Large-specification chain pin shaft-sleeve pair friction wear testing machine and testing method

Abstract

The invention belongs to the technical field of chain friction and wear testing equipment, and particularly relates to a large-specification chain pin shaft-sleeve pair friction and wear testing machine and a testing method. The testing machine comprises a control system, a workbench, a motor, a speed reducer, a coupler, a crank rocker mechanism, a rocker shaft, a transmission shaft, a torque sensor, a bearing seat, a pin shaft-sleeve pair, a pressurization fixing mechanism, an oil injection mechanism, a support and a pressure sensor. The oil injection mechanism injects lubricating oil to the two ends of the pin shaft-sleeve pair through a hydraulic oil pump and is used for simulating the oil injection lubrication mode in the actual working condition. The pressurization fixing mechanism is used for accurately simulating the positive pressure between the pin shaft-sleeve pair, and the crank rocker mechanism is used for accurately controlling the relative swing angle of the pin shaft-sleeve pair. And the control system is used for calculating the friction coefficient and drawing a friction coefficient curve so as to analyze the correlation between the positive pressure, the torque, the motor rotating speed, the oil temperature, the lubricating oil flowing condition and the friction and abrasion between the pin shaft and the sleeve.

Description

Technical Field

[0001] The invention belongs to the technical field of chain friction and wear testing equipment, and in particular relates to a large-size chain pin shaft-sleeve pair friction and wear testing machine and a testing method. Background Art

[0002] In engineering applications, friction and wear are important factors affecting the life of mechanical parts. They are related to the service life, efficiency and energy consumption of mechanical parts. With the advancement of science and technology, the requirements for the performance of mechanical equipment are getting higher and higher. How to reduce friction and wear, improve mechanical efficiency and extend the life of parts has become the focus of research. The friction and wear tester is a special equipment designed for evaluating the wear characteristics of materials. By placing different friction pairs on the friction and wear tester for testing, it is relatively easy to adjust the various parameters of the experiment and draw conclusions. Therefore, the research and development of friction and wear testers are of great significance to actual production, and this field has also received great attention from domestic and foreign researchers. Chain transmission, as a common transmission method, is widely used in various mechanical equipment. During the operation of the chain, the pin shaft swings back and forth in the sleeve, resulting in friction between the two. This friction not only causes material wear, but also generates heat, further aggravating the wear process. At present, most friction and wear testers are divided into pin-disc type, ring-block type, four-ball type and reciprocating type according to the different forms of friction pairs, while there are few reciprocating swing friction and wear testers suitable for the pin shaft-sleeve friction pair on the chain.

[0003] The device disclosed in Chinese invention patent CN113267418A drives a hollow step shaft to swing through a driving mechanism, thereby simulating the movement friction of a chain hinge pair. The patent has the following defects: 1. The device is spring-loaded and is not suitable for large-sized chain hinge pairs, nor can it accurately simulate the pressure between hinge pairs in large-sized chain working conditions; 2. The "convex" pendulum block in the device limits the rotation angle of the connecting rod of the crank rocker mechanism, making the adjustable range of the relative rotation angle of the hinge pair smaller, which is different from the actual working conditions of large-sized hinge pairs; 3. The device cannot calculate the friction coefficient and draw the friction curve, and cannot deeply analyze the internal laws of friction and wear of the hinge pair; 4. The device cannot monitor the flow of lubricating oil and the oil temperature of the lubricating oil in real time, and cannot deeply analyze the correlation between oil temperature, distribution of lubricating oil and friction and wear of the hinge pair. Summary of the invention

[0004] The present invention discloses a large-scale chain pin-sleeve pair friction and wear testing machine and a testing method, aiming to solve the problems described in the background technology part 1-4.

[0005] To achieve the above purpose, the technical solution of the present invention is:

