Crankshaft bending fatigue test system

Abstract

The invention provides a crankshaft bending fatigue test system. The crankshaft bending fatigue test system comprises a guide rail part and a plurality of clamping parts, one end of each clamping part is movably connected with the guide rail part, the other end of each clamping part extends downwards along the vertical direction, each clamping part is provided with a crankshaft mounting position, every two clamping parts in the plurality of clamping parts form a clamping group, and the clamping group is provided with a crankshaft mounting position. Each clamping group is connected with the two ends of the crankshaft to be tested through the crankshaft mounting positions; wherein one end, far away from the guide rail part, of each clamping group is respectively connected with the load loading device and the calibration plate, and the load loading device and the calibration plate are oppositely arranged. The problems of low bending fatigue performance test efficiency and reliability of the crankshaft in the prior art are solved.

Description

Technical Field

[0001] This invention relates to the field of performance testing and quality control of automotive engine components, and more specifically, to a crankshaft bending fatigue testing system. Background Technology

[0002] The crankshaft is a critical moving component of a car engine. Statistics show that bending fatigue is a major cause of crankshaft fracture, and ensuring the crankshaft's bending fatigue performance is fundamental to improving vehicle stability. Current crankshaft bending fatigue testing equipment uses a loading method where a vibrator is connected to a vibrating arm. The crankshaft is clamped by manually tightening multiple bolts, and vibration patterns are collected using strain gauges or sensors. However, this testing method involves a long crankshaft clamping time, and occasional crankshaft loosening occurs after prolonged wear at the contact surface between the testing equipment and the bolts.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] The main objective of this invention is to provide a crankshaft bending fatigue testing system to solve the problems of low efficiency and reliability in the testing of crankshaft bending fatigue performance in the prior art.

[0005] To achieve the above objectives, according to one aspect of the present invention, a crankshaft bending fatigue testing system is provided, comprising: a guide rail portion and a clamping portion, wherein there are multiple clamping portions, one end of each clamping portion is movably connected to the guide rail portion, the other end of each clamping portion extends downward in a vertical direction, each clamping portion is provided with a crankshaft mounting position, and every two clamping portions in the plurality of clamping portions form a clamping group, and each clamping group is connected to both ends of the crankshaft to be tested through the crankshaft mounting position; wherein, the end of each clamping group away from the guide rail portion is respectively connected to a load loading device and a calibration plate, and the load loading device and the calibration plate are disposed opposite to each other.

[0006] Furthermore, one of the two clamping parts in the clamping assembly is movably arranged relative to the other, and the height of the crankshaft mounting position of each clamping part is adjustable in the vertical direction.

[0007] Furthermore, each clamping assembly includes a first crankshaft mounting position and a second crankshaft mounting position. At least one clamping assembly includes: a first clamping part, the first end of which is provided with the first crankshaft mounting position, and the first end of which is movably connected to the guide rail part via a first lifting mechanism, and the second end of which is connected to the load loading device; and a second clamping part, which is disposed opposite to the first clamping part to form a clamping space for clamping the crankshaft, the first end of which is provided with the second crankshaft mounting position, and the first end of which is movably connected to the guide rail part via a second lifting mechanism, and the second end of which is connected to the bottom surface of the test bench via a calibration plate.

[0008] Furthermore, both the first clamping part and the second clamping part are provided with a locking mechanism. Part of the locking mechanism is movably provided relative to the first clamping part or the second clamping part, so that the locking mechanism has a locking position for locking the crankshaft located in the first crankshaft mounting position or the second crankshaft mounting position, and a release position for releasing the crankshaft located in the first crankshaft mounting position or the second crankshaft mounting position.

[0009] Further, the locking mechanism includes: an oil chamber housing located on one side of the first clamping portion, with a portion of the surface of the oil chamber housing facing the first clamping portion recessed away from the first clamping portion to form a mounting cavity; a hydraulic ring connected to the first clamping portion via a connector, at least a portion of the hydraulic ring being disposed within the oil chamber housing, and an oil cavity being formed between the hydraulic ring and the oil chamber housing; a locking ring assembly, one end of which is located within the first crankshaft mounting position, and the other end of which extends into the mounting cavity, the inner circle of which is used for mounting the crankshaft, and the outer circumferential surface of which is tapered, with the cavity wall of the mounting cavity fitting against the tapered surface; and an oil pump connected to the first clamping portion, communicating with the oil cavity through an oil hole on the oil chamber housing, the oil pump supplying and unloading oil into the oil cavity to control the movement of the oil chamber housing along the tapered surface of the locking ring assembly to the locking position and the release position.

[0010] Furthermore, the locking ring assembly includes: an inner bushing, one end of which is disposed within the first crankshaft mounting position, and the other end of which extends into the mounting cavity, the inner circle of which is used to mount the crankshaft; and an inner ring, the inner circular surface of which is fitted against at least a portion of the outer circular surface of the inner bushing, and at least a portion of the outer surface of the inner ring having a tapered surface.

[0011] Furthermore, the inner bushing includes: a bushing body, which has a through hole that penetrates between the inner and outer circular surfaces, and the bushing body also has a through groove that penetrates between the two end faces of the bushing body, wherein there are one or more through grooves.

[0012] Furthermore, at least one of the first lifting mechanism and the second lifting mechanism includes two lifting components, which are respectively disposed on both sides of the first clamping part or the second clamping part.

[0013] Furthermore, at least one lifting component includes: a slide rail, with a first pulley at each end of the slide rail, and a guide rail corresponding to each first pulley; the slide rail is slidably disposed along the length direction of the guide rail via the first pulleys; a slider, with a second pulley at the top of the slider, the second pulley being slidably connected to the slide rail, the slider being slidably disposed along the length direction of the slide rail via the second pulley, a connecting rod at the bottom of the slider, and an external thread on the outer surface of the connecting rod; and a lifting block, with a through lifting hole at the top of the lifting block, an internal thread in the lifting hole that mates with the external thread, and the bottom of the lifting block being connected to a first clamping part or a second clamping part via a suspension rope.

[0014] Furthermore, the crankshaft bending fatigue testing system also includes: a sensor connected to a second clamping part; and a strain gauge used to attach to the crankshaft to be tested. Both the sensor and the strain gauge are used to receive vibration information generated by the crankshaft during the test.

