A friction and wear test bench for simulating the friction pair of hydraulic pump and motor

Abstract

The present invention provides a friction and wear test bench for simulating the friction pair of a hydraulic pump motor, which includes a test bench, a motor, a motor bracket, a sample seat, a bearing assembly, a roller plunger pair simulation fixture, an end face flow distribution pair simulation fixture and a torque sensor. A motor is provided under the test bench table, and the motor is connected to the test bench through a motor bracket; the bearing assembly is arranged on the test bench table, the rotating shaft on the lower surface of the sample seat is installed in the inner hole of the bearing assembly, and the output shaft end of the motor is connected to the sample seat through a coupling; the torque sensor is arranged at the bottom of the sample seat, and the bottom surface of the torque sensor is in direct contact with the top surface of the bearing assembly. The roller plunger pair simulation fixture and the end face flow distribution pair simulation fixture are installed on the test bench table, and are both driven by hydraulic pressure. The present invention can realize two forms of friction pair simulated working condition friction and wear tests on the same test bench by switching two types of friction pair simulation fixtures, and realize accurate measurement of the friction coefficient through a torque sensor.

Description

Technical Field

[0001] The invention belongs to the field of material performance testing and research, and particularly relates to a friction and wear test bench for simulating a friction pair of a hydraulic pump motor. Background Art

[0002] Hydraulic pumps and motors contain a variety of friction pairs depending on their type. The friction and wear performance of these friction pairs is related to important indicators such as the life and stability of the hydraulic pump and motor. Among them, the roller plunger friction pair of the inner curve hydraulic pump and motor is the key friction pair for the output torque of the inner curve hydraulic pump and motor. The friction reduction and anti-wear optimization of the roller plunger pair is the key to the design of the inner curve hydraulic pump and motor. The end face distribution pair is widely present in the inclined plate type and inner curve type hydraulic pump and motor, and its friction and wear performance directly affects the performance stability of the hydraulic pump and motor. Therefore, accurately testing the friction and wear performance of the friction pair is the guarantee for the reasonable design of the friction pair structure, material and other parameters. In order to simulate the actual working conditions of the friction pair, it is necessary to ensure that the load, material and motion form are the same as the actual friction pair. Summary of the invention

[0003] In view of the above situation, the present invention provides a friction and wear test bench for simulating the friction pair of a hydraulic pump and motor. By switching between two forms of friction pair fixtures, the friction pair structure of the end face distribution pair and the friction pair structure of the roller plunger pair of the hydraulic pump and motor are simulated, the tribological performance of the friction pair of the hydraulic pump and motor under simulated working conditions is explored, and the precise measurement of the friction coefficient is achieved through a torque sensor.