[0006] A large-scale chain pin-sleeve pair friction and wear testing machine, including a control system, a workbench, a motor, a reducer, a coupling, a crank-rocker mechanism, a rocker shaft, a transmission shaft, a torque sensor, a bearing seat, a pin-sleeve pair, a pressurized fixing mechanism, an oil injection mechanism, a bracket, and a pressure sensor. The motor is fixedly connected to the workbench, the output shaft of the motor is connected to the coupling through the reducer, the output end of the coupling is connected to one end of the crank-rocker mechanism, the other end of the crank-rocker mechanism is connected to one end of the rocker, the other end of the rocker is connected to one end of the transmission shaft, and the transmission shaft is provided with a torque sensor The other end of the transmission shaft is fixedly connected to one end of the pin in the pin-sleeve pair, the left and right ends of the pressurized fixing mechanism are connected to the workbench through a bracket, the lower end of the pressurized fixing mechanism is connected to the sleeve in the pin-sleeve pair, a pressure sensor for detecting the relative pressure of the pin-sleeve pair is provided in the pressurized fixing mechanism, the front and rear ends of the pin are connected to the upper surface of the workbench through a bearing seat, the oil injection mechanism is connected to the two ends of the pin-sleeve pair through an oil injection pipe, and the control system is electrically connected to the power supply, motor, torque sensor, pressurized fixing mechanism, pressure sensor, and oil injection mechanism through wires.

[0007] Preferably, the motor and reducer are respectively detachably fixedly connected to the workbench by bolts, the front and rear ends of the coupling are respectively rotatably connected to supports, the supports are detachably fixedly connected to the workbench by bolts, the front end of the coupling is connected to the right end of the crank rocker mechanism, and the left end of the crank rocker mechanism is transmission connected to the rocker shaft through a rocker.

[0008] Preferably, the crank-rocker mechanism comprises a crank, a slider, a deep groove ball bearing, a connecting rod and a rocker, one end of the crank is connected to the front end of the coupling, the other end of the crank is expanded to form a truncated cone structure, the outer surface of the truncated cone structure is provided with a linear slide groove, and the slider is detachably fixedly connected in the linear slide groove, deep groove ball bearings are embedded at both ends of the connecting rod, a rotating shaft is rotatably connected in the deep groove ball bearing, the inner end of the rotating shaft close to one end of the linear slide groove is fixedly connected to the slider, the outer end of the other rotating shaft is fixedly connected to the upper end of the rocker, and the lower part of the rocker is fixedly connected to the middle section of the rocker shaft.

[0009] Preferably, the slider is adjusted in position in the linear slide groove by a detachable fixed connection, and the axis position of the rotating shaft relative to the crank can be adjusted outward along with the slider in a length L range of: 0∠L∠20mm, and the corresponding angle range A of the pin shaft relative to the sleeve is: 0°∠A∠30°.

[0010] Preferably, the bearing seat is embedded with a cylindrical roller bearing, the front and rear ends of the pin shaft are rotatably connected to the bearing seat via the cylindrical roller bearing, the bottom end of the bearing seat is fixedly connected to the workbench via bolts, the bracket includes a horizontally arranged reaction plate, the left and right ends of the lower surface of the reaction plate are respectively fixedly connected to the workbench via support rods, the reaction plate is detachably fixedly connected to the top end of the support rod, and a stiffening plate is also connected between the outer ends of the two support rods and the upper surface of the workbench.

[0011] Preferably, the pressurized fixing mechanism includes a pressure block, and the front and rear ends of the lower surface of the pressure block are respectively provided with grooves, and chain plates are clamped in the grooves. The contour of the chain plates is an elliptical runway shape, and the chain plate holes of the two chain plates are interference fit with the two ends of the sleeve. The bottom end of the pressure block relative to the pin shaft-sleeve pair is also provided with an arc-shaped give way groove, and the left and right ends of the pressure block are respectively fixed with V-shaped sliders, and the two V-shaped sliders are respectively slidably connected with guide rails arranged along the longitudinal direction, and the inner end of the guide rail is provided with a sliding groove matching the shape of the V-shaped slider, and the outer end of the guide rail is fixedly connected to the support rod on the same side by bolts, and a circular boss structure is provided in the middle of the top end of the pressure block, and the boss structure is used to install a pressure sensor, and the top of the pressure sensor is connected to the lower end of the reaction plate through a jack.

[0012] Preferably, the jack is a thin hydraulic jack with a load range of 0-30KN. The fixed end of the jack is fixedly connected to the lower end of the reaction plate, and the telescopic end is in contact with the top of the pressure sensor. A through hole is also provided in the center of the boss structure, and the through hole is used to install a thermocouple or a visual sensor. The thermocouple is used to measure the oil temperature of the lubricating oil sprayed from the injection pipe. The thermocouple or the visual sensor is respectively connected to the control system signal through wires.

