Comprehensive real-time monitoring experimental system and experimental method for lubrication status

Abstract

The present invention discloses a comprehensive real-time monitoring experimental system and experimental method for lubrication status. The comprehensive real-time monitoring experimental system includes a motion support mechanism, a loading mechanism, a film thickness observation mechanism, and a wear observation mechanism. The experimental system of the present invention can synchronously and real-time measure a series of data such as oil film thickness, grease morphology, friction coefficient, wear rate, etc. These data can be used as some parameters for monitoring lubrication status. Compared with previous wear testing machines, the present invention is not only simple to operate, but also can realize real-time and simultaneous monitoring, ensuring the accuracy of the data.

Description

Technical Field

[0001] The invention belongs to the technical field of friction and wear test bench design, and particularly relates to a comprehensive real-time monitoring experimental system and an experimental method for lubrication status. Background Art

[0002] The lubricating oil film of rolling bearings is the main factor affecting the smoothness and service life of bearings. The thickness of the lubricating oil film of rolling bearings is the main factor that must be considered in bearing design and bearing application. The loss of lubricating oil film of rolling bearings is a very complex issue. It is not only related to performance indicators such as the viscosity of the grease itself, but also to the working load, assembly accuracy, wear state, lubrication conditions and environmental parameters. It is a non-stationary periodic random process.

[0003] Currently, domestic and international monitoring devices for bearing lubricant film thickness during operation can only achieve real-time monitoring of lubricant film thickness. Multi-parameter monitoring methods require separate sampling and collection of lubrication samples, which can lead to inaccurate observation data. Therefore, we seek to design a comprehensive real-time monitoring method for lubrication status. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a comprehensive real-time monitoring experimental system for lubrication status, which cooperates with loads, light sources of various colors and computers to carry out lubrication wear experiments. At the same time, it also provides an experimental method corresponding to the experimental system, which can monitor friction and wear in real time, such as grease film thickness, grease distribution, wear conditions, friction coefficient and other aspects.

[0005] The present invention is achieved through the following technical solutions:

[0006] A comprehensive real-time monitoring experimental system for lubrication status, including:

[0007] A motion support mechanism comprising a test bench, a turntable mounted on the test bench and driven to rotate in a horizontal plane, a large movable platform driven to move closer to or away from the turntable, a roller support column mounted on the large movable platform with a torque sensor disposed therebetween, a connecting platform mounted on the roller support column and rotatable up and down about a horizontal axis, a roller connecting rod and a motor driving the roller connecting rod to rotate about its axis disposed on the connecting platform, a spherical roller fixedly disposed at the end of the roller connecting rod adjacent to the turntable, the turntable being made of a transparent material and coated with a semi-transmissive and semi-reflective film;

[0008] A loading mechanism comprising a loading column constructed on the end of the connecting platform away from the turntable, a weight selectively applied to the loading column, and a fine-tuning mechanism fixedly connected to the roller support column and used to adjust the posture of the connecting platform;

[0009] The film thickness observation mechanism includes a first fixed frame adjustably connected to the test bench, a first precision adjustment platform adjustably connected to the first fixed frame, a first high-speed camera and a first microscope arranged on the first precision adjustment platform and located directly above the contact point between the roller and the turntable, and a first light source;

[0010] The wear observation mechanism includes a second fixed frame that is adjustably fixedly connected to the test bench, a second precision adjustment platform that is adjustably fixedly connected to the second fixed frame, a second high-speed camera and a second microscope that are arranged on the second precision adjustment platform and located above the turntable, and a white light source that is arranged below the turntable. The second microscope is used to observe the grease distribution and wear conditions on both sides of the raceway.

[0011] As one of the embodiments, the fine-tuning structure includes a support plate fixedly connected to the roller support column, an adjusting screw vertically arranged at the tail of the support plate, a rotating nut arranged on the adjusting screw, and a support spring positioned between the rotating nut and the tail of the connecting platform.

[0012] As one embodiment, the semi-transmissive and semi-reflective film is a chromium film.

[0013] As one embodiment, the first light source is a red and green laser with a bandwidth of 3 nm, wherein the wavelength of the red light is 653 nm and the wavelength of the green light is 532 nm.

[0014] As one embodiment, the white light source and the second fixing frame are fixedly connected via a connecting arm to achieve synchronous adjustment.

