A high-temperature heavy-load high-speed thrust bearing anti-cavitation test system and method

Abstract

The application relates to the technical field of mechanical engineering, and discloses a high-temperature heavy-load high-speed thrust bearing anti-cavitation test system and method, which comprises a heavy-load simulation part, a high-temperature simulation part and a high-speed dynamic simulation part arranged in sequence; the high-temperature simulation part comprises a high-temperature box, a sealed test cabin is arranged in the high-temperature box, the test cabin is connected with a vacuum pumping subsystem through an air pipe, and the test cabin is connected with an oil injection subsystem through an oil pipe; a thrust shaft is slidably and sealingly connected to one side of the high-temperature box, a power shaft is rotatably and sealingly connected to the other side of the high-temperature box, and the thrust shaft and the power shaft are coaxially arranged; one end of the thrust shaft extends into the test cabin and is fixedly connected with a first clamp for mounting a test sample at the end, and the other end of the thrust shaft is connected with the heavy-load simulation part; one end of the power shaft extends into the test cabin and is fixedly connected with a second clamp for mounting a thrust ring, and the other end of the power shaft is transmissionally connected with the high-speed dynamic simulation part. The application solves the cavitation problem in the test process through the synergistic control of vacuum pumping and high-temperature oil, and provides accurate test conditions for bearing performance determination and product development.

Description

Technical Field

[0001] This invention relates to the field of mechanical engineering technology, specifically to a test system and method for preventing cavitation in thrust bearings under high temperature, heavy load, and high speed conditions. Background Technology

[0002] Thrust bearings, as core components for transmitting axial loads, are widely used in high-end equipment such as submersible pump protectors, aero-engine spindles, and ultra-deep well drilling tools. Their performance directly determines the reliability and lifespan of the equipment under extreme operating conditions. In deep-sea oil and gas development, aerospace, and other fields, thrust bearings must withstand coupled operating conditions of "nearly 400°C high temperature, 30T heavy load, and 12000r / min high speed" for extended periods. For example, in ultra-deep well operations, the bottom hole temperature of a submersible pump can reach 400°C, the axial thrust exceeds 25T, and the spindle speed needs to be maintained above 10000r / min. Failure of a thrust bearing will lead to the failure of the entire machine. Therefore, accurately reproducing extreme operating conditions and testing the performance of thrust bearings has become a key aspect of equipment development and reliability assessment.

[0003] However, cavitation is a prevalent and serious problem affecting the accuracy of test results in existing thrust bearing testing. Cavitation refers to the phenomenon where, during liquid flow, when the local pressure drops below the liquid vapor pressure, bubbles are generated in the liquid. These bubbles then rapidly collapse in high-pressure areas, causing repeated impacts on the material surface and resulting in damage. The mechanism of cavitation is closely related to fluid dynamics. In thrust bearing testing, to provide a high-temperature environment, the thrust bearing cap is immersed in high-temperature resistant oil. Uneven oil film pressure distribution can lead to a sharp drop in pressure in local areas. When the pressure falls below the saturated vapor pressure of the oil, dissolved gases in the oil or the oil itself will form bubbles. These bubbles flow with the oil to the high-pressure area and rapidly collapse, generating microjets and shock waves that repeatedly impact the bearing surface, ultimately leading to material fatigue spalling and surface damage. Cavitation not only shortens the bearing's service life but also alters the oil film distribution characteristics, affecting the accuracy and reliability of test data. Traditional anti-cavitation methods mainly include optimizing the bearing structure design, using anti-cavitation materials, and controlling test parameters. However, these methods often exhibit significant limitations under high temperature and high pressure environments. High temperatures reduce oil viscosity and decrease the oil film's load-bearing capacity, making it easier for localized low-pressure areas to form. High pressure environments exacerbate the impact intensity of bubble collapse, leading to more severe cavitation damage. Furthermore, traditional methods struggle to fundamentally eliminate dissolved gases in the oil; these gases will still form bubbles under pressure changes, causing cavitation problems to persist. In summary, existing thrust bearing testing processes suffer from three major technical bottlenecks, severely restricting testing accuracy and bearing sample utilization: 1. The cavitation damage mechanism remains unsolved. Traditional testing employs a "room temperature oil injection - temperature rise testing" process. At 400℃, the test oil (such as mineral oil) easily vaporizes, generating bubbles, and residual air (≥5% by volume) in the test chamber mixes into the oil. When the bearing rotates at high speed, the oil flowing through the bearing clearance creates a high-pressure zone. The instantaneous rupture of air bubbles generates an impact pressure of 50-100 MPa, resulting in dense cavitation pits on the bearing surface. Under traditional processes, the cavitation damage rate is as high as 20%, directly causing test data (such as wear and torque) to deviate by more than 15%, failing to reflect the true performance of the bearing. 2. Existing testing systems are prone to air entrapment during the oil injection process, and the degassing process is incompatible with extreme operating conditions. Some existing processes attempt to use "atmospheric pressure stirring degassing," but this can only remove 60% of the free air bubbles in the oil, failing to remove residual air from dead corners of the chamber (such as the gap between the fixture and the bearing, and sealing grooves). Furthermore, when the test temperature rises to 400℃, the dissolved air in the oil will be released again, forming secondary cavitation.

[0004] Based on the above problems, there is an urgent need for a vacuum-high temperature oil synergistic process that is deeply adapted to extreme working conditions (400℃-30T-12000r / min) and can completely remove air from the oil, so as to solve the cavitation problem of traditional processes. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a cavitation prevention testing system and method for thrust bearings under high temperature, heavy load, and high speed conditions. By using a synergistic control of "vacuuming and high-temperature oil," the cavitation problem during the testing process is completely solved, providing accurate testing conditions for bearing performance evaluation and product development.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A high-temperature, heavy-load, high-speed thrust bearing anti-cavitation test system includes a heavy-load simulation unit, a high-temperature simulation unit, and a high-speed dynamic simulation unit, wherein the heavy-load simulation unit and the high-speed dynamic simulation unit are located on both sides of the high-temperature simulation unit. The high-temperature simulation unit includes a high-temperature chamber, inside which is a sealed test chamber. A high-temperature heating assembly is located at the bottom inner side of the test chamber, and a heat insulation unit is provided between the outer perimeter of the test chamber and the outer shell of the high-temperature chamber. An air extraction port is located at the top of the test chamber, connected to a vacuum subsystem via an air pipe. A pressure regulating valve is located on the test chamber. An oil injection port is located at the top of the test chamber, connected to an oil injection subsystem via an oil pipe. An oil injection valve is located on the oil pipe, and the oil injection subsystem is used to fill the test chamber with high-temperature resistant oil. A miniature stirrer is located at the bottom of the test chamber. The high-temperature chamber has a sliding seal connecting the thrust shaft on one side and a rotating seal connecting the power shaft on the other side. The thrust shaft and the power shaft are coaxially arranged. One end of the thrust shaft extends into the test chamber and is fixedly connected to the first clamp, which is used to install the bearing housing of the thrust bearing. The other end of the thrust shaft is connected to the output end of the heavy-load simulation unit, which provides a loading force to the bearing housing through the thrust shaft. One end of the power shaft extends into the test chamber and is fixedly connected to the second clamp, which is used to install the thrust ring of the thrust bearing. The other end of the power shaft is driven to the output end of the high-speed dynamic simulation unit, which drives the thrust ring to rotate through the power shaft.

