A sliding bearing life test device

Abstract

The utility model discloses a sliding bearing life test device relates to sliding bearing test field. The device includes bearing test section subassembly, support frame, medium circulation system and medium deployment system. Through the dynamic axial loading assembly of electromagnet and the radial bearing support with eccentric hole, the accurate loading of bearing dynamic axial force and stable radial force has been realized, through setting up medium deployment and circulating system, the mud sand sea water medium environment of component, concentration and temperature stability has been established. The utility model solves the problem of traditional test load single, medium simulation distortion, can high accuracy simulation real working condition, provides reliable data support for bearing life prediction and reliability evaluation, and significantly improves test efficiency and accuracy.

Description

Technical Field

[0001] This utility model relates to the field of sliding bearing testing, specifically to a sliding bearing life testing device for conducting life tests under simulated real working conditions. Background Technology

[0002] As a core supporting component of seawater pumps, the service life of sliding bearings directly determines the operational reliability of the pump unit. In seawater containing silt, abrasive wear, corrosive wear, and particle blockage caused by silt particles can lead to abnormal expansion of bearing clearance, surface spalling, and even jamming failure. Especially in nearshore high-silt conditions, bearing life can plummet to less than 30% of that in clear water conditions. Therefore, conducting life tests simulating real-world operating conditions is of significant engineering value for bearing material selection, structural optimization, and reliability assessment. Current sliding bearing life tests have significant limitations: they generally use clear water or low-concentration suspensions, which cannot simulate the multiphase flow wear characteristics of seawater with high sediment content.

[0003] Patent CN114563295A discloses a friction and wear test bench simulating a high-pressure, turbid environment containing silt and sand on the seabed. The bench includes a high-pressure vessel, a loading device, an inner cavity partition, an inner cavity cylinder, a cover sleeve, a bottom sleeve, a rotating shaft, an inner magnetic cylinder, an outer magnetic cylinder, and a self-aligning platform. The inner cavity of the high-pressure vessel is divided into a test chamber and a pressure compensation chamber, separated by the inner cavity partition and the inner cavity cylinder. The rotating shaft extends into and passes through the pressure compensation chamber, with both ends sealed by the cover sleeve and the bottom sleeve, and their respective sealing bearings and sealing rings. The loading device drives the rotating shaft to rotate, which in turn drives the inner magnetic cylinder to rotate. The inner magnetic cylinder, through magnetic coupling with the outer magnetic cylinder, drives the self-aligning platform within the test chamber to rotate. The self-aligning platform is used to mount the test specimen. However, the constant axial load cannot replicate the dynamic axial force that varies with the pump shaft speed during actual operation. Radial loading can only apply static force, lacking the ability to reproduce the radial force caused by shaft eccentricity. These defects lead to a significant deviation between the test results and the actual failure modes, making it difficult to guide the design of high-reliability bearings. Utility Model Content

[0004] This invention provides a sliding bearing life testing device. It dynamically changes the axial force using an electromagnet and creates an eccentric hole in the radial loading bracket to provide axial and radial loads to the bearing while ensuring the load is essentially adjustable. A further objective of this invention is to simulate a seawater environment for the entire sliding bearing life test through a media circulation system and a media preparation system.

[0005] To achieve the above objectives, the present invention adopts the following technical means: the bearing test section assembly is installed on the support frame, and a water inlet is provided at the bottom; the bearing test section assembly is connected to the medium circulation system and the medium distribution system through pipe valves; the internal axial loading assembly fixes the structural assembly and the main shaft, and is installed on the support frame.

[0006] Preferably, the bearing test section assembly includes: a power and transmission assembly mounted on top of the structural assembly to provide the system with precise and controllable speed and torque; a radial bearing bracket mounted below the main shaft; and a radial test bearing mounted between the structural assembly and the radial bearing bracket.

