Confining pressure loading test device suitable for fatigue test

Abstract

The utility model discloses a confining pressure loading test device suitable for a fatigue test, and relates to the technical field of bearing test. The device comprises a workbench, the rotation testing mechanism comprises a servo motor and a testing table, the testing table is rotationally connected with the workbench, and the servo motor is installed at the bottom of the workbench and drives the testing table to rotate; the pressing mechanism comprises a hydraulic rod and a linkage block, and the hydraulic rod can drive the linkage block to move towards the rotation center of the test board; the tensioning and limiting mechanism comprises connecting rods, tensioning blocks and a series connection shaft, the connecting rods are annularly arrayed on the outer diameter of the series connection shaft and hinged to the series connection shaft, and the tensioning blocks are annularly arrayed on the test board and hinged to the test board. According to the utility model, through cooperation of the rotation testing mechanism, the pressing mechanism and the tensioning limiting mechanism, a pressure environment when a bearing is subjected to a ball centrifugal force can be effectively simulated, and the problem that fatigue testing is insufficient due to the fact that it is difficult to simulate an outward centrifugal force generated by high-speed rolling of a ball in the prior art is effectively solved.

Description

Technical Field

[0001] This utility model belongs to the field of bearing testing, specifically, it relates to a confining pressure loading test device suitable for fatigue testing. Background Technology

[0002] Bearings are critical components in mechanical equipment, used to support rotating shafts and reduce friction. In actual working environments, bearings withstand various complex loads, including axial and radial forces. Confining pressure, the pressure acting around a bearing, has a significant impact on its performance; however, there are still shortcomings in simulating the complexity of actual bearing working conditions and in the degree of automation in the testing process.

[0003] Based on the above problems, the existing patent publication number CN222166561U discloses a bearing fatigue life testing machine. Through the combined application of cylinder and motor, this testing machine can achieve efficient and accurate testing of the bearings to be tested. The cylinder provides stable thrust, ensuring the stability of the bearing during the test, while the motor is responsible for driving the bearing to rotate, simulating the fatigue load under actual working conditions. This optimized mechanical structure design not only improves the efficiency and accuracy of the test, but also reduces the dependence on complex intelligent control systems, thereby effectively controlling the cost of the testing machine.

[0004] However, when implementing the aforementioned bearing fatigue life testing machine, at least the following problems were found: Although the cooperation between the base and the pressure mechanism can simulate the pressure situation of the bearing under working conditions, the applied pressure is from the outside to the inside. In most cases, the outer shaft of the bearing mainly bears the centrifugal force from the high-speed rolling of the balls, and the centrifugal force is applied as the tension force of the outer shaft of the bearing. Therefore, there are still shortcomings in the fatigue test of bearing tension force.

[0005] In view of this, this utility model is proposed. Utility Model Content

[0006] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a confining pressure loading test device suitable for fatigue testing, thus solving the problems mentioned in the background art.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by this utility model is as follows:

[0008] A confining pressure loading test apparatus suitable for fatigue testing, comprising:

[0009] Workbench;

[0010] A rotating testing mechanism includes a servo motor and a testing platform. The testing platform is rotatably connected to the worktable. The servo motor is installed at the bottom of the worktable and drives the testing platform to rotate.

[0011] The pressing mechanism includes a hydraulic rod and a linkage block. The hydraulic rod is fixedly installed on the top of the worktable, and the linkage block is fixed to the output end of the hydraulic rod. The hydraulic rod can drive the linkage block to move towards the rotation center of the test table.

[0012] The tensioning and limiting mechanism includes a connecting rod, a tensioning block, and a series shaft. The connecting rod is arranged in an annular array on the outer diameter of the series shaft and is hinged to the series shaft. The tensioning block is arranged in an annular array on the test bench and is hinged to the test bench. The free end of the connecting rod is hinged to the middle of the tensioning block. A pressing hole is provided at the bottom of the linkage block for the series shaft to be rotatably inserted.

[0013] Optionally, the outer sides of the tensioning blocks are all arc-shaped, and the bearings can be sleeved around the periphery of multiple tensioning blocks.

[0014] Optionally, the test bench is provided with a limiting groove that is adapted to the tension block, and the tension block is partially embedded in the limiting groove. The part of the tension block embedded in the limiting groove is hinged to the test bench.

[0015] Optionally, the test bench is threaded with multiple hand-tightening screws adapted to the tensioning block. One end of the hand-tightening screw is inserted into the limiting groove, and a sliding block is slidably connected in the limiting groove. The tensioning block and the sliding block are hinged together.