[0013] Preferably, the oil injection mechanism includes a hydraulic oil pump, and a fixed baffle of a rectangular structure is provided on the periphery of the support rod and the bearing seat, the bottom end of the fixed baffle is sealed and fixedly connected to the upper end of the workbench, and a movable baffle is detachably fixedly connected to the inner side of the fixed baffle, the oil injection pipe of the oil injection pump passes through the movable baffle, and is connected to two branch pipes through a three-way joint, the output ends of the two branch pipes are respectively opposite to the two ends of the contact surface of the pin shaft sleeve pair, an oil outlet hole is provided at one end of the fixed baffle, the oil outlet hole is connected to an oil return pipe, the oil return pipe is connected to the oil tank of the hydraulic oil pump, and a one-way valve is provided in the oil return pipe to limit the flow of lubricating oil into the oil tank.

[0014] A test method for a large-size chain pin-sleeve pair friction and wear tester comprises the following steps:

[0015] (1) Connect the two ends of the pin shaft to the bearing seats on the front and rear sides through cylindrical roller bearings, connect the sleeve to the pressure block through a chain plate, connect the pressure block to the guide rail through a V-shaped slider, connect the rear end of the pin shaft to the front end of the transmission shaft, and make the telescopic end of the jack on the lower surface of the reaction plate contact the top of the pressure sensor;

[0016] (2) Install the movable baffle so that it fits tightly against the inner surface of the fixed baffle;

[0017] (3) Start the hydraulic oil pump to ensure that the lubricating oil is sprayed to both ends of the pin-sleeve pair through the oil injection pipe and two branch pipes;

[0018] (4) Turn on the power and start the motor to rotate, set the motor speed, apply pressure to the pressure block through the jack, set the speed and pressure parameters, and then conduct the friction and wear test under these parameters;

[0019] (5) The control system collects the speed and pressure values ​​through Labview software, and calculates the friction coefficient based on the torque detected by the torque sensor, obtains the friction coefficient curve, and takes the average value of the entire recording process as the friction coefficient corresponding to each parameter. The processing is repeated 3 times under each parameter, and the final result is the average value.

[0020] Preferably, in the step (4), the oil temperature of the lubricating oil is measured by a thermocouple or the flow of the lubricating oil is monitored in real time by a visual sensor, and the correlation between the oil temperature, the flow of the lubricating oil and the friction and wear of the pin-sleeve pair is analyzed by the control system.

[0021] The beneficial effects of the large-size chain pin-sleeve pair friction and wear testing machine and testing method of the present invention are:

[0022] (1) The present invention utilizes a crank-rocker mechanism to realize the reciprocating swing between the pin shaft and the sleeve, and designs the crank as a slider-type eccentric wheel mechanism. The crank length is adjusted to realize the adjustment of the relative swing angle between the pin shaft and the sleeve.

[0023] (2) The outer side of the pressure block of the present invention is provided with a V-shaped slider-guide rail that cooperates with the bracket, and the bottom is provided with a groove that cooperates with the elliptical track-shaped chain plates at both ends of the sleeve, which can limit the rotation and shaking of the sleeve under the action of a large torque, improve the stability of the relative rotation of the pin shaft-sleeve pair, and improve the accuracy of the test data.

[0024] (3) The present invention uses a thin hydraulic jack for pressurization, which has a large load range and is suitable for large-size chain testing. It can also reduce the height of the bracket and improve the stability of the device.

[0025] (4) The present invention is provided with an oil injection mechanism, which can simulate the oil injection lubrication method; an oil baffle mechanism combining a fixed baffle and a movable baffle is provided around the working mechanism, which can prevent the splashing of lubricating oil and provide sufficient operating space for workpiece replacement by removing the movable baffle.

[0026] (5) The present invention can accurately calculate the friction coefficient through the control system and draw a friction coefficient curve, and then analyze the correlation between the normal pressure, torque, motor speed, oil temperature, lubricating oil flow and the friction and wear between the pin and sleeve, providing a theoretical basis for the improvement of the pin-sleeve pair of large-size chains.

[0027] Instruction Manual

[0028] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0029] Figure 2 for Figure 1 Front view (without the fuel injection mechanism).

[0030] Figure 3 It is a schematic diagram of the main structure of the present invention for fixing the pin-sleeve pair.

[0031] Figure 4 It is a structural schematic diagram of the connection between the pin shaft-sleeve pair and the pressurized fixing mechanism of the present invention.

[0032] Figure 5 It is a schematic diagram of the crank rocker mechanism of the present invention.