[0007] Preferably, radial test bearings, thrust test bearings, radial auxiliary test bearings, and test section monitoring system components are installed from bottom to top on the structural components and the main spindle; the axial loading component and the radial loading component are used to simulate the dynamic axial force and radial force caused by misalignment, etc., that the main spindle experiences during actual operation; the radial test bearings and thrust test bearings are the core test objects, and their service behavior is the focus of monitoring and analysis; the radial auxiliary test bearings are used to assist in supporting the main spindle and ensure smooth operation of the shaft system.

[0008] Preferably, the axial loading assembly includes an axial loading bracket, a suction cup, and an electromagnet. The suction cup is mounted on the main shaft via a sleeve, and the electromagnet is bolted to a tension sensor. The axial loading bracket has threaded holes and an outlet. This structure allows for precise control of the electromagnetic force generated by the electromagnet on the rotating suction cup by adjusting the excitation current of the electromagnet. This enables dynamic, non-contact, and precise loading of the axial load on the thrust test bearing, and allows for programmed linkage with the main shaft speed, perfectly simulating the actual stress state of the pump shaft.

[0009] Preferably, the radial bearing support is mounted on the main shaft and has an eccentric hole and a flow passage. This design ensures that the sediment-containing seawater medium can flow smoothly and evenly through the radial test bearing area, avoiding the formation of flow dead zones in the bearing cavity that could lead to sediment deposition or uneven local concentration, thus ensuring the consistency of the test medium environment.

[0010] Preferably, the structural component is equipped with two displacement sensors, one aligned with the radial test bearing and the other with the thrust test bearing. These sensors can monitor the changes in wear clearance and spindle vibration displacement of the bearings in real time with micron-level precision, providing direct and accurate data support for assessing bearing life, determining failure thresholds, and studying wear mechanisms.

[0011] Preferably, the media preparation system includes an electric heating element connected to the water tank via a flange for precise control of the media temperature to simulate different sea surface temperatures; an electromagnetic stirrer is welded to the horizontal plate above the water tank to keep the sediment particles in the tank in a uniform suspended state, effectively preventing sedimentation; and a temperature sensor is welded to the inner wall of the water tank to ensure the stability of the media composition and concentration throughout the entire test cycle, thus guaranteeing the repeatability of the test conditions from the source.

[0012] Preferably, the media preparation system is connected to the outlet via a pipeline.

[0013] Preferably, the medium circulation system is equipped with a water pump, and the pipeline is equipped with a ball valve and a flow meter connecting the water inlet and the medium distribution system, forming the basis of the flow closed-loop control, so that the flow rate of the medium flowing through the test bearing can be precisely controlled to match different working condition simulation requirements.

[0014] Preferably, the support frame has round holes and threaded holes. This design not only provides modular and high-precision installation and positioning references for each component, ensuring the accuracy of the entire force transmission path, but also gives the device good structural expandability, which is convenient for subsequent functional upgrades or adaptation to test bearings of different sizes.

[0015] Beneficial Effects: This invention, through the innovative synergistic effect of electromagnetic dynamic axial loading and mechanical eccentric radial loading, achieves for the first time a high-fidelity simulation of the complex working conditions of sliding bearings in silty seawater in a laboratory environment. An integrated media preparation and circulation system ensures the long-term stability of the test medium's composition, concentration, and temperature. This device effectively solves the problems of single test load and distorted media simulation in traditional methods, significantly improving the agreement between test results and actual failure modes. It provides highly reliable data support for bearing life prediction and reliability assessment, while also greatly improving test efficiency and reducing overall testing costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a sliding bearing life testing device.

[0017] Figure 2 This is an assembly diagram of the bearing test section components.

[0018] Figure 3 This is a part drawing of an axially loaded component.

[0019] Figure 4 This is a drawing of a radial bearing bracket part.