[0004] The present invention provides a friction and wear test bench for simulating the friction pair of a hydraulic pump and motor, which comprises a test bench, a motor, a motor bracket, a sample seat, a bearing assembly, a roller plunger pair simulation fixture, an end face distribution pair simulation fixture and a torque sensor; the motor bracket is installed under the table of the test bench, and the motor is installed below the motor bracket; the bearing assembly is arranged on the table of the test bench, the sample seat is arranged above the bearing assembly, a rotating shaft is arranged on the lower surface of the sample seat, the rotating shaft is installed in the inner hole of the bearing assembly, and the output shaft end of the motor is connected to the sample seat through a coupling; the torque sensor is arranged at the bottom of the sample seat, and the bottom surface of the torque sensor is in direct contact with the top surface of the bearing assembly; the roller plunger pair simulation fixture and the end face distribution pair simulation fixture are both installed on the test bench; the roller plunger pair simulation fixture is provided with a hydraulic cylinder 1, a hydraulic cylinder 2, a central sample, a side sample 1 and a side sample 2, and the clamping structure of the roller plunger pair simulation fixture is similar to the friction pair structure of the inner curve type hydraulic pump motor roller plunger , side specimen 1 and side specimen 2 simulate a plunger structure, and the center specimen simulates a roller structure; the hydraulic cylinder 1 and the hydraulic cylinder 2 are installed opposite to each other and are in the same hydraulic circuit, and the cylinder rod of the hydraulic cylinder 1 and the cylinder rod of the hydraulic cylinder 2 are on the same axis, the side specimen 1 is connected to the cylinder rod of the hydraulic cylinder 1, and the side specimen 2 is connected to the cylinder rod of the hydraulic cylinder 2, and the side specimen 1 and the side specimen 2 are pushed out or retracted simultaneously by the hydraulic cylinder 1 and the hydraulic cylinder 2 respectively; the center specimen is installed on the specimen seat, and the axis of the cylinder rod of the hydraulic cylinder 1 and the cylinder rod of the hydraulic cylinder 2 are The axis of the center specimen is vertical; the end face flow distribution pair simulation fixture is provided with a hydraulic cylinder three, an upper specimen and a lower specimen; the clamping structure of the end face flow distribution pair simulation fixture is similar to the end face flow distribution pair structure of the inclined plate type hydraulic pump motor and the inner curve type hydraulic pump motor; the upper specimen simulates the cylinder structure of the hydraulic pump motor, and the lower specimen simulates the flow plate structure of the hydraulic pump motor; the upper specimen is threadedly connected to the cylinder rod of the hydraulic cylinder three, and the thread rotation direction is opposite to the motor rotation direction; the lower specimen is installed on the specimen seat, and the cylinder rod of the hydraulic cylinder three coincides with the axis of the specimen seat.

[0005] Preferably, the clamping force of hydraulic cylinder one and hydraulic cylinder two is controlled by hydraulic pressure, and the hydraulic pressure is set to 10MPa to 30MPa; when the motor drives the central sample, the maximum speed is set to 1000rpm.

[0006] Preferably, side sample one and side sample two are provided with arc-shaped notches to fit with the center sample, and the materials of sample one and side sample two, the inner diameter and roughness of the surface in contact with the center sample are consistent with the actual inner curve hydraulic pump motor plunger; the material, outer diameter and roughness of the center sample are consistent with the actual inner curve hydraulic pump motor roller, and the maximum diameter of the center sample is 60 mm and the minimum diameter is 10 mm.

[0007] Preferably, the maximum clamping force of the hydraulic cylinder three is set to 30 MPa; when the motor drives the lower sample, the maximum speed is set to 2000 rpm.

[0008] Preferably, the material, shape and surface roughness of the upper sample are consistent with the actual hydraulic pump motor cylinder body, and the material, shape and surface roughness of the lower sample are consistent with the actual hydraulic pump motor distribution plate, and the maximum diameters of the upper and lower samples are both 80 mm.

[0009] Preferably, the coaxiality of the cylinder rod of hydraulic cylinder one and the cylinder rod of hydraulic cylinder two is 0.01mm, and the perpendicularity of the cylinder rod of hydraulic cylinder one and the cylinder rod of hydraulic cylinder two to the rotation center of the central sample is 0.05mm; the coaxiality of the cylinder rod of hydraulic cylinder three and the rotation axis of the sample seat is 0.01mm, and the cylinder rod of hydraulic cylinder three cannot rotate.

[0010] Preferably, the side sample one, the side sample two, the center sample, the upper sample and the lower sample are all replaceable.

[0011] Preferably, the torque sensor calculates the friction coefficient between the friction pairs by detecting the rotation torque fluctuation of the sample seat, and the no-load torque of the sample seat is T 0 When the clamping force of the fixture is F, the torque of the specimen holder is T 1 , the diameter of the sample is R, and the friction coefficient between the friction pairs is μ=(T 1 -T 0 )×R÷F.

[0012] Preferably, the bearing assembly consists of a thrust bearing and a self-aligning ball bearing, and is capable of bearing axial loads and radial loads.