[0016] Optionally, a limit insertion hole is provided at the bottom of the tandem shaft, and a guide rod is fixed at the rotation center of the test bench. The hydraulic rod can push the tandem shaft to move in the direction of the guide rod and insert the guide rod into the limit insertion hole.

[0017] Optionally, a ring-shaped protective barrier is fixed on the test bench, and the bearing can be fitted between the protective barrier and multiple tensioning blocks.

[0018] Optionally, multiple limiting slide rods are fixed on the inner side of the top of the worktable, and the linkage block is slidably connected to the limiting slide rods.

[0019] Optionally, multiple limiting slide rods and the tandem shaft allow the bearing to move through.

[0020] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time:

[0021] 1. By coordinating the rotation test mechanism, the pressing mechanism and the tensioning limit mechanism, the pressure environment of the bearing under the centrifugal force of the balls can be effectively simulated. This effectively solves the problem in the existing technology that it is difficult to simulate the outward centrifugal force of the high-speed rolling of the balls, which leads to the inadequacy of fatigue testing.

[0022] 2. The outer side of the tensioning block is rounded. The rounded shape of the outer side of the tensioning block can better fit the outer contour of the specimen. When the confining pressure is applied, the contact area is more reasonable and uniform, avoiding local stress concentration. The rounded shape can reduce problems such as uneven stress transmission and stress abrupt change points.

[0023] 3. A ring-shaped protective barrier is fixed on the test stand. The bearing can be fitted between the protective barrier and multiple tensioning blocks. During the confining pressure fatigue test, the bearing and other test pieces will be subjected to various forces, including the pressure applied by the tensioning blocks and their own rotation. The ring-shaped protective barrier acts as a barrier, preventing the test piece from accidentally detaching from the test stand due to excessive force or vibration during the test, ensuring that the test can be conducted safely and orderly.

[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0026] In the picture:

[0027] Figure 1 This is a schematic diagram of the three-dimensional structure;

[0028] Figure 2 This is a partial structural diagram;

[0029] Figure 3 This is a schematic diagram of the tensioning and limiting mechanism located on the test platform;

[0030] Figure 4 This is a schematic diagram of the internal structure of the test bench;

[0031] Figure 5 This is a schematic diagram of the tensioning and limiting mechanism.

[0032] The attached diagram lists the components represented by each number as follows:

[0033] 1. Workbench; 2. Servo motor; 3. Test bench; 4. Hydraulic rod; 5. Linkage block; 6. Connecting rod; 7. Tensioning block; 8. Series shaft; 9. Pressing hole; 10. Limiting groove; 11. Hand-tightening screw; 12. Sliding block; 13. Limiting insertion hole; 14. Guide rod; 15. Protective enclosure; 16. Limiting slide bar.

[0034] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings.

[0036] Bearings function by placing rolling elements (such as balls or rollers) between inner and outer rings. When the shaft rotates, the rolling elements roll along the raceways of the inner and outer rings, and rolling friction replaces the sliding friction that might exist between the shaft and the supporting structure. For example, rolling bearings are used in bicycle wheel hubs; compared to traditional sliding friction, rolling bearings significantly reduce friction. This makes it easier to rotate the wheel when it is manually driven, reducing energy loss and improving transmission efficiency.

[0037] In actual industrial applications and mechanical operation, bearings need to withstand various loads for extended periods. Fatigue testing can simulate the working conditions of bearings under different operating conditions, such as different speeds, load magnitudes and directions, and operating temperatures, thereby predicting the bearing's lifespan in actual use.

[0038] By testing the performance of bearings with different structures (such as different rolling element shapes and cage designs) under fatigue loads, it is possible to determine which design structure can better withstand fatigue stress and reduce stress concentration. In the design of bearings for high-speed motors, fatigue testing has revealed that using specially shaped rolling elements can reduce the contact stress between the rolling elements and the raceway, thereby improving the bearing's fatigue resistance and providing a basis for optimized bearing design.

[0039] Existing fatigue testing methods generally fall into the following categories:

[0040] Radial static load testing is primarily used to evaluate a bearing's ability to withstand radial static loads. This test determines how much radial force a bearing can withstand without permanent deformation or damage when stationary. For example, in the selection of bearings for some heavy machinery, it is necessary to specify the bearing's radial static load limit to ensure that the bearing can stably support the relevant components when the equipment is stationary.

[0041] The bearing is mounted on a specialized testing device, and a radial force is gradually applied to it using a hydraulic jack or other loading equipment. During loading, a high-precision displacement sensor monitors the relative displacement changes between the inner and outer rings of the bearing. When the displacement reaches a specified limit value (such as a certain percentage of the bearing size deformation) or the loading force reaches a specified maximum value, loading is stopped, and the magnitude of the loading force at this point is recorded as an indicator of the bearing's radial static load capacity.

