In particular, length-adjustable connecting rod for a turbine rotor comprising a system for locking the length adjustment

Abstract

The connecting rod (10), in particular of a turbine rotor, extends along an axial extension axis (X-X') and comprises a connecting rod body (11) including a threaded portion and a connecting rod head (12) rotatably integral with the connecting rod body (11) and including a connecting shank (13) including an external thread (13a) cooperating with the threaded portion of the connecting rod body (11), the connecting rod (10) further comprising a system (20) for locking the relative rotation between the connecting rod head (12) and the connecting rod body (11). The locking system (20) further comprises a self-locking nut (23) mounted by screwing on the connecting shank (13) of the connecting rod head (12) and configured to block the relative rotation between the connecting rod body (11) and the connecting rod head (12), the self-locking nut (23) comprising a deformable portion configured to be plastically deformed in a radial direction between an initial configuration, in which the deformable portion has a circular cross-section, and a deformed configuration, in which the deformable portion has a non-circular cross-section and tightens the external thread (13a) of the connecting shank (13).

Description

Technical Field

[0001] This invention relates to the field of turbine engines including components for transmitting motion between two movable mechanical parts.

[0002] More specifically, the present invention relates to connecting rods or linking rods of components mounted to turbine rotors, particularly connecting rods to so-called “variable bleed valves” (VBVs) in the turbine’s bleed path duct (which regulate the flow rate at the turbine’s compressor inlet) or connecting rods to stator blades known as “variable stator vanes” (VSVs).

[0003] The present invention also relates to a so-called pitch control connector that can transmit the motion of a rotating swashplate to the turbine blade sleeve.

[0004] Generally, the linkage according to the invention is installed in all the kinematic systems of the turbine, in which the pushrod (ram) must transmit motion to the mechanical components. Background Technology

[0005] The links used in kinematic systems are typically adjustable in length by relative rotation between the body and the head. The link length adjustment should be additionally locked to prevent any improper adjustment of the link's height during operation.

[0006] As is well known, a nut that is rotatably locked by a cable is used to prevent relative rotation between the body and head of the linkage, thereby preventing improper adjustment of the linkage height.

[0007] However, such a system of relative rotation between the body and head of the locking linkage is difficult to achieve because the cable is very short, making it difficult to control the cable tension.

[0008] Furthermore, there are no foolproof measures to prevent the cable from being reversed, thus locking instead of loosening.

[0009] Finally, this locking system becomes unsatisfactory when subjected to centrifugal force generated by the rotation of the turbine rotor.

[0010] There is a need to improve the system for the relative rotation of the body and head of the locking link or connecting rod. Summary of the Invention

[0011] Therefore, the purpose of this invention is to overcome the above-mentioned disadvantages.

[0012] Therefore, the object of the present invention is to provide a system for locking the relative rotation of the body and head of a locking link, which can effectively lock the rotation in environments subjected to centrifugal force and strong vibration.

[0013] The object of the present invention is a connecting rod or link, particularly a connecting rod or link for a turbine rotor, which extends along an axially extending axis and includes a connecting rod body and a connecting rod head. The connecting rod body includes an internal tap or internal thread, and the connecting rod head is rotatably integral with the connecting rod body and includes a connecting shank, which includes an external thread that engages with the tap of the connecting rod body.

[0014] In other words, the axial length between the connecting rod head and the connecting rod body can be adjusted by the relative rotation between the connecting rod head and the connecting rod body.

[0015] "Length" refers to the dimension of the connecting rod along its extension axis.

[0016] The linkage also includes a locking system for relative rotation between the linkage head and the linkage body.

[0017] The locking system includes a first serrated washer that is radially mounted about the connecting shank of the connecting rod head and includes an axial protrusion or anti-rotation pin and a plurality of axial serrations. The axial protrusion or anti-rotation pin is designed to engage with a corresponding notch on the connecting rod body in a locked position in response to relative rotation of the connecting rod body relative to the connecting rod head. The plurality of axial serrations extend in the opposite direction to the anti-rotation axial protrusion.

