Rail vehicle component durability testing system and method

Abstract

The application discloses a rail vehicle component durability test system and method, and belongs to the technical field of test equipment, which comprises a simulation suspension assembly, two simulation wheel hubs and two track simulation assemblies, the simulation suspension assembly is arranged on a base through a fixing frame, the two simulation wheel hubs are respectively used for being sleeved on two wheel seats of a to-be-tested axle, the two track simulation assemblies are arranged on the base and are used for simulating a real track, and the bases of the two track simulation assemblies are independently adjusted in lifting. The application sets an elastic mechanism between a first hydraulic cylinder and an axle box, the vertical downward load output by the first hydraulic cylinder is buffered by the elastic mechanism and then is transmitted to the axle box, compared with the mode that an actuating cylinder directly applies a load to the axle neck of the axle through a bearing seat in the prior art, the application can simulate the filtering and buffering characteristics of the vehicle suspension system to dynamic load, so that the transmission law of the test load is more consistent with the actual working condition.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and more specifically to a durability testing system and method for rail vehicle components. Background Technology

[0002] Axles are a crucial component of rail vehicles. During the design, production, and manufacturing process, axles require durability testing to fully evaluate their various performance characteristics. Several axle fatigue testing devices already exist in the prior art. For example, Chinese invention patent application CN116183257A discloses a fatigue testing device and method for rail transit vehicle axles. This device features two actuating cylinders arranged side-by-side on a mounting base. The axle journals at both ends are directly clamped by bearing seats. Loading wheels are installed on the left and right sides of the axle, and synchronous pulleys support the loading wheels from below and drive the axle to rotate. Simultaneously, the actuating cylinders apply a vertical load to the axle journals, thereby achieving rotational bending fatigue testing.

[0003] The above-mentioned device has many shortcomings: the actuating cylinder directly applies load to the axle journal through the bearing housing, and there is no elastic buffer in the load transmission path. It cannot simulate the filtering and buffering effect of the suspension spring on the dynamic load in actual vehicle operation. It cannot adapt to the small lateral displacement and angular deflection of the axle due to the elastic deformation of the suspension under actual working conditions. This results in a significant difference between the test load and the actual stress state of the axle, leading to a single test condition and insufficient reproduction. Summary of the Invention

[0004] To address the aforementioned technical shortcomings, the purpose of this invention is to provide a durability testing system and method for rail vehicle components, which improves the realism of the test conditions by setting up simulated suspension components and track simulation components.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a durability testing system for rail vehicle components, comprising: The simulated suspension assembly is mounted on a base via a mounting bracket. The simulated suspension assembly includes two axle boxes for mounting at both ends of the axle of the vehicle under test. The mounting bracket is equipped with two first hydraulic cylinders, which are connected to the two axle boxes via two elastic mechanisms. Two simulated wheel hubs are used to be fitted onto the two wheel seats of the axle to be tested; Two track simulation components are mounted on a base. Each track simulation component includes a base plate that is lifted and lowered on the base and a mounting platform that is slidably mounted on the base plate. A motor is fixed on the mounting platform, and the output shaft of the motor is connected to a drive wheel that mates with a simulated wheel hub. A second hydraulic cylinder is provided on the base plate for driving the mounting platform to move linearly on the base plate. The first hydraulic cylinder loads the end of the axle of the vehicle under test through the axle box, the drive wheel provides support for the simulated wheel hub and drives the simulated wheel hub to rotate, and the base plates of the two track simulation components can be independently raised and lowered.

[0006] Preferably, the elastic mechanism includes: Two guide posts are fixed on the mounting bracket and parallel to the first hydraulic cylinder; The push plate is fitted onto the two guide columns and connected to the first hydraulic cylinder; A floating seat is sleeved on two guide posts and located on the side of the push plate away from the first hydraulic cylinder. A spring is sleeved on the guide post between the floating seat and the push plate. The axle box is located below the floating seat and connected by an adaptive self-aligning structure.

[0007] Preferably, the adaptive self-aligning structure includes a displacement component for coordinating the horizontal displacement of the axle box and a self-aligning component for compensating for the angular deflection of the axle, wherein the self-aligning component is disposed at the movable end of the displacement component.

