A disengagement device

Abstract

The present application relates to a kind of disengaging devices, belong to impact test technical field.The locking piece locks, the moving piece is inserted into the moving channel and is engaged with the card slot, the movement assembly is fixed in the disengaging assembly;The locking piece is unlocked, the movement assembly can slide up and down relative to the disengaging assembly, when the acceleration of external force driving the movement assembly is greater than the gravitational acceleration of the disengaging assembly, the movement assembly moves relative to the disengaging assembly towards the loading block, the inclined plane pushes the moving piece to its end close to the movement assembly completely enters the moving channel, and the movement assembly is disengaged from the disengaging assembly.The present application can ensure that loading block is synchronized when multiple test devices are tested simultaneously, and can ensure that loading block vertically impacts the tested piece.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of impact test, in particular to a disengaging device. BACKGROUND

[0002] When measuring the parameters of high-speed impact of an object, a power source is used to drive a loading block to accelerate, and when a certain speed is reached, the loading block hits the measured object. In a specific scenario, multiple test devices need to be used for high-speed synchronous motion test. The drive of the test bench is driven by the power source to accelerate at a high acceleration instantaneously, and after reaching the set specific speed value, it needs to be safely and reliably separated to achieve the purpose of simulating specific functions or performance and protecting the drive. Due to the fast movement speed and short movement time of the measured object, strict requirements are placed on the safe disengagement of the loaded object to ensure the synchronization of the response and the consistency of the experimental performance, and the disengagement needs to be fast and reliable.

[0003] The technical solution provided in the existing patent CN210005206U adopts a self-destruction rod scheme. This scheme is aimed at impact test. When rebounding, the self-destruction rod is broken to dissipate energy, thereby achieving disengagement from the measured object and protecting the impact piston rod. When multiple test devices are tested simultaneously, the movement time is short, and the disengagement time of the test object is not synchronized. The asynchronous action of the self-destruction rod will have a great impact on the test effect of the loaded object. SUMMARY

[0004] (I) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a disengaging device, which solves the technical problems of affecting the test effect due to disengagement asynchronization when the loading block disengages from the power source, and the inability to vertically hit the tested object when multiple test devices are tested simultaneously, and ensures safe and reliable disengagement from the power source and prevents damage to the power source.

[0006] (II) Technical solutions

[0007] In order to achieve the above-mentioned purposes, the main technical solutions adopted by the present application include:

[0008] The present application provides a disengaging device, which includes a movement assembly and a disengaging assembly sleeved outside the movement assembly. The movement assembly can move in the disengaging assembly, and the disengaging assembly can be connected with a loading block.

[0009] The disengaging assembly includes a moving channel, a moving piece and a locking piece. The moving piece is movably arranged in the moving channel and can extend out of the moving channel at one end. When the locking piece locks the moving piece, the position of the moving piece relative to the moving channel is fixed.

[0010] The moving assembly comprises a connecting clamping member and a moving body, the moving body is provided with an inclined surface, and the clamping member and the inclined surface form a clamping groove;

[0011] When the locking member is locked, the moving member extends into the moving channel and engages with the clamping groove, and the moving assembly is fixed in the disengaging assembly;

[0012] When the locking member is unlocked, the moving assembly can slide up and down relative to the disengaging assembly, when the acceleration of the moving assembly driven by external force is greater than the gravitational acceleration of the disengaging assembly, the moving assembly moves relative to the disengaging assembly towards the loading block, the inclined surface pushes the moving member to its end close to the moving assembly to completely enter the moving channel, and the moving assembly is disengaged from the disengaging assembly.

[0013] Optionally, the number of the moving channels is at least two, and the moving member is correspondingly arranged with the moving channels.

[0014] Optionally, the disengaging assembly comprises a ring-shaped loading block base, the loading block base is provided with a plurality of moving channels, and the plurality of moving channels are arranged in the loading block base in an axisymmetric radial manner, and one end of the moving member close to the inclined surface is a circular arc surface.

