Connecting rod, particularly for the stator of a turbomachine, adjustable in length, and associated adjusting tool

Abstract

Connecting rod (100), in particular of a turbomachine stator, extending along an extension axis (X1-X1') comprising a connecting rod body (110) and a first connecting rod head (130) connected to the connecting rod body (110) and comprising a cylindrical connecting rod (131) comprising an external thread (132). The connecting rod (100) further comprising an axial length adjustment system (140) along the extension axis (X1-X1') of the first connecting rod head (130) relative to the connecting rod body (110) comprising a sleeve (141) rotatably mounted in the connecting rod body (110) and comprising an internal thread (141b) cooperating with the external thread (132) and a transmission member (143), and a drive member (144) comprising a complementary transmission member (147) intended to cooperate with the transmission member (143) in a engaged position.The adjustment system includes a locking / unlocking member (150) configured to lock the rotation of the locking / unlocking member (150) when it is in a locked position. Figure for the abbreviation: [Fig 7].

Description

Title of the invention: Connecting rod, particularly for the stator of a turbomachine, adjustable in length, and associated adjusting tool. Technical field of the invention

[0001] The present invention relates to the field of turbomachine engines comprising a motion transmission element between two moving mechanical parts.

[0002] More particularly, the invention relates to a connecting rod or connecting rod preferably mounted on an element of the turbomachine stator, in particular a connecting rod connected to a discharge valve, called a "variable bleed valve", acronym VBV in Anglo-Saxon terms, of a discharge duct of a turbomachine, whose role is to regulate the flow at the inlet of a turbomachine compressor, or a connecting rod connected to a stator or variable-pitch stator vane, acronym VSV in Anglo-Saxon terms.

[0003] The invention also relates to a so-called pitch control connecting rod capable of transmitting the displacements of a swashplate to blade sleeves of the turbomachine.

[0004] In general, the connecting rod according to the invention is mounted in all kinematic systems of the turbomachine where a cylinder must transmit movement to mechanical parts.

[0005] The invention also relates to a connecting rod length adjustment tool associated with said connecting rod. Prior art

[0006] Connecting rods used in kinematic systems are usually adjustable in length by relative rotation between the body and the head. The connecting rod length adjustment must also be lockable to prevent any misalignment of the connecting rod height during operation.

[0007] An example of a connecting rod 1 is illustrated in [Fig. 1]. The connecting rod 1 comprises a connecting rod body 11 and two connecting rod heads 12a, 12b which are rotationally fixed to the connecting rod body 11.

[0008] The connecting rod body 11 includes on its internal surface, an internal tapping or thread (not visible in the figures) opening onto each of the open ends lia, 11b of said connecting rod body 11.

[0009] The internal thread of the connecting rod body 11 cooperates by screwing with an external thread 13a, 13b provided on the corresponding connecting rod head 12a, 12b.

[0010] As illustrated, each connecting rod head 12a, 12b includes a cylindrical connecting rod 14a, 14b, extending along the extension axis X-X' and comprising, on its external surface, the external thread 13a, 13b.

[0011] Each connecting rod head 12a, 12b further includes an end portion 15a, 15b extending from the corresponding connecting rod 14a, 14b in two opposite directions and each comprising a bore 16a, 16b extending along the transverse axis Y, perpendicular to the extension axis X-X'.

[0012] Each connecting rod head 12a, 12b further includes a joint 17a, 17b mounted in said corresponding bore 16a, 16b.

[0013] The connecting rod 1 thus allows to transmit or transform a movement between two moving mechanical parts.

[0014] Preferably, one of the external threads 13a has a right-hand thread and the other of the external threads 13b has a right-hand thread. This allows the connecting rod heads 12a, 12b to be moved away from the connecting rod body 11 by rotating said connecting rod body 11.

[0015] Indeed, thanks to the cooperation between the internal thread of the connecting rod body 11 and the external thread 13a, 13b of each connecting rod head 12a, 12b, the length along the extension axis X-X' of the connecting rod 1 can be adjusted by relative rotation between the corresponding connecting rod head 12a, 12b and the connecting rod body 11.

[0016] The connecting rod 1 further includes a system 20a, 20b for locking the relative rotation between each connecting rod head 12a, 12b and the connecting rod body 11.

[0017] Each locking system 20a, 20b includes a first serrated washer 21a, 21b mounted radially around the connecting rod 14a, 14b of the associated connecting rod head 12a, 12b.

[0018] The first notched washer 21a, 21b is axially delimited by a first lateral surface (not referenced) provided with an axial lug 22a, 22b extending axially along the extension axis X-X' towards the connecting rod body 11 and by a second lateral surface (not referenced) comprising a plurality of axial notches regularly distributed on the surface of said second lateral surface.

[0019] The axial lug 22a, 22b of the first toothed washer 21a, 21b is intended to cooperate with an axial notch 1 formed on the connecting rod body 11.

[0020] When the axial lug 22a, 22b of the first toothed washer 21a, 21b is inserted into the axial notch 1 associated with the connecting rod body 11, said first toothed washer 21a, 21b is blocked from rotation relative to the connecting rod 14a, 14b.