[0008] Preferably, the displacement assembly includes a slide rail disposed at the bottom of the floating seat and a slide block slidably mounted on the slide rail, and the self-aligning assembly is fixed on the slide block.

[0009] Preferably, the self-aligning assembly includes a ball socket fixed on the slide and a ball head rotatably mounted in the ball socket, and the axle box is fixedly connected to the ball head.

[0010] Preferably, the drive wheel includes a base wheel and an outer ring. The base wheel is rotatably mounted on the base plate via a bearing seat, and the outer ring is fixed to the base wheel and coaxial with the base wheel via a positioning structure.

[0011] Preferably, the positioning structure includes an outer conical surface disposed on the outer side of the base wheel and an inner conical surface disposed on the inner side of the outer wheel ring; the inner conical surface is fitted onto the outer conical surface, so that the outer wheel ring and the base wheel are self-centered; the base wheel is provided with a rim, and the outer wheel ring is bolted to the rim.

[0012] Preferably, the outer ring consists of a rail head ring, a rail waist ring, and a rail bottom ring from the outside to the inside. The inner conical surface is formed on the inner side of the rail bottom ring. The cross-sectional shapes of the rail head ring and the rail waist ring are the same as the cross-sectional shapes of the rails adapted to the railcar.

[0013] Preferably, the base is fixed with multiple columns by a support frame, the base plate is fixed with multiple sliding sleeves for fitting onto the columns, and the base is provided with a third hydraulic cylinder for driving the base plate to move up and down along the columns.

[0014] A method for testing the durability of rail vehicle components, using the aforementioned rail vehicle component durability testing system, includes the following steps: S1. Press the two simulated wheel hubs onto the two wheel seats of the axle to be tested, and install the journals at both ends of the axle to be tested into the two axle boxes of the simulated suspension assembly. S2. Drive the base plate to rise and fall, so that the drive wheel contacts and fits against the surface of the simulated wheel hub; S3. The first hydraulic cylinder outputs a preset load downwards, and the preset load is transmitted to the axle box through the elastic mechanism. S4. Start the motor to drive the drive wheel to rotate, and use the friction between the drive wheel and the simulated wheel hub to drive the simulated wheel hub and the axle to be tested to rotate at a preset speed. S5. Perform at least one of the following simulation tests according to the testing requirements: Vertical alternating fatigue test: The output pressure of the first hydraulic cylinder is dynamically changed to simulate the vertical vibration and weight fluctuation of the vehicle during operation. Lateral force test: The second hydraulic cylinder is controlled to drive the mounting platform to move laterally in a straight line on the base plate, and the drive wheel applies a lateral thrust to the simulated wheel hub to simulate the lateral force on the wheel when the vehicle is going through a curve or serpentine movement. Composite impact test: Control the asynchronous lifting of two base plates to dynamically change the height difference between the two drive wheels, simulating the vehicle's running state when the two sides of the track are uneven. S6. After the test cycle reaches the preset number of times or time, stop the operation of all hydraulic cylinders and motors, and perform flaw detection on the key stress parts of the axle to be tested in order to evaluate its fatigue life.

[0015] The beneficial effects of this invention are as follows: This invention incorporates an elastic mechanism between the first hydraulic cylinder and the axle box. The vertically downward load output by the first hydraulic cylinder is buffered by the elastic mechanism before being transmitted to the axle box. Compared to the prior art where the actuating cylinder directly applies load to the axle journal via the bearing housing, this invention can simulate the filtering and buffering characteristics of a vehicle suspension system for dynamic loads, making the load transmission pattern more consistent with actual working conditions. This invention also features a sliding mounting platform on the base plate. The second hydraulic cylinder drives the mounting platform and drive wheel to move laterally as a whole, allowing the lateral force to be directly transmitted to the wheel seat of the axle via the contact surface between the drive wheel and the simulated wheel hub. By aligning the position and direction with the actual lateral force between the wheel and rail when the vehicle is cornering or moving along a curve, this technology can accurately simulate the lateral force state of the axle under curved conditions, making the test results more comprehensive and reliable compared to existing technologies. The two base plates can be independently raised and lowered, allowing the drive wheels on both sides to independently support the corresponding simulated wheel hubs at the same or different heights. This simulates the force characteristics of the axle traveling on uneven road sections with height differences between the two sides of the track. The combined use of the above structures significantly improves the completeness of the simulation of the test conditions, can cover a variety of actual operating line conditions, and improves the realism of the test.

