A method for testing a safety pin of a guide vane transmission mechanism of a hydraulic turbine

Abstract

A kind of water turbine guide vane transmission mechanism safety pin test method belongs to mechanical manufacturing test field, in view of the existing guide vane transmission mechanism safety pin test poor universality, force position is not reasonable to cause small force arm and loading force, test device volume and weight are big, cost is high and stress direction is difficult to accurately control to cause the problem of low test precision, scheme is proposed by setting positioning shaft and adjusting sleeve on the bottom plate to realize coaxial centering installation of transmission mechanism, by first slider and second slider along the groove sliding to realize adaptive adjustment of supporting position and loading position, by supporting block and wedge plate cooperation to realize transmission mechanism posture correction, by hydraulic cylinder, supporting frame and supporting shaft at the connecting plate pin hole place exert loading force perpendicular to center line to increase force arm and realize safety pin shearing, and shear torque is obtained by pressure conversion, suitable for torque test and performance verification of different specifications of water turbine guide vane transmission mechanism safety pin.

Description

Technical Field

[0001] This relates to the field of mechanical manufacturing testing, and in particular to a test method for the safety pin of a water turbine guide vane transmission mechanism. Background Technology

[0002] In the field of hydroelectric turbine manufacturing and maintenance, the guide vane drive mechanism, as a crucial actuator for controlling water flow regulation, directly impacts the safety and efficiency of the unit. To prevent damage to the transmission components caused by guide vane jamming or abnormal operating conditions, a safety pin is typically installed between the connecting plate and the guide vane arm. This safety pin shears off under overload conditions, providing protection. Therefore, testing the shearing force or shearing torque of the safety pin during manufacturing or maintenance has become a standard testing method in the industry.

[0003] In existing technologies, testing methods for safety pins in guide vane drive mechanisms typically employ a fixed support structure in conjunction with a hydraulic loading device to apply external force to the connecting plate or guide vane arm to shear the safety pin. Common solutions include fixing the drive mechanism to a test platform using rigid clamps and applying force at a specific position on the connecting plate or guide vane arm to subject the safety pin to shear load; or constraining the drive mechanism in a specific posture using specialized tooling and directly applying shear force via a hydraulic cylinder to complete the test. While these methods can achieve safety pin performance testing to some extent, they generally rely on support structures customized for specific drive mechanism models, resulting in fixed structural forms and limited applicability. When the size or structure of the drive mechanism changes, it is often necessary to redesign or replace the test tooling, leading to insufficient versatility. Furthermore, existing tests often apply loads at non-optimal lever arm positions, resulting in larger required loading forces, thus requiring larger hydraulic cylinders, increasing the overall size and weight of the test apparatus, and raising manufacturing and operating costs.

[0004] Furthermore, since existing support structures mostly employ rigid fixed connections, they lack the ability to precisely adjust the posture and force direction of the transmission mechanism during testing. In actual loading, it is difficult to ensure that the applied force direction maintains an ideal relationship with the center line connecting the pin hole of the connecting plate and the shaft hole of the guide vane arm. This easily leads to additional bending moments or off-center loading, causing localized deformation of the test support and the tested component. This not only affects the accuracy of the test data but may also damage the components. Simultaneously, existing solutions have weak adaptability to different specifications of transmission mechanisms, making it difficult to meet the safety pin testing requirements of multiple models and sizes of guide vane transmission mechanisms.

[0005] In summary, the existing technology has the following drawbacks: poor versatility of the test device, unreasonable loading position leading to a small lever arm and large required force, large size and weight of the test device resulting in high cost, difficulty in accurately controlling the force direction leading to low test accuracy, and insufficient adaptability to different specifications of transmission mechanisms. Summary of the Invention

[0006] To address the shortcomings of existing technologies, such as poor versatility of testing devices, unreasonable loading positions leading to small lever arms and large required forces, large size and weight of testing devices resulting in high costs, difficulty in accurately controlling the force direction leading to low testing accuracy, and insufficient adaptability to different specifications of transmission mechanisms, the technical solution provided by this invention is as follows: A turbine guide vane drive mechanism, comprising: The system comprises a guide vane arm, a friction bushing, a connecting plate, and a safety pin. The guide vane arm has a shaft hole, and the friction bushing is located between the guide vane arm and the connecting plate. The inner side of the friction bushing is interference-fitted with the guide vane arm. The connecting plate is sleeved on the outside of the friction bushing. The connecting plate is clamped and fixed to the friction bushing by studs and nuts, so that the connecting plate and the guide vane arm form a detachable and relatively fixed connection structure. The connecting plate and the guide vane arm are respectively provided with a first hole and a second hole that are coaxially corresponding to each other. The safety pin passes through the first hole and the second hole to achieve a shear connection between the connecting plate and the guide vane arm. The connecting plate is provided with a pin hole structure parallel to the axis of the first hole. A limiting block is provided on the guide vane arm, and the limiting block has a limiting surface for contacting the external support structure. A center line is formed between the center of the pin hole of the connecting plate and the center of the shaft hole of the guide vane arm. The center line is used as a reference for the torque action when the safety pin is subjected to shear force. At least one working plane of the connecting plate and the axial reference plane of the guide vane arm are perpendicular to the center line to establish a spatial geometric reference for the guide vane transmission mechanism under stress.

[0007] Furthermore, in a preferred embodiment, the first cylinder of the positioning shaft and the third hole of the base plate are aligned, and after the positioning shaft is installed, its axis is perpendicular to the third plane of the base plate to establish a vertical installation reference for the guide vane transmission mechanism.

[0008] Furthermore, in a preferred embodiment, an adjusting sleeve is disposed between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so as to achieve the centering installation of the guide vane transmission mechanism relative to the positioning shaft.

[0009] Furthermore, in a preferred embodiment, the first slider is disposed in the first groove of the base plate and is guided and engaged with the first groove by the first key. The first slider can slide in a directional manner along the first groove. A fourth plane corresponding to the guide vane arm limiting surface is provided on the first slider to form a support structure on one side of the guide vane transmission mechanism.

[0010] Furthermore, in a preferred embodiment, the second slider is disposed in the second groove of the base plate and guided to the second groove by the second key. The second slider can slide in a directional manner along the second groove. A fifth plane is provided on the second slider to correspond to the position of the pin hole of the connecting plate, so as to form a loading support structure on the other side of the guide vane transmission mechanism.