[0021] Each locking system 20a, 20b comprises a second serrated washer 23a, 23b mounted radially around the corresponding connecting rod 14a, 14b of the associated connecting rod head 12a, 12b. The first serrated washer 21a, 21b is mounted axially between the connecting rod body 11 and the second serrated washer 23a, 23b.

[0022] The second notched washer 23a, 23b is axially delimited by a first lateral surface (not referenced) comprising a plurality of axial notches (not referenced) regularly distributed on the surface of said first lateral surface and cooperating with the notches of the first notched washer 21a, 21b and by a second lateral surface (not referenced) substantially flat.

[0023] Each locking system 20a, 20b further includes a lock nut 24a, 24b screw-mounted on the connecting rod 14a, 14b of the corresponding connecting rod head 12a, 14b and configured to clamp the toothed washers 21a, 21b, 23a, 23b against each other, engaging the respective notches, as well as the axial lug 22a, 22b in the corresponding notch 1 provided on the connecting rod body 11 and blocking the relative rotation between the connecting rod body 11 and the corresponding connecting rod head 12a, 12b.

[0024] It is known to lock the lock nut in rotation by means of a cable 26, visible on the [Fig.1A], to prevent the relative rotation of the body 10 and the head of the corresponding connecting rod 12a, 12b and thus the misalignment of the axial length of the connecting rod.

[0025] Cable 26 is also known as "brake wire".

[0026] However, such a system for locking the relative rotation of the body and the head of the connecting rod is difficult to implement because of the short cable length, which makes it difficult to control the cable tension.

[0027] Moreover, there is no keying feature to prevent the cable from being put in backwards, thus locking the tightening instead of the loosening.

[0028] One of the nuts has a left-hand thread and the other of the nuts has a right-hand thread, which makes the operation even more delicate.

[0029] Finally, such a locking system is not satisfactory when subjected to a centrifugal force generated by the rotation of the rotor of a turbomachine.

[0030] Furthermore, when adjusting the length of such connecting rods, it is necessary to loosen the two anti-rotation nuts, release the serrated washers, and hold them in the unlocked position in order to be able to work on the connecting rod body. Such operations can prove tricky when the connecting rods are located in confined spaces.

[0031] There is a need to improve the systems for adjusting the axial length of the head of a connecting rod or link. Description of the invention

[0032] The present invention therefore aims to overcome the aforementioned drawbacks.

[0033] The aim of the invention is therefore to propose a system for adjusting the axial length of an accessible connecting rod head, while allowing the axial position of the connecting rod head to be maintained, particularly in an environment subject to strong vibrations.

[0034] The invention relates to a connecting rod or link, particularly for the stator of a turbomachine, extending along an axis of extension, for example axial, comprising a connecting rod body and a first connecting rod head connected to the connecting rod body and comprising a cylindrical connecting rod, extending along the axis of extension and comprising, on its external surface, an external thread.

[0035] The connecting rod further includes an axial length adjustment system along the extension axis of the first connecting rod head relative to the connecting rod body.

[0036] The adjustment system includes a sleeve mounted for rotation in the connecting rod body and blocked in translation relative to said connecting rod body by an axial retaining member.

[0037] Said sleeve comprises an internal thread cooperating with the external thread of the first connecting rod head and a transmission element. Thus, the sleeve has a pivot joint, i.e., is movable in rotation, relative to the connecting rod body.

[0038] In other words, the axial length between the connecting rod head and the connecting rod body is adjustable by relative rotation between the connecting rod head and the sleeve.

[0039] By "length" we mean the dimension of the connecting rod along its axis of extension.

[0040] The sleeve being connected by screwing to the connecting rod of the first connecting rod head, said first connecting rod head is moved in translation relative to said sleeve.

[0041] In order to generate such a translational movement, the connecting rod of the first connecting rod head is blocked in rotation relative to the connecting rod body by simply holding it on an external mechanical part on which the connecting rod is mounted.

[0042] Thanks to the cooperation between the internal thread of the sleeve and the external thread of the first connecting rod head, the length along the extension axis of the first connecting rod head can be adjusted by relative rotation between said first connecting rod head and the sleeve.

[0043] The connecting rod thus allows to transmit or transform a movement between two moving mechanical parts.

[0044] The adjustment system further includes a drive element extending along a second axis perpendicular to the extension axis and comprising a main part and a complementary transmission element intended to cooperate with the transmission element in an adjustment position of the axial length of the first connecting rod head, in other words the engaged position.

[0045] The adjustment system further includes a locking / unlocking member configured to lock, i.e. block, the rotation of the locking / unlocking member when it is in a locked position and to unlock the rotation of the locking / unlocking member, and thus allow the rotation of the drive member.

[0046] The locking / unlocking mechanism comprises: - a lower part comprising a housing for receiving the main part of the drive element and movable exclusively in translation relative to said drive element, - an upper part comprising a housing for receiving an adjustment tool, and - a dog collar extending over at least part of the perimeter of the lower part extending along the second axis and intended to cooperate with locking pins carried by the connecting rod body, preferably by a plug integral with the connecting rod body, in the locked position of the locking / unlocking member.