[0007] As a preferred technical solution, the vacuum pumping subsystem includes a backing pump and a main pump, the backing pump and the main pump are connected in series, the ultimate vacuum of the main pump is better than that of the backing pump, and the main pump is a ZJ-40 type Roots vacuum pump.

[0008] As a preferred technical solution, the oil injection subsystem includes a preheating tank, which contains high-temperature resistant oil and is equipped with an electric heating tube. The preheating tank is connected to the test chamber via an oil pipe, and a flow sensor is also installed on the oil pipe. The oil injection subsystem also includes an oil recovery tank. An oil drain port is located at the bottom of the test chamber, and an oil drain valve is installed at the oil drain port. The oil drain port is connected to the oil recovery tank through an oil drain pipe.

[0009] As a preferred technical solution, the high-temperature resistant oil is Moruns I-PA organic heat transfer fluid.

[0010] As a preferred technical solution, the heavy-load simulation unit includes a thrust cylinder, the output shaft of which is connected to the thrust shaft via a heat-insulating connecting block, and the two ends of the thrust shaft are supported by a sliding bearing seat; The high-speed dynamic simulation unit includes a high-speed motor. The output end of the high-speed motor is connected to one end of the static pressure shaft via a coupling. The other end of the static pressure shaft is connected to the power shaft via a heat-insulating connecting block. The two ends of the static pressure shaft are supported by a static pressure bearing seat, and the two ends of the power shaft are supported by a rotary bearing seat.

[0011] As a preferred technical solution, the system also includes a sensor assembly, which comprises a thrust sensor, a dynamic torque sensor, a temperature sensor, a vibration sensor, and a speed sensor. The thrust sensor is located between the thrust cylinder and the thrust shaft, the dynamic torque sensor is located between the high-speed motor and the hydrostatic shaft, the temperature sensor is located inside the test chamber, and the vibration sensor is mounted on the hydrostatic bearing housing. The speed sensor is a built-in sensor in the motor. The sensor assembly also includes a wear test sensor, an oil condition sensor, and a vacuum sensor. The vacuum sensor is used to monitor the vacuum level inside the test chamber, the oil condition sensor is used to monitor the viscosity and gas content of the high-temperature resistant oil, and the wear test sensor is mounted on the bearing housing end face of the thrust bearing to monitor the wear condition of the thrust bearing.

[0012] A method for testing the cavitation resistance of thrust bearings under high temperature, heavy load, and high speed conditions, employing the aforementioned cavitation resistance testing system for thrust bearings under high temperature, heavy load, and high speed conditions, includes the following steps: S1. Pre-test preparation stage: This includes clamping the thrust bearing test piece, checking the sealing performance of the test chamber, and preheating the high-temperature oil. S2. Vacuum degassing stage: The test chamber is evacuated and degassed. First, the pressure inside the test chamber is reduced to 50Pa and maintained for 10 minutes. Simultaneously, the high-temperature heating component is started to heat the test chamber. Then, the vacuum is evacuated to <10Pa and maintained for 30 minutes. S3. High-temperature oil negative pressure filling stage: Open the oil injection valve of the test chamber and use the negative pressure inside the chamber to draw the preheated high-temperature oil into the test chamber; and perform secondary degassing on the oil after the oil injection is completed. S4. High-temperature pressure holding and testing stage: Start the high-temperature heating component to heat the high-temperature oil to the preset test temperature; open the pressure regulating valve of the test chamber to degas the oil under slight positive pressure and hold the pressure for 10 minutes; provide axial load conditions through the heavy load simulation unit and high speed conditions through the high speed dynamic simulation unit to simulate extreme working conditions and collect key parameters during the test process, including dynamic torque, vibration, and wear. S5. Post-processing stage: After the test, the working conditions are unloaded in the order of "unload the load first, then reduce the speed, and then reduce the temperature", and the high-temperature oil is recovered and the thrust bearing sample is tested.

[0013] As a preferred technical solution, in step S1, the method for checking the sealing performance of the test chamber is as follows: start the vacuum subsystem, close all valves of the test chamber, reduce the vacuum level in the test chamber to <10Pa, conduct a 30-minute leakage test, and if the vacuum level rises from <10Pa to >12Pa, the seal is deemed to have failed, and the sliding sealing structure of the high-temperature chamber is checked. High-temperature oil preheating is completed in the preheating tank. The electric heating tube of the preheating tank is activated to raise the temperature of the high-temperature resistant oil to 150°C, and the temperature is monitored by the oil temperature sensor.

[0014] As a preferred technical solution, in step S3, the method for secondary degassing of the oil is as follows: close the oil injection valve, maintain the vacuum degree in the test chamber <10Pa, start the micro stirrer in the test chamber, stir for 10min, extract the tiny bubbles released in the oil through the vacuum subsystem, let it stand for 5min, monitor the transparency of the oil through the wear test system, if the bubble reflection light signal is found to be >5 times / s, extend the vacuum time by 10min.

[0015] As a preferred technical solution, in step S4, the method for removing gas from the oil under micro-positive pressure is as follows: after the oil temperature reaches the preset temperature, the pressure regulating valve in the test chamber is opened, nitrogen gas is introduced to raise the pressure in the test chamber to 0.1MPa, and the pressure is maintained for 10 minutes to allow the residual micro-bubbles in the oil to escape and be discharged through the vacuum subsystem. During the pressure maintenance process, the pressure stability in the chamber is monitored by the thrust sensor.