[0011] A test method for the safety pin of a turbine guide vane transmission mechanism, based on the aforementioned mechanism, includes: The steps are as follows: Place the base plate with the third plane facing upwards, align the first cylinder of the positioning shaft with the third hole of the base plate and insert it, so that the second annular surface of the positioning shaft fits against the third plane to establish a vertical reference. The steps are as follows: the adjusting sleeve is fitted onto the positioning shaft and fits against the third annular surface of the positioning shaft; the turbine guide vane transmission mechanism is fitted onto the adjusting sleeve; and the guide vane arm shaft hole is aligned with the adjusting sleeve and positioned coaxially with the positioning shaft. The steps are as follows: insert the first slider into the first groove of the base plate and make the fourth plane of the first slider face the guide vane arm limiting surface; move the first slider to make the fourth plane aligned with the limiting surface; and set a support block and a wedge plate between the two to form a support and angle adjustment structure. Insert the second slider into the second groove of the base plate, move the second slider to align the fifth plane of the second slider with the center of the pin hole of the connecting plate, install the adjusting shim and set the support plate on the second slider, and install the hydraulic cylinder on the support plate so that its axis corresponds to the pin hole of the connecting plate. The steps include installing a support shaft and setting up a support frame in the pin hole of the connecting plate, so that the support frame is located between the hydraulic cylinder piston and the support shaft to form a loading force transmission path, and pre-extending the hydraulic cylinder piston to press the force system including the connecting plate, safety pin, guide vane arm, support block and wedge plate. The steps include measuring the vertical deviation between the center line formed by the center of the connecting plate pin hole and the center of the guide vane arm shaft hole and the hydraulic cylinder axis, and adjusting the wedge plate to rotate the turbine guide vane transmission mechanism around the positioning shaft so that the center line is perpendicular to the hydraulic cylinder axis. The process involves driving the hydraulic cylinder to continuously load the system while the center line is perpendicular to the axis of the hydraulic cylinder, causing the connecting plate to shear relative to the guide vane arm until the safety pin breaks. The steps include recording the pressure of the hydraulic cylinder when the safety pin breaks and converting it into a force, and calculating the shearing torque of the safety pin based on the distance from the center of the pin hole in the connecting plate to the center of the positioning shaft.

[0012] Furthermore, in a preferred embodiment, the first cylinder of the positioning shaft and the third hole of the base plate are aligned, and after the positioning shaft and the base plate are assembled, its axis is perpendicular to the third plane of the base plate, so as to ensure that the spatial reference of the turbine guide vane transmission mechanism is consistent after installation.

[0013] Furthermore, in a preferred embodiment, an adjusting sleeve is disposed between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so that the turbine guide vane transmission mechanism can be centered and installed through the adjusting sleeve.

[0014] Furthermore, in a preferred embodiment, the first slider is guided and engaged with the first groove of the base plate via the first key and can slide directionally along the first groove. The fourth plane of the first slider is correspondingly set with the limiting surface of the guide vane arm, and the support position is matched by adjusting the position of the first slider.

[0015] Furthermore, in a preferred embodiment, the second slider is guided and engaged with the second groove of the base plate by the second key and can slide directionally along the second groove. The fifth plane of the second slider is correspondingly set with the center of the pin hole of the connecting plate, and is fixed by adjusting the pad and screw to form a loading support surface.

[0016] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows: By setting a positioning shaft on the base plate and using the centering fit between the positioning shaft and the third hole on the base plate, and by utilizing the centering fit between the adjusting sleeve and the positioning shaft and the guide vane arm shaft hole, a unified spatial reference system is formed in the transmission mechanism during assembly. This ensures the relative positional accuracy between the guide vane arm shaft hole, the connecting plate pin hole, and the safety pin. Compared with the existing technology that uses ordinary support or clearance fit positioning methods, this method can significantly reduce the additional errors introduced by assembly deviations and improve the accuracy and repeatability of test results from the source.

[0017] By setting a first groove and a second groove on the base plate, and allowing the first slider and the second slider to slide directionally along the corresponding grooves, the support position can be continuously adjusted according to the position of the guide vane arm limiting surface and the pin hole of the connecting plate. This adapts to the structural size changes of transmission mechanisms of different specifications. Compared with the special tooling structure with fixed support points in the prior art, this adjustable sliding support method significantly improves the versatility of the test device and avoids the cost and time consumption caused by frequent replacement of test tooling.

[0018] By setting a support block and a wedge plate between the first slider and the guide vane arm limiting surface, and using the relative sliding of the wedge plate to achieve a small angle adjustment, the center line connecting the guide vane arm shaft hole and the connecting plate pin hole can be precisely adjusted to be perpendicular to the axis of the hydraulic cylinder and the support frame. This ensures that the loading direction is consistent with the force direction. Compared with the rigid structure in the prior art that is difficult to adjust the loading direction, this structure can effectively eliminate off-center loading and additional bending moment, avoid structural deformation during the test, and improve the test accuracy.

[0019] By setting an adjusting shim between the second slider and the pin hole of the connecting plate and fixing it with screws, the force transmission path between the hydraulic loading system and the transmission mechanism can be precisely adjusted and fixed according to the position of the pin hole. Compared with the direct rigid contact or simple shim adjustment method in the prior art, this structure can achieve position matching while ensuring rigidity, thereby improving loading stability and assembly reliability.

[0020] By setting up a support plate and forming a support structure on the support plate that fits the outer circle of the hydraulic cylinder, the hydraulic cylinder can obtain stable support and reliable positioning during the test, avoiding displacement or tilting of the hydraulic cylinder during loading. Compared with the existing technology of directly placing or simply supporting the hydraulic cylinder, this structure can improve the stability of the loading process and ensure the accuracy of the force direction.

[0021] By setting a support shaft in the pin hole of the connecting plate and forming a force transmission structure with the support frame, the axial force output by the hydraulic cylinder can be transmitted to the pin hole position of the connecting plate through the support frame and the support shaft, thereby achieving effective shear loading on the safety pin. Compared with the existing technology that applies force at a non-optimal position, this structure places the point of action on the side away from the guide vane arm shaft hole, thereby significantly increasing the lever arm and reducing the required loading force.

[0022] By applying a force perpendicular to the line connecting the center of the guide vane arm shaft hole and the connecting plate pin hole at the connecting plate pin hole, the safety pin is subjected to shearing force under the maximum lever arm condition. This reduces the output pressure of the hydraulic cylinder while ensuring the shearing effect. Compared with the existing technology where the lever arm is small and a large load is required, this feature effectively reduces the size of the hydraulic system, reduces the overall size and weight of the test device, and reduces the risk of damage to the test piece and support structure.

[0023] By measuring the vertical deviation between the center line and the axis of the hydraulic cylinder and the support frame before loading, and adjusting it with a wedge plate, the loading direction is corrected before the test. Compared with the existing technology that lacks measurement and correction links, this feature realizes the transformation from "experience adjustment" to "measurement feedback adjustment", which improves the controllability and consistency of the test process.

[0024] By adopting a replaceable structural design for components such as the first slider, the second slider, the support block, the support shaft, and the adjusting pad, the test device can be quickly adapted to different guide vane arm sizes, pin hole diameters, and limiting surface positions. Compared with the special fixtures designed for a single specification in the prior art, this structure achieves modular adaptability and expands the scope of application.

[0025] By employing centering fits for the positioning shaft, adjusting sleeve, support shaft, and corresponding hole structures, the problem of increased hydraulic cylinder idle stroke and force direction deviation caused by excessive clearance is avoided. Compared with the clearance fit and looseness problems commonly found in existing technologies, this feature effectively improves force transmission efficiency, reduces ineffective stroke, and ensures the stability and accuracy of the force direction.

[0026] By defining the parallel and perpendicular relationships between key planes, a stable geometric relationship is formed between the connecting plate plane, the guide vane arm annular surface, and the base plate reference plane, thereby ensuring the spatial attitude consistency of the entire test system. Compared with existing technologies that lack a unified geometric reference, this feature can avoid test deviations caused by attitude errors and improve the overall test accuracy.

[0027] By matching the angle between the first and second grooves on the base plate with the angle between the limiting surface and the center line, the transmission mechanism can quickly reach the target force direction during rotation adjustment. Compared with the existing technology that relies on repeated adjustments based on manual experience, this feature improves adjustment efficiency, reduces debugging errors, and enhances the convenience and consistency of test operations.

