Automatic liquid supplementing device and method for electro-hydraulic servo loading system of bearing tester

Abstract

The invention relates to an automatic liquid supplementing device and method for an electro-hydraulic servo loading system of a bearing tester. The automatic liquid supplementing device for the electro-hydraulic servo loading system of the bearing tester comprises an axial servo loading system, a radial servo loading system and a liquid supplementing system, the axial servo loading system comprises an axial loading electric cylinder and an axial driving cylinder; the radial servo loading system comprises a radial loading electric cylinder and a radial driving cylinder; the liquid supplementing system comprises a liquid supplementing electric cylinder and a liquid supplementing hydraulic cylinder; the liquid supplementing hydraulic cylinder is respectively communicated with the axial driving cylinder and the radial driving cylinder through pipelines; the liquid supplementing system is used for driving a liquid supplementing hydraulic cylinder through a liquid supplementing electric cylinder to supplement hydraulic oil in the liquid supplementing hydraulic cylinder to an axial driving cylinder or a radial driving cylinder through a pipeline when the axial loading electric cylinder or the radial loading electric cylinder reaches 85% limit; and until the axial loading electric cylinder or the radial loading electric cylinder retreats to reach 15% of the limit or the liquid supplementing electric cylinder reaches 85% of the limit in advance.

Description

Technical Field

[0001] The present application relates to the technical field of bearing testers, and in particular to an automatic fluid replenishing device and method for an electro-hydraulic servo loading system of a bearing tester. Background Art

[0002] A bearing tester is a test platform used to conduct performance and durability tests on bearings. It consists of a test bench, a loading system, a lubrication system, a control system, and a test system. The loading system simulates axial and radial loads on the test bearings, allowing for real-time load adjustment according to the test load spectrum. The electro-hydraulic servo loading system has become a popular new loading system for bearing testers in recent years. Its advantages include precise load control, compact footprint, ease of maintenance, and low noise. It consists of an electric cylinder, a driving hydraulic cylinder, an actuator hydraulic cylinder, and associated piping, as well as sensors. The principle is that the electric cylinder's push rod pushes the driving cylinder's piston rod, pumping hydraulic oil through the connecting pipeline between the driving and actuator cylinders into the actuator cylinder. This drives the actuator cylinder's piston rod to apply the load. In theory, there is no loss of hydraulic oil during the loading process. However, during long-term testing, vibration, high temperatures, and other factors can degrade the hydraulic seal, leading to loss of hydraulic oil. Therefore, it is necessary to automatically replenish the electro-hydraulic servo loading system to improve the automation level of the bearing tester, reduce the number and time of maintenance shutdowns, and ensure that the bearing test can be carried out continuously. Summary of the Invention

[0003] The present application provides an automatic fluid replenishing device and method for the electro-hydraulic servo loading system of a bearing tester, which is used to automatically replenish the loading oil when the loading load of the bearing tester loading system is inaccurate due to insufficient loading oil during a long test process, so as to ensure that the bearing test is uninterrupted, without stopping, and unmanned, thereby improving the automation capability of the bearing tester.

[0004] In a first aspect, the present application provides an automatic fluid replenishment device for an electro-hydraulic servo loading system of a bearing tester, comprising an axial servo loading system, a radial servo loading system, and a fluid replenishment system;

[0005] The axial servo loading system includes an axial loading electric cylinder and an axial driving cylinder; the radial servo loading system includes a radial loading electric cylinder and a radial driving cylinder; the fluid replenishment system includes a fluid replenishment electric cylinder and a fluid replenishment hydraulic cylinder; the fluid replenishment hydraulic cylinder is connected to the axial driving cylinder and the radial driving cylinder respectively through pipelines;

[0006] The fluid replenishment system is used to drive the fluid replenishment hydraulic cylinder to replenish the hydraulic oil therein to the axial drive cylinder or the radial drive cylinder through a pipeline when the axial loading electric cylinder or the radial loading electric cylinder reaches the 85% limit, until the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit or the fluid replenishment electric cylinder reaches the 85% limit in advance.