[0018] When the axial lug of the first serrated washer is inserted into the axial recess of the connecting rod body, the first serrated washer is prevented from rotating relative to the connecting handle.

[0019] The locking system also includes a second serrated washer that is radially mounted about the connecting shank of the connecting rod head and includes a plurality of axial serrations that extend toward the first serrated washer and are designed to engage with the serrations of the first serrated washer in the locked position.

[0020] The locking system also includes a self-locking nut that is screwed onto the connecting shank of the connecting rod head and is configured to abut against each other to engage the corresponding teeth, and to tighten the axial lug into a corresponding recess on the connecting rod body. The self-locking nut is also configured to prevent relative rotation between the connecting rod body and the connecting rod head in the locked position.

[0021] The self-locking nut includes a deformable portion configured to be able to plastically deform radially between an initial configuration and a deformable configuration under the action of an external load (e.g., radial tightening of the outer surface) on its outer surface. In the initial configuration, the deformable portion has a circular cross-section, and in the deformable configuration, the deformable portion has a non-circular cross-section and tightens the external thread of the connecting shank (i.e., contacts and tightens against the external thread of the connecting shank).

[0022] This creates braking, preventing any relative rotation of the link body relative to the link head.

[0023] "Capable of plastic deformation" means that any element, by virtue of its shape or its material, is configured to undergo plastic deformation under the action of an external load, and does not return to its initial shape when the load is removed.

[0024] In other words, after deformation, the deformable part retains its deformed shape.

[0025] In the modified configuration, the self-locking nut can no longer be unscrewed relative to the connecting handle, and the serrated washer is held in the locked position.

[0026] This self-locking nut provides satisfactory locking performance for the relative rotation of the connecting rod body relative to the connecting rod head in environments subjected to centrifugal force and vibration.

[0027] Typically, the length of the link is adjustable, and the locking system allows the length adjustment to be locked by locking the relative rotation between the link body and the link head.

[0028] The self-locking nut is configured to allow itself to prevent any relative rotation of the connecting rod body relative to the connecting rod head.

[0029] Advantageously, in the deformable configuration, the deformable portion of the self-locking nut has an oval cross-section defined by a major axis and a minor axis, the minor axis being at least 20% smaller than the major axis.

[0030] For example, the total axial length of a self-locking nut is between 10 mm and 25 mm.

[0031] Preferably, the axial length of the deformable portion of the self-locking nut is between 30% and 50% of the total axial length of the self-locking nut.

[0032] Advantageously, the self-locking nut includes a hollow stepped body that extends axially along a longitudinal axis and sequentially includes a support portion, a clamping portion connected to the support portion via a first shoulder, and a deformable portion connected to the clamping portion via a second shoulder. The support portion is configured to axially abut against a second serrated washer in the locked position in response to relative rotation of the connecting rod body relative to the connecting rod head.

[0033] "Shoulder" refers to any surface created by a sudden change in diameter that is substantially orthogonal to the height axis of the cylindrical component (in this case, the extended axis of the nut).

[0034] For example, the hollow stepped body of the self-locking nut is defined radially by a stepped outer surface and a stepped inner surface, and axially by a proximal end and a distal end opposite to the proximal end. The stepped outer surface includes a first surface forming the outer surface of the support portion, a second surface forming the outer surface of the clamping portion, and a third surface forming the outer surface of the deformable portion.

[0035] For example, the outer diameter of the first surface of the stepped outer surface of the self-locking nut is larger than the outer diameter of the second surface, and the outer diameter of the second surface is larger than the diameter of the third surface.

[0036] Preferably, the stepped inner surface of the self-locking nut includes an internal tap or internal thread designed to mate with the external thread of the connecting rod head, and an unthreaded inner surface, the diameter of which is larger than the diameter of the internal thread.

[0037] For example, the internal thread of the stepped inner surface of the self-locking nut extends at least along the deformable portion and the clamping portion, and has an axial length between 70% and 80% of the total axial length of the self-locking nut.