[0015] By applying the technical solution of this invention, a highly efficient and stable clamping and automated testing process for crankshafts is achieved through a guide rail and multiple movable clamping parts. During testing, the crankshaft mounting position ensures accurate alignment between the crankshaft and each clamping part. The vertical extension design of the clamping parts allows the crankshaft to withstand cyclic bending loads under the action of the load loading device and calibration plate, simulating fatigue effects under actual working conditions. This overcomes the limitations of traditional manual clamping and loading, improves the automation level of the test, and reduces labor costs. Furthermore, the relative arrangement of the load loading device and the calibration plate allows for precise control of the load and frequency during the test, thereby improving the efficiency and reliability of the crankshaft bending fatigue test. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0017] Figure 1 A schematic diagram of the structure of a first embodiment of the crankshaft bending fatigue testing system according to the present invention is shown;

[0018] Figure 2a A schematic diagram of a second embodiment of the crankshaft bending fatigue testing system according to the present invention is shown;

[0019] Figure 2b A schematic diagram of a third embodiment of the crankshaft bending fatigue testing system according to the present invention is shown;

[0020] Figure 3a A schematic diagram of the structure of a first embodiment of the inner liner according to the present invention is shown;

[0021] Figure 3b A schematic diagram of a second embodiment of the inner liner according to the present invention is shown;

[0022] Figure 4 A schematic diagram of a sixth embodiment of the crankshaft bending fatigue testing system according to the present invention is shown;

[0023] Figure 5 The diagram shows a bending fatigue limit test performed using the crankshaft bending fatigue testing system of the present invention.

[0024] The above figures include the following reference numerals:

[0025] 10. Guide rail section; 100. Sensor; 101. Strain gauge;

[0026] 20. Clamping part; 200. Crankshaft mounting position; 201. First crankshaft mounting position; 202. Second crankshaft mounting position; 2000. Slide rail; 2001. First pulley; 2002. Slider; 2003. Connecting rod; 2004. Lifting block; 2005. Lifting rope; 2006. Second pulley;

[0027] 21. First clamping part; 22. First lifting mechanism; 23. Second clamping part; 24. Second lifting mechanism;

[0028] 30. Limit bolts;

[0029] 40. Locking mechanism; 41. Oil chamber housing; 410. Mounting cavity; 411. Oil chamber; 42. Hydraulic ring; 43. Locking ring assembly;

[0030] 431. Inner bushing; 4310. Bushing body; 4311. Through hole; 4312. Through groove;

[0031] 432. Inner ring; 44. Oil pump;

[0032] 50. Connectors;

[0033] 60. Loading device;

[0034] 70. Calibration plate;

[0035] 80. Crankshaft;

[0036] 90. Bottom surface of the test bench. Detailed Implementation

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0041] Combination Figures 1 to 5 As shown, according to a specific embodiment of this application, a crankshaft bending fatigue testing system is provided.

[0042] Specifically, such as Figure 1As shown, the crankshaft bending fatigue testing system includes: a guide rail section 10 and a clamping section 20. There are multiple clamping sections 20. One end of each clamping section 20 is movably connected to the guide rail section 10, and the other end of each clamping section 20 extends downward in the vertical direction. Each clamping section 20 is provided with a crankshaft mounting position 200. Every two clamping sections 20 form a clamping group. Each clamping group is connected to both ends of the crankshaft 80 to be tested through the crankshaft mounting position 200. The end of each clamping group away from the guide rail section 10 is connected to the load loading device 60 and the calibration plate 70, respectively. The load loading device 60 and the calibration plate 70 are arranged opposite to each other.

[0043] By applying the technical solution of this embodiment, the crankshaft is efficiently and stably clamped and the automated testing process is achieved through the guide rail 10 and multiple movable clamping parts 20. During the test, the crankshaft mounting position 200 ensures accurate alignment between the crankshaft 80 and each clamping assembly. The vertical extension design of the clamping parts 20 allows the crankshaft 80 to withstand cyclic bending loads under the action of the load loading device 60 and the calibration plate 70, simulating fatigue effects under actual working conditions. This overcomes the limitations of traditional manual clamping and loading, improves the automation level of the test, and reduces labor costs. Simultaneously, the relative arrangement of the load loading device 60 and the calibration plate 70 allows for precise control of the load and frequency during the test, thereby improving the efficiency and reliability of the crankshaft bending fatigue test.

[0044] Specifically, one of the two clamping parts 20 in the clamping assembly is movably arranged relative to the other, and the height of the crankshaft mounting position 200 of each clamping part 20 is adjustable in the vertical direction.

[0045] One of the two clamping parts 20 is movably arranged relative to the other. The sliding block has built-in rollers connected to the lower slide rail, allowing it to move horizontally along the lower slide rail track. This means one clamping part 20 can move freely horizontally relative to the other, providing spatial freedom for positioning and adjusting the crankshaft 80. This allows the testing system to adapt to the clamping needs of crankshafts of different sizes and also facilitates quick clamping and disassembly of the crankshaft. The crankshaft mounting position 200 of each clamping part 20 is vertically adjustable to match the axis height of the crankshaft 80, ensuring that the crankshaft mounting position 200 can be accurately aligned with the crankshaft journal.

[0046] Specifically, each clamping assembly includes a first crankshaft mounting position 201 and a second crankshaft mounting position 202. At least one clamping assembly includes: a first clamping part 21, the first end of which is provided with the first crankshaft mounting position 201, and the first end of which is movably connected to the guide rail part 10 via a first lifting mechanism 22; the second end of which is connected to the load loading device 60; and a second clamping part 23, which is disposed opposite to the first clamping part 21 to form a clamping space for clamping the crankshaft 80, the first end of which is provided with the second crankshaft mounting position 202, and the first end of which is movably connected to the guide rail part 10 via a second lifting mechanism 24; and the second end of which is connected to the bottom surface 90 of the test bench via a calibration plate 70.