[0007] Furthermore, the axial servo loading system further includes an axial loading electric cylinder 15% limit, an axial loading electric cylinder 85% limit, a first pressure sensor, and a first solenoid valve;

[0008] The 15% limit of the axial loading electric cylinder and the 85% limit of the axial loading electric cylinder are both set on the axial loading electric cylinder; the first pressure sensor is set on the axial drive cylinder for monitoring the pressure of the axial drive cylinder; the first solenoid valve is set at the connection point between the axial drive cylinder and the pipeline.

[0009] Furthermore, the axial servo loading system further includes an axial force sensor, an axial loading hydraulic cylinder, and an axial connecting pipeline;

[0010] The axial loading hydraulic cylinder is connected to the axial driving cylinder through the axial connecting pipeline, and the axial force sensor is arranged on the axial loading hydraulic cylinder; the axial loading hydraulic cylinder is used to press onto the load to form a loading load.

[0011] Furthermore, the radial servo loading system further includes a radial loading electric cylinder 15% limit, a radial loading electric cylinder 85% limit, a second pressure sensor, and a second solenoid valve;

[0012] The 15% limit of the radial loading electric cylinder and the 85% limit of the radial loading electric cylinder are both set on the radial loading electric cylinder; the second pressure sensor is set on the radial drive cylinder to monitor the pressure of the radial drive cylinder; the second solenoid valve is set at the connection point between the radial drive cylinder and the pipeline.

[0013] Furthermore, the radial servo loading system further includes a radial force sensor, a radial loading hydraulic cylinder, and a radial connecting pipeline;

[0014] The radial loading hydraulic cylinder is connected to the radial driving cylinder through the radial connecting pipeline, and the radial force sensor is arranged on the radial loading hydraulic cylinder; the radial loading hydraulic cylinder is used to press onto the load to form a loading load.

[0015] Furthermore, the fluid replenishment system also includes a negative limit of the fluid replenishment electric cylinder, an 85% limit of the fluid replenishment electric cylinder, and a 15% limit of the fluid replenishment electric cylinder;

[0016] The negative limit of the liquid replenishing electric cylinder, the 85% limit of the liquid replenishing electric cylinder, and the 15% limit of the liquid replenishing electric cylinder are all set on the liquid replenishing electric cylinder.

[0017] Furthermore, the fluid replenishment system further includes a fluid replenishment port of a fluid replenishment hydraulic cylinder and a third pressure sensor;

[0018] The rehydration port of the rehydration hydraulic cylinder and the third pressure sensor are both arranged on the rehydration hydraulic cylinder; the rehydration port of the rehydration hydraulic cylinder is used to manually recharge hydraulic oil to the rehydration hydraulic cylinder; the third pressure sensor is used to monitor the pressure of the rehydration hydraulic cylinder.

[0019] In a second aspect, the present application also provides a method for automatically replenishing fluid in an electro-hydraulic servo loading system of a bearing tester, comprising:

[0020] When the axial loading electric cylinder or radial loading electric cylinder reaches 85% of the limit, the hydraulic cylinder is controlled to be pushed out slowly, and the pressure of the hydraulic cylinder is compared with the pressure of the axial drive cylinder or radial drive cylinder;

[0021] If the pressure of the fluid replenishing hydraulic cylinder is greater than the pressure of the axial drive cylinder or the radial drive cylinder, the first solenoid valve or the second solenoid valve is controlled to open, and the fluid replenishing hydraulic cylinder is driven by the fluid replenishing electric cylinder to replenish the hydraulic oil therein into the axial drive cylinder or the radial drive cylinder.

[0022] Furthermore, after the hydraulic oil in the hydraulic cylinder is replenished into the axial drive cylinder or the radial drive cylinder by the hydraulic cylinder, the method further includes:

[0023] The axial loading electric cylinder or the radial loading electric cylinder controls the axial loading load or the radial loading load in real time according to the feedback of the axial force sensor or the radial force sensor to keep the axial loading load or the radial loading load stable, and slowly retreats during the fluid replenishment process;

[0024] When the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit, or the fluid replenishing electric cylinder reaches the 85% limit in advance, the first solenoid valve or the second solenoid valve is closed and fluid replenishment is stopped.