[0047] In the locked position of the locking / unlocking member, rotation around the second axis of the locking / unlocking member is blocked by the cooperation between the locking pins and the dog collar.

[0048] Advantageously, the drive member further comprises a vertical projection of radial dimension less than the radial dimension of the main part and extending from the main part along the second axis on the side opposite the complementary transmission member and in which the upper part of the locking / unlocking member is connected to the lower part by a radial plate comprising in its center a hole cooperating with the axial projection of the drive member.

[0049] The vertical projection has, for example, a cylindrical section.

[0050] Alternatively, a parallelepiped section could also be provided, for example a square for the vertical projection.

[0051] Preferably, the main part of the drive member has a non-circular cross-section, for example parallelepiped, for example square, and the housing of the first part of the locking / unlocking member has a cross-section in conformity in shape with the main part of the drive member.

[0052] Thus, the lower part and the main part of the drive member are connected by a non-pivoting sliding joint, meaning that there is no relative movement between the lower part and the main part of the drive member. The non-circular cross-section prevents relative rotation between the drive member and the locking / unlocking member.

[0053] Alternatively, any device for blocking the relative rotation between the drive member and the locking / unlocking member could be provided.

[0054] For example, the dog collar comprises a plurality of teeth or dogs extending along the second axis and spaced circumferentially by spaces configured to cooperate with the locking pins in the locked position of the locking / unlocking member (150).

[0055] Advantageously, the locking / unlocking member includes an elastic return member, such as a spring, mounted around the lower part along the second axis between the dog collar and the complementary transmission member of the drive member.

[0056] The return member allows the locking / unlocking member to return to the locked position when said locking / unlocking member is not stressed in translation by the setting tool.

[0057] For example, the connecting rod includes a guide shaft extending along the second axis on which the drive member is mounted, in particular in a bore.

[0058] For example, the connecting rod further includes a lower closing plug carrying the guide pin and an upper closing plug including a passage for the upper part of the locking / unlocking member and carrying the locking pins.

[0059] The drive member is free to rotate about the second axis relative to the guide axis 1, and therefore to the connecting rod body. The drive member 144 is connected to the connecting rod body by a pivot joint.

[0060] For example, the transmission member is a gear with a plurality of axial teeth spaced circumferentially from each other by axial gaps, and wherein the complementary transmission member is a gear with a plurality of radial teeth spaced circumferentially from each other by gaps. The radial teeth constantly interpose themselves in an axial gap between two axial teeth of the transmission member and thus transmit a rotational motion to the sleeve.

[0061] The axial retaining member is, for example, an annular circlip cooperating both with an annular groove provided on the sleeve and with an annular groove provided on the connecting rod body.

[0062] Alternatively, any mechanical device for axially retaining the sleeve relative to the connecting rod body could be provided.

[0063] The first connecting rod head may further include an end portion extending from the connecting rod on the side opposite the connecting rod body and comprising a bore extending along a transverse axis, perpendicular to the axis of extension and a first joint mounted in said bore.

[0064] The first joint can be a ball joint or a pivot.

[0065] According to one embodiment, the connecting rod comprises a second connecting rod head comprising a cylindrical connecting rod, extending along the axis of extension and comprising, on its external surface, a second external thread, an end portion extending from the connecting rod on the side opposite the connecting rod body and comprising a bore extending along a transverse axis, perpendicular to the axis of extension and a second joint mounted in said bore.

[0066] The second joint can be a ball joint or a pivot.

[0067] According to one embodiment, the second connecting rod head is fixed relative to the connecting rod body.

[0068] According to another embodiment, the second connecting rod head is movable relative to the connecting rod body and in which said connecting rod includes an axial length adjustment system along the extension axis of the second connecting rod head relative to the connecting rod body.

[0069] Advantageously, the locking / unlocking member is also configured to hold the setting tool in an engaged position, and release the setting tool in a disengaged position.

[0070] According to another aspect, the invention relates to an adjustment tool configured to adjust the axial length of the first connecting rod head of the connecting rod as described above.

[0071] The tool includes: - a main body comprising a first end cooperating with a connection interface with an external tool, such as for example a ratchet wrench or any tool allowing cooperation with the connection interface for the purpose of rotating the setting tool, - an engagement head, extending from a second end of the main body in a direction opposite to the connection interface and configured to engage in the housing of the upper part of the locking / unlocking member, - a rod that moves in translation within the main body along the second axis between an engaged and an disengaged position, and is designed to abut against the axial projection of the connecting rod drive member, and - at least two locking devices, for example balls, each housed in a corresponding recess made in the thickness of the engagement head.

[0072] Said locking members are radially movable in the corresponding housing, the rod, in particular the second part, comprising two notches each cooperating with one of the locking members in the disengaged position in which the housings of the engagement head are opposite the notches of the rod, so that said locking members are free in their housing.

[0073] The specific adjustment tool was designed to ensure that the locking of the locking / unlocking member is effective, i.e. that the rotation of said locking / unlocking member cannot cause the rotation of the drive member and thus the translation of the connecting rod head.