[0015] An experimental method of the comprehensive real-time monitoring experimental system for lubrication status includes the following steps:

[0016] 1) Adjust the balance of the turntable, apply grease to the turntable and roller respectively, and rotate the roller and turntable at the same time under no-load to form a uniform grease film.

[0017] 2) Adjust the load and select the motion mode to obtain grease film thickness and wear information. The motion modes include rotating turntable and stationary roller, stationary turntable and rotating roller, or simultaneous rotation of the turntable and roller. The rotation speed, direction and time are adjusted according to the set program.

[0018] 3) Analyze the image information collected by the first and second high-speed cameras to obtain the change image of the grease film thickness, the wear spot diameter, and the torque sensor data, and output the friction coefficient, oil film thickness value, wear height, wear volume, and wear rate in real time.

[0019] The advantages and beneficial effects of the present invention are:

[0020] The experimental system of the present invention can synchronously and in real time measure a series of data such as oil film thickness, grease morphology, friction coefficient, wear rate, etc. These data can be used as some parameters for monitoring the lubrication status. Compared with previous wear testers, the present invention is not only easy to operate, but also can achieve real-time and simultaneous monitoring, ensuring the accuracy of the data. In the past, observations of the above parameters (oil film thickness, grease distribution, friction coefficient, contact area wear marks) required separate experiments on different experimental devices, and the experimental conditions on different experimental tables (lubrication status of the contact area, load and other conditions) must be different. This experimental table can monitor the above data in real time within a group of experiments, ensuring the same experimental conditions. The distribution of the oil film is actually a three-dimensional structure, and previous devices could only measure the film thickness. Z The film thickness in the region of the direction is very small, and the device of the present invention can see Z The film thickness in the direction can also be seen XY The overall scratch formation and grease distribution on the plane are observed with a wider field of view. The various systems of the present invention complement each other in terms of function and do not conflict. Compared with other devices, the present invention has significant functional advantages. It can observe the distribution of grease, measure the film thickness of the contact area, monitor the wear of the contact area in real time, and measure the friction coefficient. The above functions are performed simultaneously, improving experimental efficiency and ensuring the consistency of working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the main view of the structural diagram of the real-time comprehensive monitoring system for lubrication status.

[0022] Figure 2 This is a three-dimensional schematic diagram of the structure of the real-time comprehensive monitoring system for lubrication status.

[0023] Figure 3 This is a three-view drawing of the partial structure of the real-time comprehensive monitoring system for lubrication status.

[0024] Figure 4 Schematic diagram of grease film thickness.

[0025] Figure 5 Images for wear observation.

[0026] Figure 6 This is the image of oil film thickness observation.

[0027] Explanation of reference numerals: 11, ball disc support column; 12, large moving platform; 13, ball bar fixing frame; 14, torque sensor; 15, roller support column; 16, rotating bearing; 17, connecting platform; 31, turntable; 32, force sensor; 33, roller; 34, roller connecting rod; 35, coupling; 36, servo motor; 21, loading column; 22, supporting spring; 23, spring base; 24, rotating nut; 41, first high-speed camera; 42, first lens connecting column; 43, First lens connecting column fixing sleeve; 44. First microscope; 45. First lens adjustment column; 46. First precision adjustment platform; 47. First light source; 48. First precision adjustment platform fixing bracket; 51. Second high-speed camera; 52. Second lens connecting column; 53. Second lens connecting column fixing sleeve; 54. Second microscope; 55. Second lens adjustment column; 56. Second precision adjustment platform; 57. White light source; 58. Second adjustment column; 59. Connecting arm; 510. White light source base.

[0028] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1-3 As shown, a comprehensive real-time monitoring experimental system for lubrication status of the present invention includes a motion support mechanism, including a test bench, a turntable 31 arranged on the test bench and driven to rotate in a horizontal plane, a large movable platform 12 driven to move closer to or away from the turntable, a roller support column arranged on the large movable platform and a torque sensor arranged between the two, a connecting platform 17 arranged on the roller support column 15 and rotatable up and down around a horizontal axis, a roller connecting rod 34 and a motor driving the roller connecting rod 34 to rotate around its axial direction, preferably a servo motor, are arranged on the connecting platform 17, a spherical roller 33 is fixedly provided at the end portion of the roller connecting rod adjacent to the turntable, the turntable 31 is made of a transparent material, such as glass or quartz, and this embodiment is described using a glass disk as an example. The turntable is coated with a semi-transmissive and semi-reflective film, preferably a Cr film with a thickness of 14 nm.