[0016] The drive wheel of this invention includes a base wheel and an outer ring. The outer ring achieves self-centering positioning with the base wheel through the mating of inner and outer conical surfaces and is fastened with bolts. This makes it easy to install and remove the outer ring from the base wheel and ensures coaxial accuracy. From the outside to the inside, the outer ring consists of a rail head ring, a rail waist ring, and a rail bottom ring. Its cross-sectional shape is the same as that of the rail that is compatible with the rail. Compared with the prior art, the outer ring of this invention can more accurately reproduce the wheel-rail contact profile and contact stress distribution. Furthermore, when the outer ring is worn, needs to be adapted to different types of rails, or needs to simulate special road conditions, only the outer ring needs to be replaced without replacing the entire drive wheel, reducing the cost of use and increasing the speed of adjusting test conditions.

[0017] This invention features an adaptive self-aligning structure between the floating seat and the axle box, including a displacement assembly (slide rail and slide seat) for accommodating the horizontal displacement of the axle box and a self-aligning assembly (ball socket and ball joint) for compensating for axle angular deflection. This structure can follow the minute lateral displacements and angular deflections generated by the axle during rotation and loading in real time, eliminating the additional constraint reaction force introduced by the rigid constraint at the axle end in the prior art, avoiding the interference of constraint force on the test load, improving the accuracy of the load transmission path, and enabling the test data to more accurately reflect the actual load-bearing state of the axle. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a front-view perspective view of the overall structure of the rail vehicle component durability testing system provided in an embodiment of the present invention.

[0020] Figure 2 This is a front view of the overall structure of the present invention.

[0021] Figure 3 This is a perspective view of the overall structure of the present invention from a bottom angle.

[0022] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0023] Figure 5 This is a three-dimensional view of the simulated hub and drive wheel in this invention.

[0024] Figure 6 This is a top view of the simulated hub and drive wheel in this invention.

[0025] Figure 7 for Figure 6 Sectional view at point AA.

[0026] Figure 8 for Figure 7 A magnified view of a portion of point A in the middle.

[0027] Explanation of reference numerals in the attached figures: 1. Fixing frame, 2. Base, 3. Axle to be tested, 4. Axle box, 5. First hydraulic cylinder, 6. Simulated wheel hub, 7. Base plate, 8. Mounting platform, 9. Motor, 10. Drive wheel, 11. Second hydraulic cylinder, 12. Guide column, 13. Push plate, 14. Floating seat, 15. Spring, 16. Slide rail, 17. Slide seat, 18. Ball socket, 19. Ball head, 20. Base wheel, 21. Outer wheel rim, 22. Bearing seat, 23. Outer conical surface, 24. Inner conical surface, 25. Wheel flange, 26. Rail head ring, 27. Rail waist ring, 28. Rail bottom ring, 29. Column, 30. Support frame, 31. Sliding sleeve, 32. Third hydraulic cylinder. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: like Figures 1 to 8 As shown, Embodiment 1 of the present invention provides a durability testing system for rail vehicle components, which can perform comprehensive durability testing on the axle 3 to be tested in an experimental environment. By simulating the stress state of the vehicle during actual operation, it can realistically reproduce the various loads that the axle bears during the vehicle's operation, thereby making a more accurate assessment.

[0030] This testing system includes a robust, rigid base 2, capable of maintaining stability under high-frequency alternating loads. A simulated suspension assembly and two track simulation assemblies are mounted on the base 2. The simulated suspension assembly bears the axle 3 under test and applies vertical loads to it, simulating the effect of a bogie on the axle of a railcar. The simulated suspension assembly is mounted on the base 2 via a rigid mounting bracket 1. The mounting bracket 1 can be welded to the base 2 or bolted to it. The mounting bracket 1 has sufficient vertical height to allow for the mounting of the simulated suspension assembly above it and provides ample space for the track simulation assemblies and axle below.

