A Quantitative Measurement Method for the Lubrication State of the Running Trajectory of Rolling Elements and Its Application

Abstract

The present invention belongs to the technical field of lubrication efficiency enhancement of rolling elements, and relates to a quantitative measurement method for the lubrication state of the running trajectory of rolling elements and its application. It provides a quantitative measurement method for the lubrication state evaluation under the condition of micro-changes in the trajectory of bearing rolling elements. Based on this method, a cage structure for improving the lubrication state of rolling bearings is designed. Through experimental measurement, the effectiveness of the optimized design of the cage is verified. By optimizing the cage structure, micro-adjustment of the rolling element trajectory is achieved, and on the basis of not causing obvious changes in the kinematics and dynamics of the rolling bearing, efficient utilization of lubricant and adjustment of the lubrication state are realized. Its principle is scientific and reliable. On the basis of quantitatively testing the lubricant distribution caused by micro-offset of the rolling element trajectory and the adjustment effect on the lubrication state, and extracting the optimization parameters, the cage is designed, which has good application prospects.

Description

Technical Field:

[0001] The present invention belongs to the technical field of lubrication efficiency enhancement of rolling elements, and relates to a method for quantitatively measuring the lubrication state of the running track of rolling elements and its application. Based on the parameters of the oil supply state at the lubrication contact points of rolling bearings measured, the cage is optimized in design. Background Art:

[0002] As a key basic component of mechanical equipment, the lubrication state of rolling bearings has a significant impact on the service performance of rolling bearings and the operation reliability of equipment, and the lubricating oil film thickness is the key factor determining the lubrication state of rolling bearings. Theoretically, the lubricating oil film thickness is related to the running speed, load, lubricant viscosity and viscosity-pressure coefficient, and contact geometric characteristics: when the rolling bearing operates under high-speed conditions, the loss of lubricant on the raceway is relatively serious; when the rolling bearing operates in a low-temperature environment, the lubricant return rate is low. The loss of lubricant and the low rolling backfill efficiency cause oil-starved lubrication phenomenon due to insufficient oil supply at the entrance of the contact zone. Under severe oil-starved lubrication conditions, the lubricating oil film thickness is significantly reduced, resulting in the deterioration of the lubrication state, increasing the risk of lubrication failure of rolling bearings, and having an adverse impact on the operation reliability and life of rolling bearings. Obviously, it is particularly necessary to use the lubricant lost on the raceway to improve and adjust the lubrication state. The premise is to reveal the running characteristics of rolling bearings, propose a verification scheme for adjusting the lubrication state by using the running characteristics of rolling bearings, and on this basis, design the structure of rolling bearings.

[0003] In the basic research of rolling bearings, the contact form between the rolling elements and the inner and outer rings of the rolling bearings is equivalently simplified into a ball-disk single-point contact form, so as to simplify the contact model and measurement structure, bringing great convenience to numerical calculation and experimental measurement. By quantitatively investigating the influence of a single factor and revealing its internal lubrication mechanism, it is widely used in theoretical and experimental research. However, the ball-disk single-point contact form shields the influence of many characteristic factors of rolling bearings, and the characteristic factors of rolling bearings play an important role in the flow and redistribution of lubricants. Especially under the condition of lubricant loss on the raceway, the lubricant redistribution will have a significant impact on the backfill of lubricants and the degree of oil-starved lubrication. In the ball-disk single-point contact form, it is precisely because of the lack of characteristic factors of rolling bearings that there is a large difference, even contradiction, between the measurement results and the actual service characteristics of real rolling bearings. For example, the measurement results of the ball-disk single-point contact form can cause lubrication failure in a short time, far lower than the actual service life of rolling bearings, indicating that the characteristic factors of rolling bearings play a potential role in the flow distribution and backfill of lubricants. Based on this, exploring and using the characteristic factors of rolling bearings is beneficial to optimizing the design of rolling bearings and improving the service characteristics of rolling bearings.