[0031] The loading mechanism includes a loading column 21 constructed on the end of the connecting platform away from the turntable, and weights that can be selectively applied to the loading column; a fine-tuning mechanism fixedly connected to the roller support column and used to adjust the posture of the connecting platform, mainly applying force to the contact area between the roller 33 and the turntable 31 by adding weights; the loading column 21 can add weights thereon to change the contact force between the roller and the turntable.

[0032] The film thickness observation mechanism includes a first fixed frame that is adjustably fixedly connected to the test bench, a first precision adjustment platform 46 that is fixedly connected relative to the first fixed frame and can be adjusted in the front, back, left, right, up and down directions, a first high-speed camera 41 and a first microscope 44 and a first light source are arranged on the first precision adjustment platform 46 and located directly above the contact point between the turntable and the roller. Preferably, the first light source is a red and green light source that simultaneously emits red and green light, and a red and green laser with a bandwidth of 3nm can be used, a red and green two-color laser light source (red light 653 nm, green light 532 nm), a measurement resolution of 0.8nm, and an optical range of up to 4µm.

[0033] The wear observation mechanism includes a second fixed frame that is adjustably fixed to the test bench, a second precision adjustment platform 56 that is fixedly connected to the second fixed frame and can be adjusted in the front, back, left, right, and up and down directions, a second high-speed camera 51 and a second microscope 54 disposed on the second precision adjustment platform and above the turntable, and a white light source 57 disposed below the turntable. The second microscope is used to observe the grease distribution and wear conditions on both sides of the raceway. Since the observation data of this experiment is concentrated on a turntable, such as a glass plate, and the available observation range of the glass plate is within the area between an outer diameter of 150mm and an inner diameter of 40mm, the layout of the present invention achieves the arrangement of two sets of measurement mechanisms in a limited area that cannot interfere with each other during operation, thereby achieving simultaneous measurement of film thickness and wear. Film thickness observations utilize red and green light sources, applying the principle of optical interference. The distance between the chrome film and the steel ball is measured by the difference in interference fringes formed by the red and green light striking them. Wear experiments, on the other hand, utilize white light, based on the principle of optical microscopy. Wear observations utilize optical microscopy to observe the entire large space for light obstructions. During the experiment, wear spots, wear marks, and other phenomena block the light source, achieving the observation objective. Furthermore, the two observations focus on different areas. Film thickness observations focus on microscopic imaging of a small area at the center and sides of the grease raceway, while wear observations focus on macroscopic phenomena within the grease raceway and its sides. The entire observation system enables both large-scale wear observations and small-scale film thickness observations, comprehensively considering actual operating conditions and providing sufficient experimental data for lubricant performance observation and evaluation. The maximum observation window for film thickness is approximately 2mm×2mm, while the observation window for wear can reach 1cm×1cm.

[0034] Specifically, the turntable 31 is supported and positioned by the ball disc support column 11. A servo motor is mounted below the ball disc support column 11 to drive the turntable 31 to rotate. The large movable platform 12 and the experimental platform form a sliding pair, which can move the test equipment on the large movable platform 12 left and right to move the roller 33 radially toward or away from the turntable. Of course, the sliding pair can also move in both horizontal and vertical directions. This allows for more adjustments to the contact points between the roller and the turntable, creating more contact patterns and motion coordination modes, and providing more experimental data. The ball bar holder 13 supports the roller connecting rod 34. The roller support column 15 contains a rotating bearing 16, which allows the roller connecting rod 34 to rotate up and down around it. The connecting platform 17 connects the ball bar holder 13, the roller support column 15, and the loading column 21. The torque sensor 14 monitors the friction torque in real time and calculates the friction coefficient based on the friction torque. The connecting platform is provided with a support portion near one end of the turntable 31 to support and position the front end of the roller connecting rod. A bearing is provided between the two to ensure smooth movement. The addition of the support portion also provides preliminary front-to-back balancing of the club holder, ensuring precision when weights are applied later and ensuring the accuracy of torque measurement. The movement of two servo motors causes roller 33 and turntable 31 to rotate, simulating the movement of actual working conditions. Turntable 31 rotates under the control of the motors, with its speed controlled in real time by a computer. A force sensor 32 automatically levels turntable 31. Roller 33 is connected to roller connecting rod 34. A servo motor 36 is connected to coupling 35, which in turn connects to roller connecting rod 34 via coupling 35, giving roller 33 a certain speed.

