachine equipped with a through opening opposite the screw, the screw being in particular mounted on a ferrule of the turbomachine.

[0010] The tool comprises first and second coaxial parts that are free to translate and rotate relative to each other, the tool being capable of extending through the through opening and coming into contact with the screw, a first end of the the first part being configured to transmit the mechanical torque to the screw, one end of the second part being configured to attach to the screw.

[0011] The first and second parts, free in translation and rotation relative to each other, are able to perform their respective functions independently of each other.

[0012] The tool capable of extending through the through opening and coming into contact with the screw has an elongated shape to access the screw from outside the turbomachine, and therefore does not require removing a cover from the turbomachine to allow an operator to transmit a mechanical torque to the screw.

[0013] According to a particular design, the through opening is formed in a housing for a turbine blade foot of the turbomachine.

[0014] The first end of the first part configured to transmit the mechanical torque to the screw has a shape suitable for transmitting the mechanical torque by contact of the first end with a head of the screw during the rotation of the first part.

[0015] The first end of the second part configured to attach to the screw allows the screw to remain fixed in translation and rotation relative to the second part during the transmission of torque from the first part to the screw and eliminates the risk of losing the screw during its handling.

[0016] Advantageously, the first part comprises a hollow cylindrical body, the second part comprising a cylindrical body arranged inside the hollow cylindrical body of the first part.

[0017] The first part may include at its first end a clamping recess.

[0018] According to one embodiment, the first part comprises at its first end two axial projections spaced apart from each other, each projection being provided with a flat face opposite the other projection.

[0019] According to this embodiment, the two axial projections are able to transmit the mechanical torque by flat-flat type contact with the screw.

[0020] The second part may include a thread at its first end.

[0021] According to one embodiment, the second part comprises at its first end a threaded rod.

[0022] According to this embodiment, the threaded rod is able to be screwed into a tapped hole made in the head of the screw.

[0023] Advantageously, the first part includes at a second end a socket for applying the rotational torque on the first part.

[0024] Optionally, the socket cross-section is polygonal, in particular square, hexagonal, or octagonal. Thus, the torque can be applied using a lever arm, in particular a mechanical wrench.

[0025] Advantageously, the second piece includes at a second end a shoulder forming a handle.

[0026] The shoulder forming a handle limits the translational movement of the second part relative to the first part so that the second part is able to rest on the second end of the first part, particularly when the second part is fixed to the screw. The shoulder forming a handle allows an operator to manually apply mechanical torque to the second part, notably to fix the first end of the second part to the screw.

[0027] The present invention also relates to a method for transmitting mechanical torque to a screw, in particular a balancing screw, of a turbomachine equipped with a through opening opposite the screw, the screw being in particular mounted on a ferrule of the turbomachine, the method comprising the following steps:

[0028] - a step of positioning a tool for transmitting a mechanical torque to during which the tool is brought into contact with the screw so that the tool extends from the screw towards the opening and beyond the opening,

[0029] - a step of fixing the tool to the screw, and

[0030] - a step of transmitting mechanical torque from the tool to the screw.

[0031] The method may include the use of a tool comprising first and second coaxial parts that are free in translation and rotation relative to each other.

[0032] The tool positioning step may include positioning flat faces of a first end of the first part opposite flat sides of a screw head.

[0033] The step of fixing the tool to the screw may include screwing a first threaded end of the second part into a tapped hole in the screw.

[0034] Such a tool may be a tool for transmitting mechanical torque to a screw as defined above. Brief description of the drawings

[0035] 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:

[0036] [Fig-1] is a schematic longitudinal cross-sectional view of a turbomachine;

[0037] [Fig.2] is a schematic perspective view of a rectifier module of a turbomachine blower;

[0038] [Fig.3] schematically illustrates a mechanical torque transmission tool according to an example of an embodiment of the invention;

[0039] [Fig.4] illustrates a first end of the tool of the [Fig.3];

[0040] [Fig. 5] illustrates the tool of [Fig. 3] in contact with a balancing screw; and

[0041] [Fig.6] schematically illustrates a method of transmitting mechanical torque to a screw according to an example of an embodiment of the invention. Detailed description

[0042] Figure 1 schematically represents a longitudinal section of a turbomachine 2, in particular a test turbomachine for a test bench. The turbomachine 2 comprises a fan 4 equipped with a rotor module 6 with moving blades and a stator module 8 with fixed blades.