[0047] The first crankshaft mounting position 201 is used to clamp one end of the crankshaft 80. The first lifting mechanism 22 allows the first clamping part 21 to be dynamically adjusted in the vertical direction, ensuring that the crankshaft mounting position 200 can be accurately aligned with the journal of the crankshaft 80, while also accommodating differences in the length and diameter of different crankshafts 80. The load loading device 60 is used to apply periodic bending loads to the crankshaft 80 to simulate the actual working conditions of the crankshaft 80 in the engine. The second lifting mechanism 24 ensures that the second crankshaft mounting position 202 is also adjustable in the vertical direction, thereby maintaining the correct relative position between the two crankshaft mounting positions 201 and the crankshaft mounting position 202. The calibration plate 70 ensures that the loading force of the load loading device 60 is accurate. The two clamping parts are connected to the guide rail 10 through their respective lifting mechanisms, which not only realizes the vertical height adjustment of the crankshaft mounting position 200, but also makes the clamping and positioning of the crankshaft 80 more flexible and precise because they can move relative to each other. The test system can accurately control the bending load applied to the crankshaft. At the same time, with the assistance of the load loading device 60 and the calibration plate 70, data acquisition and load control can be performed, ultimately ensuring the reliability and effectiveness of the crankshaft bending fatigue performance test.

[0048] Specifically, both the first clamping part 21 and the second clamping part 23 are provided with a locking mechanism 40. Part of the locking mechanism 40 is movably disposed relative to the first clamping part 21 or the second clamping part 23 so that the locking mechanism 40 has a locking position for locking the crankshaft 80 located in the first crankshaft mounting position 201 or the second crankshaft mounting position 202, and a release position for releasing the crankshaft 80 located in the first crankshaft mounting position 201 or the second crankshaft mounting position 202.

[0049] The locking mechanism 40 provides precise control over the crankshaft 80, moving between a locked position and a released position to adapt to different operational needs. By positioning the locking mechanism 40 at the first clamping part 21 and the second clamping part 23, rapid and stable locking can be achieved when the crankshaft 80 is placed at the first crankshaft mounting position 201 or the second crankshaft mounting position 202, ensuring that the position of the crankshaft 80 remains unchanged during the test, thus improving the accuracy and safety of the test. When it is necessary to release the crankshaft 80, the locking mechanism 40 can smoothly move to the release position, avoiding additional damage to the crankshaft 80. It also facilitates quick replacement of the crankshaft 80, improving test efficiency. This not only ensures the smooth conduct of the test but also demonstrates the flexibility and adaptability of the device, enabling its application on crankshafts of various sizes and types, thus enhancing its versatility and practicality.

[0050] In one embodiment of this application, the locking mechanism 40 may also be implemented in different ways, such as pneumatic, electric or mechanical linkage, as long as it can meet the requirement of positioning and locking the crankshaft 80.

[0051] Specifically, such as Figure 2a and Figure 2b As shown, the locking mechanism 40 includes an oil chamber housing 41, a hydraulic ring 42, a locking ring assembly 43, and an oil pump 44. The oil chamber housing 41 is located on one side of the first clamping portion 21, and a portion of the surface of the oil chamber housing 41 facing the first clamping portion 21 is recessed away from the first clamping portion 21 to form a mounting cavity 410. The hydraulic ring 42 is connected to the first clamping portion 21 via a connector 50, and at least a portion of the hydraulic ring 42 is disposed within the oil chamber housing 41, forming an oil cavity 411 between the hydraulic ring 42 and the oil chamber housing 41. One end of the locking ring assembly 43 is located within the first crankshaft mounting position 201, and the other end of the locking ring assembly 43 extends into the mounting cavity 410. The inner circle of the locking ring assembly 43 is used to mount the crankshaft 80, and the outer peripheral surface of the locking ring assembly 43 is a tapered surface. The cavity wall of the mounting cavity 410 is fitted against the tapered surface. The oil pump 44 is connected to the first clamping part 21. The oil pump 44 communicates with the oil chamber 411 through the oil hole on the oil chamber housing 41. The oil pump 44 is used to supply oil to and unload oil into the oil chamber 411, so as to control the oil chamber housing 41 to move along the conical surface of the locking ring assembly 43 to the locking position and the release position.

[0052] In this embodiment, in order to further improve the stability between the oil chamber housing 41 and the hydraulic ring 42, a limit bolt 30 is provided inside the oil chamber housing 41, and an elastic washer is added to the contact surface between the limit bolt 30 and the hydraulic ring 42.

[0053] During the test preparation phase, the oil pump 44 is activated to supply oil to the oil chamber 411. The increased oil pressure pushes the hydraulic ring 42 outward, simultaneously forcing the oil chamber housing 41 to move along the tapered surface of the locking ring assembly 43 and enter the locking position, thereby achieving a strong clamping of the crankshaft 80. After the test or when the crankshaft needs to be replaced, the oil pump 44 performs an oil unloading action, reducing the pressure in the oil chamber 411, thereby causing the oil chamber housing 41 to return to the release position along the same tapered surface, allowing the crankshaft 80 to be easily removed. This ensures the stability and safety of the crankshaft 80 during the test, and also facilitates the loading and unloading of the crankshaft 80, improving test efficiency.

[0054] Specifically, the locking ring assembly 43 includes: an inner bushing 431, one end of which is disposed in the first crankshaft mounting position 201, and the other end of which extends into the mounting cavity 410, the inner circle of which is used to mount the crankshaft 80; and an inner ring 432, the inner circular surface of which is fitted with at least a portion of the outer circular surface of the inner bushing 431, and at least a portion of the outer surface of the inner ring 432 is provided with a tapered surface.

[0055] One end of the inner bushing 431 is positioned within the first crankshaft mounting position 201, directly contacting the journal of the crankshaft 80. Its inner circumferential surface accommodates and conforms to the shape of the crankshaft 80, providing a good contact area to distribute pressure and prevent localized damage to the crankshaft. The other end of the inner bushing 431 extends into the mounting cavity 410 formed by the oil chamber housing 41, enhancing the overall structural stability of the assembly and allowing the dynamic movement of the oil chamber housing 41 to directly act on the locking ring assembly 43. The inner circular surface of the inner ring 432 is tightly fitted with the outer circular surface of the inner bushing 431, forming a double locking mechanism. That is, when the oil chamber housing 41 moves, due to the external force, the contact between the inner ring 432 and the inner bushing 431 becomes tighter, increasing the clamping force on the crankshaft 80. The outer surface of the inner ring 432 is provided with one or more tapered surfaces that match the cavity wall structure of the mounting cavity 410. When the oil cavity housing 41 moves along the tapered surface under the push of the hydraulic ring 42, it can cause the entire locking ring assembly 43 to retract inward, locking the inner bushing 431 and the crankshaft 80 together.

