Humidity control device

Abstract

The invention belongs to the technical field of mechanical equipment, and particularly relates to a humidity control device capable of simulating the influence of air humidity on the establishment of a lubricating oil film for evaluation, the humidity can be accurately regulated and controlled, the influence of water immersion on a lubricating state can be inspected, and after a humidity control unit is arranged in the humidity control device, the humidity control device is matched with a ball-disc single-point contact measurement device for use. The problem of lubrication failure caused by free water formed by water vapor aggregation and adhered to the surface of the lubricant in a humidity environment can be reproduced, the influence of water pollution on a film forming mechanism is explored, the influence on the oil film thickness of a lubrication contact point and lubricant backfilling is observed, and a basis is provided for investigating the distribution condition of atmospheric humidity on the lubricant in a flowing process. The evolutionary law of water immersion to contact point lubrication flow is clear, and test data is provided for exploring the running mechanism of the rolling bearing; the influence of humidity on the lubricating grease evolution process can be simulated, quantitative analysis of the decline mechanism is carried out, and the flow distribution form and the film forming mechanism of the rolling bearing lubricant are determined.

Description

Technical field:

[0001] The present invention belongs to the technical field of mechanical equipment, and specifically relates to a humidity control device which can simulate the influence of air humidity on the establishment of lubricating oil film to evaluate, and provides an evaluation basis for studying the influence of water pollution on rolling bearings. Background technology:

[0002] Rolling bearings are often used in rotating components. Their operating state determines the operating accuracy, and the thickness of the oil film is directly related to key issues such as the operating state and service life of the rolling bearing. Exploring the key factors that affect the thickness of the oil film is the premise for clarifying the lubrication state. The thickness of the oil film is mainly affected by factors such as operating speed, load, lubricant viscosity, geometric contact form and contact pair inlet oil supply state. These factors interact with each other during the working process of the rolling bearing and jointly determine the formation and maintenance of the oil film: First, the operating speed is one of the important factors affecting the thickness of the oil film. As the operating speed increases, the thickness of the oil film will decrease, because high-speed operation will cause the lubricant to flow faster in the contact area, thereby reducing the formation time of the oil film; secondly, the load also has a significant effect on the thickness of the oil film. A larger load will increase the pressure in the contact area and reduce the thickness of the oil film, because under high load, the lubricant is forced to flow out under the squeezing effect of the contact area, causing the oil film to become thinner; then, the viscosity of the lubricant is also one of the important factors affecting the thickness of the oil film. A higher lubricant viscosity will increase the thickness of the oil film, because a lubricant with a higher viscosity flows slower in the contact area and has more time to form and maintain the oil film; finally, the geometric contact form and the contact pair inlet oil supply state will also affect the thickness of the oil film. Different contact forms and oil supply states make the distribution of the lubricant in the contact area uneven, thus affecting the formation and thickness of the oil film. When characterizing the flow distribution and lubrication state of lubricants, optical interference visualization measurement technology is often used to measure the oil film thickness and analyze the mechanism of lubrication film formation. The thickness of the oil film is inferred by observing the changes in the interference pattern, and the flow of the lubricant in the contact area is further studied.

[0003] In addition to the above-mentioned key factors that affect the thickness of the oil film, external factors such as high temperature and water pollution will also have a significant impact on the establishment of the oil film thickness. In-depth research has been conducted on the evolution and formation process of the oil film thickness and the oxidation behavior under high temperature environments. However, relatively little research has been conducted on water pollution. Due to the high humidity in the environment, a layer of water film formed on the surface of the grease will flow into the contact area. When water enters the rolling bearing, it mixes with the lubricating oil and forms an emulsion, which causes the oil film to be destroyed and thinned, increasing the friction and wear of the rolling bearing. At the same time, the presence of the emulsion will also change the lubrication mechanism of the rolling bearing and affect the formation and maintenance of the oil film, because the presence of water will increase the viscosity of the lubricating oil and reduce the lubrication performance. In addition, the presence of water will also cause corrosion and oxidation reactions, further damaging the surface and material of the rolling bearing. Corrosion and oxidation increase the surface roughness of the rolling bearing and the friction coefficient, thereby increasing the friction and wear of the rolling bearing. In the prior art, photoelastic flow ball-disc testing machines are often used to conduct experimental research on water pollution. The specific contents include: 1. Dissolve water into grease to change the physical and chemical properties of the lubricant, and then conduct relevant experimental research on photoelastic flow; 2. During the operation of the grease, water is injected into the contact lubrication track between the rolling element and the glass disk through a micropipette to simulate the working conditions of water immersion, and observe the evolution and decay process of the oil film thickness and the lubrication flow distribution. However, it is not highly correlated with the actual working conditions of engineering applications, because water vapor in a high humidity environment will adhere to the inner and outer surfaces of the entire rolling bearing. Only a small amount of water is injected into the contact area and does not meet the actual operating conditions. It is necessary to build a humidity control device that simulates the actual humidity environment and create an atmospheric environment with a certain humidity to explore the evolution and decay process of the lubricating oil film, the adhesion behavior of water droplets, the flow distribution of water droplets themselves, and the influence mechanism of water droplets on the flow distribution of lubricants, so as to provide experimental data for exploring the operating mechanism of rolling bearings. Summary of the invention:

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art, develop and design a humidity control device to simulate the influence of atmospheric humidity on the lubrication performance of rolling bearing grease, and combine the optical interference test method to regulate the humidity in order to analyze the influence mechanism of the water mist environment on the lubrication film formation.

[0005] In order to achieve the above-mentioned purpose, the humidity control device involved in the present invention has sealing performance and is rationally designed according to the structure of a ball-disk contact testing machine and the installation positions of a humidifier, a humidity controller and a humidity sensor. Its main structure includes a bracket and a humidity control box arranged thereon, and a humidity sensor arranged on the bracket or in the humidity control box. The humidity sensor is located near a lubrication observation point; the bracket and the humidity control box, as well as the bracket or the humidity control box and the humidity sensor are all bolted together.

[0006] The bracket involved in the present invention is provided with a through hole for installing a glass plate; the humidity control box is provided with a window for an observation unit to observe the flow distribution of internal grease, a switchable humidification port for a humidifier to supply humidity, a grease scraping port for a grease scraping unit to work, and a through hole for installing a steel ball and its driving unit. After the glass plate and the steel ball and their driving unit are installed, the through holes are closed but do not generate interference, so as to ensure constant humidity control conditions, which is conducive to humidity regulation; the humidity sensor is used to detect the internal humidity and provide a basis for the humidity supply situation.

[0007] The humidity control device of the present invention is used in conjunction with a humidifier, a humidity control unit and a ball-disk point contact test device, which can simultaneously realize the observation of the oil film thickness, evolution process and lubricant flow distribution characteristics of the lubricating flow point, and can also conduct experimental exploration of the friction characteristics of the lubricant under different motion conditions, including the response degree of the oil film thickness and friction force under different loads, speeds and humidity conditions; the specific implementation process is as follows:

[0008] 1) Install the glass plate and the steel ball to the corresponding positions, and use a micrometer to adjust the surface runout of the glass plate so that the runout does not exceed 1 micron during one rotation to ensure the stability of the contact point;

[0009] Use petroleum ether and alcohol to wipe off the pollutants adhering to the surface of the glass plate and the steel ball to avoid affecting the test results;

[0010] 2) Apply load, move the lens and adjust the focal length, find the ball-disk contact observation point, measure the contact point position and the glass disk rotation radius, and accurately control the rotation speed of the glass disk;

[0011] 3) Remove the load, rotate the glass plate, use a micro-syringe to evenly distribute the lubricant on the lubrication track formed by the lubrication contact points, and stop the operation;

[0012] 4) Install the bracket reasonably according to the position of the ball-disk contact point, ensure that there is no interference in the installation position of the humidity sensor, and close the bracket and humidity control box;

[0013] 5) Determine the use of the scraper unit based on the set test conditions;

[0014] 6) Turn on the humidity control unit, install the humidifier, and control the humidity according to the set humidity. At the same time, rotate the surface of the glass plate to ensure that the grease adhered to the surface of the glass plate is affected by the humidity of the same conditions until the set humidity is reached;

[0015] 7) Stop rotating the glass disk surface, apply load according to the test conditions, turn on the microscope, and collect the oil film thickness at the set operating speed;

[0016] 8) Save the image, close the software and control power, remove the load, and clean the residual grease.

[0017] Compared with the prior art, the present invention can precisely control humidity and investigate the influence of water immersion on the lubrication state. The built-in humidity control unit can be used in conjunction with a ball-disk single-point contact measuring device to reproduce the lubrication failure problem caused by water vapor aggregation to form free water adhering to the lubricant surface under a humid environment, investigate the influence of water contamination on the film-forming mechanism, and observe the influence on the oil film thickness of the lubricated contact point and the backfill of the lubricant, thereby providing a basis for investigating the distribution of atmospheric humidity during the flow of the lubricant, and is conducive to clarifying the evolution law of the lubrication flow of the contact point caused by water immersion, and providing experimental data for exploring the operation mechanism of the rolling bearing. The present invention has a simple structure and a scientific and reliable principle, and can simulate the influence of humidity on the evolution process of grease, conduct a quantitative analysis of the decay mechanism, clarify the flow distribution morphology and film-forming mechanism of the rolling bearing lubricant, provide data support for the state evaluation and life prediction of the rolling bearing during operation, and judge whether the lubrication of the rolling bearing has failed. Description of the drawings:

[0018] Figure 1 It is a schematic diagram of the main structural principle of the present invention.