[0031] like Figure 1 As shown, the mounting frame 1 is equipped with two vertical first hydraulic cylinders 5, corresponding to the two ends of the axle 3 under test. The simulated suspension assembly includes two axle boxes 4, which are respectively installed on the journals at both ends of the axle 3 under test. Bearings are sleeved on the journals inside the axle boxes 4. The two first hydraulic cylinders 5 are connected to the two axle boxes 4 through two elastic mechanisms, thereby positioning and supporting the axle 3 under test on the test station. The thrust output vertically downward by the first hydraulic cylinders 5 is elastically buffered by the elastic mechanisms before being transmitted to the axle boxes 4, and finally acting on the ends of the axle 3 under test. The setting of the elastic mechanisms gives the load transmission process a certain elastic buffering characteristic, which can simulate the filtering and absorption effect of the vehicle suspension system on dynamic loads during actual operation, making the load characteristics applied to the axle more consistent with the axle stress state during actual vehicle driving.

[0032] Two simulated wheel hubs 6 are respectively fitted onto the two wheel seats of the axle 3 under test. The simulated wheel hubs 6 are interference-fitted with the wheel seats, and the outer diameter, material, and surface characteristics of the simulated wheel hubs 6 correspond to those of the wheels actually used on the rail vehicle. Two track simulation components are set on the base 2 and located directly below the wheel seats on both sides of the axle 3 under test. They are used to support the simulated wheel hubs 6 from below and provide them with driving force to simulate the contact state between the real track and the wheel.

[0033] Each track simulation component includes a base plate 7 and a mounting platform 8. The base plate 7 is a height-adjustable structure, capable of vertical adjustment on the base 2. Specifically, multiple columns 29 are fixed to the base 2 via multiple support frames 30, and the columns 29 are vertically arranged. Multiple sliding sleeves 31 are fixed to the base plate 7, and the sliding sleeves 31 are fitted onto the corresponding columns 29, allowing the base plate 7 to slide up and down along the columns 29 without lateral deviation. At the same time, a third hydraulic cylinder 32 is installed on the base 2, and the movable end of the third hydraulic cylinder 32 is connected to the base plate 7, driving the base plate 7 to rise and fall along the column 29 through telescopic movement. A guide rail is fixed to the base plate 7, and a slider is fixed to the bottom of the mounting platform 8 and slidably mounted on the guide rail, allowing the mounting platform 8 to move laterally in a straight line along the horizontal direction of the base plate 7. A motor 9 and a bearing seat 22 are fixed to the mounting platform 8, and a drive wheel 10 is rotatably mounted on the bearing seat 22. The output shaft of the motor 9 is connected to the shaft of the drive wheel 10, and the motor 9 drives the drive wheel 10 to rotate.

[0034] When the third hydraulic cylinder 32 drives the base plate 7 to rise, causing the drive wheel 10 to contact and engage with the wheel surface of the corresponding simulated wheel hub 6, the engagement between the wheel and the track can be simulated. The motor 9 drives the simulated wheel hub 6 and the axle 3 under test to rotate through the friction between the drive wheel 10 and the simulated wheel hub 6.

[0035] A second hydraulic cylinder 11 is hinged to the base plate 7. The movable end of the second hydraulic cylinder 11 is hinged to the mounting platform 8. This allows the second hydraulic cylinder 11 to drive the mounting platform 8, together with the motor 9 and the drive wheel 10, to move laterally and linearly on the base plate 7, thereby applying a lateral thrust to the simulated wheel hub 6 to simulate the lateral contact force between the wheel and the rail when turning.