[0028] It is applicable to torque testing and performance verification of safety pins in the guide vane transmission mechanism of water turbines during manufacturing and maintenance. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the safety pin test for the transmission structure; Figure 2 yes Figure 1 AA section view; Figure 3 yes Figure 1 BB cross-sectional view; Figure 4 yes Figure 1 CC section view; Figure 5 This is a structural schematic diagram of the positioning shaft; Figure 6 This is a schematic diagram of the adjusting sleeve; Figure 7 This is a schematic diagram of the first slider; Figure 8 This is a schematic diagram of the second slider; Figure 9 This is a schematic diagram of the adjustment plate; Figure 10 This is a structural diagram of the pallet; Figure 11 This is a schematic diagram of the supporting shaft; Figure 12 This is a structural diagram of the support frame.

[0030] In the diagram, 1-transmission mechanism; 2-connecting plate; 3-guide vane arm; 4-friction bushing; 5-safety pin; 6-stud; 7-nut; 8-first hole; 9-second hole; 10-pin hole; 12-limiting block; 13-limiting surface; 14-first annular surface; 15-first plane; 16-second plane; 17-base plate; 18-third plane; 19-positioning shaft; 20-first cylinder; 21-third hole; 22-second annular surface; 23-adjusting sleeve; 24-third annular surface; 25-first slider; 26-first key; 27-first groove; 28-first end face; 29-center line; 30-fourth plane; 31-support block; 32-wedge plate; 3 3-Second slider; 34-Second key; 35-Second groove; 36-Second end face; 37-Fifth plane; 38-Adjusting pad; 39-Support plate; 40-Hydraulic cylinder; 41-Support shaft; 42-Support bracket; 43-Piston; 44-Fourth annular surface; 45-Screw; 46-Second cylinder; 47-Third cylinder; 48-Fourth cylinder; 49-First chamfered cylinder; 50-Third end face; 51-Threaded blind hole; 52-Sixth plane; 53-Counterhole; 54-Fourth hole; 55-First V-groove; 56-Seventh plane; 57-Eighth plane; 58-First support arm; 59-Second support arm; 60-Second V-groove; 61-Second chamfered cylinder; 62-First wedge plate; 63-Second wedge plate; 64-Fifth cylinder; 65-Sixth cylinder; 66-Seventh cylinder; 67-Fifth hole. Detailed Implementation

[0031] To make the advantages and benefits of the technical solution provided by the present invention clearer, the technical solution provided by the present invention will now be described in further detail with reference to the accompanying drawings, specifically: Implementation Method 1: This implementation method provides a turbine guide vane transmission mechanism, including: The system comprises a guide vane arm, a friction bushing, a connecting plate, and a safety pin. The guide vane arm has a shaft hole. The friction bushing is located between the guide vane arm and the connecting plate, and the inner side of the friction bushing is interference-fitted with the guide vane arm. The connecting plate is sleeved on the outside of the friction bushing. The connecting plate is clamped and fixed to the friction bushing by studs and nuts, so that the connecting plate and the guide vane arm form a detachable and relatively fixed connection structure. The connecting plate and the guide vane arm are respectively provided with a first hole and a second hole that are coaxially corresponding to each other. The safety pin passes through the first hole and the second hole to achieve a shear connection between the connecting plate and the guide vane arm. The connecting plate is provided with a pin hole structure parallel to the axis of the first hole. A limiting block is provided on the guide vane arm, and the limiting block has a limiting surface for contacting the external support structure. A center line is formed between the center of the pin hole of the connecting plate and the center of the shaft hole of the guide vane arm. The center line is used as a reference for the torque action when the safety pin is subjected to shear force. At least one working plane of the connecting plate and the axial reference plane of the guide vane arm are perpendicular to the center line to establish a spatial geometric reference for the guide vane transmission mechanism under stress.

[0032] The first cylinder of the positioning shaft and the third hole of the base plate are aligned. After the positioning shaft is installed, its axis is perpendicular to the third plane of the base plate to establish the vertical installation reference of the guide vane transmission mechanism.

[0033] The adjusting sleeve is positioned between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so as to achieve the centering installation of the guide vane transmission mechanism relative to the positioning shaft.

[0034] The first slider is set in the first groove of the base plate and is guided and engaged with the first groove by the first key. The first slider can slide in a directional manner along the first groove. A fourth plane corresponding to the guide vane arm limiting surface is provided on the first slider to form a support structure on one side of the guide vane transmission mechanism.

[0035] The second slider is set in the second groove of the base plate and is guided and engaged with the second groove by the second key. The second slider can slide in a directional manner along the second groove. A fifth plane is provided on the second slider to correspond to the position of the pin hole of the connecting plate, so as to form a loading support structure on the other side of the guide vane transmission mechanism.

[0036] A test method for the safety pin of a turbine guide vane transmission mechanism, based on the aforementioned mechanism, includes: The steps are as follows: Place the base plate with the third plane facing upwards, align the first cylinder of the positioning shaft with the third hole of the base plate and insert it, so that the second annular surface of the positioning shaft fits against the third plane to establish a vertical reference. The steps are as follows: the adjusting sleeve is fitted onto the positioning shaft and fits against the third annular surface of the positioning shaft; the turbine guide vane transmission mechanism is fitted onto the adjusting sleeve; and the guide vane arm shaft hole is aligned with the adjusting sleeve and positioned coaxially with the positioning shaft. The steps are as follows: insert the first slider into the first groove of the base plate and make the fourth plane of the first slider face the guide vane arm limiting surface; move the first slider to make the fourth plane aligned with the limiting surface; and set a support block and a wedge plate between the two to form a support and angle adjustment structure. Insert the second slider into the second groove of the base plate, move the second slider to align the fifth plane of the second slider with the center of the pin hole of the connecting plate, install the adjusting shim and set the support plate on the second slider, and install the hydraulic cylinder on the support plate so that its axis corresponds to the pin hole of the connecting plate. The steps include installing a support shaft and setting up a support frame in the pin hole of the connecting plate, so that the support frame is located between the hydraulic cylinder piston and the support shaft to form a loading force transmission path, and pre-extending the hydraulic cylinder piston to press the force system including the connecting plate, safety pin, guide vane arm, support block and wedge plate. The steps include measuring the vertical deviation between the center line formed by the center of the connecting plate pin hole and the center of the guide vane arm shaft hole and the hydraulic cylinder axis, and adjusting the wedge plate to rotate the turbine guide vane transmission mechanism around the positioning shaft so that the center line is perpendicular to the hydraulic cylinder axis. The process involves driving the hydraulic cylinder to continuously load the system while the center line is perpendicular to the axis of the hydraulic cylinder, causing the connecting plate to shear relative to the guide vane arm until the safety pin breaks. The steps include recording the pressure of the hydraulic cylinder when the safety pin breaks and converting it into a force, and calculating the shearing torque of the safety pin based on the distance from the center of the pin hole in the connecting plate to the center of the positioning shaft.

[0037] The first cylinder of the positioning shaft and the third hole of the base plate are aligned. After the positioning shaft and the base plate are assembled, its axis is perpendicular to the third plane of the base plate to ensure that the spatial reference of the turbine guide vane transmission mechanism is consistent after installation.

[0038] The adjusting sleeve is set between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so that the turbine guide vane transmission mechanism can be centered and installed through the adjusting sleeve.

[0039] The first slider is guided and engaged with the first groove of the base plate by the first key and can slide directionally along the first groove. The fourth plane of the first slider is set to correspond to the limiting surface of the guide vane arm. The support position is matched by adjusting the position of the first slider.