[0016] The beneficial effects of this invention are: The present invention relates to a high-temperature, heavy-load, and high-speed thrust bearing anti-cavitation testing system and method. The high-temperature simulation unit can provide a test environment simulating a high temperature of 400°C, the heavy-load simulation unit is used to provide a heavy-load thrust of up to 30T, and the high-speed dynamic simulation unit is used to provide a speed of up to 12000r / min. It can accurately reproduce the coupled working conditions of high-temperature, heavy-load, and high-speed. The vacuuming subsystem and the oil injection subsystem work together to achieve negative pressure oil injection. The cavitation problem in the testing process is completely solved by the coordinated control of "vacuuming-high-temperature oil", which significantly improves the cavitation prevention and control effect and provides accurate testing conditions for bearing performance evaluation and product development.

[0017] The present invention relates to a high-temperature, heavy-load, high-speed thrust bearing anti-cavitation testing system and method. A fore-pump and a main pump are connected in series. The fore-pump performs initial vacuuming to reduce the test chamber pressure to 50 Pa and maintain it for 10 minutes. Then, the main pump performs deep vacuuming to <10 Pa and maintains it for 30 minutes. Using the <10 Pa negative pressure inside the test chamber, preheated high-temperature oil is drawn into the chamber. The high-temperature oil is heated and then subjected to micro-positive pressure degassing and pressure maintenance. This process thoroughly removes air from the test chamber (air residue <0.1%), reducing the cavitation damage rate from the traditional 20% to below 0.5%. The number of bearing samples can be reused increases from once to more than five times, and the testing cost is reduced by 60%.

[0018] The high-temperature, heavy-load, and high-speed thrust bearing anti-cavitation testing system and method of the present invention avoids oil splashing and prevents air entrapment during the oil injection process by using negative pressure oil injection, thereby improving vacuum efficiency. In this invention, the high-temperature resistant oil regeneration rate is ≥80%, and with the reuse of wear samples, the cost per batch of testing is reduced by 35%; moreover, the process steps are highly automated, with only clamping and cleaning requiring manual operation, reducing human error. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a top view of the system of the present invention; Figure 3 This is a cross-sectional schematic diagram of the high-temperature simulation section; Figure 4 This is a schematic diagram of a sliding seal structure; Figure 5 This is a schematic diagram of a rotary seal structure; Figure 6 This is a flowchart illustrating the method of the present invention.

[0021] Reference numerals: 1-Heavy-load simulation unit, 2-High-temperature simulation unit, 3-High-speed dynamic simulation unit, 4-Heat insulation connecting block, 5-First clamp, 7-Coupling, 8-Second clamp, 11-Thrust sensor, 12-Dynamic torque sensor, 101-Thrust cylinder, 102-Thrust shaft, 103-Sliding bearing seat, 201-High-temperature chamber, 202-Test chamber, 203-High-temperature heating assembly, 204-Heat insulation unit, 205-Cooling circulation pipe, 206-Sliding sealing assembly, 207-Rotary sealing assembly, 301 - High-speed motor, 302- Static pressure shaft, 303- Power shaft, 304- Static pressure bearing housing, 305- Rotary bearing housing, 2061- CF sealing flange, 2062- Elastic compensation ring, 2063- Self-lubricating sealing ring, 2071- Sealing seat, 2072- Main sealing lip, 2073- Rotary bushing, 2074- Axial retaining ring, 2075- Mounting cavity, 2076- Waveform elastic compensation component base, 2077- Waveform elastic compensation component, 2078- Waveform elastic compensation component push ring, 2079- Auxiliary sealing lip. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0023] A high-temperature, heavy-load, high-speed thrust bearing anti-cavitation testing system, such as... Figure 1 , Figure 2 As shown, it includes a heavy-load simulation unit 1, a high-temperature simulation unit 2, and a high-speed dynamic simulation unit 3. The heavy-load simulation unit 1 and the high-speed dynamic simulation unit 3 are respectively disposed on both sides of the high-temperature simulation unit 2. Furthermore, it also includes a base. The heavy-load simulation unit 1, the high-temperature simulation unit 2, and the high-speed dynamic simulation unit 3 are all fixed on the base. The heavy-load simulation unit 1 is used to provide axial loading force for the thrust bearing. The high-temperature simulation unit 2 is used to simulate a high-temperature environment exceeding 400°C. The high-speed dynamic simulation unit 3 is used to provide rotational power for the thrust bearing.

[0024] The high-temperature simulation unit 2 includes a high-temperature chamber 201, such as... Figure 3As shown, the high-temperature chamber 201 contains a sealed test chamber 202. The bottom inner side of the test chamber 202 is equipped with a high-temperature heating component 203. A heat insulation unit 204 is provided between the outer periphery of the test chamber 202 and the outer shell of the high-temperature chamber 201. The top of the test chamber 202 is equipped with an air extraction port, which is connected to a vacuum subsystem through an air pipe. The test chamber 202 is equipped with a pressure regulating valve. The top of the test chamber 202 is equipped with an oil injection port, which is connected to an oil injection subsystem through an oil pipe. An oil injection valve is provided on the oil pipe. The oil injection subsystem is used to fill the test chamber with high-temperature resistant oil. A miniature stirrer is provided at the bottom of the test chamber.

[0025] The high-temperature chamber has a sliding seal connection to the thrust shaft 102 on one side and a rotating seal connection to the power shaft 303 on the other side. The thrust shaft 102 and the power shaft 303 are coaxially arranged. One end of the thrust shaft 102 extends into the test chamber 202 and is fixedly connected to the first clamp 5. The first clamp 5 is used to install the bearing seat of the thrust bearing. The other end of the thrust shaft 102 is connected to the output end of the heavy-load simulation unit 1. The heavy-load simulation unit 1 provides a loading force to the bearing seat through the thrust shaft 102. One end of the power shaft 303 extends into the test chamber 202 and is fixedly connected to the second clamp 8. The second clamp 8 is used to install the thrust ring of the thrust bearing. The other end of the power shaft 303 is driven to the output end of the high-speed dynamic simulation unit 3. The high-speed dynamic simulation unit 3 drives the thrust ring to rotate through the power shaft 303.

[0026] The vacuum pumping subsystem includes a backing pump and a main pump. The backing pump is connected in series with the main pump. The ultimate vacuum of the main pump is better than that of the backing pump. The main pump is a ZJ-40 type Roots vacuum pump with a pumping speed of 40 m³ / h and a vacuum degree of ≤0.1 Pa.

[0027] The oil injection subsystem includes a preheating tank containing high-temperature resistant oil and equipped with an electric heating element. The preheating tank is connected to the test chamber via an oil pipe, on which a flow sensor is installed. The flow sensor works in conjunction with the injection valve to control the injection rate of the high-temperature resistant oil. The high-temperature resistant oil is Moruns I-PA organic heat transfer fluid.