[0036] By controlling the extension and retraction of the two third hydraulic cylinders 32, the base plates 7 of the two track simulation components can be raised and lowered independently. That is, the lifting height of the base plates 7 on both sides can be controlled independently, so that the two drive wheels 10 can support the corresponding simulated wheel hubs 6 at the same or different heights. When the two base plates 7 are at different heights, the support of the two drive wheels 10 on the two simulated wheels creates a height difference, thereby simulating the stress state of the axle when there is unevenness in the track on both sides.

[0037] Example 2: Based on Example 1, this embodiment further optimizes the elastic mechanism to more accurately simulate the elastic characteristics of the vehicle suspension system and eliminate the influence of lateral displacement and angular deflection generated by the axle during rotation and loading on the accuracy of the test load.

[0038] like Figures 2 to 4 As shown, taking one of the elastic mechanisms as an example, the specific structure of the elastic mechanism in this embodiment is as follows: Two guide posts 12 are vertically fixed on the fixed frame 1. The two guide posts 12 are parallel to each other and both are parallel to the extension and retraction direction of the first hydraulic cylinder 5. A push plate 13 is sleeved on the two guide posts 12. The push plate 13 is fixedly connected to or hinged to the movable end of the first hydraulic cylinder 5, which allows the push plate 13 to move smoothly along the axial direction under the guidance of the guide posts 12, avoiding swaying when the first hydraulic cylinder 5 outputs pressure. A floating seat 14 is sleeved on the two guide posts 12. The floating seat 14 is located on the side of the push plate 13 away from the first hydraulic cylinder 5, that is, below the push plate 13. A spring 15 is sleeved on the guide post 12 between the floating seat 14 and the push plate 13. The spring 15 is located between the push plate 13 and the floating seat 14. When the first hydraulic cylinder 5 applies downward force through the push plate 13, the spring 15 is compressed and transmits the elastic force to the floating seat 14, which in turn transmits it to the axle box 4, thereby simulating the buffer characteristics of the vehicle suspension system. The stiffness parameters of spring 15 can be matched and selected according to the actual parameters of the suspension system of different vehicle models to improve the consistency between the test load transmission characteristics and the real working conditions.

[0039] The axle box 4 is located below the floating seat 14 and is connected to the floating seat 14 through an adaptive self-aligning structure. The adaptive self-aligning structure can follow the small lateral displacement and angular deflection generated by the axle during rotation and loading in real time, eliminate the interference of rigid constraints on the test load, and ensure that the vertical load applied by the first hydraulic cylinder 5 can be accurately and completely transmitted to the axle journal.

[0040] like Figure 4As shown, the adaptive self-aligning structure comprises two parts: a displacement component and a self-aligning component. The displacement component adapts to the lateral displacement of the axle box 4 in the horizontal direction. Specifically, a slide rail 16 is fixed to the bottom of the floating seat 14, and the slide rail 16 is arranged horizontally along the axle axis. A slide block 17 is slidably mounted on the slide rail 16 and can move freely horizontally under the guidance of the slide rail 16, thus following the lateral displacement of the axle box 4 caused by axle rotation or lateral force, without generating additional lateral constraint reaction force. The self-aligning component compensates for the small angular deflection of the axle under load. Specifically, a ball joint 18 is fixed to the slide block 17, and a ball head 19 is rotatably mounted in the ball joint 18. The ball head 19 can rotate at a small angle in any direction within the ball joint 18. The axle box 4 is fixedly connected to the ball head 19, allowing the axle box 4 to freely adjust its posture according to the angular deflection of the axle without generating additional bending moment on the axle. Since the self-aligning component is fixed at the movable end of the displacement component, i.e., the ball socket 18 is installed on the slide 17, the displacement compensation and angle compensation functions are organically combined to achieve adaptive following of the axle end attitude change. This can truly reproduce the small movement of the axle caused by the elastic deformation of the suspension under actual working conditions, making the test data more accurately reflect the real load state of the axle and significantly improving the reliability and reference value of the test results.