[0038] Advantageously, the axial length of the support portion of the self-locking nut is between 2.5 mm and 4.5 mm.

[0039] For example, the axial length of the clamping portion of a self-locking nut is between 2 mm and 10 mm.

[0040] For example, the second surface of the clamping portion of the self-locking nut includes splines designed to mate with tools such as wrenches for screwing the nut onto the connecting shank.

[0041] For example, the inner diameter of the hole on the surface of the first sawtooth is larger than the outer diameter of the connecting shank of the connecting rod head.

[0042] For example, the second serrated washer is defined radially by a hole and an outer surface.

[0043] Preferably, the inner diameter of the hole on the second sawtooth surface is larger than the outer diameter of the connecting shank of the connecting rod head.

[0044] For example, the connecting rod head also includes an end extending from the connecting shank on the side opposite the connecting rod body, the end including a hole extending along a transverse axis perpendicular to the extension axis and including a connector mounted in the hole.

[0045] For example, the joint can be a ball joint or a pivot.

[0046] Therefore, linkages enable the transmission or conversion of motion between two movable mechanical parts.

[0047] Alternatively, it can be envisioned that the link body includes a second link head with a second joint at its first end.

[0048] For example, the connecting rod body includes a body extending axially along an extension axis, the body having a first end integral with the mechanical part of the turbine and a second end integral with the connecting rod head.

[0049] For example, the second end of the connecting rod body is open.

[0050] For example, the connecting rod body includes an internal tap or internal thread on its inner surface leading to an open second end. Attached Figure Description

[0051] Other objects, features, and advantages of the invention will become apparent from the accompanying drawings and from the following description, which is provided by way of non-limiting example only, in which the following drawings are included: [ Figure 1 ] This is a partial schematic diagram of a link in the unlocked position, considering the relative rotation between the link body and the link head according to an embodiment of the present invention. [ Figure 2 ] This refers to the locked position due to the relative rotation between the connecting rod body and the connecting rod head. Figure 2 A schematic diagram of the connecting rod; [ Figure 3 ] yes Figure 2 A schematic partial axial sectional view of a self-locking nut; and [ Figure 4 ]、[ Figure 5 ] This is a top view of a locking system in the unlocked and locked positions, respectively, based on the relative rotation between the link body and the link head. Detailed Implementation

[0052] In the remainder of the instruction manual, consider the orthonormal basis X, Y, Z, where X corresponds to the extension or elongation axis, and therein: - The longitudinal axis X, which is horizontal; - A horizontal axis Y, which is horizontal and perpendicular to the vertical axis X; and - Vertical axis Z, which is perpendicular to the longitudinal axis X and the transverse axis Y, and Figure 1 and Figure 2 The middle section points from the bottom to the top.

[0053] In the remainder of the specification, the terms “axial” and “radial” are defined relative to the extended axis X-X’ of the connecting rod or link 10.

[0054] A "link" or "connecting rod" refers to any component used to transmit motion between two movable mechanical parts.

[0055] In general, the present invention relates to any connecting rod configured with adjustable length and installed in all kinematic systems of turbines, especially turbine rotors.

[0056] As shown in the figure, the connecting rod 10 includes a connecting rod body 11 and a connecting rod head 12 that is rotatably integrated with the connecting rod body 11.

[0057] The connecting rod body 11 includes a body 11a extending along the extension axis X-X', the body 11a having a first end 11b integral with the mechanical part of the turbine and a second end 11c integral with the connecting rod head 12.

[0058] The second end 11c of the connecting rod body 11 is open.

[0059] The connecting rod body 11 includes an internal tap or internal thread (not visible in the figure) on its inner surface leading to the open second end 11c.

[0060] The internal thread of the connecting rod body 11 is engaged with the external thread 13a provided on the connecting rod head 12.

[0061] As shown in the figure, the connecting rod head 12 includes a cylindrical connecting shank 13 that extends along the extension axis X-X' and includes external threads 13a on its outer surface.