[0028] The oil injection subsystem also includes an oil recovery tank. An oil drain port is located at the bottom of the test chamber, and an oil drain valve is installed at the drain port. The drain port is connected to the oil recovery tank via an oil drain pipe. A second flow sensor is installed on the oil drain pipe, and the second flow sensor works in conjunction with the oil drain valve to control the oil drain rate. Preferably, the oil recovery tank and the preheating tank are connected via a recovery pipe, which is equipped with a multi-stage filtration unit for filtering the oil to remove oil residue and metal debris. The filtered oil is then injected into the preheating tank for reuse.

[0029] The heavy-load simulation unit includes a thrust cylinder 101, the output shaft of the thrust cylinder 101 is connected to the thrust shaft 102 through a heat insulation connecting block 4, and the two ends of the thrust shaft 102 are supported by a sliding bearing seat 103. The high-speed dynamic simulation unit 3 includes a high-speed motor 301. The output end of the high-speed motor 301 is connected to one end of the static pressure shaft 302 through a coupling 7. The other end of the static pressure shaft 302 is connected to the power shaft 303 through a heat insulation connecting block 4. The two ends of the static pressure shaft 302 are supported by a static pressure bearing seat 304, and the two ends of the power shaft 303 are supported by a rotary bearing seat 305.

[0030] Preferably, the thrust cylinder 101 has a rated output pressure of 0-30T and an ultimate pressure of 35T, and the pressure is variablely controlled through a proportional valve; the high-speed motor has a power of 45KW, a rated speed of 10000r / min, an ultimate speed of 12000r / min, and is equipped with a speed controller and a G1-level dynamic balance corrector; the coupling and the heat-insulating coupling are magnetic couplings, transmitting power of 45KW, adapting to the ultimate speed of 12000r / min, and realizing non-contact power transmission.

[0031] Furthermore, it also includes a signal acquisition unit, which comprises a sensor assembly including a thrust sensor 11, a dynamic torque sensor 12, a temperature sensor, a vibration sensor, and a speed sensor. The thrust sensor 11 is located between the thrust cylinder 101 and the thrust shaft 102, with a maximum frequency of 2kHz and a thrust range of 30T. The dynamic torque sensor 12 is located between the high-speed motor 301 and the hydrostatic shaft 302, with a range of 0-100N·m, an accuracy of 0.1%FS, and an acquisition frequency of 1kHz. The temperature sensor is located inside the test chamber 202, with a range of 0-400℃ and an accuracy of ±0.5℃. The vibration sensor is mounted on the hydrostatic bearing seat 304; the vibration sensor is temperature resistant to 400℃. The measurement range is 0-10g, with a linearity of 1% and a sampling frequency of 1kHz. The speed sensor is a motor-embedded sensor with a range of 0-12000r / min and an accuracy of 0.1%FS. Furthermore, the sensor assembly also includes a wear test sensor, an oil condition sensor, and a vacuum sensor. The vacuum sensor is used to monitor the vacuum level in the test chamber, with a range of 0-10Pa and an accuracy of ±0.1Pa. The oil condition sensor is used to monitor the oil viscosity and gas content, with a sampling frequency of 100Hz. The wear test sensor is an ultrasonic sensor installed at the working end of the thrust bearing housing to monitor the wear condition on the thrust shaft side, with an accuracy of ±10µm, a sampling rate of 10MHz, and continuous operation of ≥500h.

[0032] The signal acquisition unit also includes a high-frequency acquisition module and a data processing module. The high-frequency acquisition module is communicatively connected to each sensor and the data processing module, using a 16-channel acquisition frequency band, a sampling rate ≥500kS / s, a sampling range of ±10V, and a resolution of 12bit, and can simultaneously acquire signals from multiple sensors. The data processing module has a built-in processing module that supports real-time curve display, data storage (supports Excel / PDF export), trend analysis, anomaly warning, and remote data transmission.

[0033] Furthermore, the high-temperature heating component 203 is a nano-rare earth electric heating element with a rated power of 10KW, a heating range of room temperature to 400℃, a maximum heating temperature of 500℃, and a heating rate of ≥5℃ / min. The heat insulation unit 204 is made of heat insulation cotton. The high-temperature chamber 201 is also equipped with a cooling component, which includes a cooling circulation pipe 205 and a cooling unit. The cooling circulation pipe 205 is arranged inside the heat insulation unit 204 and is connected to the cooling unit. Coolant is circulated into the cooling circulation pipe 205 through the cooling unit to cool the heat insulation unit 204 and prevent the outer shell temperature of the high-temperature chamber 201 from becoming too high.

[0034] A sliding sealing assembly 206 is provided between the thrust shaft 102 and the high-temperature chamber 201, such as Figure 3 , Figure 4 As shown, the sliding sealing assembly 206 has a through lubrication channel, and the thrust shaft is slidably connected within the lubrication channel. The sliding sealing assembly 206 includes a CF sealing flange 2061, which has a stepped hole inside. The smaller hole of the stepped hole faces the interior of the test chamber 202, allowing the thrust shaft 102 to pass through. An elastic compensation ring 2062 is installed inside the larger hole of the stepped hole, and a self-lubricating sealing ring 2063 is installed at the tail of the elastic compensation ring 2062. The self-lubricating sealing ring 2063 presses the elastic compensation ring 2062 and is connected to the CF sealing flange 2061 by screws. Preferably, the self-lubricating sealing ring 2063 is made of Al2O+TiC self-lubricating ceramic matrix composite material, which has wear resistance, high temperature resistance, and self-lubricating properties. The elastic compensation ring 2062 is made of Inconel 718 material, which has high elastic recovery rate and creep resistance, and can significantly reduce the risk of sealing surface peeling under thermal cycling.