[0015] Optionally, the moving member is a locking pin, the locking pin comprises a columnar body and a locking rod connected with the columnar body, and the end of the locking rod is provided with a pin nut, when the end of the locking rod provided with the pin nut protrudes from the moving channel and abuts against the locking member, the end of the columnar body of the locking pin abuts against the clamping groove.

[0016] Optionally, the locking rod is provided with an external thread, and the locking rod is threadedly connected with the pin nut.

[0017] Optionally, a hollow sealed bushing is arranged in the moving channel, an opening is arranged on one side of the bushing towards the inclined surface, the columnar body is arranged in the bushing, a closed space is formed between the columnar body and the bushing, and the end of the locking rod away from the opening penetrates through the inner wall of the bushing and protrudes from the bushing.

[0018] Optionally, the locking member is a locking cover plate, and the locking member is detachably connected with the side surface of the loading block base.

[0019] Optionally, a transition cover plate is arranged between the locking cover plate and the loading block base, the transition cover plate surrounds the side surface of the moving channel, and the locking cover plate is detachably connected with the transition cover plate.

[0020] Optionally, the moving body is a transition flange; the clamping member is a hoisting base, which is threadedly connected with the transition flange.

[0021] Optionally, the inner wall of the transition flange is provided with an internal thread, and the outer wall is provided with a locking nut; the transition flange is threadedly connected with the power source and is fixed through the locking nut.

[0022] (Three) beneficial effects

[0023] The beneficial effects of the present application are as follows: the disengaging device of the present application utilizes the relative motion caused by the acceleration difference of the relative mutual separation components to realize reliable mechanical structure disengagement. The moving assembly of the present application is connected with the power source (the piston rod end of the driving oil cylinder), the disengaging assembly is connected with the loading block, the disengaging assembly is sleeved outside the moving assembly, and disengagement is easy. The locking member is locked, which can make one end of the moving member protrude from the moving channel, and the moving member is fixed, and the moving member abuts against the inclined surface to make the moving assembly unable to move towards the loading block. After the locking member is unlocked, when the power source drives the moving assembly to move towards the loading block, the inclined surface on the moving assembly can extrude the moving member into the moving channel, thereby releasing the restriction of the clamping member, reaching a certain speed, and the disengaging assembly can be disengaged from the moving assembly. The moving member and the loading block are separated by relative motion, and the separation is completed before braking, which is good in reliability and rapid in disengagement, and the components can be repeatedly used. When using the device, the synchronization disengagement of the loading block can also be ensured when testing multiple groups of tests.

[0024] During the separation process of the loading block, the central hole of the loading block base and the cylindrical surface of the transition flange form a guiding effect, which ensures that the loading block vertically impacts the tested piece, and the impact simulation effect is good.

[0025] The locking rod end of the locking pin is connected with the locking nut through a thread, and the locking nut can prevent the locking pin from being pulled out of the bushing after the moving assembly and the disengaging assembly are completely disengaged.

[0026] The locking cover plate is threadedly connected with the loading block base or the transition cover plate, and when the locking cover plate is tightened, it indicates that the axial tightening of the locking pin is in place.

[0027] The transition flange is threadedly connected with the power source, and the locking nut is pressed against the lower end surface of the power source through a thread, so that the transition flange is circumferentially fixed and locked, preventing circumferential rotation during the impact process. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a 1 / 4 sectional view of the disengaging device in the embodiment of the present application.

[0029] Figure 2 is a 1 / 2 sectional view of the disengaging device in the embodiment of the present application.

[0030]

Explanation of reference signs

[0031] 1: transition flange; 2: first screw; 3: locking nut; 4: hoisting base; 5: loading block base; 6: transition cover plate; 7: second screw; 8: locking pin; 9: bushing; 10: locking cover plate; 11: loading block; 12: pin setting nut. DETAILED DESCRIPTION

[0032] In order to better explain the present application, so as to be understood, the following specific embodiments, combined with the drawings, are described in detail. Wherein, the "up", "down" and other orientation terms mentioned herein refer to the up and down movement direction perpendicular to the horizontal plane.