[0056] In one embodiment of this application, the parameters of the inner bushing 431 and the inner ring 432, such as material, heat treatment process, and bore size, can be adjusted to adapt to crankshafts of different specifications and types.

[0057] Specifically, such as Figure 3a and Figure 3bAs shown, the inner bushing 431 includes: a bushing body 4310, a through hole 4311 that penetrates between the inner and outer circular surfaces on the bushing body 4310, and a through groove 4312 that penetrates between the two end faces of the bushing body 4310, wherein there are one or more through grooves 4312.

[0058] The bushing body 4310 not only bears the main weight of the entire locking ring assembly 43, but also establishes a contact interface with the crankshaft 80 journal and the inner ring 432 to ensure structural integrity under pressure, while also possessing sufficient deformation capacity to adapt to the operation of the locking ring assembly 43. The through hole 4311, by connecting the inner and outer circular surfaces of the bushing body 4310, increases the deformation capacity and elasticity of the inner bushing 431, allowing it to contract more evenly under pressure, thus more firmly gripping the crankshaft 80 journal, reducing the risk of excessive local stress, and preventing damage to the crankshaft. One or more through grooves 4312 penetrate both end faces of the bushing body 4310, further enhancing the deformation potential of the inner bushing 431. This allows the inner bushing 431 to better conform to the contour of the crankshaft 80 in the locked state, while quickly returning to its original shape in the released state, ensuring convenient and quick crankshaft installation and removal. In addition, the distribution of multiple through grooves 4312 can optimize the stress distribution of the inner bushing 431 and improve its durability.

[0059] In one embodiment of this application, the number and position of the through grooves 4312 can be adjusted according to the specific characteristics of the crankshaft to further optimize the pressure distribution and meet more complex and precise test requirements.

[0060] Furthermore, at least one of the first lifting mechanism 22 and the second lifting mechanism 24 includes two lifting components, which are respectively disposed on both sides of the first clamping part 21 or the second clamping part 23.

[0061] In this embodiment, the configuration of two lifting components ensures more balanced vertical movement of the first clamping part 21 or the second clamping part 23, eliminating the skewness or instability that may be caused by a single lifting device. Especially under heavy loads, it provides more reliable support, ensuring the safety and stability of the crankshaft 80 during the test. The lifting components are located on both sides of the clamping part, which helps to maintain the balance of the entire test device during operation. When installing or unloading the crankshaft, the lifting components on both sides can work together to ensure that the crankshaft is in the ideal position, avoiding unnecessary stress or damage caused by unilateral force. If it is necessary to fine-tune the position of the crankshaft at one end without affecting the other end, it can be achieved by operating one of the lifting components individually, improving the flexibility of actual testing.

[0062] In one embodiment of this application, the configuration of the lifting mechanism can be further optimized, for example by adjusting the spacing of the lifting components or by using a multi-stage lifting mechanism to enhance the control accuracy and adaptability of the crankshaft.

[0063] Specifically, the lifting assembly includes: a slide rail 2000, with a first pulley 2001 at each end of the slide rail 2000, and a guide rail portion 10 corresponding to each first pulley 2001; the slide rail 2000 can be slidably arranged along the length direction of the guide rail portion 10 via the first pulleys 2001; a slider 2002, with a second pulley 2006 at the top of the slider 2002, the second pulley 2006 being slidably connected to the slide rail 2000, the slider 2002 can be slidably arranged along the length direction of the slide rail 2000 via the second pulley 2006, a connecting rod 2003 at the bottom of the slider 2002, and an external thread on the outer surface of the connecting rod 2003; and a lifting block 2004, with a through lifting hole at the top of the lifting block 2004, an internal thread that mates with the external thread in the lifting hole, and the bottom of the lifting block 2004 being connected to a first clamping portion 21 or a second clamping portion 23 via a suspension rope 2005.

[0064] The slide rail 2000, serving as the skeleton of the lifting assembly, is equipped with first pulleys 2001 at both ends, which match the guide rail 10. This allows the slide rail 2000 to move smoothly along the length of the guide rail 10, ensuring a clear and controlled vertical movement path for the clamping part and increasing the overall stability of the device. The slider 2002 is located above the slide rail 2000, and its top is equipped with a second pulley 2006, allowing the slider to slide along the length of the slide rail. This is crucial for adjusting the slider's vertical position. The connecting rod 2003 extends from the bottom of the slider 2002 and has threads on its exterior, providing the physical basis for the connection between the slider 2002 and the lifting block 2004, ensuring transmission efficiency. The lifting block 2004 is the core control element of the lifting assembly. Its top has a through-hole with internal threads that match the external threads on the connecting rod 2003, thus achieving threaded transmission between the slider 2002 and the lifting block 2004. When the connecting rod 2003 rotates, the lifting block 2004 will rise or fall according to the action of the thread. The bottom of the lifting block is connected to the first clamping part 21 or the second clamping part 23 through the suspension rope 2005. The vertical movement of the lifting block can be converted into vertical adjustment of the clamping part, which greatly improves the positioning accuracy and operation convenience of the crankshaft 80 during the test.

[0065] Furthermore, the crankshaft bending fatigue testing system also includes a sensor 100, which is connected to the second clamping part 23; and a strain gauge 101, which is used to attach to the crankshaft 80 to be tested. Both the sensor 100 and the strain gauge 101 are used to receive vibration information generated by the crankshaft 80 during the test.