[0074] Preferably, in the engaged position of the locking members, the rod is moved in translation along the second axis towards the connection interface, so that the housings of the engagement head are no longer opposite the notches of the rod, the locking members being offset radially by the rod to engage in corresponding internal notches made on the internal surface of the upper part of the locking / unlocking member.

[0075] In the engaged position, the setting tool cannot be separated from the locking / unlocking member.

[0076] For example, the rod comprises a first part movable in translation in the main body and a second part fixed to the first part and movable in translation in the engagement head, and for example, the first part has a diameter greater than the diameter of the second part and comes to a vertical stop against the engagement head in a disengaged position.

[0077] Advantageously, the tool includes a return element, such as a spring, mounted in the main body along the second axis between the rod, in particular the first part, and the connection interface.

[0078] The engagement head has a cross-section in conformity of shape with the cross-section of the housing of the upper part of the locking / unlocking member, for example square, hexagonal, etc...

[0079] When the axial length adjustment tool is inserted into the receiving slot of the upper part of the locking / unlocking member, the axial projection of the drive member is in contact along the vertical axis with the free end of the first part of the rod. The locking members are free in their corresponding slots. During this first step of tool insertion, the adjustment tool is in a disengaged position, and the rotation of the locking / unlocking member is locked by the cooperation of the dog clutches of the dog collar with the locking pins.

[0080] When the operator applies pressure to the setting tool, generating translation along the second axis, the locking / unlocking member moves towards the complementary transmission member of the drive member. With the tool rod abutting the axial projection of the drive member, said rod is displaced along the second axis towards the connection interface, i.e., in a direction opposite to the direction of movement of the locking / unlocking member. The locking elements are pushed radially by the first part of the rod, which locks them into the corresponding internal notches formed on the inner surface of the upper part of the locking / unlocking member.

[0081] During this second step of initiating the translation of the tool, the setting tool is in a position engaged by the locking members and the rotation of the locking / unlocking member is always in a locked position by the cooperation of the dog clutches of the dog clutch collar with the locking pins.

[0082] The operator applies pressure to the setting tool until the locking / unlocking member comes to a stop on the drive member, generating again the translation along the second axis of the locking / unlocking member towards the complementary transmission member of the drive member.

[0083] With the tool rod abutting the axial projection of the drive member, said rod continues to move in translation along the second axis towards the connection interface, i.e. in a direction opposite to the direction of movement of the locking / unlocking member.

[0084] The locking members are held radially by the first part of the rod in the corresponding internal notches made on the internal surface of the upper part of the locking / unlocking member.

[0085] During this last step of the end of the translation of the tool, the setting tool is in a position engaged by the locking members and the locking pins are offset vertically from the dogs of the dog collar, so that the rotation of the locking / unlocking member is in an unlocked position.

[0086] The drive member, engaged with the transmission member, specifically the axial teeth of the sleeve, is rotated by the tool via the locking / unlocking member, which in turn rotates the sleeve. Through the interaction between the internal thread of the sleeve and the external thread of the first connecting rod head, the length along the extension axis of the first connecting rod head can be adjusted by relative rotation between said first connecting rod head and the sleeve.

[0087] When the operator no longer applies pressure to the tool in order to disengage it from the connecting rod, the return spring applies force to the locking / unlocking member, which moves translationally along the second axis towards the tool. The rod is then moved translationally until the notches on the second part of the rod align with the slots in the engagement head. The locking elements are thus released from the notch of the locking / unlocking member, allowing the tool to be separated from the connecting rod.

[0088] According to another aspect, the invention relates to a turbomachine comprising a connecting rod as described above. Brief description of the drawings

[0089] 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 indexed drawings in which:

[0090] [Fig.l], is a partial schematic view of a connecting rod in a locked position of the relative rotation between the body and the head of the connecting rod, according to the prior art;

[0091] [Fig.1A], is a detail view of [Fig.1], illustrating a rotating locking cable of the brake nut;

[0092] [Fig.2], is a schematic perspective view of a connecting rod according to one embodiment of the invention;

[0093] [Fig.3], is a partial cross-sectional view of the connecting rod of [Fig.2], in a engaged position of a drive element in translation of the connecting rod head relative to the connecting rod body;

[0094] [Fig.4], [Fig.5] and [Fig.6] illustrate the successive steps of positioning a tool for adjusting the axial position of the connecting rod head relative to the connecting rod body;

[0095] [Fig.7], illustrates the connecting rod of [Fig. 3] in an engaged position of the drive member in translation of the connecting rod head relative to the connecting rod body and in an unlocked position of the drive member rotation by the setting tool; and

[0096] [Fig. 8] illustrates an engaged position of the adjusting tool in the connecting rod of [Fig.2].

[0097] Detailed description of at least one embodiment

[0098] In the following description, we consider an orthonormal basis X, Y, Z, with X corresponding to an axis of extension or elongation in which we find:

[0099] - a longitudinal axis X, horizontal;

[0100] - a horizontal transverse axis Y, perpendicular to the longitudinal axis X; and

[0101] - a vertical axis Z, orthogonal to the longitudinal axis X and the transverse axis Y and extending from bottom to top in figures 1 to 8.