[0004] Among the characteristic factors of rolling bearings, the motion characteristics of the rolling elements are one of the most important factors affecting lubricant distribution. Due to excitations such as vibration, alternating loads, slippage, and cage impact, rolling element motion trajectories vary within a small range, resulting in variations in their trajectory when passing through the same position in the rolling bearing. These subtle variations significantly impact lubricant utilization and redistribution. However, the prior art lacks observation and verification of the impact of this factor on the lubrication state of rolling bearings. Since the ball-on-disc single-point contact system utilizes a single rolling element, it is impossible to observe the impact of these subtle variations in trajectory on lubrication characteristics during the rolling element's successive motions.

[0005] Therefore, a quantitative measurement method for the lubrication state of the rolling element running trajectory was developed and designed. An auxiliary contact point was added to the ball-disk single-point contact measuring device to reproduce the lubricant redistribution and the influence on the lubrication state caused by the micro-change of the rolling element motion trajectory during the successive operation of the rolling elements; the micro-change of the rolling element trajectory was simulated by adjusting the micro-offset between the auxiliary rolling element and the measuring rolling element; the influence of the micro-offset of the auxiliary rolling element on the lubrication state of the measuring rolling element was quantitatively analyzed by observing the oil pool morphology outside the contact area of the measuring rolling element and the lubrication characteristics inside the contact area; the influence of the micro-change of the rolling element trajectory on the lubricant redistribution and the lubrication state was verified based on experimental observations, and on this basis, the cage structure was optimized and designed to effectively improve the lubricant utilization rate and lubrication performance, extend the service life of the bearing, and have positive social and economic benefits. Summary of the invention:

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology, develop and design a quantitative measurement method for the lubrication state of the rolling element running track and its application, measure the impact of micro-changes in the rolling element running track on the lubrication state, and propose a retainer for adjusting the lubrication state of the bearing based on the measurement results.

[0007] In order to achieve the above-mentioned purpose, the process of the method for quantitatively measuring the lubrication state of the rolling element running track according to the present invention is as follows:

[0008] An auxiliary contact point is added to the existing ball-disk contact test equipment, and the contact position is fine-tuned by a high-precision translation stage.

[0009] Simulate the micro-changes in the rolling element trajectory in the bearing during rolling to obtain the running trajectory of the double-point contact rolling element;

[0010] The oil pool distribution morphology and contact area interference image are collected at the observation contact point, and the lubricant redistribution caused by the micro-deflection of the auxiliary contact point and its impact on the lubrication state are quantitatively measured.

[0011] When applying the quantitative measurement method for the lubrication state of the rolling element running track involved in the present invention, the data at the observed contact point is analyzed, parameters reflecting the oil sump shape and lubrication state are defined, the influence of the auxiliary contact point offset on the lubricant distribution, lubricant usage efficiency and the improvement effect on the lubrication state is quantitatively evaluated, and combined with the micro-offset parameters of the auxiliary contact point, optimization parameters are provided for the cage structure, the cage is optimized designed, and by slightly adjusting the pocket position of the cage and optimizing the arrangement method, the set adjustment effect is achieved, and the lubrication performance and service life of the bearing are enhanced.

[0012] Compared with the prior art, the present invention provides a quantitative measurement method for evaluating the lubrication state under the condition of micro-changes in the rolling element track of the bearing. Based on this method, a cage structure for improving the lubrication state of the rolling bearing is designed. Through experimental measurement, the effectiveness of the optimized design of the cage is verified. By optimizing the cage structure, the micro-adjustment of the rolling element track is realized, and on the basis of not causing obvious changes in the kinematics and dynamics of the rolling bearing, the efficient utilization of the lubricant and the adjustment of the lubrication state are realized; its principle is scientific and reliable. On the basis of quantitatively testing the lubricant distribution caused by the micro-offset of the rolling element track and the adjustment effect on the lubrication state and extracting the optimization parameters, the cage is designed, and it has a good application prospect. Brief Description of the Drawings:

[0013] Figure 1 It is a schematic structural diagram of the measuring device for the quantitative measurement method of the lubrication state of the rolling element running track involved in the present invention.