[0013] Beneficial effects of the present invention:

[0014] 1. The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention can realize the same test bench to carry out two types of friction pair simulated working condition friction and wear tests by switching two types of friction pair simulation fixtures. The roller plunger friction pair and the end face distribution friction pair are both key friction pairs that affect the life and performance of the inner curve hydraulic pump and motor. The test bench realizes the testing of two types of friction pairs on the same test bench, which can provide convenience for the tribological performance research and life test of the friction pair of the hydraulic pump and motor.

[0015] 2. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor of the present invention performs friction and wear tests by simulating the materials, shapes, and surface roughness of the rollers, plungers, cylinders, and distribution plates of hydraulic pump and motor, which reflects the friction characteristics and wear state of the friction pair of the actual hydraulic pump and motor. The test bench can measure the friction coefficient of the friction pair. The test bench can also be used for the life test of the friction pair to explore the long-term wear characteristics of the actual friction pair materials. Compared with the life test of the actual hydraulic pump and motor, the control of the factors affecting the wear characteristics of the roller-plunger pair and the end-face distribution pair is more accurate and targeted, which can improve the design level of the friction pair of the hydraulic pump and motor.

[0016] 3. The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention is provided with a roller plunger pair simulation fixture, and the fixture is provided with a hydraulic cylinder 1 and a hydraulic cylinder 2. The coaxiality of the cylinder rod of the hydraulic cylinder 1 and the cylinder rod of the hydraulic cylinder 2 is 0.01 mm, and the perpendicularity with the rotation center of the center sample is 0.05 mm, so as to ensure that the pressure on the center sample is entirely from the hydraulic pressure, thereby reducing the influence of the processing error of the test bench on the test results.

[0017] 4. The friction and wear test bench for simulating the friction pair of the hydraulic pump motor of the present invention is provided with an end face distribution pair simulation fixture, the fixture is provided with a hydraulic cylinder three, the cylinder rod of the hydraulic cylinder three and the rotation axis of the sample seat are coaxial 0.01mm, the cylinder rod of the hydraulic cylinder three cannot rotate, the upper sample is threadedly connected with the cylinder rod, and the thread rotation direction is opposite to the motor rotation direction. When the end face distribution pair fixture is clamped, when the motor is working, the friction force on the upper sample ensures that the upper sample will not fall off, and the hydraulic pressure output by the hydraulic cylinder three is evenly distributed on the contact surface of the upper and lower samples, reducing the influence of the test bench processing error on the test results.

[0018] 5. The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention is provided with an interlocking function, so that the two friction pair simulation fixtures will not be clamped at the same time, thereby avoiding damage to the test bench and casualties caused by simultaneous clamping.

[0019] 6. The friction and wear test bench for simulating the friction pair of a hydraulic pump motor of the present invention is provided with a bearing assembly under the specimen seat. The bearing assembly is composed of a thrust bearing and a self-aligning ball bearing, and can withstand axial loads and radial loads. 5 It ensures that the motor drives the specimen to rotate stably during the two tests, thereby ensuring the stability of the equipment and the accuracy of the measurement results.

[0020] 7. The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention applies load through a hydraulic system and measures the friction coefficient through a torque sensor. The load size can be conveniently and accurately regulated, and the friction coefficient can be accurately measured, thus providing a guarantee for the experimental accuracy.

[0021] 0 8. The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention reduces the cost of experimental equipment for different experiments, saves experimental costs, has a simple structure and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 It is the control flow chart of the fixture interlocking device;

[0024] Figure 3 It is a schematic diagram of the structure of the roller plunger pair simulation fixture;

[0025] Figure 4 It is a schematic diagram of the structure of the end face flow distribution pair simulation fixture.