[0041] Considering that the drive wheel 10 is prone to wear during long-term testing, and to reduce replacement difficulty and cost, the drive wheel 10 is designed as a split structure, consisting of two main components: a base wheel 20 and an outer wheel rim 21. The axle of the base wheel 20 is rotatably mounted on the base plate 7 via a bearing seat 22. The outer wheel rim 21 is fixed to the outside of the base wheel 20 by a positioning structure and remains coaxial with the base wheel 20. The outer surface of the outer wheel rim 21 directly contacts the simulated wheel hub 6, undertaking the function of transmitting support force and driving friction to the simulated wheel hub 6.

[0042] like Figures 5 to 8 As shown, the positioning structure between the outer ring 21 and the base wheel 20 adopts a conical self-centering fit. An outer conical surface 23 is machined on the outer side of the base wheel 20, and an inner conical surface 24 corresponding to the outer conical surface 23 is machined on the inner side of the outer ring 21. During installation, the inner conical surface 24 is fitted onto the outer conical surface 23. The fit between the two conical surfaces achieves precise self-centering alignment of the outer ring 21 relative to the base wheel 20, ensuring that the coaxiality of the two meets the testing accuracy requirements and avoiding additional bending vibration caused by eccentricity. Simultaneously, a rim 25 is integrally formed on the base wheel 20. The outer ring 21 and the rim 25 are connected by bolts. The bolts provide axial tightening force to prevent the outer ring 21 from moving axially during operation, ensuring the reliability of the connection between the outer ring 21 and the base wheel 20.

[0043] With the above settings, the outer wheel rim 21 can be easily removed and installed from the base wheel 20. When the outer wheel rim 21 is worn for a long time and the contact profile deviation exceeds the allowable range, or when it is necessary to adapt to different types of rails to simulate different track conditions, only the outer wheel rim 21 needs to be replaced. There is no need to disassemble the entire drive wheel 10 assembly, which greatly reduces maintenance costs and improves the efficiency of adjusting test conditions.

[0044] The outer ring 21 consists of three layers from the outside in: a rail head ring 26, a rail waist ring 27, and a rail bottom ring 28. The inner conical surface 24 is formed on the inner side of the rail bottom ring 28. The cross-sectional shapes of the rail head ring 26 and the rail waist ring 27 are exactly the same as the cross-sectional shapes of the rails used in the train. This allows the contact profile and contact stress distribution between the drive wheel 10 and the simulated wheel hub 6 to more accurately reproduce the actual wheel-rail contact state compared with existing technologies, effectively improving the simulation accuracy of the test system.

[0045] Example 3: Based on the above embodiments, the present invention also provides a method for conducting durability testing of rail vehicle components using the above system. The specific operation steps are as follows: First, two simulated wheel hubs 6 are pressed onto the two wheel seats of the axle 3 of the vehicle under test, ensuring a reliable interference fit between the simulated wheel hubs 6 and the wheel seats, without any looseness or eccentricity. Then, the journals at both ends of the axle 3 of the vehicle under test are installed into the two axle boxes 4 of the simulated suspension assembly.

[0046] After installation, the third hydraulic cylinder 32 is driven to lift the two base plates 7 respectively. The base plates 7 rise steadily along the column 29 until the contact surfaces of the two drive wheels 10 are tightly attached to the outer surfaces of the corresponding simulated wheel hubs 6. Sufficient positive pressure is formed between the drive wheels 10 and the simulated wheel hubs 6 to ensure effective transmission of friction force in the future.

[0047] After the drive wheel 10 is in place with the simulated wheel hub 6, the first hydraulic cylinder 5 is activated. The two first hydraulic cylinders 5 output a preset load downwards respectively. The preset load is elastically buffered by the elastic mechanism and transmitted to the corresponding axle box 4, thereby simulating the actual state of the vehicle body weight and dynamic load on the axle.

[0048] After the vertical load is applied stably, two motors 9 are started. The motors 9 drive the drive wheel 10 to rotate continuously. Through the friction between the drive wheel 10 and the contact surface of the simulated wheel hub 6, the simulated wheel hub 6 and the axle under test 3 are driven to rotate continuously at a preset speed, so that the axle under test 3 is in the same rotational bending stress state as in actual operation.