[0020] 1. Bearing test section assembly; 2. Support frame; 3. Media circulation system; 4. Media preparation system; 5. Axial loading assembly; 6. Structural assembly; 7. Main shaft; 8. Power and transmission assembly; 9. Radial bearing bracket; 10. Radial test bearing; 11. Thrust test bearing; 12. Radial auxiliary test bearing; 13. Test section monitoring system assembly; 14. Inlet; 15. Outlet; 16. Displacement sensor; 17. Eccentric hole; 18. Flow passage; 31. Water pump; 32. Ball valve; 33. Flow meter; 41. Electric heating appliance; 42. Electromagnetic stirrer; 43. Temperature sensor; 51. Loading bracket; 52. Suction cup; 53. Electromagnet; 54. Tension sensor. Detailed Implementation

[0021] This invention discloses a device for testing the life of sliding bearings in seawater containing sediment. Through an innovative load-loading mechanism and precise simulation of the medium environment, this device successfully solves the industry problem that traditional testing devices cannot simulate the wear characteristics of multiphase flow and dynamic bearing loads in seawater with high sediment content. The technical solution of this invention will be described in detail below with reference to the accompanying drawings and several specific embodiments.

[0022] Specific Implementation Example 1.

[0023] like Figures 1 to 3 As shown, the sliding bearing life testing device provided by this utility model uses a support frame 2 as the load-bearing and positioning foundation for the entire device. The support frame 2 is welded from high-strength alloy steel and undergoes stress-relief annealing treatment to ensure its structural stability under long-term cyclic loads. Multiple round holes and threaded holes are precisely machined on the support frame 2 for installing and fixing other core modules. This design ensures the relative positional accuracy between components, laying the physical foundation for the repeatability and accuracy of the entire test.

[0024] The bearing test section assembly 1, as the core of the device, is mounted on the upper platform of the support frame 2 using high-strength bolts. This assembly is the execution unit for simulating the actual working conditions of the bearing, applying various loads, and collecting key data. A water inlet 14 is located on the bottom shell of the bearing test section assembly 1, which is connected to the media circulation system 3 via a high-pressure pipeline; a corresponding outlet 15 is located on its upper part for media recirculation. The media distribution system 4 is connected to the media circulation system 3 and the outlet 15 of the bearing test section assembly 1 via pipelines, forming a closed media circulation loop. This loop ensures that the test media (including sediment and seawater) can continuously and stably flow through the test bearing, thereby accurately simulating the real media environment.

[0025] The axial loading component 5, a key innovative part for realizing dynamic axial force, has its main loading bracket 5 firmly mounted on the top crossbeam of the support frame 2. Below the loading bracket 51, directly opposite the axis of the main shaft 7 of the bearing test section component 1, is a force generation unit composed of an electromagnet 53 and a suction cup 52. This invention achieves a clever fusion of mechanical structure, fluid path, and electromagnetic load by directly integrating the axial loading component 5 above the main shaft system, structurally independent yet functionally synergistic with the medium circuit. This avoids the structural interference and unclear force flow path problems associated with traditional external loading mechanisms.

[0026] Specific Implementation Example 2.

[0027] like Figure 2 and Figure 4As shown, the internal structure of the bearing test section assembly 1 is the core of this invention for achieving precise testing. Its outer shell is structural component 6, which is a precision-machined box that forms a stable space inside to accommodate the main shaft 7 and various bearings.

[0028] The power and transmission assembly 8 is mounted on top of the structural assembly 6, preferably employing a servo motor paired with a precision planetary gearbox. The servo motor features a wide speed range, high speed regulation accuracy, and strong overload capacity, enabling it to accurately simulate the speed changes of the spindle 7 under different operating conditions. The motor's output shaft is connected to the upper end of the spindle 7 via a high-rigidity diaphragm coupling. This connection method compensates for minor installation alignment errors and transmits pure torque, avoiding additional bending moments.