[0066] In this embodiment, sensor 100 can directly sense the vibration of the second clamping part 23 during the loading process, including key parameters such as vibration amplitude and frequency, which is crucial for evaluating the dynamic performance of the crankshaft. Strain gauge 101 is directly attached to the surface of the crankshaft 80 to be tested. By monitoring the resistance change of the strain gauge 101 during the test, the stress level experienced by the crankshaft 80 can be indirectly calculated. Sensor 100 and strain gauge 101 together constitute the system's monitoring network, transmitting the collected information to the data acquisition unit. After signal conversion and data processing, detailed vibration spectra and stress-strain curves are generated. Through in-depth analysis of the data, the bending fatigue strength of the crankshaft 80 can be quantitatively assessed, early signs of fatigue fracture can be identified, and its lifespan can be predicted. Furthermore, the integrated sensor and strain gauge can also participate in the closed-loop control of the test system. The controller can automatically adjust the output of the load loading device based on real-time feedback vibration and stress information, ensuring that the test load and frequency strictly adhere to the preset test specifications, thereby improving the accuracy and repeatability of the test.

[0067] According to another aspect of this application, an embodiment of a crankshaft bending fatigue testing system is also provided.

[0068] Step 1: Construct the fixed platform. Purchase SPCC cold-rolled carbon steel plates to construct the frame structure of the test bench with a 90mm base and 200mm slide rails. The outer rectangular dimension of the grounding frame is 800mm. The slide rail 2000 is installed in the groove of the slide rail 2000. The upper and lower ends of the slider 2002 are cylindrical structures. The upper end is fixed to the first pulley 2001 with its own fixing bracket by bolts. The lower cylindrical position is machined with a full thread structure with a pitch of 1.5mm. The main body of the lifting block is a hollow structure with circular upper and lower end faces. The side includes two column structures. The upper end is machined with threads that fit with the external threads at the narrow neck of the sliding block. The lower end has a ф10mm circular hole. The outer diameter of the rotating bearing is ф20mm. The outer diameter of the bearing is fixed to the lower end face of the rotating bearing by welding. The inner diameter of the bearing is ф10mm. An ф8mm steel wire rope is selected and passes through the inner hole of the bearing. Safety locks are added at both ends to achieve a fixed connection. After installation, the movement of the lifting block 2004 in the horizontal and vertical directions is tested. The slide rail 2000 and the bearing are not stuck and can move freely in the horizontal and vertical directions.

[0069] Step 2, process the hydraulic fixture; see the fixture structure below. Figure 2a and Figure 2bAs shown. After the initial machining of the fixture body is completed, multiple sets of through grooves 4312 are machined at the contact positions of the oil cavity housing 41 with the hydraulic ring 42, the locking ring assembly 43, and the oil cavity 411. These grooves are used to install O-rings to maintain sealing. Elastic washers are installed on the contact surfaces of the limit bolt 30 and the hydraulic ring 42, and anti-loosening washers are installed at the contact surfaces of the bolt heads. Subsequently, the hydraulic ring is press-fitted, and the tail of the limit bolt 30 is screwed into the oil cavity wall to about half its initial depth to ensure the oil cavity space. Then, the hydraulic ring is pressed into the oil cavity wall until it is flush with the limit bolt 30. For contact testing, the clearance between the oil chamber housing 41 and the hydraulic ring 42 at the contact surface should be controlled within 0.15mm, and after adding the oil seal ring, it will be an interference fit. Then, install the inner sleeve ring 432, which connects the oil chamber housing 41 and the vibrating arm at both ends. After aligning the holes, tighten the six circumferential fastening bolts evenly, with the bolt heads in direct contact with the anti-loosening gaskets. After completion, the inner sleeve ring should be in a compressed state. Then, perform a sealing check by pressurizing the oil pump to 14-16MPa and maintaining it for 20 minutes, and observe whether there is any oil leakage.

[0070] Step 3, process the inner liner 431, the structure of which is shown in [reference needed]. Figure 3a and Figure 3b As shown. The bushing was machined using 42CrMo material and tempered at 450±25℃. The outer diameter tolerance was ±0.2mm, and the inner diameter was set to ф121±0.1mm based on the crankshaft with a journal diameter of ф121mm used in this test. Six through holes were machined evenly distributed around the bushing to increase its deformation capacity, including one through hole and five through slots 4312. The width of both types of through holes was set to 10mm. A semi-circular arc structure was machined on the innermost side of the through slots 4312 to prevent stress concentration at the minimum thickness position of the bushing. The minimum thickness at the arc position was set to 6mm.

[0071] Step 4: Preparation of the data acquisition and loading control device. The data acquisition, control, and load loading device uses the domestic WQ-6000 crankshaft bending fatigue testing system, which has a maximum supply bending moment of 15000 N·m, meeting the test conditions. The load loading device includes: the loading device body, connecting rods, and a vibrating wall. The connecting rods are made of quenched and tempered 45# steel, with threads machined at both ends. The connecting rods are connected between the loading device body and the vibrating arm to transmit periodic loads.

[0072] Step 5, Sample preparation and clamping. Select one or more crankshafts 80 for single-crank sample taking. To avoid the influence of sample processing quality on clamping effect, grind the cut edges at both ends of the crankshaft 80. The inner bushing 431 and crankshaft are placed in the clamping position. The oil pump 44 increases the oil pressure in the oil chamber 411. As the pressure increases, the volume of the oil chamber increases. Horizontally, the hydraulic ring moves away from the crankshaft, while the oil chamber housing 41 moves towards the crankshaft. Due to the fastening bolts, the vibrating arm remains relatively stationary with respect to the hydraulic ring and moves in the opposite direction to the oil chamber wall; the inner ring 432 experiences pressure from the conical contact surface, contracting to clamp the bushing and crankshaft journal. When the pressure reaches 14-16 MPa, the six limit bolts 30 are tightened. The oil pressure is then released through the grease fitting. Due to the limit bolts 30, the oil chamber housing 41 cannot move away from the vibrating arm, and the hydraulic clamping switches to bolt fixing, completing the single-sided crankshaft clamping. The opposite crankshaft journal is then fixed using the same method.