[0035] A rotary sealing assembly 207 is provided between the power shaft 303 and the high-temperature chamber 201, such as Figure 3 , Figure 5As shown, the rotary sealing assembly 207 includes a sealing seat 2071, a main sealing lip 2072, a rotary bushing 2073, and an axial retaining ring 2074. An installation hole is provided on the side wall of the high-temperature chamber, and the sealing seat 2071 is installed in the installation hole. A stepped through hole is provided in the center of the sealing seat 2071 for the power shaft 303 to pass through. The power shaft is a stepped shaft. The main sealing lip 2072, rotary bushing 2073, and axial retaining ring 2074 are sequentially and tightly fitted onto the power shaft 303 from the inside out. The inner and outer sides refer to the inner and outer sides of the high-temperature chamber 201. The axial retaining ring 2074 is equipped with a positioning device. Preferably, the axial retaining ring 2074 is threadedly connected to the power shaft 303. The outer diameter of the main sealing lip 2072 is larger than the outer diameter of the rotating bushing 2073. The outer walls of the main sealing lip 2072 and the rotating bushing 2073 respectively abut against the inner wall of the through hole of the sealing seat 2071. The main sealing lip 2072, the rotating bushing 2073 and the through hole of the sealing seat 2071 enclose and form a safety barrier. The mounting cavity 2075 contains an elastic sealing compensation device. This device includes a waveform elastic compensation base 2076, a waveform elastic compensation component 2077, a waveform elastic compensation component push ring 2078, and an auxiliary sealing lip 2079. The waveform elastic compensation base 2076 is cylindrical and located on the side of the mounting cavity 2075 away from the main sealing lip 2072. Its bottom is locked to the sealing seat 2071 by fixing screws. The waveform elastic compensation components are sequentially connected inside the cylinder. 2077. Waveform elastic compensating element push ring 2078. The outer diameter of the waveform elastic compensating element push ring 2078 is adapted to the inner diameter of the waveform elastic compensating element base 2076. An auxiliary sealing lip 2079 is installed on the inner side of the waveform elastic compensating element push ring 2078. The auxiliary sealing lip 2079 abuts against the main sealing lip 2072. The outer diameter of the auxiliary sealing lip 2079 is smaller than the outer diameter of the main sealing lip 2072. A sealed cavity is formed between the elastic sealing compensation device, the main sealing lip 2072, and the sealing seat 2071. The inner wall of the mounting cavity 2075 is nitrided. The sealing seat 2071 and the main sealing lip 2072 form the main seal, and the main sealing lip 2072 and the auxiliary sealing lip 2079 form the auxiliary seal. A small amount of medium that permeates through the main seal will enter the sealing cavity and will then be intercepted by the auxiliary seal to prevent the medium from reaching the outer circumference of the rotating bushing 2073.

[0036] Preferably, the main sealing lip 2072 is made of ceramic fiber reinforced graphite material, possessing temperature resistance above 450℃ and excellent self-lubricating properties to achieve basic sealing. The auxiliary sealing lip 2079 adopts a nickel-based alloy-coated polytetrafluoroethylene (PTFE) composite structure, utilizing the high strength of the alloy and the low coefficient of friction of PTFE to compensate for minor gap leakage in the main sealing lip 2072. The wave-shaped elastic compensation component 2077 is made of Inconel 718 alloy, maintaining stable elastic deformation under high temperature even when under prolonged compression, continuously providing preload force to both lips and automatically compensating for thermal expansion and wear. The working principle of the rotary sealing structure of the present invention is as follows: the main sealing lip 2072 is located at the medium end, the power shaft 303 extends beyond the main sealing lip 2072, and the outer side of the axial retaining ring 2074 is the air end; the sealing seat 2071 and the main sealing lip 2072 form the main seal, which can isolate most of the medium. After a small amount of medium leaks, it enters the sealing cavity. The main sealing lip 2072 and the auxiliary sealing lip 2079 form the auxiliary seal, which further isolates the small amount of medium leaked from the main seal. Moreover, due to the continuous compensation effect of the elastic compensation device, it can continuously provide sufficient pre-tightening force under high temperature, high speed and heavy load conditions to ensure sealing performance.

[0037] Preferably, the sealing seat 2071 is further provided with an annular cooling chamber 20711. The annular cooling chamber 20711 is spaced apart in the corresponding area of ​​the outer periphery of the main sealing lip 2072 and the sealed cavity. The cooling chamber 20711 is connected to the cooling oil passage. By circulating and injecting cooling medium into the cooling chamber, the temperature of the sealing seat is reduced.

[0038] Furthermore, the high-temperature resistant oil can meet the requirements for use in high-temperature environments up to 400℃; preferably, the high-temperature resistant oil is Moruns I-PA organic heat transfer fluid, with a flash point of 110℃, an auto-ignition point of 620℃, a kinematic viscosity of 2.5mm² / s at 40℃, and a density (20℃) of 1056kg / m³, and can be used safely in a temperature range of 12-400℃.

[0039] The heat-insulating connecting block 4 is made of ZC800 material, which can withstand high temperatures of 800℃ for a long time. It is suitable for extreme environments such as high-temperature machinery and molds. It has anti-deformation ability, and its high modulus characteristics ensure that it is not easily deformed during long-term use. It is also resistant to chemical corrosion, extending its service life. Its compressive strength reaches 500MPa, far exceeding that of ordinary heat-insulating materials. Heat-insulating connecting blocks 4 are set between the output shaft of the thrust shaft 102 and the thrust cylinder 101, and between the static pressure shaft 302 and the power shaft 303, to prevent the high temperature inside the test chamber 202 from being conducted to the thrust cylinder 101 and the high-speed motor 301 through the thrust shaft 102 and the power shaft 303.

[0040] Furthermore, it also includes a control module, which comprises a temperature control unit, a pressure control unit, and a speed control unit. The high-temperature heating component and temperature sensor are electrically connected to the temperature control unit. The temperature control unit controls the activation of the high-temperature heating component to heat the high-temperature resistant oil and adjusts the power of the high-temperature heating component based on the temperature data monitored by the temperature sensor. The thrust cylinder is connected to a hydraulic station via a hydraulic pipeline. The hydraulic station and pressure sensor are electrically connected to the pressure control unit. The pressure control unit adjusts the output pressure of the thrust cylinder through the hydraulic station and adjusts the pressure of the thrust cylinder based on the pressure data monitored by the pressure sensor. The high-speed motor is electrically connected to the speed control unit. The speed control unit adjusts the speed of the high-speed motor based on the speed data monitored by the speed sensor.

[0041] A method for testing thrust bearing cavitation prevention using the aforementioned high-temperature, heavy-load, high-speed anti-cavitation test system is as follows: Figure 6 As shown, the steps include: S1. Pre-test preparation stage: This includes clamping the thrust bearing test piece and preheating it with high-temperature oil.

[0042] S11. Test piece clamping and fixing: Install the bearing seat of the thrust bearing test piece into the first clamp, install the thrust ring into the second clamp, and tighten the nut with a wrench to ensure that the test piece does not move during the test.