[0029] The main shaft 7, as the core component for torque and load transmission, is made of high-strength alloy steel with a nitrided surface, possessing extremely high core toughness and surface hardness to resist erosion from mud and sand. From top to bottom, the main shaft 7 is equipped with a radial test bearing 12, a thrust test bearing 11, and a radial test bearing 10. Among these, the thrust test bearing 11 and the radial test bearing 10 are the core test objects in this life test, and their materials, processes, and structures are the focus of the research. The main function of the radial test bearing 12 is to provide additional radial support to the main shaft 7, ensuring the rotational accuracy and stability of the shaft system.

[0030] The most innovative load-bearing component of this invention lies in the axial and radial loading assemblies. The detailed structure of the axial loading assembly 5 is as follows... Figure 3 As shown. Its core lies in the suction cup 52, which is fixedly mounted on the top of the main shaft 7 via an interference-fit sleeve and rotates with the main shaft. Directly above the suction cup 52, an electromagnet 53 is bolted to a high-precision tension sensor 54, which in turn is fixed to a stationary loading bracket 51. By precisely adjusting the excitation voltage or current of the electromagnet 53 through an external control system, the electromagnetic attraction it generates on the rotating suction cup 52 can be linearly changed. This attraction force, through the main shaft 7, is ultimately converted into an axial load acting on the thrust test bearing 11. The tension sensor 54 monitors and feeds back the actual axial force in real time, forming a closed-loop control circuit, thereby achieving synchronous, dynamic, and precise loading of the axial load and the main shaft speed.

[0031] like Figure 4As shown, a specially designed radial bearing bracket 9 is keyed to the spindle 7, located below the radial test bearing 10. The key feature of this radial bearing bracket 9 is that its center is not concentric with the spindle, but rather machined with an eccentric hole 17 with a preset eccentricity. When the spindle 7 rotates at high speed, a continuous centrifugal force is generated due to the mass eccentricity. This centrifugal force is transmitted through the radial bearing bracket 9 to the radial test bearing 10, and then acts on the structural component 6, achieving radial load application on the radial test bearing 10. By replacing radial bearing brackets 9 with different eccentricities and eccentric holes of different sizes, the magnitude of the radial load can be easily adjusted. This mechanical radial loading scheme requires no complex external actuators, is simple and reliable in structure, low in cost, and can perfectly simulate the actual radial force caused by misalignment or mass imbalance of the shaft system. Furthermore, the radial bearing bracket 9 is also machined with a flow hole 18 to ensure that the test medium can flow smoothly through the bearing area, avoiding sediment deposition caused by dead zones.

[0032] To monitor the bearing's operating status in real time during the test, two non-contact eddy current displacement sensors 16 were installed on structural component 6 at positions corresponding to the radial test bearing 10 and the thrust test bearing 11, respectively. These sensors can monitor the wear clearance changes of the bearings under load and media erosion, as well as the vibration displacement of the spindle, with micron-level accuracy in real time, providing the most direct data support for evaluating the bearing's life and failure modes.

[0033] Specific Implementation Example 3.

[0034] Simulation of a real-world media environment is another core aspect of this invention. For example... Figure 1 As shown, the medium preparation system 4 provides a simulated environment for the entire test apparatus. Its main body is a large-capacity water tank, inside which a temperature sensor 43 is welded for real-time monitoring of the medium temperature. An electric heating element 41 is mounted on the bottom of the tank via a flange, and an electromagnetic stirrer 42 is welded to the top horizontal plate.

[0035] Before the experiment, a sediment-containing seawater medium with appropriate components and concentrations was prepared in a water tank based on the sediment parameters of the target sea area (such as particle size distribution, mineral composition, and concentration). The electromagnetic stirrer 42 was activated; its powerful magnetic drive generated a uniform vortex within the water tank, ensuring that the sediment particles were uniformly suspended and effectively preventing sedimentation, thus guaranteeing the stability of the medium's component concentration throughout the experiment. The electric heating element 41 was used to precisely control the medium temperature, simulating seawater temperature environments at different sea areas or working depths, as temperature significantly affects the corrosion rate and lubrication performance of materials.