[0014] Figure 2 It is a schematic diagram of the running track of the double-point contact rolling element involved in the present invention.

[0015] Figure 3 It is a schematic diagram of the principle of the optimized design of the cage involved in the present invention.

[0016] Figure 4 It is a schematic diagram of the optimized design result of the cage of the thrust ball bearing involved in the present invention.

[0017] Figure 5 It is the oil sump shape diagram and oil film interference image under the micro-adjustment of the rolling element track involved in the present invention.

[0018] Figure 6 It is a schematic diagram of the lubrication enhancement mechanism under the micro-adjustment of the rolling element track involved in the present invention. Detailed Embodiments:

[0019] The present invention will be further described below through embodiments in conjunction with the drawings.

[0020] Embodiment 1:

[0021] The quantitative measurement method for the lubrication state of the rolling element running track involved in this embodiment is implemented based on the measurement device as shown in Figure 1 . The main structure of the measurement device includes an observation contact point 1, a driving motor 2, an auxiliary observation point 3, a high-precision translation stage 4, a glass disk 5, a rotary system 6, a microscope 7, and an optical system 8. Among them, the auxiliary contact point 3 is a contact point added to the existing ball-disk point contact test equipment. The micro-adjustment of the contact position is realized through the high-precision translation stage 4 to simulate the micro-changes in the rolling element track inside the bearing during rolling. The running track of the double-point contact rolling element obtained is as shown in Figure 2 . At the observation contact point 1, the oil pool distribution pattern and the interference image of the contact area are collected to quantitatively measure the lubricant redistribution caused by the micro-offset of the auxiliary contact point 3 and its influence on the lubrication state.

[0022] The specific process of the quantitative measurement method for the lubrication state of the rolling element running track involved in this embodiment is as follows:

[0023] 1. Use chemical reagents to clean the rolling elements at the observation contact point 1, the rolling elements at the auxiliary contact point 3, and the glass disk 5.

[0024] 2. Apply a load to the rolling elements at the observation contact point 1, and the driving motor 2 drives the glass disk 5 to move slowly. At the same time, inject a quantitative lubricant into the gap between the rolling elements at the observation contact point 1 and the glass disk 5. The lubricant is evenly distributed on the surface of the glass disk 5 under the movement of the rolling elements at the observation contact point 1 and the glass disk 5.

[0025] 3. Increase the load of the rolling elements at the observation contact point 1 to the set test load. After the driving motor 2 drives the glass disk 5 to run 5 laps at the set speed and a reference raceway is formed on the surface of the glass disk 5, turn off the driving motor 2 to make the glass disk 5 in a static state.

[0026] 4. Apply a load to the rolling elements at the auxiliary contact point 3, switch the microscope 7 above the rolling elements at the auxiliary contact point 3, and adjust the focal length of the microscope 7 so that a clear image of the rolling elements at the auxiliary contact point 3 can be observed.

[0027] 5. Measure the distance from the contact center of the rolling elements at the auxiliary contact point 3 to the center of the reference track, define this distance as the rolling element track offset L, and adjust the rolling elements at the auxiliary contact point 3 through the precision translation stage 4 to make the rolling element track offset L reach the set value.

[0028] 6. Switch the microscope 7 above the rolling elements at the observation contact point 1, and adjust the focal length of the microscope 7 so that a clear image of the rolling elements at the observation contact point 1 can be observed.

[0029] 7. Turn on the drive motor 2 and set its rotational speed to drive the glass disk 5 to rotate. Observe the oil pool morphology diagram and interference image of the outer periphery of the rolling element at the contact point 1 through the microscope 7, and collect and store the oil pool morphology diagram and interference image.