[0033] The disengaging device proposed in the embodiment of the present application adopts the locking pin disengaging scheme, and uses the slope on the transition flange to push out the two symmetrically arranged locking pins at the same time when accelerating, so that the loading block realizes safe and smooth disengagement under high-speed movement. In the technical scheme, the transition flange moves relatively along the center hole of the hoisting base during disengagement, and the two are gap-fitted, so that the separation movement guarantees good synchronism and reliability.

[0034] In order to better understand the above technical scheme, the exemplary embodiments of the present application will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present application can be more clearly and thoroughly understood, and the scope of the present application can be completely conveyed to those skilled in the art.

[0035] Embodiment 1:

[0036] Reference Figure 1 and Figure 2 A disengaging device, comprising a movement assembly and a disengaging assembly sleeved outside the movement assembly, the movement assembly being movable in the disengaging assembly, and the disengaging assembly being connectable with the loading block 11; the movement assembly being movable in the axial direction in the disengaging assembly, and the axial end of the disengaging assembly being connected with the loading block 11, so that the movement assembly can contact the loading block 11 when moving.

[0037] The disengaging assembly comprises a moving channel, a moving piece and a locking piece, the moving piece being movably arranged in the moving channel and having one end extending out of the moving channel, and the locking piece being capable of fixing the position of the moving piece relative to the moving channel when locking the moving piece; preferably, the moving channel, the moving piece and the locking piece are coaxial, and the axis thereof is perpendicular to the central axis of the disengaging assembly.

[0038] The locking component can be any existing method that can lock the moving component. For example, it can be a lifting block set in the moving channel to lock the moving component and prevent it from moving; it can also be an electromagnet set in the inner wall of the cavity, which works to attract the moving component and achieve fixation; or it can be a threaded connection locking method, etc.

[0039] The motion assembly includes a connecting engaging component and a motion body. The motion body has an inclined surface, and the engaging component and the inclined surface form a groove; this groove is used to restrict the motion assembly from moving away from the loading block. (Reference) Figure 1 The locking mechanism prevents the moving components from disengaging and moving upwards from the disengagement group.

[0040] When the locking component is engaged, the moving component extends into the moving channel and engages with the slot, while the moving component is fixed within the disengagement component. Specifically, the moving component extends into the moving channel and abuts against the inclined surface, and also abuts against the engaging component. The abutment between the moving component and the inclined surface fixes the disengagement component and the moving component, while the abutment between the moving component and the engaging component allows the disengagement component to hang on the moving component and move upward together.

[0041] refer to Figure 1 The inclined surface on the moving body makes the bottom diameter of the moving component (transition flange) smaller than the top diameter. When the moving component moves downward, it will squeeze the moving part to move away from the moving component. If the moving part is locked and fixed by the locking part, the moving component cannot move downward. At the same time, the moving component cannot move upward, so it is fixed in the detachment component.

[0042] When the locking component is unlocked, the moving component can slide up and down relative to the disengaging component. When the acceleration of the moving component driven by the external force is greater than the gravitational acceleration of the disengaging component, the moving component moves towards the loading block 11 relative to the disengaging component. The inclined plane pushes the moving component until its end near the moving component is fully inserted into the moving channel, and the moving component disengages from the disengaging component.

[0043] In this embodiment, the width of the inclined surface on the moving body is greater than the diameter of the locking pin 8. The transition flange 1 is pressed against the end face of the lifting base 4 by means of threads. The maximum diameter of the transition flange 1, the locking nut 3 and the lifting base 4 is less than the diameter of the hole in the loading block base 5, so that they do not interfere with each other during relative movement.