[0026] Main reference numerals:

[0027] Test bench 1; motor 2; motor bracket 3; coupling 4; bearing assembly 5; sample seat 6; end 0 face distribution pair simulation fixture 7; hydraulic cylinder 71; upper sample 72; roller plunger pair simulation fixture 8; hydraulic

[0028] Cylinder 1 81; hydraulic cylinder 2 82; side specimen 2 83; side specimen 1 84; center specimen 9; lower specimen 10;

[0029] Torque sensor 11. DETAILED DESCRIPTION

[0030] 5 In order to fully describe the technical content, structural features, objectives and effects of the present invention, the following will be combined with

[0031] The specification booklet is described in detail with the attached drawings.

[0032] The present invention provides a friction and wear test bench for simulating the friction pair of a hydraulic pump and a motor. Figure 1 As shown, it includes a test bench 1, a motor 2, a motor bracket 3, a coupling 4, a bearing assembly 5, a sample seat 6, an end face flow distribution pair simulation fixture 7, a roller plunger pair simulation fixture 8 and a torque sensor 11.

[0033] The motor 2 is installed under the motor bracket 3 by bolts, the output shaft end of the motor 2 is upward, and the motor bracket 3 is installed under the table of the test bench 1 by bolts. The end face flow distribution pair simulation fixture 7 and the plunger pair simulation fixture 8 are both fixedly installed on the test bench 1 by bolts. The plunger pair simulation fixture and the end face flow distribution pair simulation fixture 7 are driven by hydraulic pressure, and the fixture load is controlled according to the hydraulic pressure.

[0034] The bearing assembly 5 is arranged on the table of the test bench 1, the sample seat 6 is arranged above the bearing assembly 5, the lower surface of the sample seat 6 is provided with a rotating shaft, and the rotating shaft is installed in the inner hole of the bearing assembly 5. The bearing assembly 5 is composed of a thrust ball bearing and a self-aligning ball bearing, which can meet the requirements of the sample to withstand axial load and radial load, reduce the measurement error caused by installation and processing, and improve the measurement accuracy.

[0035] The output shaft end of the motor 2 is connected to the sample holder 6 through the coupling 4, and the sample speed control is accurate and convenient, which is conducive to accurately analyzing the tribological performance of the friction pair under different speed conditions.

[0036] The bottom of the sample seat 6 is threadedly connected to the torque sensor 11 with a central through hole. The bottom surface of the torque sensor 11 is in direct contact with the top surface of the bearing assembly 5. The torque sensor 11 is used to measure the torque fluctuation during the operation of the sample seat 6. The torque sensor 11 calculates the friction coefficient between the friction pairs by detecting the rotation torque fluctuation of the sample seat 6. The no-load torque of the sample seat is T 0 When the clamping force of the fixture is F, the torque of the specimen holder is T 1 , the diameter of the sample is R, and the friction coefficient between the friction pairs is μ=(T 1 -T 0 )×R÷F.

[0037] like Figure 3 As shown, the roller plunger pair simulation fixture 8 is composed of hydraulic cylinder 1 81, hydraulic cylinder 2 82, side sample 2 83, side sample 1 84 and center sample 9. The clamping structure of the roller plunger pair simulation fixture 8 is similar to the friction pair structure of the actual inner curve hydraulic pump motor roller plunger. The side sample 1 84 and the side sample 2 83 simulate the plunger structure, and the center sample 9 simulates the roller structure. The hydraulic pump motor plunger is provided with an arc-shaped notch to fit the roller, and the side sample 1 84 and the side sample 2 83 are provided with an arc-shaped notch to fit the center sample 9. The material, arc-shaped notch size and surface roughness of the side sample 1 84 and the side sample 2 83 are consistent with those of the actual hydraulic pump motor plunger, and the material, outer diameter and roughness of the center sample 9 are consistent with those of the actual inner curve hydraulic pump motor roller. The side sample 1 84, the side sample 2 83 and the center sample 9 are replaceable, and the material, outer size and surface roughness of different types of inner curve hydraulic motor plungers and rollers can be simulated according to the test requirements.