[0102] In the following description, the terms "axial" and "radial" are defined with respect to the extension axis Xl-Xl' of a connecting rod or link 100.

[0103] By "connecting rod" or "connecting rod" we mean any device for transmitting movement between two moving mechanical parts.

[0104] In general, the invention relates to any connecting rod configured to be adjustable in length and to be mounted in all kinematic systems of a turbomachine, in particular a turbomachine stator.

[0105] As illustrated, the connecting rod 100 comprises a connecting rod body 110 and, here, a first connecting rod head 130 and a second connecting rod head 120, each connected to the connecting rod body 110.

[0106] The connecting rod body 110 comprises a body 111 extending axially along the extension axis Xl-Xl' and provided with a first end 112 integral with the second connecting rod head 120 and a second end 113 connected to the first connecting rod head 130.

[0107] The first end 112 of the connecting rod body 111 is open and includes on its internal surface, a second internal tapping or thread (not visible in the figures) opening onto the first open end 112.

[0108] The second internal thread of the connecting rod body 111 engages by screwing with an external thread 121 provided on the second connecting rod head 120. A rotational and translational locking element (not visible) is disposed between the second internal thread of the connecting rod body 110 and the external thread 121 provided on the second connecting rod head 120. For example, the locking element is threaded locking compound. Alternatively, the second connecting rod head 120 could be fitted into the first open end 112 of the connecting rod body 110. Generally, the second connecting rod head 120 is fixed to the connecting rod body 110, that is, it has no relative movement with respect to said connecting rod body 110.

[0109] The second end 113 of the connecting rod body 110 is open and includes on its internal surface, a bore 114 opening onto the second open end 113.

[0110] As illustrated, the second connecting rod head 120 includes a cylindrical connecting rod 122, extending along the extension axis Xl-Xl' and comprising, on its external surface, the second external thread 121.

[0111] The second connecting rod head 120 further includes an end portion 123 extending from the connecting rod 122 on the opposite side of the connecting rod body 110 and including a bore 124 extending along the transverse axis Y, perpendicular to the extension axis Xl-Xl'.

[0112] The second connecting rod head 120 further includes a second joint 125 mounted in said bore 124.

[0113] The second joint 125 can be a ball joint or a pivot.

[0114] As illustrated, the first connecting rod head 130 includes a cylindrical connecting rod 131, extending along the extension axis Xl-Xl' and comprising, on its external surface, an external thread 132.

[0115] The first connecting rod head 130 further includes an end portion 133 extending from the connecting rod 131 on the opposite side of the connecting rod body 110 and including a bore 134 extending along the transverse axis Y, perpendicular to the extension axis Xl-Xl'.

[0116] The first connecting rod head 130 further includes a first joint 135 mounted in said bore 134.

[0117] The first joint 135 can be a ball joint or a pivot.

[0118] The connecting rod 100 thus allows to transmit or transform a movement between two moving mechanical parts.

[0119] The connecting rod 100 further includes a system 140 for adjusting the axial length of the first connecting rod head 130 relative to the connecting rod body 110.

[0120] As illustrated, the length adjustment system 140 allows the axial length of the first connecting rod head 130 to be adjusted only.

[0121] The system 140 for adjusting the length of the first connecting rod head 130 relative to the connecting rod body 110 comprises a sleeve 141 including a cylindrical part 141a mounted in the bore 114 of the connecting rod body 110 and including on its inner surface, a tapping 141b cooperating with the external thread 132 of the connecting rod 131 of the first connecting rod head 130.

[0122] The cylindrical portion 141a includes at a first end 141c, an annular groove 14Id cooperating with an axial retaining element 142 of the sleeve 141 relative to the connecting rod body 110. The axial retaining element 142 is, for example, an annular circlip cooperating both with the annular groove 141d provided on the sleeve 141 and with an annular groove (not visible) provided on the connecting rod body 110. Alternatively, any mechanical axial retaining element of the sleeve 141 relative to the connecting rod body 110 could be provided.

[0123] Thus, the sleeve 141 has a pivot joint, i.e., mobile in rotation, relative to the connecting rod body 110.

[0124] The sheath 141 further includes, at a second end, opposite the first end 141c, a transmission member 143, here a toothed wheel provided with a plurality of axial teeth 143a spaced circumferentially from each other by axial spaces 143b.

[0125] The length adjustment system 140 further includes a drive member 144 comprising a main part 145 extending along an axis, here vertical Z, perpendicular to the axial axis of translation of the connecting rod 100 and comprising at a first end a vertical projection 145a of radial dimension less than the radial dimension of the main part 145.

[0126] The main part 145 has a parallelepiped cross-section, for example square. The vertical projection 145a has a cylindrical cross-section. Alternatively, a parallelepiped cross-section, for example square, could also be provided for the vertical projection 145a.