[0035] The film thickness observation mechanism includes: a first high-speed camera 41, a first lens connecting column 42, a first lens connecting column fixing sleeve 43, a first microscope 44, a first lens adjusting column 45, a first precision adjusting platform 46, a first light source 47, and a first precision adjusting platform fixing frame 48; the film thickness observation mechanism is used to observe the film thickness of the contact area in real time; wherein the first high-speed camera 41 is connected to the computer, and can shoot the film thickness in real time and then transmit it to the computer to form an image, the first lens connecting column 42 can connect the first high-speed camera 41 and the first microscope 44, and the first lens connecting column fixing sleeve 43. The sleeve 43 is used to fix the first lens connecting column 42 and the first lens adjusting column 45. The first microscope can be used to observe the film thickness imaging and transmit the imaging to the first high-speed camera 41. The function of the first lens adjusting column 45 is to adjust the first microscope 44 up and down; the first precision adjustment platform 46 can adjust the observation instrument in all directions front, back, left, right, and front; the first light source 47 is used to provide the first light source, and the light source can be selected according to the experimental requirements; the first precision adjustment platform fixing frame 48 is used to fix the first high-speed camera 41 and the first microscope 44, and it is connected to the first precision adjustment platform 46 through a sliding pair.

[0036] The wear observation mechanism 5 includes: a second high-speed camera 51, a second lens connecting column 52, a second lens connecting column fixing sleeve 53, a second microscope 54, a second lens adjustment column 55, a second precision adjustment platform 56, a white light source 57, a second adjustment column 58, a connecting arm 59, and a white light source base 510. The wear observation mechanism 5 is mainly used for real-time observation of the oil film distribution and wear conditions on the raceway and both sides thereof; wherein the second high-speed camera 51 is connected to the computer, and can form an image on the computer in real time to facilitate observation of the wear conditions; the second lens connecting column 52 connects the second high-speed camera 51 with the second microscope 54; the second lens connecting column fixing sleeve 53 is used to fix the second lens connecting column 52 and the second lens adjustment column 55; the function of the second microscope 54 is to observe the grease distribution and wear conditions on both sides of the raceway and transmit them to the second high-speed camera 51 in real time to form an image; the function of the second lens adjustment column 55 is to cooperate with the second adjustment column 58 to adjust the second lens up and down to make the observation clearer; the second precision adjustment platform 56 can adjust the second observation instrument in all directions, front, back, left and right; the white light source 57 is used to provide light source for the second microscope; the second adjustment column 58 is used to connect the second precision adjustment platform 56 and the second lens adjustment column 55; the connecting arm 59 is used to connect the white light source base 510 and the second lens adjustment column 55; the white light source base 510 is used to place the white light source 57.

[0037] The fine-tuning structure includes a support plate fixedly connected to the roller support column, an adjustment screw vertically mounted at the rear of the support plate, a rotating nut 24 mounted on the adjustment screw, and a support spring 22 positioned between the rotating nut and the rear of the connecting platform to elastically support and position the rear of the connecting platform. The support spring 22 supports the connecting platform 17, while a spring base 23 houses the support spring 22 and connects to the rotating nut 24. The rotating nut 24 can be used to adjust the height to change the force applied to the support spring, achieving fine adjustments to the height of the connecting platform. This also ensures a certain degree of elastic contact between the roller and the turntable, allowing for better contact between the turntable 31 and the roller 33.