[0042] Rotational life testing is one of the most common dynamic testing methods used to evaluate the service life of bearings under rotational conditions. It simulates the actual rotational conditions of a bearing during operation, including different speeds and loads, to observe the bearing's fatigue life. For example, in testing motor bearings, rotational life testing helps determine how long the bearing can continuously operate under normal motor operation.

[0043] Mount the bearing on a test device equipped with a drive motor and apply a certain radial or axial load (this can be achieved using weights, spring loading devices, etc.). Start the motor to rotate the bearing at a set speed. During the test, monitor the bearing's temperature changes using a temperature sensor, as excessively high temperatures may indicate accelerated bearing wear or poor lubrication. Simultaneously, use a vibration sensor to detect bearing vibration; increased vibration amplitude may indicate internal bearing damage, such as worn rolling elements or damaged cages. Continue testing until the bearing fails (e.g., jamming, excessive vibration, overheating), and record the bearing's rotation time or number of revolutions as an indicator of its rotational life.

[0044] However, in most cases, the outer shaft of a bearing bears the centrifugal force exerted outward by the high-speed rolling of the balls. In this case, the centrifugal force exerted by the high-speed rolling of the balls acts as the tension force on the outer shaft of the bearing. Existing testing methods are mostly unable to test the tension force on the outer shaft of the bearing. They can test the pressure on the outer shaft from the outside to the inside, but tension endurance testing is still not available. Further analysis of bearing data is needed to further optimize the bearing.

[0045] Please see Figure 1-5 As shown, this embodiment provides a confining pressure loading test apparatus suitable for fatigue testing, comprising:

[0046] The workbench 1, as the basic support structure of the entire test device, provides a stable mounting platform for other components such as the rotating test mechanism, the pressing mechanism, and the tensioning and limiting mechanism, ensuring that each component can maintain a relatively accurate positional relationship during the test and guaranteeing the normal progress of the test;

[0047] The rotating testing mechanism includes a servo motor 2 and a test platform 3. The test platform 3 is rotatably connected to the workbench 1. The servo motor 2 is installed at the bottom of the workbench 1 and drives the test platform 3 to rotate. As a power source, the servo motor 2 can precisely control the output speed and torque. By driving the test platform 3 to rotate, the rotation of the bearing in actual operation can be simulated. For example, fatigue tests can be performed on the bearing at different speeds to examine its performance during dynamic rotation. This is because many bearings are in a continuous rotational state during actual use, and changes in speed will affect their stress, wear, and other conditions. After the specimen is installed on the test platform 3, it will experience various forces as the test platform 3 rotates, making it easy to observe and record its response during rotation.

[0048] The pressing mechanism includes a hydraulic rod 4 and a linkage block 5. The hydraulic rod 4 is fixedly mounted on the top of the workbench 1, and the linkage block 5 is fixed to the output end of the hydraulic rod 4. The hydraulic rod 4 can drive the linkage block 5 to move towards the rotation center of the test bench 3. The hydraulic rod 4 provides a vertically downward linear driving force, and its output force can be adjusted according to the test requirements. For example, when conducting different confining pressure loading tests, the pressure of the hydraulic system can be changed to control the output force of the hydraulic rod 4 to different magnitudes, thereby applying different degrees of pressing force to the linkage block 5. The linkage block 5, as an intermediate transmission component, receives the force output by the hydraulic rod 4 on the one hand, and transmits this force to the tension limit on the other hand. The positioning mechanism plays a role in force transmission and conversion. Simultaneously, as the test bench 3 rotates, the connecting shaft 8 rotates within the pressure hole 9. It should be noted that during the rotation of the test bench 3, the hydraulic rod 4 remains stationary, thus limiting the reset of the tensioning limit mechanism, rather than continuously pressing down during the rotation of the tensioning limit mechanism. Otherwise, the connecting rod 6 in the tensioning limit mechanism would bend. In practical applications, the rotation of the tensioning limit mechanism does not cause the connecting shaft 8 to move upwards; instead, it moves downwards due to inertia. This is achieved simply by not continuously pressing down the hydraulic rod 4. Of course, components to reduce friction with the connecting shaft 8, such as bearings, need to be added to the pressure hole 9 of the hydraulic rod 4.