[0025] Furthermore, it also includes:

[0026] When the rehydration is completed and the rehydration electric cylinder reaches the 85% limit, but the axial loading electric cylinder or the radial loading electric cylinder has not reached the 15% limit, the rehydration hydraulic cylinder is manually rehydrated through the rehydration port of the rehydration hydraulic cylinder;

[0027] During manual rehydration, the rehydration electric cylinder slowly retreats. When the rehydration electric cylinder reaches the 15% limit, manual rehydration stops.

[0028] The above technical solution of this application has the following advantages:

[0029] The first aspect of the present application provides an automatic rehydration device for the electro-hydraulic servo loading system of a bearing tester. When the axial or radial loading electric cylinder reaches the 85% limit, the rehydration electric cylinder is controlled to slowly push forward, driving the rehydration hydraulic cylinder to replenish the hydraulic oil therein to the driving hydraulic cylinder through the pipeline. The axial or radial loading electric cylinder will slowly retreat during the rehydration process until it reaches the 15% limit, or the rehydration electric cylinder reaches the 85% limit in advance, at which point the rehydration is completed. This device can realize the function of automatically replenishing the hydraulic oil required by the electro-hydraulic servo loading system in an unattended state, which can improve the automation level of the bearing tester, improve the bearing test efficiency, ensure the accuracy of the test load, and meet the requirements of the bearing durability test.

[0030] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 Schematic diagram of the automatic fluid replenishing device of the electro-hydraulic servo loading system of the bearing tester provided in this application;

[0033] Figure 2 Schematic diagram of the fluid replenishment principle of the electro-hydraulic servo loading system provided for this application;

[0034] Figure 3 This is the fluid replenishment logic diagram of the electro-hydraulic servo loading system provided in this application.

[0035] Figure markings: 1. Fluid replenishing electric cylinder; 2. Axial loading electric cylinder 15% limit; 3. Axial loading electric cylinder; 4. Radial loading electric cylinder 15% limit; 5. Axial loading electric cylinder 85% limit; 6. Radial loading electric cylinder; 7. Axial drive cylinder; 8. Radial drive cylinder; 9. First pressure sensor; 10. Second pressure sensor; 11. Second solenoid valve; 12. Radial connecting pipeline; 13. Radial force sensor; 14. Radial loading hydraulic cylinder; 15. Axial force sensor; 16. Axial loading hydraulic cylinder; 17. Axial connecting pipeline; 18. First solenoid valve; 19. Fluid replenishing hydraulic cylinder fluid replenishment port; 20. Third pressure sensor; 21. Fluid replenishing hydraulic cylinder; 22. Fluid replenishing electric cylinder negative limit; 23. Fluid replenishing electric cylinder 85% limit; 24. Fluid replenishing electric cylinder 15% limit; 25. Radial loading electric cylinder 85% limit. DETAILED DESCRIPTION

[0036] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0037] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0038] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0039] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of the present application include a particular feature, structure, or characteristic described in conjunction with that embodiment. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized. "Multiple" means "two or more."

[0040] The present application provides an automatic fluid replenishment device and method for the electro-hydraulic servo loading system of a bearing tester. Its purpose is to address the problem that during a long period of non-stop testing of a bearing tester, the hydraulic cylinder of the loading system may slowly leak hydraulic oil due to factors such as vibration and high temperature, which ultimately affects the loading load of the bearing tester. The application provides a device controlled by a computer program that replenishes oil during the non-stop testing process, which can improve the automation level of the bearing tester, improve the efficiency of bearing testing, ensure the accuracy of the test load, and meet the requirements of bearing durability testing.

[0041] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] An embodiment of the present application provides an automatic fluid replenishment device for an electro-hydraulic servo loading system of a bearing tester, comprising an axial servo loading system, a radial servo loading system, and a fluid replenishment system; the axial servo loading system comprises an axial loading electric cylinder and an axial drive cylinder; the radial servo loading system comprises a radial loading electric cylinder and a radial drive cylinder; the fluid replenishment system comprises a fluid replenishment electric cylinder and a fluid replenishment hydraulic cylinder; the fluid replenishment hydraulic cylinder is connected to the axial drive cylinder and the radial drive cylinder respectively through pipelines; the fluid replenishment system is used to, when the axial loading electric cylinder or the radial loading electric cylinder reaches the 85% limit, drive the fluid replenishment hydraulic cylinder through the pipeline to replenish the hydraulic oil therein to the axial drive cylinder or the radial drive cylinder through the pipeline until the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit or the fluid replenishment electric cylinder reaches the 85% limit in advance.