[0044] refer to Figure 1Or 2, specifically, in this embodiment, the bottom end of the transition flange 1 is connected with the lifting base 4, and the locking nut 3 is sleeved outside the lateral wall of the transition flange 1. The central axes of the transition flange 1, the locking nut 3 and the lifting base 4 coincide. The moving assembly composed of the transition flange 1, the locking nut 3 and the lifting base 4 is sleeved with a disengaging assembly, and the moving assembly can move up and down in the disengaging assembly. The bottom end of the transition flange 1 is symmetrically provided with an inclined surface, and the inclined surface and the lifting base 4 form a clamping groove. The inclination direction of the inclined surface is that the bottom of the inclined surface is close to the central axis of the transition flange 1, and the top of the inclined surface is away from the central axis of the transition flange 1. The disengaging assembly includes a ring-shaped loading block base 5, the loading block base 5 is provided with a radial bushing 9, the bushing 9 is provided with a locking pin 8, the central axes of the bushing 9 and the locking pin 8 coincide and are perpendicular to the central axis of the moving assembly. The bottom of the loading block base 5 is connected with a loading block 11, and there is a space between the moving assembly and the loading block 11 in the vertical direction.

[0045] In this embodiment, the number of moving channels is at least two, and the moving member is correspondingly arranged with the moving channel. The number of cavities is a positive integer greater than or equal to 2. When the number of cavities is two, the two cavities are oppositely arranged, as shown in the drawings. When the number of cavities is three, the included angle between the cavities is 120°. When the number of cavities is four, the included angle between the cavities is 90°, and so on. The uniform arrangement of the cavities can improve the stability of the moving assembly fixed in the disengaging assembly.

[0046] The disengaging assembly in this embodiment further includes a ring-shaped loading block base 5, and the loading block base 5 is provided with a plurality of moving channels. The plurality of moving channels are arranged radially in the loading block base 5 in axial symmetry. The end of the moving member close to the inclined surface is a circular arc surface. The circular arc surface contacting the inclined surface can reduce the resistance of movement, so that the moving assembly can quickly disengage relative to the disengaging assembly.

[0047] In this embodiment, the moving member is a locking pin 8, which includes a cylindrical body and a locking rod connected with the cylindrical body. The end of the locking rod is provided with a pin nut 12. When the end of the locking rod provided with the pin nut 12 protrudes from the moving channel and abuts against the locking member, the end of the cylindrical body of the locking pin abuts against the clamping groove.

[0048] The locking rod is provided with external threads, and the locking rod is threadedly connected with the pin nut 12.

[0049] In this embodiment, the moving channel is provided with a hollow sealed bushing 9. The side of the bushing 9 facing the inclined surface is provided with an opening. The cylindrical body is arranged in the bushing 9, and there is a sealed space between the cylindrical body and the bushing 9. The end of the locking rod away from the opening penetrates through the inner wall of the bushing 9 and protrudes from the bushing 9. Referring to Figure 1 When the locking pin 8 moves away from the moving assembly, the air in the sealed space is compressed, which can slow down the movement of the locking pin 8.

[0050] The locking member in this embodiment is a locking cover plate 10, which is detachably connected to the side of the loading block base 5.

[0051] A transition cover plate 6 is arranged between the locking cover plate 10 and the loading block base 5, and the transition cover plate 6 surrounds the side of the moving channel, and the locking cover plate 10 is detachably connected to the transition cover plate 6.

[0052] When the locking cover plate 10 is connected to the loading block base 5 or the transition cover plate 6, it is in the locked state of the locking member; when the locking cover plate 10 is detached, it is in the unlocked state of the locking member.

[0053] In this embodiment, the moving body is a transition flange 1, which is a hollow cylindrical shape as a whole, and the bottom end is reduced in diameter, so that the diameter of the bottom end is smaller than that of the top end. The maximum diameter of the transition flange 1 is the same as the inner diameter of the loading block base 5, and the two can be arranged in close contact.

[0054] In this embodiment, the clamping member is a lifting base 4, which is threadedly connected to the transition flange 1. The end face of the transition flange 1 is in close contact with the end face of the lifting base 4, forming a stepped face structure.