[0043] S12. Test chamber sealing performance check: Start the vacuum system, close all valves in the test chamber, reduce the vacuum level in the test chamber to <10Pa, and conduct a 30-minute leakage test. If the vacuum level rises from <10Pa to >12Pa, the seal is deemed to have failed. Check the sliding seal structure of the high-temperature chamber; check the linkage status between the vacuum sensor and the vacuum system to ensure that the pressure data sampling frequency is ≥1Hz and the data delay is ≤0.1ms.

[0044] S13. High-temperature oil preheating: Inject high-temperature oil into the preheating tank of the oil injection subsystem, start the electric heating tube of the preheating tank to heat the oil to 150°C, so as to avoid the formation of bubbles due to temperature difference when injecting low-temperature oil into the high-temperature test chamber. The temperature stability inside the preheating tank is monitored by the oil temperature sensor, and the temperature difference is controlled to ≤1°C.

[0045] S2. Vacuum degassing stage: The test chamber is evacuated and degassed. First, the pressure inside the test chamber is reduced to 50Pa and maintained for 10 minutes. At the same time, the high-temperature heating component is started to heat the test chamber. Then, the vacuum is evacuated to <10Pa and maintained for 30 minutes.

[0046] S21. Primary vacuuming (free air discharge): Turn on the forepump of the vacuuming subsystem to reduce the pressure inside the test chamber from atmospheric pressure to 50 Pa at a rate of 5 Pa / min and maintain it for 10 minutes. This stage mainly discharges the large volume of free air inside the test chamber, accounting for 70% of the total air volume. Simultaneously, start the high-temperature heating component inside the test chamber to heat it up to 80°C, reducing the adsorption of air on the surface of the chamber wall (adsorption amount reduced by 40%).

[0047] S22. Deep vacuuming (expelling adsorbed and dissolved air), switching to the main pump (connected in series with the backing pump), further reducing the vacuum level inside the test chamber to <10Pa, maintaining this for 30 minutes; the heat insulation unit between the outer perimeter of the test chamber and the outer shell of the high-temperature chamber controls the temperature of the outer wall of the chamber below 50℃ (preventing external heat transfer that could cause pressure fluctuations inside the chamber). Preferably, three sets of distributed temperature sensors are installed inside the test chamber, located at the upper, middle, and lower positions respectively, to monitor the temperature uniformity inside the chamber, controlling the temperature difference to ≤2℃, ensuring stable vacuum levels.

[0048] S3. High-temperature oil negative pressure filling stage: Open the oil injection valve of the test chamber and use the negative pressure inside the chamber to draw the preheated high-temperature oil into the test chamber; and perform secondary degassing of the oil after the oil injection is completed.

[0049] S31. Negative pressure oil injection (to prevent air from being drawn in): Open the oil injection valve of the test chamber and use the negative pressure of <10Pa inside the chamber to draw the preheated high-temperature oil into the test chamber. The amount of oil injected is dynamically adjusted according to the specifications of the thrust bearing test piece, so that the oil level is 8~12mm higher than the upper surface of the thrust bearing.

[0050] The oil injection flow rate is monitored by a flow sensor on the oil pipe (range 0-50L / min, accuracy 0.5%FS), and the flow rate is controlled to be ≤5L / min by a process sensor and the oil injection valve to avoid turbulence and air entrainment caused by excessive flow rate. During the oil injection process, the vacuum sensor monitors the pressure in the chamber in real time. If the pressure is >15Pa, the oil injection is stopped and the vacuum is replenished.

[0051] S32. Oil degassing (secondary degassing): After oil injection, close the oil injection valve, maintain the vacuum level in the chamber <10Pa, start the micro stirrer in the chamber (speed 500r / min, material Inconel 718), stir for 10min - through stirring, the dissolved air (accounting for 30%) in the oil is released into tiny bubbles, which are then extracted by the vacuum subsystem; after stirring, let stand for 5min, and monitor the transparency of the oil through the wear test system (ultrasonic sensor, accuracy ±10μm, sampling rate 10MHz). If the bubble reflection light signal is found to be >5 times / s, extend the vacuum time by 10min.

[0052] S4. High-temperature pressure holding and testing stage: Start the high-temperature heating component to heat the high-temperature oil to the preset test temperature; open the pressure regulating valve of the test chamber to degas the oil under slight positive pressure and hold the pressure for 10 minutes; provide axial load conditions through the heavy load simulation unit and high speed conditions through the high-speed dynamic simulation unit to simulate extreme working conditions and collect key parameters during the test process, including dynamic torque, vibration, and wear.

[0053] S41. Oil temperature rise and chamber temperature control: Start the high-temperature heating components in the test chamber to raise the oil temperature from 150°C to 400°C at a heating rate of 5°C / min.

[0054] Specifically, the temperature value is first set according to the test requirements. Then, the temperature control unit activates the high-temperature heating component to heat the test environment. During the heating process, the temperature sensor inside the test chamber monitors the temperature of the test environment in real time and feeds the temperature signal back to the temperature control unit. Based on the set temperature value and the feedback temperature signal, the temperature control unit automatically adjusts the power of the high-temperature heating component, gradually raising the temperature of the test environment to the set value.

[0055] Once the ambient temperature reaches the set value, the temperature control unit enters the constant temperature control phase. By adjusting the power of the high-temperature heating element, it maintains the ambient temperature stable near the set value. During the test, the temperature control unit continuously monitors the ambient temperature and adjusts the power of the high-temperature heating element promptly based on temperature changes to ensure the ambient temperature meets the test requirements.

[0056] The cooling unit of the high-temperature chamber cooling component is activated simultaneously, and coolant is introduced into the cooling circulation pipe to control the chamber wall temperature below 60°C. A heat-insulating connecting block is connected between the thrust cylinder and the thrust shaft. The material is ZC800 heat insulation board, which is heat-resistant up to 800°C and has a thermal conductivity of 0.15W / (m・K). This prevents the high temperature inside the high-temperature chamber from being transferred to the thrust cylinder through the thrust shaft, and controls the temperature at the thrust cylinder end below 60°C. This also prevents the loading accuracy deviation caused by the decrease in hydraulic oil viscosity (viscosity decreases by 50% when the temperature is >80°C).

[0057] S42. High-temperature pressure holding (slight positive pressure degassing): After the temperature of the high-temperature resistant oil reaches 400℃, the pressure regulating valve of the test chamber is opened, and nitrogen is introduced to raise the pressure in the test chamber to 0.1MPa (slight positive pressure), and the pressure is held for 10 minutes—so that the residual trace bubbles (diameter <10μm) in the oil can completely escape and be discharged through the vacuum subsystem; during the pressure holding process, the pressure stability in the chamber is monitored by a thrust sensor (range 0-30T, frequency 2kHz, accuracy ±5%FS), and the pressure fluctuation is ≤±0.005MPa.