[0030] 8. Adjust the rotational speed of the drive motor 7 and repeat the rotation and observation operations in step 7 to obtain a series of oil pool morphology diagrams and interference images at set rotational speeds.

[0031] 9. Adjust the rolling element trajectory offset L and repeat steps 7 and 8 to obtain oil pool morphology diagrams and interference images at different offsets.

[0032] 10. Perform offline processing on the collected and stored oil pool morphology diagrams and interference images, define parameters characterizing the oil pool morphology and lubrication state, analyze the influence mechanism of the micro-offset of the rolling element on the lubricant distribution and lubrication state, and extract the optimized parameters of the trajectory offset to improve the lubrication characteristics on this basis.

[0033] Example 2:

[0034] When applying the quantitative measurement method for the lubrication state of the rolling element running trajectory involved in this example, as Figure 3 shown, use the optimized parameters of the trajectory offset as the input parameters for the cage and design the cage: set the center distance between two adjacent cages to the offset L and arrange them alternately to cause a micro-offset in the running trajectories of adjacent rolling elements to achieve the set effect.

[0035] Since the offset L is extremely small, for high-speed rolling bearings, the contact radius between the rolling element and the inner and outer rings is about dozens of micrometers, and the offset L is of the same order of magnitude as the contact radius of the inner and outer rings. The offset L is not sufficient to cause significant changes in the kinematics and dynamics of the rolling element.

[0036] The cages with the offset L can be arranged at intervals of multiple cages without the offset L.

[0037] To verify the feasibility of this cage, on the ball-disk point contact visualization lubrication measurement device in the prior art, adopt the double-rolling-element contact method, and by adjusting the offset distance between the rolling element at the observation contact point 1 and the rolling element at the auxiliary contact point 3, observe the oil pool distribution of the rolling element at the observation contact point 1 to verify the influence of the micro-change of the rolling element trajectory on the lubrication state.

[0038] Example 3:

[0039] The result of applying the quantitative measurement method for the lubrication state of the rolling element running trajectory involved in this example to the optimized design of the cage of the thrust ball bearing is as Figure 4As shown, 9 is the upper shaft ring of the thrust ball bearing, 10 is the retaining frame, 11 is the seat ring, 12 and 13 are rolling bodies with non-overlapping motion trajectories, and the offset between two adjacent retaining frames 10 is L, which can achieve a lubrication enhancement effect.

[0040] Example 4:

[0041] The present embodiment relates to a method for quantitatively measuring the lubrication state of a rolling element running track. When the oil supply is 20 μL, under different offset conditions, the track oil film of the rolling element at the observation contact point 1 and the auxiliary contact point 3 is observed with the entrainment speed u. e The oil pool morphology and oil film interference image are as follows Figure 5 As shown, it can be seen that when the trajectory offset is 0, a large amount of lubricant is lost to both sides of the raceway and cannot be effectively utilized, resulting in an obvious lack of lubricant at the contact entrance and severe oil shortage, and the lubrication effect is poor; when there is an offset in the trajectory of the rolling element at the observation contact point 1 and the rolling element at the auxiliary contact point 3, the oil ridge formed by the lubricant lost by the rolling element at the auxiliary contact point 3 is utilized by the rolling element at the observation contact point 1, so that the lubricant at the rolling element entrance at the observation contact point 1 is effectively supplemented, thereby improving the lubrication state of the rolling element at the observation contact point 1; at the same time, the oil ridge formed by the rolling element at the observation contact point 1 is also used by the rolling element at the auxiliary contact point 3, and the redistribution of lubricant caused by the operation of the two rolling elements makes the limited amount of lubricant efficiently utilized and significantly improves the lubrication state.