[0043] Fig. 2 schematically represents in perspective the rectifier module 8 which includes a hub 10 provided with a plurality of receiving housings 12 for blade feet 14 and a ferrule 16 arranged inside the hub 10 and provided with a plurality of holes 18 each receiving a balancing screw 20.

[0044] A through opening 22 is formed in each receiving housing 12 so that each through opening 22 opens opposite a balancing screw 20. A blade has not been shown on [Fig.2] in order to illustrate such a through opening 22.

[0045] Figures 3 and 4 schematically represent in perspective a tool 23 for transmitting a mechanical torque to a screw, the tool 23 allowing, for example, the replacement of a balancing screw of a given mass by another balancing screw having a different mass.

[0046] The tool 23 is generally elongated in shape and comprises first and second parts 24, 26 coaxial along the elongation axis A of the tool 23, the axial direction corresponding to the elongation axis A of the tool 23.

[0047] The first part 24 comprises a hollow cylindrical body 28. The second part 26 comprises a cylindrical body 30.

[0048] The hollow cylindrical body 28 of the first part 24 has an inner diameter greater than or equal to the outer diameter of the cylindrical body 30 of the second part 26, and an outer diameter less than or equal to the diameter of the through opening 22.

[0049] The cylindrical body 30 of the second part 26 is arranged inside the hollow cylindrical body 28 of the first part 24. The first and second parts 24, 26 are free to rotate relative to each other around the elongation axis A of the tool 23 and free to translate relative to each other along the elongation axis A.

[0050] With reference to [Fig.5] which illustrates a use of the tool 23, the tool 23 is able to extend from outside the turbomachine 2 through the through opening 22 to come into contact with the balancing screw 20 opposite the through opening 22.

[0051] The tool 23 is shown in contact with the balancing screw 20 which comprises a threaded body 32 and a screw head 34 having a flange 36 and a projection 38 extending from the flange 36 on the side opposite the threaded body 32, a tapped hole 40 being formed in the projection 38 of the screw head 34. The projection 38 of the screw head 34 is here cylindrical and comprises two parallel and opposite flat faces 42.

[0052] A first end of the first part 24, located on the side of the balancing screw 20, is adapted to transmit the mechanical torque to the balancing screw 20. In particular, the first part 24 is provided at its first end with a clamping recess 44 adapted to the shape of the screw head 34. More specifically, the first part 24 comprises two projections 46 extending from the hollow cylindrical body 28 on the side of the first end, each projection 46 extending axially such that the projections 46 are spaced apart from each other. Each projection 46 has a flat face opposite the other projection 46 so that a notch is formed in the first part 24 at its first end between the two projections 46.The notch thus formed is suitable for transmitting the mechanical torque to the projection 46 of the screw head 34, the torque being transmitted in particular between the flat faces of the two projections 46 of the first part 24 and the flat flats 42 of the projection 46 of the screw head 34. Alternatively, another form of clamping recess 44 could be envisaged according to the shape of the screw head 34.

[0053] A first end of the second part 26, located on the side of the balancing screw 20, is adapted to be fixed to the balancing screw 20. In particular, the second part 26 is provided at its first end with a thread. More precisely, the second part 26 comprises a threaded rod 48 extending from the cylindrical body 30 on the side of the first end and adapted to be screwed into the threaded hole 40 in the head of the screw 34.

[0054] Again with reference to [Fig.3], the first part 24 includes at a second end, opposite the first end, a socket 50 for applying the rotational torque to the first part 24.

[0055] The first part 24 here includes a portion of square cross-section extending the hollow cylindrical body 28 on the side of the second end and forming the socket 50. Thus, the torque can be applied to the first part 24 via the socket 50 using a lever arm such as a mechanical wrench, one end 52 of which is shown.

[0056] The second part 26 includes a shoulder 54 forming a handle extending the cylindrical body 30 on the side of the second end. The shoulder 54 is able to rest on the first part 24 on the side of the second end when the second part 26 is fixed to the balancing screw 20, in particular when the threaded rod 48 is screwed into the thread 40 of the screw head 34. In other words, the axial lengths of the threaded rod 48 and the cylindrical body 30 of the second part 26 are such that the shoulder 54 rests on the first part 24 when the threaded rod 48 is screwed into the tapped hole 40 of the screw head 34.