[0058] S43. Extreme operating condition simulation and cavitation monitoring: The test is started according to the "speed-load-data acquisition" collaborative logic. Speed ​​loading: The speed is increased from 1500 r / min to 12000 r / min in 1000 r / min increments, with each increment stabilizing for 5 minutes. Speed ​​fluctuations are monitored using a speed sensor (range 0-15000 r / min, accuracy 0.1% FS), with fluctuations ≤ ±1 r / min. A high-speed motor is started, transmitting power through a hydrostatic shaft and a thrust bearing test piece. The high-speed motor meets the speed requirement of 10000 r / min, with a maximum speed of 12000 r / min. The coupling has a power transmission capacity of 45 kW and a maximum speed of 12000 r / min. An adaptive controller ensures speed control accuracy of 0.1% FS.

[0059] First, the rotational speed is set according to the test requirements. Then, the speed control unit starts the motor, which transmits power to the thrust ring of the thrust bearing via the hydrostatic shaft and thrust shaft, causing the thrust ring to rotate. During rotation, the speed sensor monitors the rotational speed in real time and feeds the speed signal back to the speed control unit. Based on the set rotational speed and the feedback speed signal, the speed control unit automatically adjusts the motor speed so that the thrust bearing gradually reaches the set speed.

[0060] Once the thrust bearing reaches the set speed, the speed control unit enters the constant speed control phase, adjusting the motor speed to maintain the thrust bearing speed stable near the set value. During the test, the speed control unit continuously monitors the thrust bearing speed and adjusts the motor speed promptly based on speed changes to ensure the thrust bearing speed meets the test requirements.

[0061] Loading: After the rotational speed stabilizes, the load is increased from 0T to 30T in a gradient of 2T / min. During the loading process, the hydraulic valve opening is adjusted in real time by an adaptive controller to ensure the loading force control accuracy is ±5%FS. A thrust cylinder driven by a high-power hydraulic station applies axial pressure to the thrust bearing test piece. The high-power hydraulic station has a rated pressure of 20MPa and a rated flow rate of 20L / min. The thrust cylinder can achieve a pressure output of 0-30T, and the pressure control unit, in conjunction with a proportional valve, enables variable pressure.

[0062] Specifically, first, the axial load value is set according to the test requirements. Then, the pressure control unit activates the thrust cylinder to apply the axial load to the thrust bearing. During the loading process, the pressure sensor monitors the pressure of the thrust cylinder in real time and feeds the pressure signal back to the pressure control system. Based on the set pressure value and the feedback pressure signal, the pressure control unit automatically adjusts the pressure of the thrust cylinder so that the axial load gradually reaches the set value.

[0063] Once the axial load reaches the set value, the pressure control unit enters the constant load control phase, maintaining the axial load stable near the set value by adjusting the pressure of the thrust cylinder. During the test, the pressure control unit continuously monitors the pressure of the thrust cylinder and adjusts it promptly according to pressure changes to ensure the axial load meets the test requirements.

[0064] The hydraulic station is described as follows: the hydraulic fluid used in the hydraulic station meets the requirements of GB / T16750-2015 "Submersible Electric Pump Unit" standard, can work for a long time under ISO4406 pollution level 22 / 22 working oil source, and has a self-locking function after the oil source is lost.

[0065] Real-time cavitation monitoring: Activate the 500kS / s high-frequency acquisition module to simultaneously acquire the following parameters to identify cavitation: Dynamic torque: Monitored by a dynamic torque sensor (range 0-100 N·m, accuracy 0.1% FS). If the torque sudden change is >5 N·m (at 12000 r / min), it is determined to be a precursor to cavitation. Vibration: Radial vibration is monitored by a vibration sensor (range 0-10g, linearity 1%). The warning value is set to 1g. If the vibration value is >1g and lasts for >2s, an alarm is triggered. Wear amount: The wear on the bearing surface is monitored by a wear testing system. If the wear amount suddenly changes by more than 5 μm / h, it is determined to be cavitation damage.

[0066] S5. Post-processing stage: After the test, the working conditions are unloaded in the order of "unload the load first, then reduce the speed, and then reduce the temperature", and the high-temperature oil is recovered and the thrust bearing sample is tested.

[0067] S51. Load unloading and cooling: After the test, operate in the following sequence: "unload first - reduce speed - then cool down": The load is reduced from 30T to 0T at a rate of 5T / min to avoid bearing impact caused by instantaneous unloading; The rotational speed was reduced from 12000 r / min to 1500 r / min, maintained for 5 minutes, and then reduced to 0 r / min. The high-temperature heating components are turned off, and the oil temperature is reduced from 400℃ to below 150℃ by the cooling unit (cooling rate ≤10℃ / min) to prevent the oil from cracking due to excessive temperature difference.

[0068] S52. High-temperature oil recovery and filtration: Open the drain valve at the bottom of the test chamber to discharge the high-temperature oil into the oil recovery tank (100L capacity). During the recovery process, the discharge rate is monitored by a second flow sensor, and the drain valve is adjusted to control the oil flow rate to ≤8L / min to avoid oil splashing and burns. Preferably, the oil recovered in the oil recovery tank is connected to the preheating tank through a recovery pipe. After passing through multi-stage filtration (50μm→20μm→10μm) on the recovery pipe, oil residue and metal debris are removed. The filtered oil can be reused (regeneration rate ≥80%).

[0069] S53. Bearing Inspection and Chamber Cleaning: After the temperature inside the test chamber drops below 80℃, open the test chamber and remove the thrust bearing test piece. Detect cavitation damage on the bearing surface using a wear testing system; a damage area percentage of ≤0.5% is acceptable. Clean the residual oil residue inside the test chamber with anhydrous ethanol and check the wear condition of the sliding seal structure (if the seal gap is >0.1mm, replace the seal). Close the test chamber and conduct a 10-minute vacuum test (vacuum degree <15Pa is acceptable) to prepare for the next round of testing.