[0040] The second slider is guided and engaged with the second groove of the base plate by the second key and can slide directionally along the second groove. The fifth plane of the second slider is set in accordance with the center of the pin hole of the connecting plate and is fixed by adjusting the pad and screw to form a loading support surface.

[0041] Implementation Method Two: This implementation method is a further detailed description of the technical solution provided in Implementation Method One, specifically: A test structure for the safety pin of a turbine guide vane transmission mechanism is disclosed. A base plate 17 serves as the overall installation and load-bearing foundation. An installation and positioning system, a support and adjustment system, and a hydraulic loading system for the transmission mechanism 1 are established around the base plate 17 to test the shearing torque of the safety pin 5 in guide vane transmission mechanisms of different specifications. In this structure, the transmission mechanism 1 consists of a connecting plate 2, a guide vane arm 3, a friction bushing 4, a safety pin 5, a stud 6, and a nut 7. The friction bushing 4 is interference-fitted onto the guide vane arm 3, and the connecting plate 2 is fitted onto the outside of the friction bushing 4. After assembly, the connecting plate 2 and the guide vane arm 3 are relatively fixed around the same center. The connecting plate 2 is clamped and fixed to the friction bushing 4 by the stud 6 and the nut 7, ensuring that the connecting plate 2 and the guide vane arm 3 remain linked under normal conditions. The safety pin 5 passes through a concentric hole formed by the first hole 8 of the connecting plate 2 and the second hole 9 of the guide vane arm 3, and serves as a shear protection element under abnormal overload conditions. A pin hole 10 is formed on the connecting plate 2, and a shaft hole 11 and a limiting block 12 are formed on the guide vane arm 3. The limiting block 12 forms a limiting surface 13 facing the test support side. The guide vane arm 3 has a first annular surface 14, and the connecting plate 2 has a first plane 15 and a second plane 16. These surfaces, together with the safety pin 5, the pin hole 10, the shaft hole 11, and the limiting surface 13, constitute the geometric reference of the transmission mechanism 1 in terms of assembly relationship. After the transmission mechanism 1 is assembled, the safety pin 5, the pin hole 10 on the connecting plate 2, the shaft hole 11 on the guide vane arm 3, and the limiting surface 13 of the limiting block 12 are parallel to each other and are perpendicular to the first annular surface 14 of the guide vane arm 3 and the first plane 15 and the second plane 16 of the connecting plate 2, so that the transmission mechanism can participate in the force with a clear spatial posture during the test.

[0042] The base plate 17 serves as the mounting platform for the entire test structure, and its upper surface is defined as the third plane 18. The third plane 18 is both a common mounting reference surface for components such as the positioning shaft 19, the first slider 25, the second slider 33, and the support plate 39, and an important reference surface for establishing the spatial positional relationship of the transmission mechanism 1. The base plate 17 is provided with a third hole 21, a first groove 27, and a second groove 35. The third hole 21, located between the first groove 27 and the second groove 35, is used to mount the positioning shaft 19; the first groove 27 is used to mount the first slider 25; and the second groove 35 is used to mount the second slider 33. Both the first groove 27 and the second groove 35 are oblong through-hole structures, allowing the corresponding sliders to be guided and moved along the length of the groove, thus achieving position adjustment capability. The third hole 21 is perpendicular to the third plane 18, used to establish the vertical mounting relationship of the positioning shaft 19 relative to the base plate 17.

[0043] The positioning shaft 19 is the core positioning component in the entire test structure, used to support the transmission mechanism 1 and determine its rotation center. The positioning shaft 19 is a stepped component, with a first cylinder 20 at the lower end, a second cylinder 46 in the middle, and a third cylinder 47 at the top, all three arranged coaxially. The first cylinder 20 mates with the third hole 21 of the base plate 17, preferably using a centering fit, so that after the positioning shaft 19 is installed on the base plate 17, it can reliably establish a vertical state with the base plate 17 as a reference. A second annular surface 22 is formed between the first cylinder 20 and the second cylinder 46. This second annular surface 22 fits against the third plane 18 of the base plate 17 during installation, limiting the axial installation height of the positioning shaft 19 and further ensuring stable support between the positioning shaft 19 and the base plate 17. A third annular surface 24 is formed between the second cylinder 46 and the third cylinder 47. The third annular surface 24 is used to fit against the fourth annular surface 44 of the adjusting sleeve 23, serving as a further reference for the installation height and position of the transmission mechanism 1. Since the first cylinder 20, the second cylinder 46, and the third cylinder 47 are all coaxial, the positioning shaft 19 not only provides support but also provides a rotational correction center for the transmission mechanism 1, allowing the transmission mechanism 1 to be adjusted in attitude around this axis during the test setup.

[0044] The adjusting sleeve 23 is positioned between the positioning shaft 19 and the shaft hole 11 of the guide vane arm 3, serving as an intermediate centering component. The adjusting sleeve 23 has an overall annular cross-section. Its inner hole, the fifth hole 67, mates with the third cylinder 47 of the positioning shaft 19, and its outer circle, the seventh cylinder 66, mates with the shaft hole 11 of the guide vane arm 3. The lower end of the adjusting sleeve 23 forms a fourth annular surface 44, which fits against the third annular surface 24 of the positioning shaft 19. Through this structure, the adjusting sleeve 23 connects the positioning shaft 19 and the shaft hole 11 of the guide vane arm 3, allowing the transmission mechanism 1 to be stably mounted on the positioning shaft 19. Furthermore, because the fifth hole 67 and the seventh cylinder 66 are coaxial, the adjusting sleeve 23 can precisely transmit the axis of the positioning shaft 19 to the guide vane arm 3, thereby achieving the effect of centering the transmission mechanism 1 around the axis of the positioning shaft 19. For guide vane arm 3 shaft hole 11 of different specifications, different transmission mechanisms 1 can be adapted by replacing the adjusting sleeve 23 with different inner and outer diameters. Therefore, the adjusting sleeve 23 has the dual function of precise positioning and specification adaptation.

[0045] After the transmission mechanism 1 is installed onto the positioning shaft 19 via the adjusting sleeve 23, the first annular surface 14 of the guide vane arm 3 is in contact with the third annular surface 24 of the positioning shaft 19, and the transmission mechanism 1 can establish an initial installation state on the base plate 17. At this time, the transmission mechanism 1 can rotate around the positioning shaft 19. Since the positioning shaft 19 has been defined as vertical by the third hole 21 on the base plate 17, the rotation of the transmission mechanism 1 occurs in a stable reference system. Subsequently, by rotating the transmission mechanism 1, the center line 29 formed by the pin hole 10 of the connecting plate 2 and the center of the shaft hole 11 of the guide vane arm 3 can be gradually adjusted to a direction that is approximately parallel to the second groove 35, while the limiting surface 13 of the limiting block 12 faces the position of the first slider 25, thereby creating space conditions for subsequent side support and loading arrangements.