[0033] Figure numerals: 1, workbench; 2, motor; 3, reducer; 4, coupling; 5, crank-rocker mechanism; 5-1, crank; 5-2 slider; 5-3 deep groove ball bearing; 5-4 connecting rod; 5-5, rocker; 6, rocker shaft; 7, torque sensor; 8, transmission shaft; 9, bearing seat; 9-1 upper bearing seat; 9-2 lower bearing seat; 9-3, cylindrical roller bearing; 10, pin-sleeve pair; 10-1, sleeve; 10-2, pin ; 10-3, chain plate; 11, pressure block; 12, pressure sensor; 13, jack pressure point; 14, hydraulic oil pump; 14-1, oil return pipe; 14-2, oil injection pipe; 15, movable oil baffle; 16, reaction plate; 17, support rod; 18, stiffening plate; 19, V-shaped slider; 20, guide rail; 21, oil outlet hole; 22, fixed baffle; 23, arc-shaped give way groove; 24, boss structure; 25, through hole; 26, fixed baffle. DETAILED DESCRIPTION

[0034] The following description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0035] The following embodiments may be understood as individually expressing a part of a local structure or method of the present invention, or may be understood as a combination of the embodiments to explain the connotation of a larger structure or method of the present invention.

[0036] Example 1

[0037] A large-size chain pin-sleeve pair friction and wear testing machine, such as Figure 1-5 As shown, it includes a control system, a workbench 1, a motor 2, a reducer 3, a coupling 4, a crank rocker mechanism 5, a rocker shaft 6, a transmission shaft 8, a torque sensor 7, a bearing seat, a pin-sleeve pair 10, a pressurized fixing mechanism, an oil injection mechanism, a bracket, and a pressure sensor 12. The motor 2 is fixedly connected to the workbench 1, and the output shaft of the motor 2 is connected to the coupling 4 through the reducer 3. The output end of the coupling 4 is connected to one end of the crank rocker mechanism 5, and the other end of the crank rocker mechanism 5 is connected to one end of the rocker shaft 6, and the other end of the rocker shaft 6 is connected to one end of the transmission shaft 8. The transmission shaft 8 is provided with a torque sensor 7, and the other end of the transmission shaft 8 The end is fixedly connected to one end of the pin 10-2 in the pin-sleeve pair 10, the left and right ends of the pressurized fixing mechanism are connected to the workbench 1 through a bracket, the lower end of the pressurized fixing mechanism is connected to the sleeve 10-1 in the pin-sleeve pair, and a pressure sensor 12 for detecting the relative pressure of the pin-sleeve pair is provided in the pressurized fixing mechanism. The front and rear ends of the pin 10-2 are connected to the upper surface of the workbench 1 through a bearing seat 9, and the oil injection mechanism is connected to the two ends of the pin-sleeve pair 10 through an oil injection pipe 14-2. The control system is electrically connected to the power supply, motor 2, torque sensor 7, pressurized fixing mechanism, pressure sensor 12, and oil injection mechanism through wires.

[0038] In this embodiment, the pressure sensor and torque sensor can detect the magnitude of the positive pressure and torque in real time, and transmit them to the control system for friction coefficient calculation and display. The oil injection mechanism uses a hydraulic oil pump to spray lubricating oil to both ends of the pin-sleeve pair to simulate the oil injection lubrication method in actual working conditions. The pressurized fixing mechanism is used to accurately simulate the positive pressure between the pin-sleeve pair, and the crank rocker mechanism is used to accurately control the relative swing angle of the pin-sleeve pair. The control system is used to calculate the friction coefficient and draw a friction coefficient curve, and then analyze the correlation between the positive pressure, torque, motor speed, oil temperature, lubricating oil flow and the friction and wear between the pin and sleeve.

[0039] Example 2

[0040] like Figure 1 As shown, the motor 2 and reducer 3 are detachably fixedly connected to the workbench 1 by bolts, the front and rear ends of the coupling 4 are rotatably connected with supports (not marked in the figure), the supports are detachably fixedly connected to the workbench 1 by bolts, the front end of the coupling 4 is connected to the right end of the crank rocker mechanism 5, and the left end of the crank rocker mechanism 5 is transmission-connected to the rocker shaft 6 via the rocker 5-5.