[0062] The connecting rod head 12 also includes an end portion 14 extending from the connecting handle 13 on the side opposite to the connecting rod body 11, the end portion 14 including a hole 14a extending along a transverse axis Y perpendicular to the extension axis X-X'.

[0063] The connecting rod head 12 also includes a connector 15 installed in the hole 14a.

[0064] Connector 15 can be a ball joint or a pivot.

[0065] Therefore, the link 10 enables the transmission or conversion of motion between two movable mechanical parts.

[0066] Alternatively, it is conceivable that the link body 11 includes a second link head with a second joint at its first end.

[0067] Due to the fit between the internal thread of the connecting rod body 11 and the external thread 13a of the connecting rod head 12, the length along the extension axis X-X' of the connecting rod 10 can be adjusted by the relative rotation between the connecting rod head 12 and the connecting rod body 11.

[0068] The link 10 also includes a locking system 20 for relative rotation between the link head 12 and the link body 11.

[0069] The locking system 20 includes a first serrated washer 21 that is radially mounted with respect to the connecting shank 13 of the connecting rod head 10.

[0070] The first serrated washer 21 is defined radially by a hole (not visible in the figure) and an outer surface 21b, and axially by a first side surface 21c and a second side surface 21e. The first side surface 21c is provided with an axial lug 21d extending axially toward the connecting rod body 11 along the extension axis X-X'. The second side surface 21e includes a plurality of axial serrations evenly distributed on the surface of the second side surface 21e.

[0071] The axial lug 21d of the first serrated washer 21 is designed to mate with an axial recess 11e made on the connecting rod body 11, which leads to an open second end 11c.

[0072] When the axial lug 21d of the first serrated washer 21 is inserted into the axial recess 11e of the connecting rod body 11, the first serrated washer 21 is prevented from rotating relative to the connecting handle 13.

[0073] The inner diameter of the hole on the first sawtooth surface 21 is larger than the outer diameter of the connecting handle 13 of the connecting rod head 12.

[0074] The locking system 20 includes a second serrated washer 22 radially mounted with respect to the connecting shank 13 of the connecting rod head 10. A first serrated washer 21 is axially mounted between the connecting rod body 11 and the second serrated washer 22.

[0075] The second serrated washer 22 is defined radially by a hole (not visible in the figure) and an outer surface 22b, and axially by a first side surface 22c and a second side surface 22d. The first side surface 22c includes a plurality of axial serrations regularly distributed on the surface of the first side surface 22c and engaging with the serrations of the second side surface 21e of the first serrated washer 21. The second side surface 22d is substantially planar.

[0076] The inner diameter of the hole on the second sawtooth surface 22 is larger than the outer diameter of the connecting handle 13 of the connecting rod head 12.

[0077] The locking system 20 also includes a self-locking nut 23, which is screwed onto the connecting handle 13 of the connecting rod head 12 and configured to abut against each other and tighten the serrated washers 21 and 22 so that the corresponding serrations engage, and to tighten the axial pin 21d into the corresponding recess 11e provided on the connecting rod body 11, thereby preventing relative rotation between the connecting rod body 11 and the connecting rod head 12.

[0078] The self-locking nut 23 includes a hollow stepped body 24, which extends along the longitudinal axis X and sequentially includes a support portion 25, a clamping portion 26 connected to the support portion via a first shoulder 27, and a deformable portion 28 connected to the clamping portion 26 via a second shoulder 29.

[0079] "Shoulder" refers to any surface created by a sudden change in diameter that is substantially orthogonal to the height axis of the cylindrical component (in this case, the extended axis of nut 23).

[0080] The hollow stepped body 24 of the nut 23 is defined radially by a stepped outer surface 30 and a stepped inner surface 31, and axially by a proximal end 32 and a distal end 33 opposite to the proximal end 32.

[0081] The stepped outer surface 30 here includes three surfaces 30a, 30b, and 30c that are connected to each other through shoulders 27 and 29.