[0046] A first slider 25 is provided on one side of the limiting surface 13 of the transmission mechanism 1. The first slider 25 is installed in the first groove 27 of the base plate 17, and a first key 26 is provided at its lower part. The shape of the first key 26 is adapted to the first groove 27, and a guiding connection is achieved by inserting it into the first groove 27. The first key 26 not only restricts the first slider 25 from detaching from the base plate 17, but also ensures that the first slider 25 can only slide in a directional direction along the length of the first groove 27, and cannot move in any direction. A first end face 28 is formed above the first key 26. The first end face 28 fits against the third plane 18 of the base plate 17, thereby ensuring that the load can be reliably transmitted to the base plate 17 when the first slider 25 is subjected to force. A second chamfered cylinder 61 is formed on the upper part of the first slider 25. One side of the second chamfered cylinder 61 is flattened to form a fourth plane 30. The fourth plane 30 is the working surface where the first slider 25 contacts the wedge plate 32. This plane is parallel to the two sides of the first key 26 and perpendicular to the first end face 28. Therefore, the first slider 25 establishes a stable and accurate support direction on the base plate 17. By adjusting the position of the first slider 25 along the first groove 27, the fourth plane 30 can be aligned in space with the limiting surface 13 of the upper limit block 12 of the guide vane arm 3.

[0047] The first slider 25 and the limiting block 12 are not directly and rigidly pressed together. Instead, a support block 31 and a wedge plate 32 are sequentially arranged between them. The support block 31 is located between the limiting surface 13 and the wedge plate 32, and the planes on both sides of the support block 31 that contact the limiting surface 13 and the wedge plate 32 are parallel to each other. The function of the support block 31 is to act as a transition force-bearing component. On the one hand, it transmits the supporting force from the first slider 25 to the limiting surface 13 of the guide vane arm 3. On the other hand, it prevents the wedge adjustment component from directly acting on the transmission mechanism 1 body, thereby improving the contact state. The wedge plate 32 consists of a first wedge plate 62 and a second wedge plate 63. Both have the same structural dimensions, one side is a plane, and the other side is an inclined plane with a taper of 1:50. During installation, the inclined planes of the first wedge plate 62 and the second wedge plate 63 are arranged opposite each other. The plane side of the first wedge plate 62 is in contact with the fourth plane 30 of the first slider 25, and the plane side of the second wedge plate 63 is in contact with the support block 31. Because the relative sliding between the two wedge plates can produce minute and precise thickness changes, the angle of the transmission mechanism 1 around the positioning axis 19 can be finely adjusted without changing the overall support relationship. In other words, the wedge plate 32 not only provides support, but more importantly, it provides attitude correction to ensure that the center line 29 can be ultimately adjusted to the ideal state that is perpendicular to the axis of the hydraulic cylinder 40 and the support frame 42.

[0048] A second slider 33 is provided on one side of the pin hole 10 of the connecting plate 2. The second slider 33 is installed in the second groove 35 of the base plate 17, and a second key 34 is provided at its lower part. The second key 34 cooperates with the second groove 35, so that the second slider 33 can only slide in a directional direction along the length of the second groove 35. A second end face 36 is formed above the second key 34. The second end face 36 is in contact with the third plane 18 of the base plate 17 to ensure that the second slider 33 maintains stable support when under force. A fourth cylinder 48 is formed in the middle of the second slider 33, and a first chamfered cylinder 49 is formed at the top. One side of the first chamfered cylinder 49 is flattened to form a fifth plane 37, which serves as a working plane for contacting the adjusting shim 38. A threaded blind hole 51 is provided in the middle of the fifth plane 37 for connecting screws 45. The fifth plane 37 is parallel to both sides of the second key 34, while the second end face 36 and the third end face 50 located below the fifth plane 37 are perpendicular to the fifth plane 37, thus ensuring that the second slider 33 also forms a stable and directional force-bearing installation relationship on the base plate 17. By adjusting the position of the second slider 33 along the second groove 35, its fifth plane 37 can be aligned with the center of the pin hole 10 of the connecting plate 2, establishing an accurate geometric position for the hydraulic loading chain.

[0049] An adjusting shim 38 is installed on the side of the second slider 33 near the hydraulic cylinder 40. The adjusting shim 38 is generally circular, and its side away from the second slider 33 is defined as the sixth plane 52. A countersunk hole 53 is machined at the center of the sixth plane 52, and a fourth hole 54 is machined at the bottom of the countersunk hole 53. During installation, the adjusting shim 38 is placed upright on the third end face 50 of the second slider 33, with the sixth plane 52 facing the fifth plane 37 of the second slider 33. Then, a screw 45 is passed through the fourth hole 54 and screwed into the threaded blind hole 51 in the fifth plane 37, thereby fixing the adjusting shim 38 to the second slider 33. The countersunk hole 53 is used to accommodate the head of the screw 45, so that the screw 45 does not protrude from the surface of the adjusting shim 38, thus avoiding affecting the subsequent fitting and installation of the hydraulic cylinder 40. The adjustment of the pad 38 allows for the selection of different thicknesses or sizes according to actual needs, to accommodate different pin hole 10 positions and hydraulic cylinder 40 installation requirements; on the other hand, it provides a flat and reliable abutment surface for the hydraulic cylinder 40, thereby making the rear end of the hydraulic cylinder 40 more stable under force.

[0050] A support plate 39 is positioned below the hydraulic cylinder 40 to support it. The upper end of the support plate 39 has a first V-groove 55, and the lower end forms a seventh plane 56. The seventh plane 56 fits into the third plane 18 of the base plate 17, and the first V-groove 55 is parallel to the seventh plane 56. When the hydraulic cylinder 40 is placed on the support plate 39, its cylindrical outer wall fits into the first V-groove 55, thereby limiting the hydraulic cylinder 40 laterally and maintaining a stable posture. Since the hydraulic cylinder 40 needs to output a large axial force during the test, the support plate 39 provides stable support, preventing the hydraulic cylinder 40 from rolling, tilting, or displacing during loading. The position of the support plate 39 can be adjusted according to the center position of the pin hole 10 of the connecting plate 2, so that the axis of the hydraulic cylinder 40 is as consistent as possible with the target loading direction.

[0051] A support shaft 41 is installed in the pin hole 10 of the connecting plate 2. The support shaft 41 is a stepped component, with a fifth cylinder 64 at the top and a sixth cylinder 65 at the bottom. The sixth cylinder 65 is inserted into the pin hole 10 of the connecting plate 2, and its height is greater than the thickness between the first plane 15 and the second plane 16 of the connecting plate 2. Therefore, after the sixth cylinder 65 is inserted into the pin hole 10, a portion of it will protrude outside the connecting plate 2. The fifth cylinder 64 is located at the upper end of the support shaft 41 and can serve as an assembly and positioning auxiliary part. The support shaft 41 and the pin hole 10 of the connecting plate 2 preferably adopt a centering fit, so that the hydraulic loading chain can be accurately established with the center of the pin hole 10 as the point of action, thereby ensuring that the test force is transmitted to the connecting plate 2 along the expected position. The function of the support shaft 41 is to transmit the axial thrust from the support frame 42 and the hydraulic cylinder 40 to the connecting plate 2, so that the connecting plate 2 has a force tendency relative to the guide vane arm 3 around the positioning shaft 19, thereby allowing the safety pin 5 to bear the shear load.