[0043] In some embodiments, the axial servo loading system also includes an axial loading electric cylinder 15% limit, an axial loading electric cylinder 85% limit, a first pressure sensor, and a first solenoid valve; the axial loading electric cylinder 15% limit and the axial loading electric cylinder 85% limit are both set on the axial loading electric cylinder; the first pressure sensor is set on the axial drive cylinder for monitoring the pressure of the axial drive cylinder; the first solenoid valve is set at the connection point between the axial drive cylinder and the pipeline.

[0044] In some embodiments, the axial servo loading system further includes an axial force sensor, an axial loading hydraulic cylinder, and an axial connecting pipeline; the axial loading hydraulic cylinder is connected to the axial drive cylinder through the axial connecting pipeline, and the axial force sensor is arranged in the axial loading hydraulic cylinder; the axial loading hydraulic cylinder is used to press onto the load to form a loading load.

[0045] In some embodiments, the radial servo loading system further includes a radial loading electric cylinder 15% limit, a radial loading electric cylinder 85% limit, a second pressure sensor, and a second solenoid valve; the radial loading electric cylinder 15% limit and the radial loading electric cylinder 85% limit are both set on the radial loading electric cylinder; the second pressure sensor is set on the radial drive cylinder for monitoring the pressure of the radial drive cylinder; the second solenoid valve is set at the connection point between the radial drive cylinder and the pipeline.

[0046] In some embodiments, the radial servo loading system further includes a radial force sensor, a radial loading hydraulic cylinder, and a radial connecting pipeline; the radial loading hydraulic cylinder is connected to the radial drive cylinder through the radial connecting pipeline, and the radial force sensor is arranged on the radial loading hydraulic cylinder; the radial loading hydraulic cylinder is used to press onto the load to form a loading load.

[0047] In some embodiments, the fluid replenishment system also includes a negative limit of the fluid replenishment electric cylinder, an 85% limit of the fluid replenishment electric cylinder, and a 15% limit of the fluid replenishment electric cylinder; the negative limit of the fluid replenishment electric cylinder, the 85% limit of the fluid replenishment electric cylinder, and the 15% limit of the fluid replenishment electric cylinder are all set on the fluid replenishment electric cylinder.

[0048] In some embodiments, the fluid replenishment system also includes a fluid replenishment port of a fluid replenishment hydraulic cylinder and a third pressure sensor; the fluid replenishment port of the fluid replenishment hydraulic cylinder and the third pressure sensor are both arranged on the fluid replenishment hydraulic cylinder; the fluid replenishment port of the fluid replenishment hydraulic cylinder is used to manually replenish hydraulic oil to the fluid replenishment hydraulic cylinder; the third pressure sensor is used to monitor the pressure of the fluid replenishment hydraulic cylinder.

[0049] like Figure 1 As shown, the rehydration system consists of a rehydration electric cylinder 1, a rehydration hydraulic cylinder rehydration port 19, a third pressure sensor 20, a rehydration hydraulic cylinder 21, a rehydration electric cylinder negative limiter 22, a rehydration electric cylinder 85% limiter 23, and a rehydration electric cylinder 15% limiter 24. The rehydration electric cylinder 1 pushes the piston rod of the rehydration hydraulic cylinder 21, pushing the oil in the hydraulic cylinder to the axial drive cylinder 7 or radial drive cylinder 8 through the connecting pipeline. The rehydration electric cylinder negative limiter 22 is used to determine whether the rehydration hydraulic cylinder 21 is low on hydraulic oil. The rehydration electric cylinder 85% limiter 23 indicates that the rehydration hydraulic cylinder 21 needs to be replenished with hydraulic oil, and the rehydration electric cylinder 15% limiter 24 indicates that the rehydration hydraulic cylinder 21 has been completed. The third pressure sensor 20 is used to display the pressure of the rehydration hydraulic cylinder 21 and provide an overpressure alarm. The rehydration hydraulic cylinder rehydration port 19 is a self-sealing quick-connect interface used to manually refill the hydraulic cylinder 21 with hydraulic oil.