[0082] The first surface 30a forms the outer surface of the support portion 25, the second surface 30b forms the outer surface of the clamping portion 26, and the third surface 30c forms the outer surface of the deformable portion 28.

[0083] The outer diameter of the first surface 30a is greater than the diameter of the second surface 30b, and the outer diameter of the second surface 30b is greater than the diameter of the third surface 30c.

[0084] The support portion 25 has an axial length G between 2.5 mm and 4.5 mm.

[0085] The clamping portion 26 has an axial length H between 2 mm and 10 mm.

[0086] The deformable part 28 has an axial length I between 4.5 mm and 8.5 mm.

[0087] The body 24 of nut 23 has a total axial length T between 10 mm and 25 mm.

[0088] For example, the axial length I of the deformable part 28 is between 30% and 50% of the total axial length T of the nut 23.

[0089] "Axial length" refers to the dimension along the extended axis of nut 23.

[0090] The second surface 30b of the clamping portion 26 includes a spline designed to mate with a tool, such as a wrench for screwing the nut 23 onto the connecting shank 13.

[0091] The stepped inner surface 31 here includes two surfaces 31a, 31b connected to each other by a shoulder (not shown).

[0092] The second inner surface 31b includes an internal tap or internal thread designed to mate with the external thread 13a of the connecting shank 13 of the connecting rod head 12.

[0093] The first inner surface 31a has no threads, and the diameter E of the first inner surface 31a is greater than the diameter of the second inner surface 31b.

[0094] The second inner surface 31b extends along the deformable portion 28, the clamping portion 26, and a portion of the support portion 25.

[0095] The first inner surface 31a has an axial length D between 20% and 30% of the total axial length T of the nut 23.

[0096] In the locked rotational position, the support portion axially abuts against the side surface 21d of the second serrated washer 21.

[0097] The deformable portion 28 is configured to be able to plastically deform in the radial direction under the action of an external load (e.g., radial tightening of the outer surface 30c) on the third outer surface 30c.

[0098] "Capable of plastic deformation" means that any element, by virtue of its shape or its material, is configured to undergo plastic deformation under the action of an external load, and does not return to its initial shape when the load is removed.

[0099] In other words, after deformation, the deformable part 28 retains its deformed shape.

[0100] Figure 4 and Figure 5 The deformable part 28 before and after deformation is shown.

[0101] like Figure 4 As shown, before deformation, the deformable part 28 has a circular cross-section with an inner diameter of A.

[0102] like Figure 5 As shown, after deformation, the deformable part 28 has a non-circular cross-section, which is an oval cross-section defined by the long axis A1 and the short axis A2, the length of which is shorter than that of the long axis A1.

[0103] Once deformed, the deformable portion 28 of the self-locking nut 23 abuts against the connecting handle 13 and tightens, creating a brake that prevents any relative rotation of the connecting rod body 11 relative to the connecting rod head 12.

[0104] The advantages of the present invention are particularly evident in the performance of the locking system for the relative rotation of the connecting rod body 11 relative to the connecting rod head 12 in environments subjected to centrifugal force and vibration.