[0049] With the axle 3 of the vehicle under test rotating and continuously subjected to a preset vertical load, the following tests can be performed according to testing requirements: Vertical alternating fatigue test: By controlling the first hydraulic cylinder 5 to dynamically change its output pressure, the vertical load applied to the axle box 4 changes periodically according to the set amplitude and frequency, thereby simulating the vertical alternating load caused by factors such as track irregularities, vehicle body vibration and vehicle body weight fluctuation during vehicle operation. This causes the test axle 3 to be subjected to periodically changing bending stress while rotating, thus realistically reproducing the working condition of the axle.

[0050] Lateral force test: With the axle 3 under test continuously rotating and the first hydraulic cylinder 5 maintaining a vertical load output, the mounting platform 8 is driven to move linearly in the lateral direction on the base plate 7 by controlling the second hydraulic cylinder 11. The mounting platform 8, together with the motor 9 and the drive wheel 10, undergoes lateral displacement as a whole. The contact surface of the drive wheel 10 applies a lateral thrust to the wheel surface of the simulated wheel hub 6. This lateral thrust is transmitted to the wheel seat area of ​​the axle 3 under test through the simulated wheel hub 6. The position and direction of the lateral force are completely consistent with the actual lateral force between the wheel and rail when the vehicle is cornering or swerving. Therefore, it can accurately simulate the combined stress state of the axle under curve conditions, simultaneously bearing vertical load and lateral force, making the test conditions more comprehensive and realistic. The magnitude of the lateral thrust can be precisely controlled by adjusting the output pressure of the second hydraulic cylinder 11 to match the lateral force amplitude under different speeds and curve radii.

[0051] Composite impact test: By implementing independent asynchronous control of the third hydraulic cylinder 32 of the two track simulation components, the two side base plates 7 move asynchronously according to the preset timing and amplitude, so that the contact height of the two drive wheels 10 produces a dynamic height difference. As a result, the two ends of the test axle 3 generate asymmetrical support force and torsional bending moment, simulating the torsional and bending composite impact load on the axle when the vehicle is traveling on an uneven road section with a height difference between the two sides of the track, and realistically reproducing the stress state of the axle under harsh track conditions.

[0052] With the testing system provided in the above embodiments, the three test conditions can be executed individually or combined and superimposed according to actual test requirements to form a multi-condition composite loading mode. This allows for a comprehensive evaluation of the fatigue life of the axle 3 under various typical operating scenarios under a single loading condition, significantly improving the integrity and efficiency of the test.

[0053] After the test cycle reaches the preset number of times or time, stop the operation of all hydraulic cylinders and motors 9. After the axle 3 under test has completely stopped rotating, use non-destructive testing methods such as ultrasonic testing and magnetic particle testing to conduct comprehensive flaw detection on the key stress-bearing parts of the axle 3 under test. Focus on checking whether there are fatigue cracks or damage in stress concentration locations such as the wheel seat transition fillet area, the root of the journal and the middle section of the axle. Based on the test results, evaluate the fatigue life and structural integrity of the axle.

[0054] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A durability testing system for rail vehicle components, characterized in that, include: The simulated suspension assembly is mounted on a base via a mounting bracket. The simulated suspension assembly includes two axle boxes for mounting at both ends of the axle of the vehicle under test. The mounting bracket is equipped with two first hydraulic cylinders, which are connected to the two axle boxes via two elastic mechanisms. Two simulated wheel hubs are used to be fitted onto the two wheel seats of the axle to be tested; Two track simulation components are mounted on a base. Each track simulation component includes a base plate that is lifted and lowered on the base and a mounting platform that is slidably mounted on the base plate. A motor is fixed on the mounting platform, and the output shaft of the motor is connected to a drive wheel that mates with a simulated wheel hub. A second hydraulic cylinder is provided on the base plate for driving the mounting platform to move linearly on the base plate. The first hydraulic cylinder loads the end of the axle of the vehicle under test through the axle box, the drive wheel provides support for the simulated wheel hub and drives the simulated wheel hub to rotate, and the base plates of the two track simulation components can be independently raised and lowered.