[0050] The axial servo loading system consists of the axial loading electric cylinder 15% limit 2, the axial loading electric cylinder 3, the axial loading electric cylinder 85% limit 5, the axial drive cylinder 7, the first pressure sensor 9, the axial force sensor 15, the axial loading hydraulic cylinder 16, the axial connecting line 17, and the first solenoid valve 18. The axial loading electric cylinder 3 pushes the piston rod of the axial drive cylinder 7, pushing the hydraulic oil inside into the axial loading hydraulic cylinder 16 through the axial connecting line 17. This pushes the piston rod of the axial loading hydraulic cylinder 16 and its connected axial force sensor 15 together onto the load, creating a loading load. Load feedback from the axial force sensor 15 controls the displacement of the axial loading electric cylinder 3, achieving closed-loop force control. The axial loading electric cylinder 15% limit 2 indicates that the axial loading electric cylinder 3 has approached its negative limit during unloading (retraction of the axial loading electric cylinder 3). The 85% limit 5 of the axial loading cylinder is used to control the hydraulic pressure. When the axial loading cylinder 3 is extended and reaches the 85% limit, the first solenoid valve 18 opens, and the fluid replenishment system begins to replenish hydraulic oil to the axial drive cylinder 7. When the replenishment causes the axial loading cylinder 3 to retract to the 15% limit 2 of the axial loading cylinder, the first solenoid valve 18 closes, and the replenishment stops. The first pressure sensor 9 monitors the pressure of the axial drive cylinder 7 and provides overpressure alarm protection.

[0051] The radial servo loading system consists of the radial loading electric cylinder 15% limit 4, radial loading electric cylinder 6, radial drive cylinder 8, second pressure sensor 10, second solenoid valve 11, radial connecting pipe 12, radial force sensor 13, radial loading hydraulic cylinder 14, and radial loading electric cylinder 85% limit 25. The radial loading electric cylinder 6 pushes the piston rod of the radial drive cylinder 8, pushing the hydraulic oil inside into the radial loading hydraulic cylinder 14 through the radial connecting pipe 12. This pushes the piston rod of the radial loading hydraulic cylinder 14 and its connected radial force sensor 13 together onto the load, creating a loading load. Load feedback from the radial force sensor 13 controls the displacement of the radial loading electric cylinder 6, achieving closed-loop force control. The radial loading electric cylinder 15% limit 4 indicates that the radial loading electric cylinder 6 has approached its negative limit during unloading (retraction of the radial loading electric cylinder 6). The radial loading cylinder 85% limit 25 controls the radial loading cylinder 6. When the radial loading cylinder 6 reaches the 85% limit, the second solenoid valve 11 opens, and the fluid replenishment system begins replenishing hydraulic oil to the radial drive cylinder 8. When the replenished fluid causes the radial loading cylinder 6 to retract to the 15% limit 4, the second solenoid valve 11 closes, halting the replenishment. The second pressure sensor 10 monitors the pressure in the radial drive cylinder 8, providing overpressure alarm protection.

[0052] During a bearing test, if one of the axial or radial loading cylinders in the electro-hydraulic servo loading system displays the "85% limit reached" alarm, it indicates that the axial or radial drive cylinder is low on hydraulic oil. When the system control software determines that one of the loading cylinders has reached the 85% limit, it issues a command to slowly advance the hydraulic cylinder. The system monitors the hydraulic pressure in the hydraulic cylinder in real time and compares it with the pressure in the axial or radial drive cylinder being replenished. When the hydraulic pressure in the hydraulic cylinder slightly exceeds that of the axial or radial drive cylinder being replenished, the solenoid valve opens, initiating replenishment. Simultaneously, the axial or radial cylinder, based on feedback from the force sensor, maintains a stable loading force and slowly retracts during the replenishment process, while the hydraulic cylinder slowly advances.

[0053] When the electric cylinder connected to the axial or radial drive cylinder being recharged reaches the 15% limit, or when the recharge cylinder reaches 85%, the solenoid valve closes, stopping recharge and completing recharge. If recharge ends when the recharge cylinder reaches the 85% limit but the axial or radial cylinder has not reached the 15% limit, the control software will prompt "Manually refill the recharge cylinder." However, during manual recharge of the recharge cylinder, the solenoid valve remains closed, which does not affect the output and control of the axial or radial loads, and the test continues normally. When manually recharging the recharge cylinder, if the software indicates that the axial or radial cylinder has reached the 15% limit, manual recharge should be stopped, indicating that recharge is complete. Depressurize the manual oil pump and disconnect the recharge line.