[0055] The inner wall of the transition flange 1 is provided with internal threads, and the lifting base 4 is in the shape of a convex letter. The lifting base 4 can be threadedly connected to the loading block base 5. In this way, the lifting base 4 is convenient to replace. The outer wall is provided with a locking nut 3, the transition flange 1 is threadedly connected to the power source, and is fixed through the locking nut 3.

[0056] In this embodiment, the outer cylindrical surface of the side where the loading block base 5 is connected to the loading block 11 is provided with a through slot, which facilitates axial positioning when the device is lowered.

[0057] When testing, the transition flange 1 is threadedly connected to the end of the driving cylinder piston rod, the transition flange 1 and the locking nut 3 are threadedly connected together, and the locking nut 3 can be moved along the axis of the transition flange by screwing, the locking nut 3 will press the driving cylinder piston rod through the threads, so that the transition flange 1 is circumferentially fixed and locked, preventing circumferential rotation during impact. The transition flange 1 and the lifting base 4 are continuously fixed by threads.

[0058] The loading block base 5 and the transition cover plate 6 are fixedly connected by screws, the bushing 9, the locking pin 8 and the pin fixing nut 12 are assembled, and the loading block base 5 and the loading block are fixedly connected by the connecting screw 2. One end of the locking pin 8 is engaged with the clamping groove, the locking cover plate 10 is tightened, the locking pin 8 is in abutment with the clamping groove, and the moving assembly is fixed in the disengaging assembly. At this time, there is a certain height space between the moving assembly and the loading block 11. By checking whether the locking cover plate 10 is tightened, it can be judged whether the locking pin 8 is axially tightened in place.

[0059] When the driving oil cylinder lifts the moving assembly with the piston rod, the disengaging assembly is lifted out of synchronization. After the moving assembly is lifted to the required height, the locking cover plate 10 is removed. At this time, the moving assembly is relatively static due to the gravity acting on the disengaging assembly, and the locking pin can continue to abut in the clamping groove.

[0060] When the driving oil cylinder moves at an acceleration value of thousands of times of gravity acceleration under the action of high-pressure oil gas (power source), the disengaging assembly only moves as a free fall under the action of gravity acceleration. Due to the obvious difference in acceleration between the two, the driving oil cylinder piston rod pushes the transition flange 1 to move at high speed relative to the loading block base 5. When the transition flange 1 moves relative to the loading block base 5, the inclined surface interacts with the locking pin 8 to generate a force, and the locking pin 8 moves at high speed in the axial direction under the action of external force, so that the locking pin 8 retreats into the bushing 9, thereby achieving the effect of disengaging from the moving assembly.

[0061] When the bottom of the hoisting base 4 contacts the loading block 11, the moving assembly and the disengaging assembly move at the same acceleration. At this time, the locking pin 8 continues to move away from the moving assembly under the action of inertia. However, due to the existence of gas in the closed space formed by the locking pin and the bushing, the gas will generate a pressure value of up to dozens of atmospheres under rapid compression, so that the locking pin 8 generates a buffer braking effect.

[0062] Before the locking pin 8 brakes, the driving oil cylinder piston rod connected to the transition flange 1 brakes in the opposite direction, and the loading block 11 continues to hit the test piece at high speed under the action of inertia, and the two are separated. Since the locking pin has completely retreated to the contact surface of the transition flange, the locking pin is disengaged from the action surface of the transition flange, so that the driving oil cylinder piston rod connected to the transition flange 1 is free to exit from the loading block base 5. Since the locking pin 8 is provided with a pin retaining nut 12 at the end of the locking pin, the locking pin 8 will not be ejected from the bushing 9 when it is bounced back by the buffer brake. The present application realizes the function of quick and reliable disengagement.