2. The rail vehicle component durability testing system as described in claim 1, characterized in that, The elastic mechanism includes: Two guide posts are fixed on the mounting bracket and parallel to the first hydraulic cylinder; The push plate is fitted onto the two guide columns and connected to the first hydraulic cylinder; A floating seat is sleeved on two guide posts and located on the side of the push plate away from the first hydraulic cylinder. A spring is sleeved on the guide post between the floating seat and the push plate. The axle box is located below the floating seat and connected by an adaptive self-aligning structure.

3. The rail vehicle component durability testing system as described in claim 2, characterized in that, The adaptive self-aligning structure includes a displacement component for coordinating the horizontal displacement of the axle box and a self-aligning component for compensating for the angular deflection of the axle, wherein the self-aligning component is disposed at the movable end of the displacement component.

4. The rail vehicle component durability testing system as described in claim 3, characterized in that, The displacement assembly includes a slide rail disposed at the bottom of the floating seat and a slide block slidably mounted on the slide rail, with the self-aligning assembly fixed on the slide block.

5. The rail vehicle component durability testing system as described in claim 4, characterized in that, The self-aligning assembly includes a ball socket fixed on the slide and a ball head rotatably installed in the ball socket, and the axle box is fixedly connected to the ball head.

6. The rail vehicle component durability testing system as described in claim 1, characterized in that, The drive wheel includes a base wheel and an outer ring. The base wheel is rotatably mounted on the base plate via a bearing seat, and the outer ring is fixed to the base wheel and coaxial with the base wheel via a positioning structure.

7. The rail vehicle component durability testing system as described in claim 6, characterized in that, The positioning structure includes an outer conical surface disposed on the outer side of the base wheel and an inner conical surface disposed on the inner side of the outer wheel ring; the inner conical surface is fitted onto the outer conical surface, so that the outer wheel ring and the base wheel are self-centered; the base wheel is provided with a rim, and the outer wheel ring is bolted to the rim.

8. The rail vehicle component durability testing system as described in claim 7, characterized in that, The outer ring consists of a rail head ring, a rail waist ring, and a rail bottom ring from the outside to the inside. The inner conical surface is formed on the inner side of the rail bottom ring. The cross-sectional shapes of the rail head ring and the rail waist ring are the same as the cross-sectional shapes of the rails adapted to the rail train.

9. The rail vehicle component durability testing system as described in claim 1, characterized in that, The base is fixed with multiple columns by a support frame, and the base plate is fixed with multiple sliding sleeves for fitting onto the columns. The base is provided with a third hydraulic cylinder for driving the base plate to move up and down along the columns.

10. A method for testing the durability of rail vehicle components, employing the rail vehicle component durability testing system according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Press the two simulated wheel hubs onto the two wheel seats of the axle to be tested, and install the journals at both ends of the axle to be tested into the two axle boxes of the simulated suspension assembly. S2. Drive the base plate to rise and fall, so that the drive wheel contacts and fits against the surface of the simulated wheel hub; S3. The first hydraulic cylinder outputs a preset load downwards, and the preset load is transmitted to the axle box through the elastic mechanism. S4. Start the motor to drive the drive wheel to rotate, and use the friction between the drive wheel and the simulated wheel hub to drive the simulated wheel hub and the axle to be tested to rotate at a preset speed. S5. Perform at least one of the following simulation tests according to the testing requirements: Vertical alternating fatigue test: The output pressure of the first hydraulic cylinder is dynamically changed to simulate the vertical vibration and weight fluctuation of the vehicle during operation. Lateral force test: The second hydraulic cylinder is controlled to drive the mounting platform to move laterally in a straight line on the base plate, and the drive wheel applies a lateral thrust to the simulated wheel hub to simulate the lateral force on the wheel when the vehicle is going through a curve or serpentine movement. Composite impact test: Control the asynchronous lifting of two base plates to dynamically change the height difference between the two drive wheels, simulating the vehicle's running state when the two sides of the track are uneven. S6. After the test cycle reaches the preset number of times or time, stop the operation of all hydraulic cylinders and motors, and perform flaw detection on the key stress parts of the axle to be tested in order to evaluate its fatigue life.

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