[0073] Step 6, Calibrate the test system. See the calibration diagram below. Figure 4 As shown, before calibration, an overhead crane was used to hoist the installed fixtures and crankshaft onto a wire rope. Then, the connecting rod and calibration plate 70 were installed, and the calibration plate 70 was fastened to the groove 90 on the bottom surface of the test bench with a single bolt. Since the test bench is controlled by AC during vibration, the crankshaft loading spectrum is approximately sinusoidal. However, the control method during calibration is DC, therefore the corresponding DC loading force F = M / (L·), where M is the initial bending moment and L is the distance from the loading point to the effective stress point of the crankshaft. Strain gauges were installed at the unclamped journal position on the crankshaft, and the strain gauge terminals were connected to the data acquisition device leads via soldering. Then, the controller was adjusted to DC mode, and a predetermined load was applied using the loading device. The initial displacement X was recorded based on the strain gauge feedback results.

[0074] Step 7, Test Control and Parameter Setting. After calibration, remove the calibration plate 70 and attach the sensor 100 to the unloaded side. See [link to sensor location] for details. Figure 1As shown; the controller mode is set to AC mode, and the vibration load is gradually increased from low to high. When the real-time displacement reaches the calibrated value X, the initial bending moment M is input to correct the real-time bending moment value. After correction, the current, frequency and other data collected by the sensor are calculated by the controller, which can display information such as the actual bending moment, number of cycles, and load value. According to the QC / T 637-2000 standard, the number of test cycles is set to 1×107, the cracking criterion of the specimen is a 1% decrease in frequency from the initial value, and the stress increment is within 5% of the initial load. After the test is passed or the test cracks, the crankshaft needs to be replaced. When disassembling the crankshaft, the hydraulic pressure in the oil chamber is first increased by the oil pump so that the limit bolt 30 can be easily rotated back to the initial position before the test, avoiding excessive wear of the bolt contact surface; then the oil pressure is released, and under the influence of the spring deformation of the bushing and inner ring, the hydraulic ring 42, the oil chamber housing 41 and the vibration arm all move in opposite directions during the clamping process, and the crankshaft journal is loosened. After replacing the crankshaft, since the crankshaft model remains unchanged for this test, it can be directly clamped and tested without recalibration.

[0075] Step 8, Test Data Processing. This test uses the "increase-decrease method" to test the fatigue limit, that is, increasing the stress level by one level upon passing and decreasing the stress level by one level upon fracture to test the new crankshaft. The number of effective pairs must be no less than 4. With a 50% survival rate, the fatigue limit can be expressed as follows:

[0076] M-1 = / n

[0077] In the formula, Mri = (Mi + Mi + 1) / 2, Mi and Mi + 1 are the bending moments of two adjacent test levels that show opposite test results, i = 1, 2 ... n, and n is the number of effective pairs.

[0078] Step 9: Evaluate the effectiveness of the hydraulic fixture and testing device for the crankshaft bending fatigue test. During the test, pay attention to whether there are abnormal noises at the connection points, whether the marked positions have moved outwards, and record whether there are journal jamming problems during the disassembly and assembly process of replacing the crankshaft, whether there are loosening or cracking problems with the fastening and limit bolts 30, and whether the fixture leaks oil, etc.

[0079] According to another embodiment of this application, a method for manufacturing a crankshaft bending fatigue testing system is provided, as follows:

[0080] Step 1: Construct the fixed platform. Purchase SPCC cold-rolled carbon steel plates to construct the frame structure of the test bench with a 90mm base and 2000mm slide rails. The outer rectangular dimension of the grounding frame is 750mm. The slide block 2002 is 2050mm in diameter. A first pulley 2001 and a slide rail 2000 are installed within the groove of the slide rail. Both the upper and lower ends of the slider 2002 are cylindrical. The upper end is fixed to the first pulley 2001 with its own mounting bracket via bolts. The lower cylindrical end is machined with a 1mm pitch fully threaded structure. The main body of the lifting block is a hollow structure with circular upper and lower surfaces. The side includes two column structures. The upper end is threaded to mate with the external thread at the narrow neck of the sliding block. The lower end has an 8mm diameter circular hole. The outer diameter of the rotating bearing is 18mm, and the outer diameter of the bearing is fixed to the lower rotating surface by welding. The inner diameter of the bearing is 8mm. A 6mm steel wire rope is used to pass through the inner hole of the bearing, and safety locks are added at both ends for secure connection. After installation, the movement of the lifting block 2004 in the horizontal and vertical directions was tested. The slide rail 2000 and bearing showed no jamming, allowing for free movement in both horizontal and vertical directions.

[0081] Step 2, process the hydraulic fixture; see the fixture structure below. Figure 2a and Figure 2b As shown. After the initial machining of the fixture body is completed, multiple sets of through grooves 4312 are machined at the contact positions between the oil cavity housing 41 and the hydraulic ring 42, the locking ring assembly 43, and the oil cavity 411. These grooves are used to install O-rings to maintain sealing. Elastic washers are installed on the contact surfaces between the limit bolts and the hydraulic ring 42, and anti-loosening washers are installed on the contact surfaces of the bolt heads. Subsequently, the hydraulic ring is press-fitted, with the tail of the limit bolt screwed into the oil cavity wall to approximately half its initial depth to ensure sufficient space in the oil cavity. The hydraulic ring is then pressed into the oil cavity wall until it contacts the limit bolts. The clearance between the oil chamber housing 41 and the hydraulic ring 42 at the contact surface is controlled within 0.1mm, and after the oil seal ring is installed, it is an interference fit; then the inner ring 432 is installed, and the two ends of the inner ring 432 are connected to the oil chamber housing 41 and the vibrating arm. After aligning the holes, tighten the 6 circumferential fastening bolts evenly, so that the bolt heads are in direct contact with the anti-loosening gaskets. After completion, the inner ring should be in a compressed state; then a sealing check is performed, using an oil pump to pressurize to 14-16MPa and maintain it for 18 minutes, and observe whether there is any oil leakage.

[0082] Step 3, process the inner liner 431, the structure of which is shown in [reference needed]. Figure 3a and Figure 3b As shown, the bushing was machined using 42CrMo material and tempered at a temperature of 450±25℃. The outer diameter tolerance was ±0.2mm, and the inner diameter was set to ф121±0.1mm based on the crankshaft with a journal diameter of ф121mm used in this test. Six through holes were machined evenly distributed around the bushing to increase its deformation capacity, including one through hole and five through slots 4312. The width of both types of through holes was set to 10mm. A semi-circular arc structure was machined on the innermost side of the through slots 4312 to prevent stress concentration at the minimum thickness position of the bushing. The minimum thickness at the arc position was set to 5mm.