[0054] An embodiment of the present application also provides an automatic fluid replenishment method for an electro-hydraulic servo loading system of a bearing tester, including: when the axial loading electric cylinder or the radial loading electric cylinder reaches the 85% limit, controlling the fluid replenishment electric cylinder to slowly push out, and comparing the pressure of the fluid replenishment hydraulic cylinder with the pressure of the axial drive cylinder or the radial drive cylinder; if the pressure of the fluid replenishment hydraulic cylinder is greater than the pressure of the axial drive cylinder or the radial drive cylinder, controlling the first solenoid valve or the second solenoid valve to open, and driving the fluid replenishment hydraulic cylinder through the fluid replenishment electric cylinder to replenish the hydraulic oil therein into the axial drive cylinder or the radial drive cylinder.

[0055] In some embodiments, after the rehydration electric cylinder drives the rehydration hydraulic cylinder to replenish the hydraulic oil therein into the axial drive cylinder or the radial drive cylinder, it also includes: the axial loading electric cylinder or the radial loading electric cylinder controls the axial loading load or the radial loading load in real time according to the feedback of the axial force sensor or the radial force sensor to keep it stable, and slowly retreats during the rehydration process; when the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit, or the rehydration electric cylinder reaches the 85% limit in advance, the first solenoid valve or the second solenoid valve is closed and the rehydration is stopped.

[0056] In some embodiments, it also includes: when the rehydration is completed and the rehydration electric cylinder reaches the 85% limit, and the axial loading electric cylinder or the radial loading electric cylinder has not reached the 15% limit, the rehydration hydraulic cylinder is manually rehydrated through the rehydration port of the rehydration hydraulic cylinder; during manual rehydration, the rehydration electric cylinder slowly retreats, and when the rehydration electric cylinder reaches the 15% limit, manual rehydration is stopped.

[0057] During long, unattended bearing performance and endurance tests, loading is a crucial requirement. Therefore, ensuring consistent loading accuracy is crucial. However, during extended testing, the piston of the loading hydraulic cylinder can develop poor sealing due to high temperatures, vibration, and other factors, leading to slow leakage of the loading hydraulic oil. To ensure accurate loading, the electric cylinder in the electro-hydraulic servo loading system slowly advances, moving the piston rod of the drive hydraulic cylinder. This slowly pushes hydraulic oil from the drive hydraulic cylinder into the loading hydraulic cylinder through connecting pipes to compensate for any leakage. If the axial or radial loading cylinder in the electro-hydraulic servo loading system reaches the 85% limit and the software displays an alarm, this indicates that the axial or radial drive hydraulic cylinder is low on hydraulic oil. However, the test can still proceed normally.

[0058] like Figure 2 and Figure 3 As shown, when the system control software determines that one of the loading cylinders has reached the 85% limit, it issues a command to slowly extend the hydraulic cylinder. A third pressure sensor mounted on the hydraulic cylinder monitors the hydraulic pressure in real time and compares it with the pressure reported by the first pressure sensor on the axial drive cylinder or the second pressure sensor on the radial drive cylinder being infused. When the feedback value from the third pressure sensor on the hydraulic cylinder is slightly higher than the pressure reported by the first pressure sensor on the axial drive cylinder or the second pressure sensor on the radial drive cylinder being infused, the first solenoid valve connected to the axial drive cylinder or the second solenoid valve connected to the radial drive cylinder opens. As the hydraulic cylinder continues to slowly extend, it drives the piston rod of the hydraulic cylinder, replenishing the hydraulic oil in the hydraulic cylinder into the axial drive cylinder or the radial drive cylinder.