[0049] The tensioning and limiting mechanism includes a connecting rod 6, a tensioning block 7, and a connecting shaft 8. The connecting rod 6 is arranged in a ring on the outer diameter of the connecting shaft 8 and is hinged to the connecting shaft 8. The tensioning block 7 is arranged in a ring on the test platform 3 and is hinged to the test platform 3. The free end of the connecting rod 6 is hinged to the middle of the tensioning block 7. A pressing hole 9 is opened at the bottom of the linkage block 5 for the connecting shaft 8 to be rotatably inserted. The connecting rod 6 is arranged in a ring on the outer diameter of the connecting shaft 8 and is hinged to it. Its free end is hinged to the middle of the tensioning block 7. When the linkage block 5 presses down to push the connecting shaft 8, the connecting rod 6 will rotate around the hinge point with the connecting shaft 8, and at the same time drive the tensioning block 7 to move, thus converting the downward linear motion of the linkage block 5 into the downward linear motion of the connecting block 5. The tensioning action of the tensioning blocks 7, through the coordinated action of multiple connecting rods 6, can make the tensioning action relatively evenly distributed around the test bench 3, simulating a relatively uniform confining pressure loading on the specimen. The tensioning blocks 7 are arranged in a ring on the test bench 3 and are hinged to the test bench 3. Driven by the connecting rods 6, they will be displaced towards the center of the test bench 3, thereby applying radial pressure to the specimen mounted on the test bench 3. The combined action of multiple tensioning blocks 7 can realize the confining pressure loading on the specimen, simulating the pressure environment of bearings and other components under the centrifugal force of the balls in actual working conditions, so as to observe the changes in the fatigue performance of the specimen under this confining pressure condition.

[0050] The confining pressure loading test device for fatigue testing described above, through the cooperation of the rotating test mechanism, the pressing mechanism and the tensioning and limiting mechanism, can effectively simulate the pressure environment when the bearing is subjected to the centrifugal force of the balls. This effectively solves the problem in the prior art that it is difficult to simulate the outward centrifugal force of the high-speed rolling of the balls, which leads to the inadequacy of fatigue testing.

[0051] The outer side of tension block 7 is rounded. The rounded shape of the outer side of tension block 7 can better fit the outer contour of the specimen. When the confining pressure is applied, the contact area is more reasonable and uniform, avoiding local stress concentration. The rounded shape can reduce problems such as uneven stress transmission and stress abrupt change points.

[0052] The test bench 3 has a limiting groove 10 adapted to the tension block 7. The tension block 7 is partially embedded in the limiting groove 10, and the part of the tension block 7 embedded in the limiting groove 10 is hinged to the test bench 3. When the tension block 7 moves under the drive of the connecting rod 6, the limiting groove 10 provides a clear direction of movement guidance. The tension block 7 can only move towards or away from the center of the test bench 3 along the direction defined by the limiting groove 10. This can effectively avoid the tension block 7 from deflecting or misaligning during movement, ensuring the standardization and stability of the confining pressure loading action, so that the pressure can be accurately applied to the specimen, and improving the accuracy and reliability of the test data.

[0053] The test bench 3 is threaded with multiple hand-tightening screws 11 that are compatible with the tensioning block 7. One end of the hand-tightening screw 11 is inserted into the limiting groove 10, and a sliding block 12 is slidably connected in the limiting groove 10. The tensioning block 7 is hinged to the sliding block 12. By manually rotating the hand-tightening screw 11, the sliding block 12 can be pushed to slide within the limiting groove 10. Since the tensioning block 7 is hinged to the sliding block 12, the position of the tensioning block 7 can be adjusted indirectly. For example, during the preparation stage before installing the specimen or conducting the test, if it is found that the initial position of the tensioning block 7 is not accurate enough, or if it is necessary to adjust the position of the tensioning block 7 according to specimens of different sizes, the operator can easily turn the hand-tightening screw 11 to move the sliding block 12 to move the tensioning block 7 to the appropriate position, thereby better adapting to the specimen and ensuring the uniformity of the action of each tensioning block 7 during confining pressure loading.

[0054] A limiting insertion hole 13 is provided at the bottom of the inner part of the tandem shaft 8. A guide rod 14 is fixed at the rotation center of the test bench 3. The hydraulic rod 4 can push the tandem shaft 8 to move in the direction of the guide rod 14 and insert the guide rod 14 into the limiting insertion hole 13. The guide rod 14 is fixed at the rotation center of the test bench 3. When the hydraulic rod 4 pushes the tandem shaft 8 to move, the guide rod 14 can be inserted into the limiting insertion hole 13 at the bottom of the inner part of the tandem shaft 8. This provides a clear and precise guide for the movement of the tandem shaft 8. The tandem shaft 8 can only move in a straight line along the direction defined by the guide rod 14, avoiding deviation or misalignment during the movement.