[0036] The media circulation system 3 is responsible for continuously pumping the prepared media to the test section. The system is equipped with a wear-resistant and corrosion-resistant centrifugal water pump 31, whose outlet pipe is sequentially equipped with a ball valve 32 for on / off control and a flow meter 33 for precise monitoring and feedback of the media flow rate. By adjusting the pump frequency or valve opening, the flow rate of the media flowing through the bearing test section component 1 can be precisely controlled, simulating the flow conditions during actual pump operation. The media enters through the inlet 14, washes the test bearing, carries wear particles, and flows out through the outlet 15, then flows back to the water tank of the media preparation system 4, forming a complete and controllable closed-loop circulation. This ensures long-term stability of the test conditions and provides the possibility for long-term accelerated life testing.

[0037] Specific Implementation Example 4.

[0038] The advanced nature of this invention is also reflected in its highly integrated monitoring and control system. As mentioned earlier, the tension sensor 54, displacement sensor 16, temperature sensor 43, flow meter 33, etc., together constitute the "sensory nerves" of the device. Signals from all these sensors are connected to a central data acquisition and control system (such as one based on a PLC or industrial PC).

[0039] This system not only displays and records all test parameters (speed, axial force, vibration, temperature, flow rate, medium concentration, etc.) in real time, but more importantly, it implements complex control logic. For example, a "speed-axial force" relationship curve can be preset, and the system automatically adjusts the output of electromagnet 53 according to the real-time speed, ensuring that the axial force changes strictly according to the preset curve, perfectly replicating the actual stress condition of the pump shaft. When displacement sensor 16 detects that the bearing wear clearance exceeds the safety threshold, the system can automatically alarm or even shut down to protect the equipment. All test data are fully recorded for subsequent bearing life analysis, failure model establishment, and reliability assessment.

[0040] Specific Implementation Example 5.

[0041] The working process of this utility model device is described in detail below using a complete test cycle: Initial state: All components of the device are in the off position. The seawater medium containing silt and sediment at the predetermined concentration and temperature has been prepared in the medium preparation system 4. The water pump 31 and ball valve 32 of the medium circulation system 3 are in the closed state. The electromagnet 53 of the axial loading component 5 is not energized.

[0042] System preparation and sample installation: The operator installs the thrust test bearing 11 and radial test bearing 10 to be tested into the designated positions on the structural component 6, and installs the radial test bearing 12 into place. Then, the radial bearing bracket 9 with pre-fabricated eccentricity and eccentric hole size is installed onto the main shaft 7. After checking that all sensor connections are correct, the electromagnetic stirrer 42 and electric heating element 41 of the medium preparation system 4 are started to make the medium reach and maintain the preset uniform state and temperature.

[0043] Start media circulation and shaft rotation: Turn on the media circulation system 3, slowly open the ball valve 32, and start the water pump 31 to pump the media into the bearing test section assembly 1 at a preset flow rate. After the flow rate stabilizes, start the servo motor of the power and transmission assembly 8 to slowly raise the spindle 7 to the preset initial speed.

[0044] Applying dynamic load: While the spindle 7 rotates, the control system applies a voltage signal matching the current rotational speed to the electromagnet 53 of the axial loading assembly 5 according to a preset program, generating an axial load. This load is transmitted to the thrust test bearing 11 via the chuck 52 and the spindle 7. Simultaneously, due to the eccentric structure of the radial bearing support 9, a stable radial load is automatically applied to the radial test bearing 10 as the spindle rotates.

[0045] Operation and Monitoring: The device enters the stable test operation phase. During this period, the servo motor may change its speed according to the program, and the axial loading component 5 will synchronously adjust the load to simulate variable operating conditions. The monitoring system continuously collects data from all sensors, including bearing temperature, vibration displacement, actual axial force, and medium flow rate and temperature. This data is displayed, recorded, and used for status assessment in real time.