[0042] Example 5:

[0043] The present embodiment relates to a method for quantitatively measuring the lubrication state of a rolling element running track. The lubricant distribution and lubrication efficiency enhancement mechanism under the condition of slight deviation of the rolling element track are as follows: Figure 6 As shown, it can be seen that the oil ridges on both sides of the rolling element track at the auxiliary contact point 3 provide effective lubricant replenishment for the rolling element entrance at the observation contact point 1, so that the rolling element at the observation contact point 1 maintains a good lubrication state.

Claims

1. A quantitative measurement method for the lubrication state of the running track of rolling elements, characterized in that , The process is as follows: Add auxiliary contact points to the ball-disk point contact test equipment, and adjust the contact position through a high-precision translation stage; Simulate the micro-changes in the trajectory of the rolling elements inside the bearing during rolling to obtain the running trajectory of the double-point contact rolling elements; Collect the oil pool distribution pattern and the interference image in the contact area at the observation contact point, and quantitatively measure the lubricant redistribution caused by the offset of the auxiliary contact point and its influence on the lubrication state; Implement based on an improved measuring device. The main structure of the improved measuring device includes an observation contact point, a driving motor, an auxiliary observation point, a high-precision translation stage, a glass disk, a rotary system, a microscope, and an optical system; the auxiliary contact point is a contact point added to the ball-disk point contact test equipment; The specific process is as follows: (1) Clean the rolling elements and the glass disk at the observation contact point and the auxiliary contact point; (2) Apply a load to the rolling element at the observation contact point. While the driving motor drives the glass disk to move, inject lubricant into the gap between the rolling element and the glass disk at the observation contact point. The lubricant is evenly distributed on the surface of the glass disk under the movement of the rolling element and the glass disk at the observation contact point; (3) Increase the load on the rolling element at the observation contact point to the set test load. The glass disk runs under the drive of the driving motor. After a reference raceway is formed on its surface, turn off the driving motor; (4) Apply a load to the rolling element at the auxiliary contact point, switch the microscope above the rolling element at the auxiliary contact point, and observe the image of the rolling element at the auxiliary contact point; (5) Define the distance from the contact center of the rolling element at the auxiliary contact point to the center of the reference track as the rolling element trajectory offset L, and adjust the rolling element at the auxiliary contact point to make the rolling element trajectory offset L reach the set value; (6) Switch the microscope above the rolling element at the observation contact point and observe the image of the rolling element at the observation contact point; (7) Turn on the driving motor to drive the glass disk to rotate, and collect and store the oil pool morphology map and the interference image of the periphery of the rolling element at the observation contact point observed through the microscope; (8) Adjust the rotation speed of the driving motor, and repeat the rotation and observation operations in step (7) to obtain a series of oil pool morphology maps and interference images at the set rotation speeds; (9) Adjust the rolling element trajectory offset L, and repeat steps (7) and (8) to obtain the oil pool morphology maps and interference images at different offsets; (10) Perform offline processing on the collected and stored oil pool morphology maps and interference images, define parameters characterizing the oil pool morphology and the lubrication state, analyze the influence mechanism of the rolling element offset on the lubricant distribution and the lubrication state, and extract the optimized parameters of the trajectory offset to improve the lubrication characteristics; The process of using the optimized parameters of the trajectory offset as the input parameters for the cage design is as follows: Set the center distance between two adjacent cages to the offset L, and arrange them alternately to cause the running trajectories of adjacent rolling elements to offset; The cages with the offset L are arranged at intervals of several cages without the offset L.

2. The quantitative measurement method for the lubrication state of the rolling element running track according to claim 1, wherein , during application, analyze the data at the observed contact points, define parameters reflecting the oil sump shape and lubrication state, quantitatively evaluate the influence of the auxiliary contact point offset on the lubricant distribution, lubricant usage efficiency and the improvement effect on the lubrication state, combine with the offset parameters of the auxiliary contact points, provide optimization parameters for the cage structure, optimize the design of the cage, adjust the pocket positions of the cage, optimize the arrangement method, achieve the set adjustment effect, and enhance the lubrication performance and service life of the bearing.

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