[0019] Figure 2 It is a schematic diagram of the local structural principle of the present invention.

[0020] Figure 3 It is a schematic diagram of the use state of the present invention.

[0021] Figure 4 This is a contrast diagram of oil film interference under the condition of sufficient fat supply involved in the present invention.

[0022] Figure 5 This is a comparison diagram of the oil film interference evolution under the limited fat supply condition involved in the present invention.

[0023] Figure 6 This is a comparison diagram of the oil film thickness evolution with and without the influence of humidity involved in the present invention.

[0024] Figure 7 This is a comparison diagram of the track oil film with and without the influence of humidity involved in the present invention. Specific implementation method:

[0025] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings.

[0026] Embodiment 1:

[0027] The main structure of a humidity control device according to this embodiment is as follows Figure 1-2As shown, it includes a bracket 1, a humidity control box 2 and a humidity sensor 3; the humidity control box 2 is arranged on the bracket 1, and the humidity sensor 3 is arranged on the inner wall of the humidity control box 2 or on the bracket 1 inside the humidity control box 2; the main structure of the bracket 1 includes a vertical plate 11, a horizontal plate 12, a glass plate mounting hole 13, a bottom sealing enclosure 14 and a movable plate 15; the vertical plate 11 of the L-shaped structure is fixedly connected to the horizontal plate 12 of the L-shaped structure, the center and end of the horizontal plate 12 are provided with a glass plate mounting hole 13, and the center of the glass plate mounting hole 13 is provided with a bottom sealing enclosure 14. The enclosure 14 is provided with a detachable movable plate 15 at the end; the main structure of the humidity control box 2 includes a box body 21, a top cover 22, a humidification port 23, a grease scraping port 24, a steel ball mounting hole 25, an observation point 26 and a top sealing enclosure 27; the top of the box body 21 with an inner hollow cylindrical structure is provided with a top cover 22, and the side wall is provided with a switchable humidification port 23, a grease scraping port 24 and a steel ball mounting hole 25, an observation point 26 with a transparent arc-shaped strip structure is provided on the top cover 22, and a top sealing enclosure 27 is provided at the steel ball mounting hole 25.

[0028] The glass plate mounting hole 13 involved in the present embodiment is used to penetrate the glass plate 4, the bottom sealing enclosure 14 encloses the axis of the glass plate 4, the movable plate 15 is bolted to the horizontal plate 12, when a single-drive test is performed, the movable plate 15 is not used, and when a double-drive test is performed, the movable plate 15 is used to ensure sealing; a cylindrical boss is arranged at the center of the top cover 22, and an observation unit 5 is arranged above it, a humidification port 23 facilitates the humidification operation of the humidifier, a grease scraping port 24 is provided for the grease scraping operation of the grease scraping unit 6, a steel ball mounting hole 25 is used to penetrate the steel ball and its driving unit 7, an observation point 26 facilitates the observation of the observation unit 5, and a top sealing enclosure 27 encloses the axis of the steel ball and its driving unit.

[0029] When a humidity control device according to this embodiment is used, Figure 3 As shown, a synchronous test is carried out with a ball-on-disc testing machine. The PLC controls the ball-on-disc running speed and applies the corresponding load, and the humidity is controlled within the set range. The impact of the rolling bearing movement on the lubricant flow distribution and film-forming characteristics is quantitatively evaluated.

[0030] To study the effect of humidity on the lubrication state of the contact points, the following two tests were conducted:

[0031] Experiment 1: Investigating the effect of ambient humidity on the film-forming properties of grease under sufficient grease supply conditions

[0032] Take a set volume of grease and apply it evenly to the running track of the glass disk and the steel ball. Because the lubricant is pushed to both sides of the lubrication track under the action of the pressure gradient during the rotation, it is difficult to fill back into the lubrication track, which may cause insufficient oil supply at the inlet and lead to oil-starved lubrication. In order to meet the test requirements of sufficient grease supply, a grease scraping unit 6 is used to replenish the grease;

[0033] The test results are as follows Figure 4 As shown in the figure, under the condition of sufficient grease supply, humidity has little effect on the oil film thickness, but it will affect the flow distribution of the lubricant around the contact point. This is because the contact point is a high-pair contact, and the central pressure reaches the GPa level. A large amount of free water moves around the contact area under the action of the pressure gradient and cannot enter the contact area.