[0127] The drive member 144 further includes at a second end of the main part 145, a complementary transmission member 147 intended to cooperate with the transmission member 143 in an axial length adjustment position of the first connecting rod head 130, visible in figures 6 and 7, in other words the engaged position.

[0128] The complementary transmission member 147 is here a toothed wheel provided with a plurality of radial teeth 147a spaced circumferentially from each other by spaces 147b.

[0129] In the engaged position or axial length adjustment position, the radial teeth 147a come to be interposed in an axial space 143b between two axial teeth 143a of the transmission member 143 and thus transmit a rotational movement to the sleeve 141.

[0130] The sleeve 141 being connected by screwing to the connecting rod 131 of the first connecting rod head 130, said first connecting rod head 130 is moved in translation relative to said sleeve 141.

[0131] In order to generate such a translational movement, the connecting rod 131 of the first connecting rod head 130 is blocked in rotation relative to the connecting rod body 110 by a rotation blocking device (not shown), for example a key, axial notches, or even by simple retention on an external mechanical part.

[0132] The drive member 144 includes in addition a bore 144a cooperating with a guide shaft 148 extending along the vertical axis Z.

[0133] The drive member 144 is free to rotate about the vertical axis Z relative to the guide axis 148 and therefore to the connecting rod body. The drive member 144 is connected to the connecting rod body 110 by a pivot joint.

[0134] The length adjustment system 140 further includes a locking / unlocking member 150 configured to lock, i.e. block, the rotation of the locking / unlocking member 150 and to unlock the rotation of the locking / unlocking member 150, and thus allow the rotation of the drive member.

[0135] The locking / unlocking member 150 is also configured to hold a setting tool 200 in an engaged position, visible in Figures 6 and 7 and release the setting tool 200 in a disengaged position, visible in [Fig.4].

[0136] The locking / unlocking member 150 comprises a lower part 151 and an upper part 152 connected to each other by a radial plate 153.

[0137] The lower part 151 includes a housing 15la for receiving the main part 145 of the drive element 144.

[0138] Said housing 151a has a parallelepiped cross-section, for example square, in conformity of form with the main part 145 of the drive member 144. Thus, the lower part 151 and the main part 145 of the drive member 144 are connected by a sliding, non-pivoting link, that is to say there is no relative between the lower part 151 and the main part 145 of the drive member 144.

[0139] The upper part 152 includes a housing 152a for receiving the setting tool 200.

[0140] Said dwelling 152a has a parallelepiped section, for example square, in conformity of shape

[0141] The radial plate 153 includes in its center, a hole 153a cooperating with the axial projection 145a of the drive member 144.

[0142] The locking / unlocking member 150 further includes a dog collar 154 extending over a part of the perimeter of the lower part 151.

[0143] The dog collar 154 comprises a plurality of teeth or dogs 154a extending along the vertical axis Z and spaced apart by gaps 154b, as seen in detail in [Fig.8].

[0144] A return member 155, such as a spring, is mounted around the lower part 151 vertically between the dog collar 154 and the complementary transmission member 147 of the drive member 144. The return member 155 allows the locking / unlocking member 150 to return to the locked position when said locking / unlocking member 150 is not stressed in translation by the setting tool 200.

[0145] The connecting rod 100 further includes a lower closing plug 160 carrying the guide pin 148 and an upper closing plug 161 including a passage 162 for the upper part 152 of the locking / unlocking member 150 and carrying locking pins 163 extending along the vertical axis Z and configured to cooperate with the spaces 154b of the dog collar 154 in the locked position of the locking / unlocking member 150.

[0146] In the locked position of the locking / unlocking member 150, the rotation around the vertical axis Z of the locking / unlocking member 150 is blocked by the cooperation between the locking pins 163 and the dog collar 154.

[0147] In order to ensure that the locking of the locking / unlocking member 150 is effective, i.e. that the rotation of said locking / unlocking member 150 cannot cause the rotation of the drive member 140 and thus the translation of the connecting rod head 130, a specific adjustment tool 200 has been designed.

[0148] The setting tool 200 includes a main body 201 comprising a first end 201a cooperating with an interface 202 for connection with an external tool (not shown), such as for example a ratchet wrench or any tool enabling cooperation with the connection interface 202 for the purpose of rotating the setting tool 200.

[0149] The adjustment tool 200 further includes an engagement head 203, extending from a second end 201b of the main body 201 in a direction opposite to the connection interface 202.

[0150] The engagement head 203 is configured to engage in the housing 152a of the upper part 152 of the locking / unlocking member 150.

[0151] The engagement head 203 has a cross-section in conformity of shape with the cross-section of said housing 152a, for example square, hexagonal, etc...

[0152] The adjustment tool 200 further includes a rod 204 comprising a first part 204a movable in translation in the main body 201 and a second part 204b movable in translation in the engagement head 203.

[0153] The first part 204a has a diameter greater than the diameter of the second part 204b and comes to a vertical stop against the engagement head 203 in a disengaged position, visible on the [Fig.4].

[0154] The adjustment tool 200 further comprises two locking elements 205, here balls, each housed in a corresponding recess 203a formed in the thickness of the engagement head 203. Said locking elements 205 are radially movable within the corresponding recess 203a.