[0038] Generally speaking, the ball disc support column 11 and the large movable table 12 in the experimental table support system 1 are fixed on the desktop, and are equipped with threaded holes inside and fixed by bolts. A servo motor is installed under the ball disc support column 11 to drive the turntable 31 to rotate. The ball bar fixing frame 13 is fixed to the connecting table 17, and has threaded holes inside and is connected by bolts. The torque sensor 14 is connected to the large movable table 12 through the turntable. The roller support column 15 is respectively connected to the connecting table 17 and the torque sensor 14 above and below. The rotating bearing 16 is connected to the inside of the roller support column 15. The roller 33, the roller connecting rod 34, the ball bar fixing frame 13 and other mechanisms rotate as a whole through the rotating bearing 16; the loading column 21 is fixed to the connecting table On the platform 17, the support spring 22 is placed on the spring base 23 for supporting the connecting platform 17, the rotating nut 24 supports the spring base 23, and the rotating screw corresponding to the rotating nut is vertically arranged at the tail of the support plate; the turntable 31 is fixed to the ball disc support column 11 through the force sensor 32, and the turntable 31 can be driven to rotate by the motor under the ball disc support column 11. The roller 33 has a threaded hole in it and is threadedly connected to the roller connecting rod 34. The roller connecting rod 34 is connected to the coupling 35 through the ball bar fixing frame 13 and the rotating bearing 16. The coupling 35 has a threaded hole in it and is threadedly connected to the roller connecting rod 34. The coupling 35 is connected to the servo motor 36 through a threaded connection.

[0039] The first precision adjustment platform fixing frame 48 in the film thickness observation mechanism is connected to the motion support mechanism by bolts. The first high-speed camera 41 is provided with a threaded line on the outside and a threaded hole is provided on the inside of the first lens connecting column 42, which is fixed by threaded connection. The first lens adjustment column 45 is fixed by the first lens connecting column fixing sleeve 43. A threaded hole is provided under the first lens connecting column 42. The first light source 47 is fixed to the first lens connecting column 42 by threaded connection. The first precision adjustment platform 46 is fixed to the first precision adjustment platform fixing frame 48 by bolt connection, and the first precision adjustment platform 46 is connected to the first lens adjustment column 45 by the connecting column; the second precision adjustment platform 56 in the wear observation mechanism 5 is fixed by bolt connection. Fixed on the base, the second adjusting column 58 is provided with a threaded line on the outside, and is connected to the second precision adjustment platform 56 through a threaded connection. The second adjusting column 58 is connected to the second lens adjusting column 55 through a bolt. The second high-speed camera 51 is provided with a threaded line on the outside, and the second lens connecting column 52 is provided with a threaded line inside, and the two are connected through a threaded connection. The second lens connecting column 52 and the second lens adjusting column 55 are fixedly connected through the second lens connecting column fixing sleeve 53. The lower end of the second lens connecting column is provided with a threaded hole, and the second microscope 54 is provided with a threaded line on the outside, and the two are connected through a threaded connection. The second lens adjusting column is provided with a threaded hole, and the connecting arm 59 is provided with a threaded hole of the same caliber, and the two are connected through bolts. The white light source base 510 and the connecting arm 59 are connected through an interference fit.

[0040] The semi-reflective, semi-transmissive, and semi-reflective film is a chromium film. The present invention uses the principle of light interference to measure the thickness of the oil film. A semi-reflective, semi-transmissive, and semi-reflective film (chromium film) is coated on the glass plate to make the interference fringes clearer. Figure 6 As shown in the figure, a thickness and color comparison chart is made based on the color of Newton's rings in air, which expands the measurement range of lubricating film thickness. The presence of chromium film also greatly improves the mechanical properties and wear resistance of glass.

[0041] The present invention also discloses an experimental method of the lubrication state comprehensive real-time monitoring experimental system, which includes the following steps:

[0042] 1) Adjust the balance of the turntable. Apply grease to the turntable and roller respectively. Rotate the roller and turntable simultaneously under no-load to form a uniform grease film. When leveling, install a level sensor above the turntable and let the turntable rotate. When the swing amplitude of the level sensor exceeds 5nm when the turntable rotates, adjust the tightening force of the bolts at the position where the swing amplitude is too large. When the change in the reading on the level sensor does not exceed 5nm by adjusting the tightening force of the bolts one by one, remove the level sensor and the leveling is completed.

[0043] 2) Adjust the load and select the motion mode to obtain grease film thickness and wear information. The motion modes include rotating turntable and stationary roller, stationary turntable and rotating roller, or simultaneous rotation of the turntable and roller. The rotation speed, direction and time are adjusted according to the set program.

[0044] 3) Synchronously collect torque sensor data and process and output wear, time, film thickness and wear information in real time.