[0059] At this point, as the replenishment cylinder pumps hydraulic fluid into the depleted drive cylinder, the oil pressure in the depleted drive cylinder inevitably increases. The connection between the depleted drive cylinder and the loading hydraulic cylinder also increases the oil pressure in the loading hydraulic cylinder, ultimately increasing the loading load. Therefore, while hydraulic fluid is replenishing the axial or radial drive cylinder, the axial or radial loading cylinder, based on feedback from the axial or radial force sensor, maintains a stable loading force in real time. During the replenishment process, the axial or radial loading cylinder slowly retracts, while the replenishment cylinder slowly advances. When the loading cylinder connected to the replenished axial or radial drive cylinder reaches the 15% limit, or when the replenishment cylinder reaches 85%, the first or second solenoid valve closes, stopping the replenishment, and the replenishment is complete. Throughout the replenishment process, the axial or radial loading load remains unaffected, thus preventing the normal operation of the bearing tester.

[0060] If the hydraulic cylinder reaches the 85% limit at the end of rehydration, but the axial or radial loading cylinder has not yet reached the 15% limit, the control software will prompt "Manually refill the hydraulic cylinder." However, during manual rehydration, the first or second solenoid valve remains closed, which does not affect the output and control of the axial or radial loads, and the test continues normally. When manually rehydrating the hydraulic cylinder using the manual oil pump through the rehydration port, the push rod of the hydraulic cylinder connected to the piston rod of the hydraulic cylinder will slowly retract as hydraulic oil continues to be replenished. When the software prompts that the hydraulic cylinder has reached the 15% limit, manual rehydration should be stopped, and rehydration of the hydraulic cylinder is complete. Depressurize the manual oil pump and disconnect the rehydration line.

[0061] The embodiment of the present application provides an automatic rehydration device and method for the electro-hydraulic servo loading system of a bearing tester. When the loading electric cylinder of the axial servo loading system or the radial servo loading system reaches the 85% limit, the control software issues a command to control the rehydration electric cylinder of the rehydration system to slowly push forward, driving the rehydration hydraulic cylinder to replenish the hydraulic oil therein through the pipeline to the driving hydraulic cylinder of the axial servo loading system or the radial servo loading system. During the rehydration process, the axial servo loading system or the radial servo loading system will control the axial or radial loading load in real time through the feedback of the force sensor. The axial or radial loading electric cylinder will slowly retreat during the rehydration process until it reaches the 15% limit, or the rehydration electric cylinder reaches the 85% limit in advance, the control system will close the solenoid valve, and the rehydration is completed at this time. The device can realize the function of automatically replenishing the hydraulic oil required by the electro-hydraulic servo loading system in an unattended state, which can improve the automation level of the bearing tester, improve the bearing test efficiency, ensure the accuracy of the test load, and meet the requirements of the bearing durability test.

[0062] Those skilled in the art will clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. In addition, the specific names of the functional units and modules are only for the purpose of distinguishing each other and are not used to limit the scope of protection of this application.

[0063] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. An automatic fluid replenishing device for an electro-hydraulic servo loading system of a bearing tester, characterized in that: Including axial servo loading system, radial servo loading system, and fluid replenishment system; The axial servo loading system includes an axial loading electric cylinder and an axial driving cylinder; the radial servo loading system includes a radial loading electric cylinder and a radial driving cylinder; the fluid replenishment system includes a fluid replenishment electric cylinder and a fluid replenishment hydraulic cylinder; the fluid replenishment hydraulic cylinder is connected to the axial driving cylinder and the radial driving cylinder respectively through pipelines; The fluid replenishment system is used to drive the fluid replenishment hydraulic cylinder to replenish the hydraulic oil therein to the axial drive cylinder or the radial drive cylinder through a pipeline when the axial loading electric cylinder or the radial loading electric cylinder reaches the 85% limit, until the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit or the fluid replenishment electric cylinder reaches the 85% limit in advance.

2. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The axial servo loading system further includes a 15% limit of the axial loading electric cylinder, an 85% limit of the axial loading electric cylinder, a first pressure sensor, and a first solenoid valve; The 15% limit of the axial loading electric cylinder and the 85% limit of the axial loading electric cylinder are both set on the axial loading electric cylinder; the first pressure sensor is set on the axial drive cylinder for monitoring the pressure of the axial drive cylinder; the first solenoid valve is set at the connection point between the axial drive cylinder and the pipeline.

3. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The axial servo loading system also includes an axial force sensor, an axial loading hydraulic cylinder, and an axial connecting pipeline; The axial loading hydraulic cylinder is connected to the axial driving cylinder through the axial connecting pipeline, and the axial force sensor is arranged on the axial loading hydraulic cylinder; the axial loading hydraulic cylinder is used to press onto the load to form a loading load.

4. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The radial servo loading system also includes a radial loading electric cylinder 15% limit, a radial loading electric cylinder 85% limit, a second pressure sensor, and a second solenoid valve; The 15% limit of the radial loading electric cylinder and the 85% limit of the radial loading electric cylinder are both set on the radial loading electric cylinder; the second pressure sensor is set on the radial drive cylinder to monitor the pressure of the radial drive cylinder; the second solenoid valve is set at the connection point between the radial drive cylinder and the pipeline.

5. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The radial servo loading system also includes a radial force sensor, a radial loading hydraulic cylinder, and a radial connecting pipeline; The radial loading hydraulic cylinder is connected to the radial driving cylinder through the radial connecting pipeline, and the radial force sensor is arranged on the radial loading hydraulic cylinder; the radial loading hydraulic cylinder is used to press onto the load to form a loading load.

6. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The rehydration system also includes a negative limit of the rehydration electric cylinder, an 85% limit of the rehydration electric cylinder, and a 15% limit of the rehydration electric cylinder; The negative limit of the liquid replenishing electric cylinder, the 85% limit of the liquid replenishing electric cylinder, and the 15% limit of the liquid replenishing electric cylinder are all set on the liquid replenishing electric cylinder.

7. The automatic fluid replenishing device for the electro-hydraulic servo loading system of a bearing tester according to claim 1, characterized in that: The fluid replenishment system also includes a fluid replenishment port of a fluid replenishment hydraulic cylinder and a third pressure sensor; The rehydration port of the rehydration hydraulic cylinder and the third pressure sensor are both arranged on the rehydration hydraulic cylinder; the rehydration port of the rehydration hydraulic cylinder is used to manually recharge hydraulic oil to the rehydration hydraulic cylinder; the third pressure sensor is used to monitor the pressure of the rehydration hydraulic cylinder.

8. A method for automatically replenishing fluid in an electro-hydraulic servo loading system of a bearing tester, characterized in that: include: When the axial loading electric cylinder or radial loading electric cylinder reaches 85% of the limit, the hydraulic cylinder is controlled to be pushed out slowly, and the pressure of the hydraulic cylinder is compared with the pressure of the axial drive cylinder or radial drive cylinder; If the pressure of the fluid replenishing hydraulic cylinder is greater than the pressure of the axial drive cylinder or the radial drive cylinder, the first solenoid valve or the second solenoid valve is controlled to open, and the fluid replenishing hydraulic cylinder is driven by the fluid replenishing electric cylinder to replenish the hydraulic oil therein into the axial drive cylinder or the radial drive cylinder.

9. The automatic fluid replenishing method for the electro-hydraulic servo loading system of a bearing tester according to claim 8, characterized in that: After the hydraulic oil in the hydraulic cylinder is replenished into the axial drive cylinder or the radial drive cylinder by the hydraulic cylinder, the method further includes: The axial loading electric cylinder or the radial loading electric cylinder controls the axial loading load or the radial loading load in real time according to the feedback of the axial force sensor or the radial force sensor to keep the axial loading load or the radial loading load stable, and slowly retreats during the fluid replenishment process; When the axial loading electric cylinder or the radial loading electric cylinder retreats to the 15% limit, or the fluid replenishing electric cylinder reaches the 85% limit in advance, the first solenoid valve or the second solenoid valve is closed and fluid replenishment is stopped.

10. The automatic fluid replenishing method for the electro-hydraulic servo loading system of a bearing tester according to claim 8, characterized in that: Also includes: When the rehydration is completed and the rehydration electric cylinder reaches the 85% limit, but the axial loading electric cylinder or the radial loading electric cylinder has not reached the 15% limit, the rehydration hydraulic cylinder is manually rehydrated through the rehydration port of the rehydration hydraulic cylinder; During manual rehydration, the rehydration electric cylinder slowly retreats. When the rehydration electric cylinder reaches the 15% limit, manual rehydration stops.

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