[0155] The second part 204b of the rod 204 includes two notches 204c each cooperating with a locking member 205 in the disengaged position.

[0156] A return member 206, such as a spring, is mounted in the main body 201 between the first part 204a of the rod 204 and the connection interface 202.

[0157] In the disengaged position of the locking members 205, i.e. the rest position, visible on the [Fig.4], the rod 204 is in stop, the housings 203a of the engagement head 203 are opposite the notches 204c of the second part 204b of the rod 204, so that said locking members 205 are free in their housing 203a.

[0158] In the engaged position of the locking members 205, visible in figures 5 to 8, the rod 204 is axially offset upwards, so that the housings 203a of the engagement head 203 are no longer opposite the notches 204c of the second part 204b of the rod 204, the locking members 205 being radially offset by the rod 204 to engage in corresponding internal notches 152b made on the internal surface 152a of the upper part 152 of the locking / unlocking member 150.

[0159] In the engaged position, the setting tool 200 cannot be separated from the locking / unlocking member 150.

[0160] When the axial length adjustment tool 200 is inserted into the receiving slot 152a of the upper part 152 of the locking / unlocking member 150, the axial projection 145a of the drive member 144 is in contact along the vertical axis with the free end of the first part 204a of the rod 204, as shown in [Fig. 4]. The locking members 205 are free in their corresponding slots 203a. During this first step of the tool 200's engagement, the adjustment tool 200 is in a disengaged position, and the locking / unlocking member 150 is locked by the interaction of the dog clutches of the dog collar 154 with the locking pins 163.

[0161] When the operator applies pressure to the setting tool 200, generating translation along the vertical axis Z, the locking / unlocking member 150 moves towards the complementary transmission member 147 of the drive member 144.

[0162] With the rod 204 of the tool 200 bearing against the axial projection 145a of the drive member 144, said rod 204 is moved in translation along the vertical axis Z towards the connection interface 202, i.e. in a direction opposite to the direction of movement of the locking / unlocking member 150. The locking members 205 are pushed radially by the first part 204a of the rod 204, which locks them in the corresponding internal notches 152b formed on the internal surface 152a of the upper part 152 of the locking / unlocking member 150, as seen in [Fig. 5].

[0163] During this second step of initiating the translation of the tool 200, the setting tool 200 is in a position engaged by the locking members 205 and the rotation of the locking / unlocking member 150 is still in a locked position by the cooperation of the dog clutches of the dog collar 154 with the locking pins 163.

[0164] The operator applies pressure to the setting tool 200 until the locking / unlocking member 150 comes to a stop on the drive member 144, as seen in Figures 6 and 7, again generating translation along the vertical axis Z of the locking / unlocking member 150 towards the complementary transmission member 147 of the drive member 144.

[0165] The rod 204 of the tool 200 being in contact with the axial projection 145a of the drive member 144, said rod 204 continues to move in translation along the vertical axis Z towards the connection interface 202, that is to say in a direction opposite to the direction of movement of the locking / unlocking member 150.

[0166] The locking members 205 are held radially by the first part 204a of the rod 204 in the corresponding internal notches 152b made on the internal surface 152a of the upper part 152 of the locking / unlocking member 150.

[0167] During this last step of the translation of the tool 200, the setting tool 200 is in a position engaged by the locking members 205 and the locking pins 163 are vertically offset from the dogs of the dog collar 154, so that the rotation of the locking / unlocking member 150 is in an unlocked position.

[0168] The drive member 144, engaged with the axial teeth 143a of the sleeve 141, is driven in rotation by the tool 200 via the locking / unlocking member 50, which in turn drives the said sleeve 141 in rotation. Thanks to the cooperation between the internal thread 141b of the sleeve 141 and the external thread 132 of the first connecting rod head 130, the length along the extension axis Xl-Xl' of the first connecting rod head 130 can be adjusted by relative rotation between said first connecting rod head 130 and the sleeve 141.

[0169] When the operator no longer applies pressure to the tool 200 in order to disengage it from the connecting rod 100, the return spring 155 applies a force to the locking / unlocking member 150, which moves translationally along the vertical axis Z towards the tool 200. The rod 204 is then moved translationally until the notches 204c of the second part 204a of the rod 204 are aligned with the recesses 203a of the engagement head 203. The locking members 205 are thus released from the notch 152b of the locking / unlocking member 150, thereby separating the tool 200 from the connecting rod 100.

[0170] In the event that during this removal operation the locking pins 163 are not correctly engaged with the dog teeth of the dog collar 154, as seen in [Fig.8], the locking members 205 remain in the engaged position, so that the tool 200 cannot be separated from the locking / unlocking member 150.

[0171] The advantages of the present invention include the offset position of the connecting rod length adjustment system and thus the ease of length adjustment of connecting rods that are difficult to access.

[0172] Finally, the present invention makes it possible to ensure a locked position of the rotation of the locking / unlocking member 150.