[0045] The specific operation method is as follows:

[0046] The turntable 31 is leveled to ensure that it rotates smoothly during rotation, and the force sensor 32 is used for automatic leveling; the first high-speed camera 41 and the first microscope 44 are adjusted for imaging, and the first lens adjustment column 45 is adjusted to move the first microscope 44 and the first high-speed camera 41 up and down to a position where the imaging can be observed on the workbench, and then the first microscope 44 is rotationally focused to ensure a clear image on the workbench; the roller 33 and the turntable 31 are then debugged, and the rotating nut 24 is rotated to make the two fit together to ensure that they are just in contact. The image from the first high-speed camera 41 is observed on the computer and the display just appears, indicating that the debugging is complete. Then the connecting table 17 is supported, and the ball disc is separated by rotating the bearing 16 as the fulcrum. A circle of grease is applied to the turntable 31 and the roller 33 respectively to make them contact again, and the turntable 31 and the roller are allowed to move without adding load. 33 rotate separately, and a certain speed and forward and reverse directions are input. There are many ways to obtain the suction speed of the roller pair composed of the roller 33 and the turntable 31. The turntable 31 can be rotated and the roller 33 can be stationary; the turntable 31 can also be stationary and the roller 33 can be rotated; the turntable 31 and the roller 33 can also be rotated at the same time; among them, the simultaneous rotation of the turntable 31 and the roller 33 can be divided into a single drive mode and a double drive mode. In order to be close to the actual project, the double drive mode is generally adopted, that is, the turntable 31 and the roller 33 rotate at the same time, so that a smooth and uniform grease film is formed on their contact surfaces. After a period of no-load rotation, the required load is added to the loading column 21 to simulate the stress state in actual production. The required ball disc rotation cycle is set on the software Controlplatform on the workbench computer, and the variable parameters such as the required speed of the ball disc, the forward and reverse directions of the ball disc, etc. are input to make the ball disc rotate separately.

[0047] Turn on the first light source 47 and the white light source 57 at the same time. A chrome film is coated on the turntable 31 as a semi-transmissive and semi-reflective film. The roller 33 contacts the turntable 31 with the chrome film on its surface. After loading, a Hertz contact area is formed. The metal chrome film on the surface of the turntable 31 has the characteristics of a semi-transmissive and semi-reflective film. When the red and green light incident light penetrates the glass, a part of it is reflected on the surface of the chrome film, and the other part penetrates the chrome film and is reflected on the surface of the roller 33. The two parts of the reflected light produce interference fringes due to the optical path difference, and an image is formed on the computer connected to the first high-speed camera 41; after the set period, the ball and the disk stop rotating. Through the image formed on the computer connected to the first high-speed camera 41, the software Pylonviewer is used to observe the change image of the grease film thickness formed between the ball and the disk under the required load, speed, and a certain period. Then, the image data formed by the principle of optical interference is analyzed and integrated to obtain the light intensity. According to formula (1), the oil film thickness can be calculated:

[0048] (1)

[0049] Where H: oil film thickness, referred to as film thickness;

[0050] : wavelength of light;

[0051] n : refractive index of lubricant;

[0052] k : Interference half level;

[0053] I : light intensity at any point;

[0054] : Light intensity at the minimum film thickness;

[0055] K : Visibility of interference fringes.

[0056] The second high-speed camera 51 is connected to the workbench, and the second lens adjustment column 55 is used to adjust the height of the second high-speed camera 51 and the second microscope 54 so that the desired image appears on the workbench. Then, the second microscope 54 is rotated to adjust the magnification of the second microscope 54 and perform focus adjustment to make the image clearer. The second precision adjustment stage 56 is adjusted to adjust the second microscope 54 and the white light source 57 forward, backward, left and right so that the second microscope 54 is aligned with the center of the track to be observed. Through the software Pylonviewer, a series of macroscopic images such as the surface shape of the grease at the center and both sides of the raceway at the contact point of the roller 33 and the turntable 31 after rotation, the grease distribution, grease whiskers, etc. can be observed in real time. The observed results can be used to make a certain amount of evaluation of the lubricating effect, flow behavior, wear spot morphology and grease supply capacity of the grease.