[0034] Experiment 2: Investigating the effect of ambient humidity on the film-forming properties of grease under limited grease supply conditions

[0035] Rolling bearings are often in an oil-deficient state under grease lubrication conditions. The free water in the track will affect the appearance time of the oil-deficient boundary at the front entrance of the contact area and enter the contact area along the lubricated track.

[0036] The comparison results of the oil film interference evolution process with and without humidity conditions are as follows: Figure 5 and Figure 6 As shown, the free water in the track will affect the evolution and decay process of the oil film thickness, resulting in a decrease in the oil film thickness;

[0037] Comparison results of track oil film with and without humidity conditions are shown in Figure 2. Figure 7 As shown, free water adheres to the lubricant surface, affecting the flow distribution of the lubricant and causing a decrease in the backfill volume inside the track.

Claims

1. A humidity control device is rationally designed according to the structure of the ball-panel contact tester and the installation positions of the humidifier, humidity controller and humidity sensor, characterized in that: The main structure comprises a bracket and a humidity control box arranged thereon, and a humidity sensor arranged on the bracket or in the humidity control box. The humidity sensor is located near the lubrication observation point.

2. The humidity control device according to claim 1, characterized in that: The main structure of the bracket includes a vertical plate, a horizontal plate, a glass plate mounting hole, a bottom sealing enclosure and a movable plate; the vertical plate of the L-shaped structure is fixedly connected to the horizontal plate of the L-shaped structure, the center and end of the horizontal plate are provided with glass plate mounting holes, the center of the glass plate mounting hole is provided with a bottom sealing enclosure, and the end is provided with a detachable movable plate.

3. The humidity control device according to claim 2, characterized in that: The main structure of the humidity control box includes a box body, a top cover, a humidification port, a grease scraping port, a steel ball mounting hole, an observation point and a top sealing enclosure; a top cover is arranged on the top of the box body with an inner hollow cylindrical structure, and a switchable humidification port, a grease scraping port and a steel ball mounting hole are opened on the side wall, an observation point with an arc-shaped strip structure with a transparent structure is arranged on the top cover, and a top sealing enclosure is arranged at the steel ball mounting hole.

4. The humidity control device according to claim 2, characterized in that: The glass plate installation hole is used to pass the glass plate, the bottom sealing plate encloses the axis of the glass plate, and the movable plate is bolted to the cross plate. When a single-drive test is performed, the movable plate is not used, and when a double-drive test is performed, the movable plate is used.

5. The humidity control device according to claim 3, characterized in that A cylindrical boss is arranged at the center of the top cover, and an observation unit is arranged on the top. The humidification port is convenient for the humidification operation of the humidifier, the grease scraping port is for the grease scraping operation of the grease scraping unit, the steel ball mounting hole is used for penetrating the steel ball and its driving unit, the observation point is convenient for the observation of the observation unit, and the top sealing enclosure encloses the axis of the steel ball and its driving unit.

6. The humidity control device according to any one of claims 1 to 5, characterized in that: The bracket and the humidity control box as well as the bracket or the humidity control box and the humidity sensor are all connected by bolts.

7. The humidity control device according to claim 6, characterized in that: Used in conjunction with a humidifier, humidity control unit and ball-disk contact test device, it can simultaneously realize the observation of oil film thickness, evolution process and lubricant flow distribution characteristics at the lubrication flow point, as well as experimental exploration of the friction characteristics of the lubricant under different motion conditions, including the response degree of oil film thickness and friction force under different load, speed and humidity conditions.

8. The humidity control device according to claim 7, characterized in that: The specific implementation process is as follows: 1) Install the glass plate and the steel ball to the corresponding positions, and adjust the surface runout of the glass plate so that the runout does not exceed 1 micron during one rotation; Wipe away the contaminants adhering to the surface of the glass plate and the steel ball; 2) Apply load, measure the contact point position and the rotation radius of the glass plate through the observation point, and control the rotation speed of the glass plate; 3) Remove the load, rotate the glass plate, evenly distribute the lubricant on the lubrication track formed by the lubrication contact points, and stop running; 4) Install the bracket, enclose the bracket and the humidity control box; 5) Determine the use of the scraper unit based on the set test conditions; 6) Turn on the humidity control unit, install the humidifier, and control the humidity according to the set humidity. At the same time, rotate the surface of the glass plate until the set humidity is reached; 7) Stop rotating the glass disk surface, apply load according to the test conditions, turn on the microscope, and collect the oil film thickness at the set operating speed; 8) Save the image, close the software and control power.

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