[0041] like Figure 1 , 5 As shown, the crank-rocker mechanism includes a crank 5-1, a slider 5-2, a deep groove ball bearing 5-3, a connecting rod 5-4, and a rocker 5-5. One end of the crank 5-1 is connected to the front end of the coupling, and the other end of the crank 5-1 is formed into a truncated cone structure by expanding the diameter. The outer surface of the truncated cone structure is provided with a linear slide groove, and the slider 5-2 is detachably fixedly connected in the linear slide groove. Deep groove ball bearings 5-3 are embedded at both ends of the connecting rod 5-4, and a rotating shaft is rotatably connected in the deep groove ball bearing 5-3. The inner end of the rotating shaft close to one end of the linear slide groove is fixedly connected to the slider 5-2, and the outer end of the other rotating shaft is fixedly connected to the upper end of the rocker 5-5. The lower part of the rocker is fixedly connected to the middle section of the rocker shaft.

[0042] In this embodiment, the motor rotates continuously, driving the coupling to rotate together, and then driving the crank to rotate continuously. Through the transmission of the connecting rod, the rocker can be driven to swing within a certain angle, and then the pin shaft is driven to rotate relative to the sleeve through the transmission shaft 8 to simulate the motion state between the pin shaft and the sleeve.

[0043] Example 3

[0044] like Figure 1 , 5 As shown, the slider is adjusted in position in the linear slide groove by a detachable fixed connection, and the axis position of the rotating shaft relative to the crank can be adjusted outward along with the slider in a length L range of: 0∠L∠20mm, and the corresponding angle range A of the pin shaft relative to the sleeve is: 0°∠A∠30°.

[0045] In this embodiment, the position of the slider is adjusted in the linear slide groove by means of a detachable fixed connection, that is, after the slider moves along the linear slide groove, it can be fixedly connected to the linear slide groove again by bolts. The present invention sets the adjustable length L range of the rotating shaft along the linear slide groove to the outside as the slider moves relative to the axis position of the crank: 0∠L∠20mm, thereby also realizing the adjustment of the relative rotation angle between the sleeve and the pin shaft. Correspondingly, the angle range A of the pin shaft swinging relative to the sleeve is: 0°∠A∠30°.

[0046] Example 4

[0047] like Figure 1, 2 As shown in Figure 3, the bearing seat 9 is embedded with a cylindrical roller bearing 9-3, the front and rear ends of the pin shaft 10-2 are rotatably connected to the bearing seat 9 through the cylindrical roller bearing 9-3, the bottom end of the bearing seat 9 is fixedly connected to the workbench 1 through bolts, and the bracket includes a horizontally arranged reaction plate 16, the left and right ends of the lower surface of the reaction plate 16 are fixedly connected to the workbench 1 through support rods 17 respectively, the reaction plate 16 and the top of the support rod 17 are detachably fixedly connected, and a stiffening plate 18 is also connected between the outer ends of the two support rods 17 and the upper surface of the workbench 1.

[0048] like Figure 1 , 2 , 3, and 4, the pressurized fixing mechanism includes a pressure block 11, and the front and rear ends of the lower surface of the pressure block 11 are respectively provided with a card slot (a common structure, not shown in the figure), and a chain plate 10-3 is clamped in the card slot. The outline of the chain plate 10-3 is an elliptical runway shape, and the chain plate holes of the two chain plates 10-3 are interference fit with the two ends of the sleeve 10-1. The bottom end of the pressure block 11 is relative to the pin shaft-sleeve pair 10 and is also provided with an arc-shaped clearance groove 23. The left side of the pressure block 11 A V-shaped slider 19 is fixedly provided at the right end, and the two V-shaped sliders 19 are slidably connected to a guide rail 20 arranged along the longitudinal direction. The inner end of the guide rail 20 is provided with a sliding groove matching the shape of the V-shaped slider 19, and the outer end of the guide rail 20 is fixedly connected to the support rod 17 on the same side by bolts. A circular boss structure 24 is provided in the middle of the top end of the pressure block 11, and the boss structure 24 is used to install the pressure sensor 12. The top end of the pressure sensor 12 is connected to the lower end of the reaction plate 16 through a jack.

[0049] like Figure 1 As shown, the jack is a thin hydraulic jack with a load range of 0-30KN. The fixed end of the jack is fixedly connected to the lower end of the reaction plate 16, and the telescopic end is in contact with the top of the pressure sensor 12; a through hole 25 (such as Figure 3 , 4 As shown), the through hole 25 is used to install a thermocouple or a visual sensor, and the thermocouple is used to measure the oil temperature of the lubricating oil sprayed from the injection pipe. The thermocouple or the visual sensor is connected to the control system signal through a wire.