[0057] Among them, by calculating the film thickness, the relationship between the film thickness and the performance of the grease can be established. The uniformity of the oil film thickness is one of the important indicators for measuring the performance of the grease. An oil film with uniform thickness can provide better lubrication and reduce friction and wear. If the oil film thickness is uneven, it may cause increased local friction and accelerate the wear of mechanical parts. Then, the wear observation system is used to observe the shape of the lubricating oil film, the distribution of grease whiskers and the wear to establish a relationship between the wear condition and the quality of the grease. The continuity of the oil film is also one of the important indicators for evaluating the performance of the grease. A continuous oil film can continuously provide lubrication protection for the friction pair and prevent direct contact between the friction pairs. If the oil film is discontinuous, it may cause direct contact between the friction pairs and increased wear. Thus, the relationship between film thickness and wear can be established. Such as Figure 5 As shown, the crowns on both sides are fat whiskers, and there are some small white spots inside that are the places of wear.

[0058] Take the example of establishing evaluation criteria by generating wear spot morphology on an image:

[0059] The morphology of the wear spots on the raceway and its two sides is observed through images, and the wear spot diameter is obtained by measurement. d The wear height can be calculated by formula (2) h ,

[0060] (2)

[0061] in: h : wear height;

[0062] R : roller radius;

[0063] d : wear spot diameter;

[0064] The wear volume can be calculated by formula (3): V ,

[0065] (3)

[0066] in: V : wear volume;

[0067] The wear rate can be calculated by formula (4): k ,

[0068] (4)

[0069] in: k : wear rate;

[0070] : Load applied in the wear test;

[0071] V : friction speed;

[0072] t : friction time;

[0073] The better the lubricating effect of the grease, the smaller the wear spot diameter, the lower the wear height, the smaller the wear volume, and the lower the wear rate; vice versa.

[0074] Remove the load and use petroleum ether and alcohol to clean the turntable 31 and roller 33 after the experiment. When cleaning, keep the turntable 31 and roller 33 rotating at a low speed (20 rad / min). Use a sterile test paper soaked in petroleum ether or alcohol to wipe them. While wiping, use your finger to hold it against the surface and let it rotate until no color appears in the surface image.

[0075] The experimental platform mainly realizes the measurement and comprehensive evaluation of friction, grease distribution, contact area wear, and contact area film thickness.

[0076] (1) Friction measurement: The friction force is detected by a torque sensor. The torque sensor transmits the friction torque in real time and then calculates the value of the friction force. The calculation formula is: F = T / r , T is the friction torque, F is the friction force, r is the radius of action of the force, that is, the distance from the point of action of the friction force to the center of rotation. According to the formula μ = F / F n , μ is the friction coefficient, F n is the pressure between the ball and the disk, and the friction coefficient is calculated.

[0077] (2) Observe the distribution of grease and the wear of the contact area: The wear observation mechanism can observe the distribution of grease and the wear state of the contact area in a wider range. Figure 4 In the middle S area, XY The generation of wear scars and the distribution of grease can be directly observed in real time in the planar direction.

[0078] (3) Measurement of film thickness in the contact area: The film thickness observation mechanism can measure the oil film thickness at the center of the raceway by the principle of optical interference. H , That Can show grease along Z The distribution of the direction can be accurately observed to the nanometer level.

[0079] The wear observation mechanism in the present invention can observe the distribution and wear status of grease in real time, and this method of collecting data is original. Existing experimental devices can only measure the thickness of the oil film alone, or observe the wear of the contact area after the experiment is completed. The present invention integrates a film thickness observation mechanism and a real-time wear observation mechanism, which has significant functional advantages. In addition, the leveling process of the existing test bench is complicated and takes a lot of time. The present invention adds a force sensor to the test bench, which can realize the leveling function and greatly improve the efficiency of the experiment.

[0080] Pylonviewer is a universal camera driver software. It allows direct display of camera images. Using the camera and associated driver software, this test bench can directly observe grease distribution and wear marks on the raceways, further assessing the lubrication status of the contact area.

[0081] The evaluation results need to be judged by combining the friction coefficient, grease distribution, contact area film thickness, and scratch conditions measured by this test bench: (1) Under normal elastohydrodynamic lubrication conditions, the friction coefficient is low, the fluctuation is small, the contact area oil film thickness is high, the grease is evenly distributed, and there are no scratches; (2) When the lubrication condition is poor, some tiny scratches and wear spots may appear on the raceway surface, the friction coefficient increases, the contact area film thickness is very low, and the grease in the center of the raceway is significantly less than the sides of the raceway; (3) When the lubrication condition is poor, the scratches in the contact area increase, the film thickness is almost 0, the grease in the raceway is squeezed to the sides of the raceway, and the friction coefficient increases significantly. (4) When the lubrication condition is extremely poor, the surface of the glass disk and the steel ball is obviously damaged, there is no grease on the raceway, and large areas of wear spots appear, and the film thickness cannot be measured. In addition, the wear height, wear volume, and wear rate can be calculated by observing the wear spots, and finally an evaluation is formed.