[0052] The support frame 42 is located between the hydraulic cylinder 40 and the support shaft 41, serving as an intermediate force transmission component between the output force of the hydraulic cylinder 40 and the support shaft 41. The support frame 42 has a U-shaped overall cross-section, with one end forming an eighth plane 57 that contacts the end of the piston 43 of the hydraulic cylinder 40. The other end extends to form a first arm 58 and a second arm 59 that are parallel to each other. The distance between the first arm 58 and the second arm 59 is greater than the height from the first plane 15 to the second plane 16 of the connecting plate 2. Therefore, the support frame 42 can straddle the outside of the connecting plate 2, with the portion of the support shaft 41 extending out of the pin hole 10 located between its two arms. The ends of the first arm 58 and the second arm 59 away from the eighth plane 57 form a second V-groove 60. The second V-grooves 60 on both sides are machined at the same station and have the same structure, enabling them to fit together with the sixth cylinder 65 extending from the support shaft 41. In this way, when the hydraulic cylinder 40 pushes the support frame 42 forward, the support frame 42 transmits the thrust stably to the support shaft 41 through the second V-groove 60, and then the support shaft 41 transmits it to the pin hole 10 of the connecting plate 2. The contact method between the V-groove and the cylinder can enhance the self-centering ability between the support frame 42 and the support shaft 41 and reduce the risk of off-center loading.

[0053] After the overall test structure is established, the base plate 17 provides basic support. The positioning shaft 19 and the adjusting sleeve 23 constitute the installation and rotation center of the transmission mechanism 1. The first slider 25, the support block 31, and the wedge plate 32 constitute the limiting support and attitude adjustment system. The second slider 33, the adjusting pad 38, the support plate 39, the hydraulic cylinder 40, the support shaft 41, and the support frame 42 constitute the loading force transmission system. During the test, after the transmission mechanism 1 is positioned on the positioning shaft 19, the transmission mechanism 1 is first rotated so that the center line 29 formed by the pin hole 10 of the connecting plate 2 and the shaft hole 11 of the guide vane arm 3 is approximately parallel to the direction of the second groove 35. At the same time, the limiting surface 13 on the guide vane arm 3 is approximately facing the fourth plane 30 of the first slider 25. Then, the position of the first slider 25 is adjusted along the first groove 27 so that the fourth plane 30 is aligned with the limiting surface 13, and the support block 31 and the wedge plate 32 are installed between them to form a force support point on one side of the guide vane arm 3. Next, adjust the position of the second slider 33 along the second groove 35 so that the fifth plane 37 is aligned with the center of the pin hole 10 of the connecting plate 2. Then, install the adjusting shim 38 and the support plate 39, and place the hydraulic cylinder 40 on the support plate 39. The support shaft 41 is inserted into the pin hole 10 of the connecting plate 2, and the support frame 42 is set between the support shaft 41 and the piston 43 of the hydraulic cylinder 40, thereby establishing a complete force chain.

[0054] After the piston 43 of the hydraulic cylinder 40 extends, the hydraulic cylinder 40 forms a closed force path through the support frame 42, support shaft 41, connecting plate 2, safety pin 5, guide vane arm 3, support block 31, and wedge plate 32, and the overall structure enters the clamping state. At this time, the vertical deviation between the center line 29 and the axis of the hydraulic cylinder 40 and the support frame 42 can be measured. If there is a deviation, the pressure is released by the return stroke of the hydraulic cylinder 40, and the relative positions of the first wedge plate 62 and the second wedge plate 63 in the wedge plate 32 are adjusted to push the support block 31 and the limit block 12 to make a very small angle adjustment, thereby driving the transmission mechanism 1 to rotate slightly around the positioning shaft 19. In this way, the center line 29 can be adjusted to be perpendicular to the axis of the hydraulic cylinder 40 and the support frame 42. This vertical relationship is crucial because the loading torque arm at the pin hole 10 of the connecting plate 2 is maximized only when the force direction of the hydraulic cylinder 40 is perpendicular to the center line 29, and the required output force of the hydraulic cylinder 40 is minimized. Only then can the test results more accurately reflect the shearing torque of the safety pin 5. After this correction, the hydraulic cylinder 40 extends again, continuously applying pressure until the safety pin 5 breaks. At this point, the pressure value of the hydraulic cylinder 40 is recorded, and combined with the distance from the center of the pin hole 10 of the connecting plate 2 to the center of the positioning shaft 19, the shearing torque of the safety pin 5 can be calculated.

[0055] From the perspective of overall structural relationships, this technical solution is not simply about applying pressure to the transmission mechanism 1 by aligning the hydraulic cylinder 40 with it. Instead, it establishes a complete test structure based on the principles of "centering installation, adjustable position, calibrated posture, reasonable force application, and compatible specifications." The centering fit between the positioning shaft 19, adjusting sleeve 23, support shaft 41, and corresponding holes ensures the coaxiality of the transmission mechanism 1 during installation and the accuracy of the loading point. The structure of the first slider 25 and the second slider 33 sliding along the groove ensures that the support position and loading position can be adapted to different specifications of the transmission mechanism 1. The double-wedge surface fine-tuning structure of the wedge plate 32 allows for correction of the force direction and torque arm relationship during testing. The loading layout at the pin hole 10 of the connecting plate 2 places the force application point on the side away from the positioning center, thereby increasing the torque arm and reducing the required hydraulic pressure. The fit between the support frame 42 and the support shaft 41 makes the loading direction more stable and avoids uneven local force application. Therefore, this structure can reduce the requirements for hydraulic cylinder 40 specifications and support component size while ensuring test accuracy, thereby reducing the cost of the test device, and is suitable for safety pin tests of guide vane transmission mechanisms of different specifications.

[0056] Looking further, Figure 2The AA cross-sectional view shown primarily illustrates the support relationship between the first slider 25, the support block 31, the wedge plate 32, and the guide vane arm 3 limiting block 12. In this cross-section, it is clearly visible that the first slider 25 is embedded in the first groove 27 of the base plate 17 via the first key 26, its first end face 28 is in contact with the third plane 18, and its fourth plane 30 faces the limiting surface 13 of the guide vane arm 3. The support block 31 is located between the limiting surface 13 and the wedge plate 32, which is formed by stacking a first wedge plate 62 and a second wedge plate 63. This structure illustrates that the guide vane arm 3 does not directly and rigidly abut against the first slider 25, but rather forms a finely adjustable support chain through the support block 31 and the wedge plate 32, providing a basis for the angle correction of the guide vane arm 3 before being subjected to force.

[0057] Figure 3 The BB cross-sectional view shown primarily illustrates the loading and engagement relationships between the second slider 33, adjusting shim 38, support plate 39, hydraulic cylinder 40, support frame 42, and support shaft 41. It is evident that the second slider 33 is embedded in the second groove 35 of the base plate 17 via the second key 34, its second end face 36 is in contact with the third plane 18, and its fifth plane 37 faces the hydraulic cylinder 40. The adjusting shim 38 is fixed to the second slider 33 with screws 45. The hydraulic cylinder 40 is mounted on the support plate 39, and the piston 43 of the hydraulic cylinder 40 presses against the support frame 42. The support frame 42, in turn, is held and acts on the support shaft 41 by its two side structures. This cross-sectional view clearly demonstrates the hierarchical relationship of the hydraulic loading chain: the second slider 33 is responsible for the positional reference; the adjusting shim 38 is responsible for contact and compensation; the support plate 39 is responsible for support; the hydraulic cylinder 40 is responsible for power output; the support frame 42 is responsible for intermediate force transmission; and the support shaft 41 is responsible for guiding the load into the connecting plate 2.