Claims

1. Demands Connecting rod (100), in particular for the stator of a turbomachine, extending along an extension axis (Xl-Xl'), comprising a connecting rod body (110) and a first connecting rod head (130) connected to the connecting rod body (110) and comprising a cylindrical connecting rod (131), extending along the extension axis (XI-XI') and comprising, on its external surface, an external thread (132), the connecting rod (100) further comprising an axial length adjustment system (140) along the extension axis (XI-XI') of the first connecting rod head (130) relative to the connecting rod body (110), characterized in that the adjustment system (140) comprises: - a sleeve (141) rotatably mounted in the connecting rod body (110) and blocked in translation relative to said connecting rod body (110) by an axial retaining member (142), said sleeve (141) comprising an internal thread (141b) cooperating with the external thread (132) of the first connecting rod head (130) and a transmission member (143), - a drive member (144) extending along a second axis (Z) perpendicular to the extension axis (XI-XI') and comprising a main part (145) and a complementary transmission member (147) intended to cooperate with the transmission member (143) in an engaged position, and - a locking / unlocking member (150) configured to lock the rotation of the locking / unlocking member (150) when it is in a locked position, the locking / unlocking member (150) comprising: - a lower part (151) comprising a housing (151a) for receiving the main part (145) of the drive member (144) and movable exclusively in translation relative to said drive member (144), - an upper part (152) comprising a housing (152a) for receiving a setting tool (200), and - a dog collar (154) extending over at least part of the perimeter of the lower part (151) extending along the second axis (Z) and intended to cooperate with locking pins (163) carried by the connecting rod body (110) in the locked position of the locking / unlocking member (150).

2. Connecting rod (100) according to claim 1, wherein the drive member (144) further comprises a vertical projection (145a) of radial dimension less than the radial dimension of the main part (145) and extending from the main part (145) along the second axis (Z) on the side opposite the complementary transmission member (147) and wherein the upper part (152) of the locking / unlocking member (150) is connected to the lower part (151) by a radial plate (153) comprising in its center a hole (153a) cooperating with the axial projection (145a) of the drive member (144).

3. Connecting rod (100) according to claim 1 or 2, wherein the main part (145) of the drive member (144) has a non-circular cross-section, and wherein the housing (151a) of the first part (151) of the locking / unlocking member (150) has a cross-section in conformity of form with the main part (145) of the drive member (144).

4. Connecting rod (100) according to any one of the preceding claims, wherein the dog collar (154) comprises a plurality of dog claws (154a) extending along the second axis (Z) and circumferentially spaced by gaps (154b) configured to cooperate with the locking pins (163) in the locked position of the locking / unlocking member (150).

5. Connecting rod (100) according to any one of the preceding claims, wherein the locking / unlocking member (150) comprises a return member (155) mounted around the lower part (151) along the second axis (Z) between the dog collar (154) and the complementary transmission member (147) of the drive member (144).

6. Connecting rod (100) according to any one of the preceding claims, comprising a guide shaft (148) extending along the second axis (Z) on which the drive member (144) is mounted.

7. Connecting rod (100) according to claim 6, further comprising a lower closing plug (160) carrying the guide pin (148) and an upper closing plug (161) comprising a passage (162) for the upper part (152) of the locking / unlocking member (150) and carrying the locking pins (163).

8. Connecting rod (100) according to any one of the preceding claims, wherein the locking / unlocking member (150) is also configured to hold the setting tool (200) in an engaged position, and release the setting tool (200) in a disengaged position.

9. Adjustment tool (200) configured to adjust the axial length of the first connecting rod head (130) of the connecting rod (100) according to claim 8, the tool (200) comprising: - a main body (201) including a first end (201a) cooperating with an interface (202) for connection with an external tool, - an engagement head (203) extending from a second end (201b) of the main body (201) in a direction opposite to the connection interface (202) and configured to engage in the housing (152a) of the upper part (152) of the locking / unlocking member (150), - a rod (204) movable in translation within the main body (201) about the second axis (Z) between an engaged position and a disengaged position, and intended to abut against the axial projection (145a) of the drive member (144) of the connecting rod (100) according to claim 2,and - at least two locking members (205) each housed in a corresponding recess (203a) formed in the thickness of the engagement head (203), said locking members (205) being radially movable within the corresponding recess (203a), the rod (204) comprising two notches (204c) each cooperating with one of the locking members (205) in the disengaged position in which the recesses (203a) of the engagement head (203) are opposite the notches (204c) of the rod (204).

10. Adjustment tool (200) according to claim 9, wherein in the engaged position of the locking members (205), the rod (204) is moved in translation along the second axis (Z) towards the connection interface (202), so that the housings (203a) of the engagement head (203) are no longer opposite the notches (204c) of the rod (204), the locking members (205) being offset radially by the rod (204) to engage in corresponding internal notches (152b) made on the internal surface (152a) of the upper part (152) of the locking / unlocking member (150).

11. Adjustment tool (200) according to claim 9 or 10, comprising an elastic return member (206) mounted in the main body (201) along the second axis (Z) between the rod (204), in particular the first part, and the connection interface (202).

12. Turbomachine comprising a connecting rod (100) according to any one of claims 1 to 8.

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