[0083] Step 4: Preparation of data acquisition and loading control device. The data acquisition, control and loading device selected is the domestic WQ-6000 crankshaft bending fatigue testing system, which has a maximum supply bending moment of 15050 N·m, meeting the test conditions; the connecting part 50 is made of quenched and tempered 45# steel, with threads machined at both ends, and connects the loading device and the vibrating arm respectively to transmit the periodic load.

[0084] Step 5, Sample Preparation and Clamping. Multiple crankshafts 80 are selected for single-crank sample collection. To avoid the influence of sample processing quality on the clamping effect, the cut edges at both ends of the crankshaft 80 are ground. The inner bushing 431 and crankshaft are placed in the clamping position sequentially. The oil pump 44 is used to increase the oil pressure in the oil chamber 411. As the pressure increases, the volume of the oil chamber increases. Horizontally, the hydraulic ring moves away from the crankshaft, while the oil chamber housing 41 moves towards the crankshaft. Due to the fastening bolts, the vibrating arm and hydraulic ring remain relatively stationary while moving in the opposite direction to the oil chamber wall; that is, the vibrating arm and oil chamber wall move towards each other. The inner ring 432 is subjected to pressure from the conical contact surface, contracting to clamp the bushing and crankshaft journal. When the pressure reaches 14-16 MPa, the six limit bolts are tightened. Then, the oil pressure is released through the oil nozzle. Due to the limit bolts, the oil chamber housing 41 cannot move away from the vibrating arm, and the hydraulic clamping switches to bolt fixing. The single-sided crankshaft clamping is complete. Use the same method to fix the opposite crankshaft journal.

[0085] Step 6, Calibrate the test system. See the calibration diagram below. Figure 4 As shown, before calibration, an overhead crane was used to hoist the installed fixtures and crankshaft onto a wire rope. Then, connector 50 and calibration plate 70 were installed, and calibration plate 70 was fastened to the groove 90 on the bottom surface of the test bench with a single bolt. The initial bending moment M was 10500 N·m. Since the test bench was controlled by AC during vibration, the crankshaft loading spectrum was approximately sinusoidal. However, the control mode during calibration was DC, therefore the corresponding DC loading force F = M / (L·m). Based on the distance of the measured loading point from the effective stress point of the crankshaft being 0.73 m, the loading force F was calculated to be approximately 10171 N. Strain gauges were installed at the unclamped journal position on the crankshaft, and the strain gauge terminals were connected to the data acquisition device leads via soldering. The controller was then adjusted to DC mode, and a predetermined load was applied using the loading device. Based on the strain gauge feedback, the initial displacement was recorded as 0.041 mm.

[0086] Step 7, Test Control and Parameter Setting. After calibration, remove the calibration baffle and attach the sensor to the unloaded side. See [link to sensor location] for details. Figure 1As shown; the controller mode is set to AC mode, and the vibration load is gradually increased from low to high. When the real-time displacement reaches the calibrated value of 0.041mm, an initial bending moment of 10500 N·m is input to correct the real-time bending moment value. After correction, the current, frequency, and other data collected by the sensor are calculated by the controller, which can display information such as the actual bending moment, number of cycles, and load value. According to the QC / T 637-2000 standard, the number of test cycles is set to 1×107, the cracking criterion for the specimen is a 1% decrease in frequency from the initial value, and the stress increment is within 5% of the initial load. After the test is passed or after cracking, the crankshaft needs to be replaced. When disassembling the crankshaft, the hydraulic pressure in the oil chamber is first increased by the oil pump so that the limit bolt can be easily rotated back to the initial position before the test, avoiding excessive wear on the bolt contact surface; then the oil pressure is released, and under the influence of the springback deformation of the bushing and inner ring, the hydraulic ring, oil chamber wall, and vibration arm all move in the opposite direction during the clamping process, and the crankshaft journal is loosened. After disassembly, the new crankshaft is reinstalled for testing.

[0087] Step 8, Data Processing. This experiment used the "fatigue limit increase / decrease method" to test the fatigue limit. Twelve valid data points were obtained, with six pairs, meeting the standard requirements. The fatigue limit increase / decrease chart is shown below. Figure 5 As shown, the fatigue limit torque for a survival rate P=50% is calculated as follows:

[0088] M-1 (50%) = 10333 (Nm)

[0089] Step 9: Evaluate the effectiveness of the hydraulic fixture and testing device for the crankshaft bending fatigue test. During the natural gas engine crankshaft bending fatigue test: no abnormal noise was observed at the fixture connection position; no significant movement was observed at the marked position relative to the fixture, and the crankshaft did not loosen; the crankshaft disassembly and assembly process was smooth, with no journal jamming issues; after the test, the fastening and limit bolts showed no loosening or cracking issues, and the bolt hole threads were normal; there was no obvious oil leakage on the outside of the fixture. The hydraulic fixture and testing device for the crankshaft bending fatigue test meet the test requirements.

[0090] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0091] (1) Improve test efficiency: By using the guide rail part 10 and multiple clamping parts 20 to replace the traditional manual bolt fastening method, the crankshaft 80 clamping time is greatly shortened and the clamping process is simplified, thereby improving the overall efficiency of bending fatigue test.

[0092] (2) Enhanced test reliability: The designed clamping part 20 and locking mechanism 40 ensure that the crankshaft 80 is firmly clamped during the test, avoiding errors or data deviations caused by insufficient clamping, and improving the reliability and repeatability of the test.

[0093] (3) Reduce wear and maintenance costs: The inner bushing 431 and inner ring 432 effectively reduce the wear of key components and reduce maintenance and replacement costs under long-term use.

[0094] (4) Optimize data acquisition: By combining the data acquisition technology of sensor 100 and strain gauge 101, the stress change and vibration of crankshaft 80 during the test can be monitored in real time, providing more accurate data support for analyzing the fatigue performance of crankshaft 80.

[0095] (5) Increased flexibility and versatility: The inner bushing 431 allows the same set of hydraulic clamps to adapt to crankshafts of different sizes without the need for frequent adjustment of clamp parameters, thus improving the system's flexibility and application range.