[0058] Figure 4 The sectional view shown primarily illustrates the assembly relationships between the positioning shaft 19, adjusting sleeve 23, guide vane arm 3 shaft hole 11, and connecting plate 2 and guide vane arm 3. The first cylinder 20 of the positioning shaft 19 is installed in the third hole 21 of the base plate 17, the second annular surface 22 presses against the third plane 18 of the base plate 17, and the third annular surface 24 is in contact with the fourth annular surface 44 of the adjusting sleeve 23. The adjusting sleeve 23 is fitted outside the third cylinder 47 of the positioning shaft 19 and continues to mate with the shaft hole 11 of the guide vane arm 3. The connecting plate 2 is connected to the guide vane arm 3 via a safety pin 5 and clamps the friction bushing 4 via studs 6 and nuts 7. This sectional view indicates that the installation center, rotation datum, and experimental loading geometry of the transmission mechanism 1 are all established around the positioning shaft 19 and adjusting sleeve 23; therefore, these two components are prerequisites for ensuring the accuracy of the entire experimental structure.

[0059] Figures 5 to 12The structural design of each individual component is further illustrated. The positioning shaft 19, through three cylinders of different diameters and two annular surfaces, forms a two-stage positioning relationship with the base plate 17 and the adjusting sleeve 23. The adjusting sleeve 23, through its inner and outer coaxial cylindrical surfaces and the fourth annular surface 44, forms a replaceable intermediate centering sleeve. The first slider 25, through the first key 26, the first end face 28, and the second chamfered cylinder 61, constitutes a composite structure of "guide + support + working surface". The second slider 33, through the second key 34, the fourth cylinder 48, the first chamfered cylinder 49, the fifth plane 37, the third end face 50, and the threaded blind hole 51, constitutes a composite structure of "guide + load-bearing + connection". The adjusting pad 38 achieves planar fit and concealed screw fixing through the sixth plane 52, the countersunk hole 53, and the fourth hole 54. The support plate 39 provides stable support for the hydraulic cylinder 40 through the first V-groove 55 and the seventh plane 56. The support shaft 41 forms a two-stage structure—a socket positioning and an exposed load-bearing structure—through the fifth cylinder 64 and the sixth cylinder 65. The support frame 42 forms a bridging force transmission component through the eighth plane 57, the first support arm 58, the second support arm 59, and the second V-groove 60. The components are not isolated but work together to achieve the goals of "accurate positioning, stable support, precise adjustment, and reasonable loading" during the test, ultimately forming a complete implementation structure suitable for safety pin tests of guide vane drive mechanisms of different specifications of water turbines.

[0060] After completing the assembly of the above-mentioned test structure and the installation and positioning of the transmission mechanism 1, the implementation process of the safety pin test method is as follows: First, place the base plate 17 on a stable working platform, with the third plane 18 facing upwards as the overall installation reference. Place the positioning shaft 19 above the base plate 17, align the first cylinder 20 with the third hole 21 and insert it, and make the second annular surface 22 fit against the third plane 18, thereby establishing the vertical positioning relationship of the positioning shaft 19 relative to the base plate 17 and forming the rotation center reference for the entire test. Then, the adjusting sleeve 23 is fitted onto the third cylinder 47 of the positioning shaft 19, so that the fourth annular surface 44 of the adjusting sleeve 23 is in contact with the third annular surface 24 of the positioning shaft 19. On this basis, the transmission mechanism 1 is placed above the positioning shaft 19, so that the shaft hole 11 of the guide vane arm 3 is aligned with the adjusting sleeve 23 and fitted in, so that the first annular surface 14 of the guide vane arm 3 is in contact with the third annular surface 24 of the positioning shaft 19. Thus, the transmission mechanism 1 is mounted on the positioning shaft 19 with the adjusting sleeve 23 as the intermediate centering element, and obtains the degree of freedom to rotate around the positioning shaft 19. Insert the first key 26 of the first slider 25 into the first groove 27 of the base plate 17, so that the first end face 28 is in contact with the third plane 18. By moving the first slider 25 along the first groove 27, the fourth plane 30 is brought closer to the limiting surface 13 of the limiting block 12 of the guide vane arm 3. At the same time, rotate the transmission mechanism 1 around the positioning shaft 19 so that the center line 29 formed by the pin hole 10 of the connecting plate 2 and the shaft hole 11 of the guide vane arm 3 is approximately parallel to the direction of the second groove 35, and the limiting surface 13 faces the fourth plane 30. Then continue to adjust the position of the first slider 25 so that the fourth plane 30 and the limiting surface 13 are aligned in space. A support block 31 is placed between the fourth plane 30 and the limiting surface 13, and a wedge plate 32 is inserted between the support block 31 and the fourth plane 30, so that the first wedge plate 62 of the wedge plate 32 is in contact with the fourth plane 30, and the second wedge plate 63 is in contact with the support block 31. An adjustable support structure is formed by the wedge plate 32, so that one side of the guide vane arm 3 obtains a stable and finely adjustable support state. Insert the second key 34 of the second slider 33 into the second groove 35 of the base plate 17, so that the second end face 36 is in contact with the third plane 18. Move the second slider 33 along the second groove 35 to align the fifth plane 37 with the center of the pin hole 10 of the connecting plate 2. After alignment, place the adjusting shim 38 on the third end face 50 of the second slider 33 so that the sixth plane 52 is opposite to the fifth plane 37. Fix the adjusting shim 38 on the second slider 33 by passing the screw 45 through the fourth hole 54 and screwing it into the threaded blind hole 51, thereby forming a stable loading support surface on the second slider 33. Place a support plate 39 on one side of the adjusting shim 38, so that the seventh plane 56 of the support plate 39 fits against the third plane 18 of the base plate 17. Adjust the position of the support plate 39 so that its first V-groove 55 is roughly aligned with the center of the pin hole 10 of the connecting plate 2. Then place the hydraulic cylinder 40 in the first V-groove 55 of the support plate 39, so that the axis of the hydraulic cylinder 40 is basically consistent with the direction of the pin hole 10 of the connecting plate 2. Insert the support shaft 41 into the pin hole 10 of the connecting plate 2, so that the sixth cylinder 65 fits into the pin hole 10, and position the extended portion of the support shaft 41 on the outside of the connecting plate 2. Install the support bracket 42 on the outside of the support shaft 41, so that the second V-groove 60 of the support bracket 42 fits against the exposed sixth cylinder 65 of the support shaft 41, and at the same time, align the eighth plane 57 of the support bracket 42 with the end of the piston 43 of the hydraulic cylinder 40, thereby forming a complete force transmission path between the hydraulic cylinder 40 and the connecting plate 2. Hydraulic cylinder 40 is activated, causing piston 43 to extend pre-exist. This creates a closed force system formed by hydraulic cylinder 40, support frame 42, support shaft 41, connecting plate 2, safety pin 5, guide vane arm 3, support block 31, and wedge plate 32. In this state, the perpendicular deviation between the center line 29 and the axis of hydraulic cylinder 40 is measured. If a deviation exists, piston 43 of hydraulic cylinder 40 retracts to release the load. By adjusting the relative positions of the first wedge plate 62 and the second wedge plate 63 in wedge plate 32, support block 31 pushes guide vane arm 3 to rotate slightly. This causes transmission mechanism 1 to adjust around positioning shaft 19, gradually bringing center line 29 closer to being perpendicular to the axes of hydraulic cylinder 40 and support frame 42. Repeat the above preloading and measurement process until the center line 29 is perpendicular to the axis of the hydraulic cylinder 40 and the support frame 42. In this state, drive the hydraulic cylinder 40 again to continuously extend the piston 43. Through the support frame 42 and the support shaft 41, apply axial thrust to the pin hole 10 of the connecting plate 2. This causes the connecting plate 2 to experience a force tendency around the positioning shaft 19 relative to the guide vane arm 3, causing the safety pin 5 to bear shear load and gradually reach the fracture state. When safety pin 5 breaks, the pressure value of hydraulic cylinder 40 is recorded and converted into a force value acting on pin hole 10 of connecting plate 2. At the same time, the torque is calculated based on the distance from the center of pin hole 10 of connecting plate 2 to the center of positioning shaft 19, thus obtaining the shearing torque test result of safety pin 5. Through the above test method, the direction of the force is always perpendicular to the center line 29 throughout the loading process, so that the force arm is kept at its maximum, thereby reducing the output force required by the hydraulic cylinder 40 and improving the test accuracy. At the same time, the adaptation of different specifications of transmission mechanism 1 and the correction of loading direction are achieved by adjusting the slider and fine-tuning the wedge plate, so that the test results have good accuracy and versatility.