[0055] A ring-shaped protective barrier 15 is fixed on the test bench 3. The bearing can be fitted between the protective barrier 15 and multiple tensioning blocks 7. During the confining pressure fatigue test, the bearing and other test pieces will be subjected to various forces, including the pressure applied by the tensioning blocks 7 and their own rotation. The ring-shaped protective barrier 15 can act as a barrier to prevent the test piece from accidentally falling off the test bench 3 due to excessive force or vibration during the test, ensuring that the test can be carried out safely and orderly.

[0056] Multiple limiting slide rods 16 are fixed to the inner top of the workbench 1. The linkage block 5 is slidably connected to the limiting slide rods 16. In the confining pressure loading test device, the hydraulic rod 4 of the pressing mechanism drives the linkage block 5 to move towards the rotation center of the test bench 3. The presence of the limiting slide rods 16 provides precise linear guidance for the movement of the linkage block 5. The linkage block 5 can only slide along the direction defined by the limiting slide rods 16, avoiding deviation or swaying during its movement.

[0057] This utility model is not limited to the above-described embodiments. Anyone should know that structural changes made under the guidance of this utility model, and any technical solutions that are the same as or similar to this utility model, fall within the protection scope of this utility model. Technical aspects, shapes, and structures not described in detail in this utility model are all publicly known technologies.

Claims

1. A confining pressure loading test device suitable for a fatigue test, characterized by, The utility model relates to a test bench for testing the rotation of a rotating body, comprising: a workbench (1); a rotating test mechanism comprising a servo motor (2) and a test bench (3), the test bench (3) being rotationally connected to the workbench (1), the servo motor (2) being installed at the bottom of the workbench (1) and driving the test bench (3) to rotate; a pressing mechanism comprising a hydraulic rod (4) and a linkage block (5), the hydraulic rod (4) being fixedly installed at the top of the workbench (1), the linkage block (5) being fixed at the output end of the hydraulic rod (4), the hydraulic rod (4) being capable of driving the linkage block (5) to move towards the rotation center of the test bench (3); a tensioning and limiting mechanism comprising a connecting rod (6), a tensioning block (7) and a serial shaft (8), the connecting rod (6) being annularly arranged on the outer diameter of the serial shaft (8) and being hingedly connected to the serial shaft (8), the tensioning block (7) being annularly arranged on the test bench (3) and being hingedly connected to the test bench (3), the free end of the connecting rod (6) being hingedly connected to the middle of the tensioning block (7), and the inner bottom of the linkage block (5) being provided with a pressing hole (9) for the rotation insertion of the serial shaft (8).

2. A confining pressure loading test device for a fatigue test according to claim 1, characterized by The outer side of the tensioning block (7) is arc-shaped, and bearings can be sleeved around the tensioning blocks (7).

3. The apparatus for hydrostatic testing according to claim 1, wherein The test bench (3) is provided with a limiting groove (10) matching the tensioning block (7), the tensioning block (7) is partially embedded in the limiting groove (10), and the part of the tensioning block (7) embedded in the limiting groove (10) is hingedly connected to the test bench (3).

4. A confining pressure loading test device for a fatigue test according to claim 3, characterized by A plurality of hand screws (11) matching the tensioning block (7) are threadedly connected to the test bench (3), one end of the hand screw (11) is inserted into the limiting groove (10), a sliding block (12) is slidably connected in the limiting groove (10), and the tensioning block (7) is hingedly connected to the sliding block (12).

5. The apparatus for hydrostatic testing according to claim 1, wherein The inner bottom of the serial shaft (8) is provided with a limiting insertion hole (13), the rotation center of the test bench (3) is fixedly provided with a guide rod (14), and the hydraulic rod (4) can push the serial shaft (8) to move towards the guide rod (14) and make the guide rod (14) inserted into the limiting insertion hole (13).

6. The hydrostatic loading test apparatus for fatigue testing of claim 1, wherein The test bench (3) is fixedly provided with an annular protective fence (15), and bearings can be sleeved between the protective fence (15) and the plurality of tensioning blocks (7).

7. The apparatus for hydrostatic testing according to claim 1, wherein A plurality of limiting sliding rods (16) are fixedly arranged on the inner side of the top of the workbench (1), and the linkage block (5) is slidably connected to the limiting sliding rods (16).

8. A confining pressure loading test apparatus for a fatigue test according to claim 7, characterized by The spacing between the plurality of limiting sliding rods (16) and the serial shaft (8) can allow bearings to pass through.

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