[0096] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0097] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0098] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A crankshaft bending fatigue testing system, characterized in that, include: Guide rail section (10); Clamping part (20), there are multiple clamping parts (20), one end of each clamping part (20) is movably connected to the guide rail part (10), the other end of each clamping part (20) extends downward in the vertical direction, each clamping part (20) is provided with a crankshaft mounting position (200), every two clamping parts (20) in the multiple clamping parts (20) form a clamping group, each clamping group is connected to both ends of the crankshaft (80) to be tested through the crankshaft mounting position (200); In this case, the end of each clamping group away from the guide rail (10) is connected to the load loading device (60) and the calibration plate (70) respectively, and the load loading device (60) and the calibration plate (70) are arranged opposite to each other.

2. The crankshaft bending fatigue testing system according to claim 1, characterized in that, One of the two clamping parts (20) in the clamping assembly is movably disposed relative to the other, and the height of the crankshaft mounting position (200) of each clamping part (20) is adjustable in the vertical direction.

3. The crankshaft bending fatigue testing system according to claim 1 or 2, characterized in that, Each of the clamping assemblies includes a first crankshaft mounting position (201) and a second crankshaft mounting position (202), and at least one of the clamping assemblies includes: The first clamping part (21) has a first crankshaft mounting position (201) at its first end, and the first end of the first clamping part (21) is movably connected to the guide rail part (10) through the first lifting mechanism (22), and the second end of the first clamping part (21) is connected to the load loading device (60). The second clamping part (23) is disposed opposite to the first clamping part (21) to form a clamping space for clamping the crankshaft (80). The first end of the second clamping part (23) is provided with the second crankshaft mounting position (202), and the first end of the second clamping part (23) is movably connected to the guide rail part (10) through the second lifting mechanism (24). The second end of the second clamping part (23) is connected to the bottom surface (90) of the test bench through the calibration plate (70).

4. The crankshaft bending fatigue testing system according to claim 3, characterized in that, Both the first clamping part (21) and the second clamping part (23) are provided with a locking mechanism (40). Part of the locking mechanism (40) is movably disposed relative to the first clamping part (21) or the second clamping part (23) so that the locking mechanism (40) has a locking position for locking the crankshaft (80) located in the first crankshaft mounting position (201) or the second crankshaft mounting position (202), and the locking mechanism (40) has a release position for releasing the crankshaft (80) located in the first crankshaft mounting position (201) or the second crankshaft mounting position (202).

5. The crankshaft bending fatigue testing system according to claim 4, characterized in that, The locking mechanism (40) includes: Oil cavity housing (41), the oil cavity housing (41) is located on one side of the first clamping part (21), and a portion of the surface of the oil cavity housing (41) facing the first clamping part (21) is recessed away from the first clamping part (21) to form an installation cavity (410). Hydraulic ring (42), the hydraulic ring (42) is connected to the first clamping part (21) through a connector (50), at least part of the hydraulic ring (42) is disposed in the oil cavity housing (41), and an oil cavity (411) is formed between the hydraulic ring (42) and the oil cavity housing (41). A locking ring assembly (43) is provided, one end of which is located in the first crankshaft mounting position (201), and the other end of which extends into the mounting cavity (410). The inner circle of the locking ring assembly (43) is used to mount the crankshaft (80). The outer circumferential surface of the locking ring assembly (43) is a tapered surface, and the cavity wall of the mounting cavity (410) is fitted to the tapered surface. Oil pump (44) is connected to the first clamping part (21). The oil pump (44) communicates with the oil cavity (411) through the oil hole on the oil cavity housing (41). The oil pump (44) is used to supply oil to the oil cavity (411) and unload oil to control the oil cavity housing (41) to move along the conical surface of the locking ring assembly (43) to the locking position and the releasing position.

6. The crankshaft bending fatigue testing system according to claim 5, characterized in that, The locking ring assembly (43) includes: Inner bushing (431), one end of which is disposed in the first crankshaft mounting position (201), and the other end of which extends into the mounting cavity (410), the inner circle of which is used to mount the crankshaft (80). The inner ring (432) has its inner circular surface in contact with at least a portion of the outer circular surface of the inner bushing (431), and at least a portion of the outer surface of the inner ring (432) is provided with the conical surface.

7. The crankshaft bending fatigue testing system according to claim 6, characterized in that, The inner liner (431) includes: The bushing body (4310) has a through hole (4311) that passes through the inner and outer circular surfaces, and the bushing body (4310) also has a through groove (4312) that passes through the two end faces of the bushing body (4310), and the through groove (4312) can be one or more.

8. The crankshaft bending fatigue testing system according to claim 3, characterized in that, At least one of the first lifting mechanism (22) and the second lifting mechanism (24) includes two lifting components, which are respectively disposed on both sides of the first clamping part (21) or the second clamping part (23).

9. The crankshaft bending fatigue testing system according to claim 8, characterized in that, At least one of the lifting components includes: A slide rail (2000) is provided at both ends of the slide rail (2000) with a first pulley (2001) and a guide rail (10) corresponding to each first pulley (2001). The slide rail (2000) is slidably provided along the length direction of the guide rail (10) via the first pulley (2001). A slider (2002) is provided with a second pulley (2006) at its top. The second pulley (2006) is slidably connected to the slide rail (2000). The slider (2002) can be slidably arranged along the length direction of the slide rail (2000) via the second pulley (2006). A connecting rod (2003) is provided at the bottom of the slider (2002). The outer surface of the connecting rod (2003) is provided with an external thread. The lifting block (2004) has a through lifting hole at its top and an internal thread that mates with the external thread inside the lifting hole. The bottom of the lifting block (2004) is connected to the first clamping part (21) or the second clamping part (23) via a hanging rope (2005).

10. The crankshaft bending fatigue testing system according to claim 3, characterized in that, The crankshaft bending fatigue testing system also includes: Sensor (100), the sensor (100) is connected to the second clamping part (23); A strain gauge (101) is used to attach to the crankshaft (80) to be tested. Both the sensor (100) and the strain gauge (101) are used to receive vibration information generated by the crankshaft (80) during the test.

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