[0061] The above description of several specific embodiments further details the technical solution provided by the present invention in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above-described specific embodiments are not intended to limit the present invention. Any reasonable modifications and improvements to the present invention, combinations of embodiments, and equivalent substitutions based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A turbine guide vane transmission mechanism, characterized in that, include: The system comprises a guide vane arm, a friction bushing, a connecting plate, and a safety pin. The guide vane arm has a shaft hole, and the friction bushing is located between the guide vane arm and the connecting plate. The inner side of the friction bushing is interference-fitted with the guide vane arm. The connecting plate is sleeved on the outside of the friction bushing. The connecting plate is clamped and fixed to the friction bushing by studs and nuts, so that the connecting plate and the guide vane arm form a detachable and relatively fixed connection structure. The connecting plate and the guide vane arm are respectively provided with a first hole and a second hole that are coaxially corresponding to each other. The safety pin passes through the first hole and the second hole to achieve a shear connection between the connecting plate and the guide vane arm. The connecting plate is provided with a pin hole structure parallel to the axis of the first hole. A limiting block is provided on the guide vane arm, and the limiting block has a limiting surface for contacting the external support structure. A center line is formed between the center of the pin hole of the connecting plate and the center of the shaft hole of the guide vane arm. The center line is used as a reference for the torque action when the safety pin is subjected to shear force. At least one working plane of the connecting plate and the axial reference plane of the guide vane arm are perpendicular to the center line to establish a spatial geometric reference for the guide vane transmission mechanism under stress.

2. The turbine guide vane transmission mechanism according to claim 1, characterized in that, The first cylinder of the positioning shaft and the third hole of the base plate are aligned. After the positioning shaft is installed, its axis is perpendicular to the third plane of the base plate to establish the vertical installation reference of the guide vane transmission mechanism.

3. The turbine guide vane transmission mechanism according to claim 1, characterized in that, The adjusting sleeve is positioned between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so as to achieve the centering installation of the guide vane transmission mechanism relative to the positioning shaft.

4. The turbine guide vane transmission mechanism according to claim 1, characterized in that, The first slider is set in the first groove of the base plate and is guided and engaged with the first groove by the first key. The first slider can slide in a directional manner along the first groove. A fourth plane corresponding to the guide vane arm limiting surface is provided on the first slider to form a support structure on one side of the guide vane transmission mechanism.

5. The turbine guide vane transmission mechanism according to claim 1, characterized in that, The second slider is set in the second groove of the base plate and is guided and engaged with the second groove by the second key. The second slider can slide in a directional manner along the second groove. A fifth plane is provided on the second slider to correspond to the position of the pin hole of the connecting plate, so as to form a loading support structure on the other side of the guide vane transmission mechanism.

6. A test method for the safety pin of a turbine guide vane transmission mechanism, characterized in that, Based on the mechanism described in claim 1, it includes: The steps are as follows: Place the base plate with the third plane facing upwards, align the first cylinder of the positioning shaft with the third hole of the base plate and insert it, so that the second annular surface of the positioning shaft fits against the third plane to establish a vertical reference. The steps are as follows: the adjusting sleeve is fitted onto the positioning shaft and fits against the third annular surface of the positioning shaft; the turbine guide vane transmission mechanism is fitted onto the adjusting sleeve; and the guide vane arm shaft hole is aligned with the adjusting sleeve and positioned coaxially with the positioning shaft. The steps are as follows: insert the first slider into the first groove of the base plate and make the fourth plane of the first slider face the guide vane arm limiting surface; move the first slider to make the fourth plane aligned with the limiting surface; and set a support block and a wedge plate between the two to form a support and angle adjustment structure. Insert the second slider into the second groove of the base plate, move the second slider to align the fifth plane of the second slider with the center of the pin hole of the connecting plate, install the adjusting shim and set the support plate on the second slider, and install the hydraulic cylinder on the support plate so that its axis corresponds to the pin hole of the connecting plate. The steps include installing a support shaft and setting up a support frame in the pin hole of the connecting plate, so that the support frame is located between the hydraulic cylinder piston and the support shaft to form a loading force transmission path, and pre-extending the hydraulic cylinder piston to press the force system including the connecting plate, safety pin, guide vane arm, support block and wedge plate. The steps include measuring the vertical deviation between the center line formed by the center of the connecting plate pin hole and the center of the guide vane arm shaft hole and the hydraulic cylinder axis, and adjusting the wedge plate to rotate the turbine guide vane transmission mechanism around the positioning shaft so that the center line is perpendicular to the hydraulic cylinder axis. The process involves driving the hydraulic cylinder to continuously load the system while the center line is perpendicular to the axis of the hydraulic cylinder, causing the connecting plate to shear relative to the guide vane arm until the safety pin breaks. The steps include recording the pressure of the hydraulic cylinder when the safety pin breaks and converting it into a force, and calculating the shearing torque of the safety pin based on the distance from the center of the pin hole in the connecting plate to the center of the positioning shaft.

7. The test method for the safety pin of the guide vane transmission mechanism of a water turbine according to claim 6, characterized in that, The first cylinder of the positioning shaft and the third hole of the base plate are aligned. After the positioning shaft and the base plate are assembled, its axis is perpendicular to the third plane of the base plate to ensure that the spatial reference of the turbine guide vane transmission mechanism is consistent after installation.

8. The test method for the safety pin of the guide vane transmission mechanism of a water turbine according to claim 6, characterized in that, The adjusting sleeve is set between the positioning shaft and the guide vane arm shaft hole. The inner hole of the adjusting sleeve is coaxially fitted with the positioning shaft, and the outer circle is coaxially fitted with the guide vane arm shaft hole, so that the turbine guide vane transmission mechanism can be centered and installed through the adjusting sleeve.

9. The test method for the safety pin of the guide vane transmission mechanism of a water turbine according to claim 6, characterized in that, The first slider is guided and engaged with the first groove of the base plate by the first key and can slide directionally along the first groove. The fourth plane of the first slider is set to correspond to the limiting surface of the guide vane arm. The support position is matched by adjusting the position of the first slider.

10. A test method for the safety pin of a turbine guide vane transmission mechanism according to claim 6, characterized in that, The second slider is guided and engaged with the second groove of the base plate by the second key and can slide directionally along the second groove. The fifth plane of the second slider is set in accordance with the center of the pin hole of the connecting plate and is fixed by adjusting the pad and screw to form a loading support surface.

Images