[0070] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A method for testing the cavitation resistance of thrust bearings under high temperature, heavy load, and high speed conditions, characterized in that: The test was conducted using a high-temperature, heavy-load, and high-speed thrust bearing anti-cavitation test system. The high-temperature, heavy-load, and high-speed thrust bearing anti-cavitation test system includes a heavy-load simulation section, a high-temperature simulation section, and a high-speed dynamic simulation section. The heavy-load simulation section and the high-speed dynamic simulation section are located on both sides of the high-temperature simulation section. The high-temperature simulation unit includes a high-temperature chamber, inside which is a sealed test chamber. A high-temperature heating assembly is located at the bottom inner side of the test chamber, and a heat insulation unit is provided between the outer perimeter of the test chamber and the outer shell of the high-temperature chamber. An air extraction port is located at the top of the test chamber, connected to a vacuum subsystem via an air pipe. A pressure regulating valve is located on the test chamber. An oil injection port is located at the top of the test chamber, connected to an oil injection subsystem via an oil pipe. An oil injection valve is located on the oil pipe, and the oil injection subsystem is used to fill the test chamber with high-temperature resistant oil. A miniature stirrer is located at the bottom of the test chamber. The high-temperature chamber has a sliding seal connecting the thrust shaft on one side and a rotating seal connecting the power shaft on the other side. The thrust shaft and the power shaft are coaxially arranged. One end of the thrust shaft extends into the test chamber and is fixedly connected to the first clamp, which is used to install the bearing housing of the thrust bearing. The other end of the thrust shaft is connected to the output end of the heavy-load simulation unit, which provides a loading force to the bearing housing through the thrust shaft. One end of the power shaft extends into the test chamber and is fixedly connected to the second clamp, which is used to install the thrust ring of the thrust bearing. The other end of the power shaft is driven to the output end of the high-speed dynamic simulation unit, which drives the thrust ring to rotate through the power shaft. The testing steps include: S1. Pre-test preparation stage: This includes clamping the thrust bearing test piece, checking the sealing performance of the test chamber, and preheating the high-temperature oil. S2. Vacuum degassing stage: The test chamber is evacuated and degassed. First, the pressure inside the test chamber is reduced to 50Pa and maintained for 10 minutes. Simultaneously, the high-temperature heating component is started to heat the test chamber. Then, the vacuum is evacuated to <10Pa and maintained for 30 minutes. S3. High-temperature oil negative pressure filling stage: Open the oil injection valve of the test chamber and use the negative pressure inside the chamber to draw the preheated high-temperature oil into the test chamber; and perform secondary degassing on the oil after the oil injection is completed. S4. High-temperature pressure holding and testing stage: Start the high-temperature heating component to heat the high-temperature oil to the preset test temperature; open the pressure regulating valve of the test chamber to degas the oil under slight positive pressure and hold the pressure for 10 minutes; provide axial load conditions through the heavy load simulation unit and high speed conditions through the high speed dynamic simulation unit to simulate extreme working conditions and collect key parameters during the test process, including dynamic torque, vibration, and wear. S5. Post-processing stage: After the test, the working conditions are unloaded in the order of "unload the load first, then reduce the speed, and then reduce the temperature", and the high-temperature oil is recovered and the thrust bearing sample is tested.

2. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: The vacuum pumping subsystem includes a backing pump and a main pump. The backing pump is connected in series with the main pump. The ultimate vacuum of the main pump is better than that of the backing pump. The main pump is a ZJ-40 type Roots vacuum pump.

3. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: The oil injection subsystem includes a preheating tank containing high-temperature resistant oil and an electric heating tube inside. The preheating tank is connected to the test chamber via an oil pipe, and a flow sensor is also installed on the oil pipe. The oil injection subsystem also includes an oil recovery tank. An oil drain port is located at the bottom of the test chamber, and an oil drain valve is installed at the oil drain port. The oil drain port is connected to the oil recovery tank through an oil drain pipe.

4. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: The high-temperature resistant oil is Moruns I-PA organic heat transfer fluid.

5. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: The heavy-load simulation unit includes a thrust cylinder, the output shaft of which is connected to the thrust shaft via a heat-insulating connecting block, and the two ends of the thrust shaft are supported by a sliding bearing seat. The high-speed dynamic simulation unit includes a high-speed motor. The output end of the high-speed motor is connected to one end of the static pressure shaft via a coupling. The other end of the static pressure shaft is connected to the power shaft via a heat-insulating connecting block. The two ends of the static pressure shaft are supported by a static pressure bearing seat, and the two ends of the power shaft are supported by a rotary bearing seat.

6. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 5, characterized in that: The high-temperature, heavy-load, high-speed thrust bearing anti-cavitation testing system also includes a sensor assembly, which includes a thrust sensor, a dynamic torque sensor, a temperature sensor, a vibration sensor, and a speed sensor. The thrust sensor is located between the thrust cylinder and the thrust shaft, the dynamic torque sensor is located between the high-speed motor and the hydrostatic shaft, the temperature sensor is located inside the test chamber, and the vibration sensor is mounted on the hydrostatic bearing housing. The speed sensor is a built-in sensor in the motor. The sensor assembly also includes a wear test sensor, an oil condition sensor, and a vacuum sensor. The vacuum sensor is used to monitor the vacuum level inside the test chamber, the oil condition sensor is used to monitor the viscosity and gas content of the high-temperature resistant oil, and the wear test sensor is mounted on the bearing housing end face of the thrust bearing to monitor the wear condition of the thrust bearing.

7. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: In step S1, the method for checking the sealing performance of the test chamber is as follows: start the vacuum subsystem, close all valves in the test chamber, reduce the vacuum level in the test chamber to <10Pa, conduct a 30-minute leakage test, and if the vacuum level rises from <10Pa to >12Pa, the seal is deemed to have failed, and the sliding sealing structure of the high-temperature chamber is checked. High-temperature oil preheating is completed in the preheating tank. The electric heating tube of the preheating tank is activated to raise the temperature of the high-temperature resistant oil to 150°C, and the temperature is monitored by the oil temperature sensor.

8. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: In step S3, the method for secondary degassing of the oil is as follows: close the oil injection valve, maintain the vacuum degree in the test chamber <10Pa, start the micro stirrer in the test chamber, stir for 10min, extract the tiny bubbles released in the oil through the vacuum subsystem, let it stand for 5min, monitor the transparency of the oil through the wear test system, if the bubble reflection light signal is found to be >5 times / s, extend the vacuum time by 10min.

9. The method for testing the anti-cavitation properties of thrust bearings under high temperature, heavy load, and high speed according to claim 1, characterized in that: In step S4, the method for micro-positive pressure degassing of the oil is as follows: after the oil temperature reaches the preset temperature, the pressure regulating valve in the test chamber is opened, nitrogen gas is introduced to raise the pressure in the test chamber to 0.1MPa, and the pressure is maintained for 10 minutes to allow the residual micro bubbles in the oil to escape and be discharged through the vacuum subsystem. During the pressure maintenance process, the pressure stability in the chamber is monitored by the thrust sensor.

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