[0038] Hydraulic cylinder 1 81 and hydraulic cylinder 2 82 are installed opposite to each other and are in the same hydraulic circuit to ensure the synchronization of movement. The cylinder rod of hydraulic cylinder 1 81 and the cylinder rod of hydraulic cylinder 2 82 are on the same axis. Side specimen 2 83 is connected to the end of the hydraulic cylinder rod of hydraulic cylinder 2 82 by threading, and side specimen 1 84 is connected to the end of the hydraulic cylinder rod of hydraulic cylinder 1 81 by threading. Side specimen 1 84 and side specimen 2 83 are pushed out or retracted by hydraulic cylinder 1 81 and hydraulic cylinder 2 82 respectively. The pressing force of hydraulic cylinder 1 81 and hydraulic cylinder 2 82 is controlled by hydraulic pressure. According to the actual working pressure of the hydraulic pump motor to be simulated, the hydraulic pressure can be set to 10MPa to 30MPa. The center specimen 9 is installed on the specimen seat 6. According to the speed setting of the actual hydraulic pump motor when working, the maximum speed of the motor 2 can be set to 1000rpm. The axis of the cylinder rod of hydraulic cylinder 1 81 and the cylinder rod of hydraulic cylinder 2 82 is perpendicular to the axis of the center specimen 9. Due to the stroke limit of the hydraulic cylinder, the maximum diameter of the center specimen 9 is 60mm and the minimum diameter is 10mm. The coaxiality of the two hydraulic cylinder rods is 0.01mm, and the perpendicularity to the rotation axis of the center sample 9 is 0.05mm. High precision is used to ensure that the pressure is evenly distributed on the contact surfaces of side sample 1 84, side sample 2 83 and center sample 9, reducing the influence of the test bench processing error on the test results. During operation, side sample 1 84 and side sample 2 83 clamp the center sample 9 at the same time.

[0039] like Figure 4 As shown, the end face distribution pair simulation fixture 7 is composed of a hydraulic cylinder 71, an upper sample 72 and a lower sample 10. The clamping structure of the end face distribution pair simulation fixture 7 is similar to the structure of the end face distribution pair of the inclined plate type hydraulic pump motor and the inner curve type hydraulic pump motor. The upper sample 72 simulates the structure of the hydraulic pump motor cylinder body, and the lower sample 10 simulates the structure of the hydraulic pump motor distribution plate. The material, shape and surface roughness of the upper sample 72 are consistent with the actual hydraulic pump motor cylinder body, both of which are circular and have a distribution window. The material, shape, and surface roughness of the lower sample 10 are consistent with those of the hydraulic pump motor distribution plate, so as to accurately reflect the friction and wear conditions of the actual hydraulic pump motor end face distribution pair during operation. The upper sample 72 and the lower sample 10 are replaceable, and according to the test requirements, the materials, external dimensions and surface roughness of different types of hydraulic pump motor cylinder bodies and distribution plates can be simulated respectively.

[0040] The upper sample 72 is connected to the end of the cylinder rod of hydraulic cylinder three 71 by threads, and the direction of thread rotation is opposite to that of motor 2, ensuring that the upper sample 72 will not fall off during the test. The clamping force of hydraulic cylinder three 71 is set according to the actual working pressure of the hydraulic pump motor to be simulated, and can be set to 30MPa at most. The lower sample 10 is installed on the sample seat 6. According to the actual working speed of the hydraulic pump motor, the speed of motor 2 can be set to 2000rpm at most. The axis of the cylinder rod of hydraulic cylinder three 71 coincides with the rotation axis of sample seat 6, with a coaxiality of 0.01mm. The cylinder rod of hydraulic cylinder three 71 cannot rotate, ensuring that the output pressure of the hydraulic cylinder is evenly distributed on the contact surfaces of the upper and lower samples, reducing the influence of the processing error of the test bench on the test results.