[0050] In this embodiment, the thin hydraulic jack can apply a load of 0 to 30kN, which can meet the test requirements of the 72B large-size chain at most. Moreover, the thickness of the thin hydraulic jack is only 41mm, which can reduce the height of the bracket and improve the stability of the device. The two ends of the sleeve are covered with 10mm thick chain plates, which are processed into an elliptical runway shape. After cooperating with the pressure block, the rotation of the sleeve can be limited to ensure the accuracy of the relative rotation angle of the pin-sleeve pair. There is a circular boss structure with a diameter of 27mm and a height of 10mm at the center of the pressure block to position the pressure sensor 12. There is a through hole with a diameter of 6mm in the center of the truncated cone, which is used to install a thermocouple to measure the oil temperature or install a visual sensor to observe the flow of lubricating oil; a V-shaped slider-guide mechanism is installed between the two sides of the pressure block 11 and the bracket, which can allow the pressure block to move up and down for loading and limit the shaking of the pressure block, further improving the stability of the sleeve during work and ensuring the accuracy of the experimental results.

[0051] Example 5

[0052] like Figure 1 , 2 As shown, the oil injection mechanism includes a hydraulic oil pump 14, and a rectangular fixed baffle 22 is arranged on the periphery of the support rod 17 and the bearing seat 9. The bottom end of the fixed baffle 22 is sealed and fixedly connected to the upper end of the workbench 1, and a movable baffle 15 is detachably fixedly connected to the inner side of the fixed baffle 22. The oil injection pipe 14-2 of the oil injection pump 14 passes through the movable baffle 15, and is connected to two branch pipes (a commonly used structure, not shown in the figure) through a three-way joint. The output ends of the two branch pipes are respectively opposite to the two ends of the contact surface of the pin shaft sleeve pair 10. An oil outlet hole 21 is arranged at one end of the fixed baffle 22, and the oil outlet hole 21 is connected to an oil return pipe 14-1. The oil return pipe 14-1 is connected to the oil tank of the hydraulic oil pump 14, and a one-way valve (a commonly used structure, not shown in the figure) is arranged in the oil return pipe 14-1 for limiting the flow of lubricating oil into the oil tank.

[0053] In this embodiment, an oil baffle device composed of a fixed baffle and a movable baffle is provided outside the working area of ​​the pin sleeve pair, which can prevent the splashing of lubricating oil while providing sufficient working space for the replacement of the pin sleeve by removing the movable baffle.

[0054] Example 6

[0055] A test method for a large-size chain pin-sleeve pair friction and wear testing machine, such as Figure 1-5 As shown, the following steps are included:

[0056] (1) Connect the two ends of the pin shaft 10-2 to the bearing seats 9 on the front and rear sides through cylindrical roller bearings, connect the sleeve 10-1 to the pressure block 11 through a chain plate, connect the pressure block 11 to the guide rail through a V-shaped slider, connect the rear end of the pin shaft 10-2 to the front end of the transmission shaft 8, and make the telescopic end of the jack on the lower surface of the reaction plate contact the top of the pressure sensor 12;

[0057] (2) Installing the movable baffle 15 so that the movable baffle 15 is closely fitted to the inner surface of the fixed baffle 22;

[0058] (3) Start the hydraulic oil pump 14 to ensure that the lubricating oil is sprayed to both ends of the pin-sleeve pair 10 through the oil injection pipe 14-2 and the two branch pipes (entering through the gap between the pin and sleeve);

[0059] (4) Turn on the power supply and start the motor 2 to rotate, set the speed of the motor 2, apply pressure to the pressure block through the jack (the pressure is transmitted to the contact part between the sleeve and the pin through the chain plate, and the hydraulic jack applies positive pressure to the sleeve through the pressure block to simulate the load of the pin-sleeve pair after the chain is tensioned). After setting the speed and pressure parameters, conduct the friction and wear test under these parameters;

[0060] (5) The rotation speed and pressure values ​​are collected through Labview software, and the friction coefficient is calculated based on the torque detected by the torque sensor 7 to obtain the friction coefficient curve. The average value of the entire recording process is taken as the friction coefficient corresponding to each parameter. The processing is repeated 3 times under each parameter, and the final result is the average value.

[0061] In this embodiment, the friction coefficient between the pin and sleeve pair can be accurately calculated, and then the friction and wear of the pin and sleeve pair can be quantitatively analyzed, and the correlation between the friction coefficient and the positive pressure, torque and rotation speed between the pin and sleeve pair can be sorted out, providing a theoretical basis for the improvement of the pin and sleeve pair of large-size chains in the future.