Claims

1. A connecting rod (10), particularly a connecting rod for a turbine rotor, the connecting rod extending along an axially extending axis (X-X'), the connecting rod including a connecting rod body (11) and a connecting rod head (12), the connecting rod body including a tapped portion, the connecting rod head being rotatably integral with the connecting rod body (11) and including a connecting shank (13), the connecting shank including an external thread (13a) engaging with the tapped portion of the connecting rod body (11), the connecting rod (10) further including a system (20) for locking relative rotation between the connecting rod head (12) and the connecting rod body (11), the locking system (20) including: - A first serrated washer (21), which is radially mounted about the connecting shank (13) of the connecting rod head (10) and includes an anti-rotation axial protrusion (21d) and a plurality of axial serrations. The anti-rotation axial protrusion is designed to engage with a corresponding notch (11e) on the connecting rod body (11) in a locked position against relative rotation of the connecting rod body (11) relative to the connecting rod head (12). The plurality of axial serrations extend in the opposite direction to the anti-rotation axial protrusion (21d). - A second serrated washer (22), which is radially mounted about the connecting shank (13) of the connecting rod head (10) and includes a plurality of axial serrations extending toward the first serrated washer (21) and intended to engage with the serrations of the first serrated washer (21) in the locked position, characterized in that: The locking system (20) further includes a self-locking nut (23), which is screwed onto the connecting handle (13) of the connecting rod head (12). The self-locking nut is configured to tighten the serrated washers (21, 22) against each other, engaging the corresponding serrations, and to tighten the axial pin (21d) into a corresponding recess (11e) on the connecting rod body (11). The self-locking nut is configured to prevent relative rotation between the connecting rod body (11) and the connecting rod head (12) in the locked position. The connector includes a deformable portion (28) configured to be able to plastically deform radially between an initial configuration and a deformable configuration under an external load on its outer surface (30c), wherein in the initial configuration the deformable portion (28) has a circular cross-section and in the deformable configuration the deformable portion (28) has a non-circular cross-section and is threaded (13a) with the external thread (13a) of the connecting shank (13), and the self-locking nut (23) is configured to allow itself to prevent any relative rotation of the connecting rod body (11) relative to the connecting rod head (12).

2. The connecting rod (10) according to claim 1, wherein, In the deformable configuration, the deformable portion (28) of the self-locking nut (23) has an oval cross-section defined by a long axis (A1) and a short axis (A2) smaller than the long axis (A1).

3. The connecting rod (10) according to claim 1 or 2, wherein, The self-locking nut (23) has a total axial length (T) between 10 mm and 25 mm.

4. The connecting rod (10) according to claim 3, wherein, The deformable portion (28) of the self-locking nut (23) has an axial length (I) between 30% and 50% of the total axial length (T) of the self-locking nut (23).

5. The link (10) according to any one of the preceding claims, wherein, The self-locking nut (23) includes a hollow stepped body (24) that extends axially along a longitudinal axis (X) and sequentially includes a support portion (25), a clamping portion (26) connected to the support portion via a first shoulder (27), and a deformable portion (28) connected to the clamping portion (26) via a second shoulder (29). The support portion (25) is configured to axially abut against the second serrated washer (22) in the locked position in response to the relative rotation of the connecting rod body (11) relative to the connecting rod head (12).

6. The connecting rod (10) according to claim 5, wherein, The hollow stepped body (24) of the self-locking nut (23) is defined radially by a stepped outer surface (30) and a stepped inner surface (31), and axially by a proximal end (32) and a distal end (33) opposite to the proximal end (32). The stepped outer surface (30) includes a first surface (30a) forming the outer surface of the support portion (25), a second surface (30b) forming the outer surface of the clamping portion (26), and a third surface (30c) forming the outer surface of the deformable portion (28).

7. The connecting rod (10) according to claim 6, wherein, The stepped inner surface (31) of the self-locking nut (23) includes an inner thread (31b) designed to mate with the external thread (13a) of the connecting shank (13) of the connecting rod head (12) and an unthreaded inner surface (31a) having a diameter (E) greater than that of the inner thread (31b).

8. The link (10) according to claim 7, wherein, The internal thread (31b) of the stepped inner surface (31) of the self-locking nut (23) extends at least along the deformable portion (28) and the clamping portion (26), and has an axial length (D) between 70% and 80% of the total axial length (T) of the self-locking nut (23).

9. The link (10) according to any one of claims 5 to 8, wherein, The support portion (25) of the self-locking nut (23) has an axial length (G) between 2.5 mm and 4.5 mm.

10. The link (10) according to any one of the preceding claims, wherein, The connecting rod head (12) also includes an end (14) extending from the connecting handle (13) on the side opposite to the connecting rod body (11), the end including a hole (14a) extending along a transverse axis (Y) perpendicular to the extension axis (X-X') and also including a connector (15) installed in the hole (14a).

Images