[0063] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0064] In the present application, unless specifically defined otherwise, the terms "mounting", "connected", "connection", "fixed", "unfixed", and the like should be construed broadly, for example, can be fixed connection, can be detachable connection, or integral; can be mechanical connection, can be electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal communication of two elements, or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0065] In the present application, unless specifically defined otherwise, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature is "above", "over" and "on" the second feature, which can be directly above or obliquely above the first feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature is "below", "under" and "under" the second feature, which can be directly below or obliquely below the first feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0066] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0067] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can modify, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A disengagement device, characterized in that The device comprises a moving assembly and a disengaging assembly, the moving assembly is capable of moving in the disengaging assembly, and the disengaging assembly is capable of being connected with a loading block (11); The disengaging assembly comprises a moving channel, a moving piece and a locking piece, the moving piece is movably arranged in the moving channel and one end of the moving piece is capable of extending out of the moving channel, and the locking piece is capable of fixing the position of the moving piece relative to the moving channel when locking the moving piece; The moving assembly comprises a clamping piece and a moving body connected with each other, and the moving body is provided with an inclined surface, and the clamping piece and the inclined surface form a clamping groove; When the locking piece is locked, the moving piece extends into the moving channel and engages with the clamping groove, and the moving assembly is fixed in the disengaging assembly; When the locking piece is unlocked, the moving assembly is capable of sliding up and down relative to the disengaging assembly, when the acceleration of the moving assembly driven by external force is greater than the gravitational acceleration of the disengaging assembly, the moving assembly moves relative to the disengaging assembly towards the loading block (11), the inclined surface pushes the moving piece to its end close to the moving assembly to completely enter the moving channel, when the bottom of the clamping piece contacts the loading block (11), the moving assembly and the disengaging assembly move at the same acceleration, at this time, the moving piece continues to move away from the moving assembly under the action of inertia, before the moving piece is braked, the moving assembly is reversely braked, and the loading block (11) continues to hit the tested piece at high speed under the action of inertia, and the moving assembly and the disengaging assembly are disengaged.

2. The disengagement device of claim 1, wherein The number of the moving channels is at least two, and the moving piece is correspondingly arranged with the moving channels.

3. The disengagement device of claim 1, wherein The disengaging assembly comprises a ring-shaped loading block base (5), the loading block base (5) is provided with a plurality of moving channels, and the plurality of moving channels are arranged in the loading block base (5) in an axis-symmetrical and radial manner, and one end of the moving piece close to the inclined surface is a circular arc surface.

4. The disengagement device of claim 3, wherein The moving piece is a locking pin (8), the locking pin (8) comprises a columnar body and a locking rod connected with the columnar body, and the end of the locking rod is provided with a pin fixing nut (12), when the end of the locking rod provided with the pin fixing nut (12) protrudes out of the moving channel and abuts against the locking piece, the end of the columnar body of the locking pin abuts against the clamping groove.

5. The disengagement device of claim 4, wherein The locking rod is provided with an external thread, and the locking rod is threadedly connected with the pin fixing nut (12).

6. The disengagement device of claim 4, wherein The moving channel is provided with a hollow sealed bushing (9), one side of the bushing (9) facing the inclined surface is provided with an opening, the columnar body is arranged in the bushing (9), there is a sealed space between the columnar body and the bushing (9), and one end of the locking rod away from the opening penetrates through the inner wall of the bushing (9) and protrudes out of the bushing (9).

7. The disengagement device of claim 4, wherein The locking piece is a locking cover plate (10), and the locking piece is detachably connected with the side surface of the loading block base (5).

8. The disengagement device of claim 7, wherein The transition cover plate (6) is arranged between the locking cover plate (10) and the loading block base (5), surrounds the side of the moving channel, and is detachably connected with the locking cover plate (10).

9. The disengagement device of claim 1, wherein The moving body is a transition flange (1), and the clamping member is a hoisting base (4) which is threadedly connected with the transition flange (1).

10. The disengagement device of claim 9, wherein The inner wall of the transition flange (1) is provided with an internal thread, and the outer wall is provided with a locking nut (3); the transition flange (1) is threadedly connected with a power source and is fixed through the locking nut (3).

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