[0062] Example 7

[0063] like Figure 1-5 As shown, in the step (4), the oil temperature of the lubricating oil is measured by a thermocouple or the flow of the lubricating oil is monitored in real time by a visual sensor, and the correlation between the oil temperature, the flow of the lubricating oil and the friction and wear of the pin-sleeve pair is analyzed by the control system.

[0064] In this embodiment, when the thermocouple is installed, the probe of the thermocouple extends downward through the through hole, can contact the injected lubricating oil through the pores of the perforated sleeve, and detect the temperature of the lubricating oil; when the visual sensor is installed, the camera can observe the flow of the lubricating oil through the pores of the perforated sleeve, and according to the difference in oil temperature and the difference in the flow of the lubricating oil combined with the friction and wear of the pin-sleeve pair, the correlation between the oil temperature, the flow of the lubricating oil and the friction coefficient can be analyzed, thereby providing a theoretical basis for the improvement of the pin-sleeve pair of large-size chains. It can be understood that during this test, the force of the oil injection can be changed by adjusting the pressure of the oil injection pipe to simulate the effect of different oil injection pressures on the flow of the lubricating oil. Similarly, the oil temperature of the lubricating oil can be changed to simulate different oil temperature conditions, thereby analyzing the effect of different oil temperatures and different lubricating oil flow conditions on the friction and wear of the pin-sleeve pair.

Claims

1. A large-size chain pin-sleeve pair friction and wear testing machine, characterized by: The invention comprises a control system, a workbench, a motor, a reducer, a coupling, a crank-rocker mechanism, a rocker shaft, a transmission shaft, a torque sensor, a bearing seat, a pin-sleeve pair, a pressurized fixing mechanism, an oil injection mechanism, a bracket, and a pressure sensor. The motor is fixedly connected to the workbench, the output shaft of the motor is connected to the coupling through the reducer, the output end of the coupling is connected to one end of the crank-rocker mechanism, the other end of the crank-rocker mechanism is connected to one end of the rocker shaft, the other end of the rocker shaft is connected to one end of the transmission shaft, the transmission shaft is provided with a torque sensor, and the other end of the transmission shaft The end is fixedly connected with one end of the pin in the pin-sleeve pair, the left and right ends of the pressurized fixing mechanism are connected to the workbench through a bracket, the lower end of the pressurized fixing mechanism is connected to the sleeve in the pin-sleeve pair, a pressure sensor for detecting the relative pressure of the pin-sleeve pair is provided in the pressurized fixing mechanism, the front and rear ends of the pin are connected to the upper surface of the workbench through a bearing seat, the oil injection mechanism is connected to the two ends of the pin-sleeve pair through an oil injection pipe, and the control system is electrically connected to the power supply, the motor, the torque sensor, the pressurized fixing mechanism, the pressure sensor, and the oil injection mechanism through wires.

2. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 1, characterized in that: The motor and reducer are detachably fixedly connected to the workbench by bolts respectively, the front and rear ends of the coupling are rotatably connected to supports respectively, the supports are detachably fixedly connected to the workbench by bolts, the front end of the coupling is connected to the right end of the crank rocker mechanism, and the left end of the crank rocker mechanism is connected to the rear end of the rocker shaft through a rocker.

3. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 2, characterized in that: The crank-rocker mechanism comprises a crank, a slider, a deep groove ball bearing, a connecting rod and a rocker. One end of the crank is connected to the front end of the coupling, and the other end of the crank is expanded to form a truncated cone structure. A linear slide groove is provided on the outer surface of the truncated cone structure, and a slider is detachably and fixedly connected in the linear slide groove. Deep groove ball bearings are embedded at both ends of the connecting rod, and a rotating shaft is rotatably connected in the deep groove ball bearing. The inner end of the rotating shaft close to one end of the linear slide groove is fixedly connected to the slider, and the outer end of the other rotating shaft is fixedly connected to the upper end of the rocker. The lower part of the rocker is fixedly connected to the middle section of the rocker shaft.

4. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 3, characterized in that: The slider is adjusted in position in the linear slide groove by a detachable fixed connection. The axis position of the rotating shaft relative to the crank can be adjusted outward along with the slider within a length L range of: 0∠L∠20mm, and the corresponding swing angle range A of the pin relative to the sleeve is: 0°∠A∠30°.

5. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 4, characterized in that: The bearing seat is embedded with a cylindrical roller bearing, the front and rear ends of the pin shaft are rotatably connected to the bearing seat through the cylindrical roller bearing, the bottom end of the bearing seat is fixedly connected to the workbench through bolts, the bracket includes a horizontally arranged reaction plate, the left and right ends of the lower surface of the reaction plate are respectively fixedly connected to the workbench through support rods, the reaction plate is detachably fixedly connected to the top end of the support rod, and a stiffening plate is also connected between the outer ends of the two support rods and the upper surface of the workbench.

6. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 5, characterized in that: The pressurized fixing mechanism includes a pressure block, and the front and rear ends of the lower surface of the pressure block are respectively provided with grooves, and a chain plate is clamped in the groove. The outline of the chain plate is an elliptical runway shape, and the chain plate holes of the two chain plates are interference fit with the two ends of the sleeve. The bottom end of the pressure block is relative to the pin shaft-sleeve pair and is also provided with an arc-shaped give way groove. The left and right ends of the pressure block are respectively fixed with V-shaped sliders, and the two V-shaped sliders are respectively slidably connected with guide rails arranged along the longitudinal direction. The inner end of the guide rail is provided with a sliding groove matching the shape of the V-shaped slider, and the outer end of the guide rail is fixedly connected to the support rod on the same side by bolts. A circular boss structure is provided in the middle of the top end of the pressure block, and the boss structure is used to install a pressure sensor. The top end of the pressure sensor is connected to the lower end of the reaction plate through a jack.

7. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 6, characterized in that: The jack is a thin hydraulic jack with a load range of 0-30KN. The fixed end of the jack is fixedly connected to the lower end of the reaction plate, and the telescopic end is in contact with the top of the pressure sensor. A through hole is also provided in the center of the boss structure. The through hole is used to install a thermocouple or a visual sensor. The thermocouple is used to measure the oil temperature of the lubricating oil sprayed from the injection pipe. The thermocouple or the visual sensor is connected to the control system signal through wires.

8. A large-size chain pin-sleeve pair friction and wear testing machine as claimed in claim 7, characterized in that: The oil injection mechanism includes a hydraulic oil pump, and a rectangular fixed baffle is provided on the periphery of the support rod and the bearing seat. The bottom end of the fixed baffle is sealed and fixedly connected to the upper end of the workbench, and a movable baffle is detachably fixedly connected to the inner side of the fixed baffle. The oil injection pipe of the oil injection pump passes through the movable baffle and is connected to two branch pipes through a three-way joint. The output ends of the two branch pipes are respectively opposite to the two ends of the contact surface of the pin shaft sleeve pair. An oil outlet hole is provided at one end of the fixed baffle, and the oil outlet hole is connected to an oil return pipe. The oil return pipe is connected to the oil tank of the hydraulic oil pump, and a one-way valve is provided in the oil return pipe to limit the flow of lubricating oil into the oil tank.

9. The testing method of a large-size chain pin-bushing pair friction and wear testing machine as claimed in claim 8, characterized in that: The steps include: (1) Connect the two ends of the pin shaft to the bearing seats on the front and rear sides through cylindrical roller bearings, connect the sleeve to the pressure block through a chain plate, connect the pressure block to the guide rail through a V-shaped slider, connect the rear end of the pin shaft to the front end of the transmission shaft, and make the telescopic end of the jack on the lower surface of the reaction plate contact the top of the pressure sensor; (2) Install the movable baffle so that it fits tightly against the inner surface of the fixed baffle; (3) Start the hydraulic oil pump to ensure that the lubricating oil is sprayed to both ends of the pin-sleeve pair through the oil injection pipe and two branch pipes; (4) Turn on the power and start the motor to rotate, set the motor speed, apply pressure to the pressure block through the jack, set the speed and pressure parameters, and then conduct the friction and wear test under these parameters; (5) The control system collects the speed and pressure values ​​through Labview software, and calculates the friction coefficient based on the torque detected by the torque sensor, obtains the friction coefficient curve, and takes the average value of the entire recording process as the friction coefficient corresponding to each parameter. The processing is repeated 3 times under each parameter, and the final result is the average value.

10. The test method of a large-size chain pin-bushing pair friction and wear tester as claimed in claim 9, characterized in that: In the step (4), the oil temperature of the lubricating oil is measured by a thermocouple or the flow of the lubricating oil is monitored in real time by a visual sensor, and the correlation between the oil temperature, the flow of the lubricating oil and the friction and wear of the pin-sleeve pair is analyzed by the control system.

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