[0082] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by other skilled in the art without expending creative labor falls within the scope of protection of the present invention.

Claims

1. An experimental method for a comprehensive real-time monitoring experimental system for lubrication status, characterized in that: The comprehensive real-time monitoring experimental system for lubrication status includes: The motion support mechanism includes a test bench, a turntable mounted on the test bench and driven to rotate in a horizontal plane, a large movable platform driven to move closer to or away from the turntable, a roller support column mounted on the large movable platform and having a torque sensor disposed therebetween, a connecting platform mounted on the roller support column and rotatable up and down about a horizontal axis, a roller connecting rod and a motor driving the roller connecting rod to rotate about its axial direction disposed on the connecting platform, a spherical roller fixedly disposed at the end of the roller connecting rod adjacent to the turntable, the turntable being made of a transparent material and coated with a semi-transmissive and semi-reflective film; a red and green light source is used to observe the film thickness, and the distance between the steel ball and the chrome film is measured by the difference in interference fringes formed by the red and green light hitting the chrome film and the steel ball; A loading mechanism comprising a loading column constructed on the end of the connecting platform away from the turntable, a weight selectively applied to the loading column, and a fine-tuning mechanism fixedly connected to the roller support column and used to adjust the posture of the connecting platform; The film thickness observation mechanism includes a first fixed frame adjustably connected to the test bench, a first precision adjustment platform adjustably connected to the first fixed frame, a first high-speed camera and a first microscope arranged on the first precision adjustment platform and located directly above the contact point between the roller and the turntable, and a first light source; A wear observation mechanism, comprising a second fixed frame adjustably connected to the test bench, a second precision adjustment platform adjustably connected to the second fixed frame, a second high-speed camera and a second microscope disposed on the second precision adjustment platform and located above the turntable, and a white light source disposed below the turntable, the second microscope being used to observe the grease distribution and wear conditions on both sides of the raceway, adjust the load, and select a motion mode to obtain grease film thickness information, wear information, and grease whisker distribution information, the motion modes including the turntable rotating while the rollers stationary, the turntable stationary while the rollers rotating, or the turntable and rollers rotating simultaneously, and adjusting the rotation speed, rotation direction, and time according to a set program; The experimental method comprises the following steps, 1) Adjust the balance of the turntable, apply grease to the turntable and roller respectively, and rotate the roller and turntable at the same time under no-load to form a uniform grease film. 2) Adjust the load and select the motion mode to obtain grease film thickness and wear information. The motion modes include rotating turntable and stationary roller, stationary turntable and rotating roller, or simultaneous rotation of the turntable and roller. The rotation speed, direction and time are adjusted according to the set program. 3) Analyze the images captured by the first and second high-speed cameras It can obtain the change image of grease film thickness, wear spot diameter and torque sensor data, and output the friction coefficient, oil film thickness value, wear height, wear volume and wear rate in real time.

2. The experimental method of the comprehensive real-time monitoring experimental system for lubrication status according to claim 1 is characterized in that: The fine-tuning structure includes a support plate fixedly connected to the roller support column, an adjusting screw vertically arranged at the tail of the support plate, a rotating nut arranged on the adjusting screw, and a support spring positioned between the rotating nut and the tail of the connecting platform.

3. The experimental method of the comprehensive real-time monitoring experimental system for lubrication status according to claim 1 is characterized in that: The semi-transmissive and semi-reflective film is a chromium film.

4. The experimental method of the comprehensive real-time monitoring experimental system for lubrication status according to claim 1 is characterized in that: The first light source is a red and green laser with a bandwidth of 3 nm, wherein the wavelength of the red light is 653 nm and the wavelength of the green light is 532 nm.

5. The experimental method of the comprehensive real-time monitoring experimental system for lubrication status according to claim 1 is characterized in that: The white light source and the second fixing frame are fixedly connected via a connecting arm to achieve synchronous adjustment.

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