[0057] In the example shown, the first part 24 is able to transmit the mechanical torque to the balancing screw 20, the second part 26 being able to fix the balancing screw 20. Alternatively, it could be envisaged that the first part 24 is able to be fixed to the balancing screw 20, for example by screwing onto the head of the screw 34, and that the second part 26 is able to transmit the mechanical torque to the balancing screw 20, for example via a tenon adapted to a recess of the balancing screw.

[0058] The tool 23 is also suitable for transmitting mechanical torque to turbomachine screws other than the balancing screws of the test turbomachine.

[0059] Fig. 6 schematically represents a method of transmitting mechanical torque to the balancing screw 20.

[0060] We begin with a positioning step 56 of the mechanical torque transmission tool 23 during which the tool 23 comes into contact with the balancing screw 20 by extending from the outside of the turbomachine 2, through the through opening 22. Preferably, we position the flat face of each of the two projections 46 of the first part 24 opposite a flat face 42 of the screw head 34.

[0061] Then a fixing step 58 of the tool 23 to the balancing screw 20 is carried out, for example by screwing the threaded rod 48 of the second part 26 into the tapping 40 of the screw head 34, in particular until the shoulder 54 of the second part 26 is in contact with the second end of the first part 24.

[0062] Then a transmission step 60 of the mechanical torque is carried out from the tool 23 to the balancing screw 20, for example to loosen the balancing screw 20 in order to replace it.

[0063] Finally, a step of removing the balancing screw 20 is carried out during which the balancing screw 20 is secured by being fixed to the second part 26.

Claims

Demands

1. A tool (23) for transmitting mechanical torque to a screw (20), in particular a balancing screw, of a turbomachine (2) having a through opening (22) opposite the screw (20), the screw (20) being mounted, in particular, on a ferrule (16) of the turbomachine (2), the tool (23) comprising first and second coaxial parts (24, 26) free in translation and rotation relative to each other, the tool (23) being capable of extending through the through opening (22) and coming into contact with the screw (20), a first end of the first part (24) being configured to transmit the mechanical torque to the screw (20), a first end of the second part (26) being configured to be fixed to the screw (20), the second part (26) comprising at its first end a threaded rod (48), characterized in that the second part (26) comprises at a second end a shoulder (54) forming a handle,the shoulder (54) being able to rest on the first part (24) on the side of the second end when the threaded rod (48) is screwed into a tapped hole (40) in a screw head (34) of the screw (20).

2. Tool (23) according to claim 1, wherein the first part (24) comprises a hollow cylindrical body (28), the second part (26) comprising a cylindrical body (30) arranged inside the hollow cylindrical body (28) of the first part (24).

3. Tool (23) according to claim 1 or 2, wherein the first part (24) includes at its first end a clamping impression (44).

4. Tool (23) according to claim 3, wherein the first part (24) comprises at its first end two axial projections (46) spaced apart from each other, each projection (46) being provided with a flat face opposite the other projection (46).

5. Tool (23) according to any one of claims 1 to 4, wherein the first part (24) includes at a second end a socket (50) for applying the rotational torque on the first part (24).

6. A method for transmitting mechanical torque to a screw (20), in particular a balancing screw, of a turbomachine (2) having a through opening (22) opposite the screw (20), the screw (20) being in particular mounted on a ferrule (16) of the turbomachine (2), characterized in that it comprises the following steps: - a positioning step (56) of a mechanical torque transmission tool (23) according to any one of claims 1 to 5 during which the tool (23) is brought into contact with the screw (20) so that the tool (23) extends from the screw (20) towards the opening (22) and beyond the opening (22), - a fixing step (58) of the tool (23) to the screw (20), and - a mechanical torque transmission step (60) from the tool (23) to the screw (20).

7. A method according to claim 6, comprising the use of a tool (23) comprising first and second parts (24, 26) coaxial and free in translation and rotation relative to each other, and wherein: - the positioning step (56) of the tool (23) comprises the positioning of planar faces of a first end of the first part (24) opposite planar flats (42) of a head of the screw (34), and - the fixing step (58) of the tool (23) to the screw (20) comprises the face of a first threaded end of the second part (26) in a tapped hole (40) of the screw (20).

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