[0046] Test Termination and Data Analysis: The test can be set to run continuously until bearing failure (e.g., wear exceeding a threshold, excessive vibration, or jamming), or until a predetermined time / number of cycles is reached. Upon reaching the endpoint, the system sequentially stops the motor, removes the axial load, and stops media circulation. Operators disassemble the test bearing and, combining the complete data recorded during operation, perform macroscopic and microscopic analyses of the bearing's wear morphology and failure mode to accurately assess its lifespan and performance under simulated real-world conditions.

[0047] In summary, through the synergistic implementation of the five specific embodiments described above, this utility model constructs a complete solution encompassing mechanical structure, load simulation, environmental reproduction, and intelligent measurement and control. It achieves precise simulation of complex service loads on sliding bearings through an innovative combination of dynamically adjusting axial force with an electromagnet and generating radial force using an eccentric mechanical structure; it creates a stable and controllable corrosive and abrasive environment in silt-laden seawater through an integrated media distribution and circulation system; and finally, through a highly integrated monitoring system, it provides a solid and scientific data foundation for bearing life prediction and reliability assessment.

Claims

1. A sliding bearing life testing device, characterized in that, include: The bearing test section assembly (1) is mounted on the support frame (2) and has a water inlet (14) at the bottom. The bearing test section assembly (1) is connected to the medium circulation system (3) and the medium preparation system (4) through pipeline valves; The internal axial loading assembly (5) fixes the structural assembly (6) and the spindle (7) and is mounted on the support frame (2).

2. The sliding bearing life testing device according to claim 1, characterized in that, The bearing test section assembly (1) includes: a power and transmission assembly (8) mounted on top of the structural assembly (6); a radial bearing bracket (9) mounted below the main shaft (7); and a radial test bearing (10) mounted between the structural assembly (6) and the radial bearing bracket (9).

3. A sliding bearing life testing device according to claim 1 or 2, characterized in that, Radial test bearing (10), thrust test bearing (11), radial auxiliary test bearing (12), and test section monitoring system assembly (13) are installed from bottom to top on the structural assembly (6) and the main shaft (7).

4. A sliding bearing life testing device according to claim 1 or 2, characterized in that, The axial loading assembly (5) includes an axial loading bracket (51), a suction cup (52) and an electromagnet (53), wherein the suction cup (52) is mounted on the main shaft (7) by a sleeve, the electromagnet (53) is mounted on the tension sensor (54) by bolts, and the axial loading bracket (51) has a threaded hole and a water outlet (15).

5. A sliding bearing life testing device according to claim 1 or 2, characterized in that, The radial bearing bracket (9) is mounted on the spindle (7) and has an eccentric hole (17) and a through hole (18).

6. The sliding bearing life testing device according to claim 4, characterized in that, The structural component (6) is equipped with two displacement sensors (16) that are aligned with the radial test bearing (10) and the thrust test bearing (11), respectively.

7. A sliding bearing life testing device according to claim 1 or 6, characterized in that, The medium preparation system (4) includes an electric heating appliance (41) connected to the water tank via a flange, an electromagnetic stirrer (42) welded to the horizontal plate above the water tank, and a temperature sensor (43) welded to the inner wall of the water tank.

8. A sliding bearing life testing device according to claim 1 or 6, characterized in that, The media preparation system (4) is connected to the outlet (15) via a pipeline.

9. The sliding bearing life testing device according to claim 8, characterized in that, The medium circulation system (3) is equipped with a water pump (31), and a ball valve (32) and a flow meter (33) are installed on the pipeline to connect the water inlet (14) and the medium preparation system (4).

10. A sliding bearing life testing device according to claim 1 or 9, characterized in that, The support frame (2) has a round hole and a threaded hole.

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