[0041] The two friction pair simulation fixtures are driven by hydraulic pressure, and the pressure control is convenient and accurate. They can simulate the friction and wear of different types of hydraulic pump motors under different pressure friction pairs under multiple working conditions. In addition, the two friction pair simulation fixtures have an interlocking function, which can prevent the two fixtures from being clamped at the same time, causing equipment damage and casualties, thereby improving equipment safety.

[0042] like Figure 2 As shown, the friction and wear test bench for simulating the friction pair of a hydraulic pump and motor of the present invention has an interlocking function. When conducting the friction and wear test of the friction pair of a hydraulic pump and motor, the equipment is first powered on to start the pump station to determine what kind of test is to be conducted.

[0043] If the end face distribution pair friction and wear test is conducted, first check whether the hydraulic cylinder 1 81 and the hydraulic cylinder 2 825 are clamped. If they are already clamped, first open the hydraulic cylinder 1 81 and the hydraulic cylinder 2 82, and then install the upper sample 72 and the lower sample 10. If the hydraulic cylinder 1 81 and the hydraulic cylinder 2 82 are not clamped, directly install the upper sample 72 and the lower sample 10. After the upper sample 72 and the lower sample 10 are installed, clamp the hydraulic cylinder 3 71 and adjust the torque sensor 11 to zero. Start the motor 2 and record the changes of the hydraulic cylinder pressure, motor speed and torque sensor 11 over time.

[0044] 0 If the piston pair friction and wear test is carried out, first check whether the hydraulic cylinder 3 71 is clamped. If it is

[0045] After clamping, open the hydraulic cylinder 3 71, and then install the side specimen 1 84, the side specimen 2 83 and the center specimen 9. If the hydraulic cylinder 3 71 has been opened, directly install the side specimen 1 84, the side specimen 2 83 and the center specimen 9. After the side specimen 1 84, the side specimen 2 83 and the center specimen 9 are installed, clamp the hydraulic cylinder 1 81 and the hydraulic cylinder 1 81.

[0046] Press cylinder 2 82 to zero the torque sensor 11. Start the motor 2 and record the changes of the hydraulic cylinder pressure, motor speed 5 and torque sensor 11 over time.

[0047] The friction and wear test bench for simulating the friction pair of a hydraulic pump and motor provided by the present invention can be applied to the friction and wear experiments of the friction pair of two pump and motors, and the method of use is simple. Moreover, the experimental equipment well simulates the actual working conditions of the friction pair inside the hydraulic pump and motor, and the experimental results are closer to reality. The same set of experimental equipment can be used for a variety of related experiments, which broadens the application field and saves experimental costs.

[0048] The above-described embodiments are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A friction and wear test bench simulating the friction pair of hydraulic pump and motor, It is characterized in that It includes a test bench, a motor, a motor bracket, a sample seat, a bearing assembly, a roller plunger pair simulation fixture, an end face flow distribution pair simulation fixture and a torque sensor; the motor bracket is installed under the table of the test bench, and the motor is installed below the motor bracket; the bearing assembly is arranged on the table of the test bench, the sample seat is arranged above the bearing assembly, a rotating shaft is arranged on the lower surface of the sample seat, the rotating shaft is installed in the inner hole of the bearing assembly, and the output shaft end of the motor is connected to the sample seat through a coupling; the torque sensor is arranged at the bottom of the sample seat, and the bottom surface of the torque sensor is in direct contact with the top surface of the bearing assembly; the roller plunger pair simulation fixture and the end face flow distribution pair simulation fixture are both installed on the test bench; The roller plunger pair simulation fixture is provided with hydraulic cylinder 1, hydraulic cylinder 2, center specimen, side specimen 1 and side specimen 2. The clamping structure of the roller plunger pair simulation fixture is similar to the friction pair structure of the inner curve hydraulic pump motor roller plunger. Side specimens 1 and 2 simulate plunger structures, and the center specimen simulates roller structure. The hydraulic cylinder 1 and the hydraulic cylinder 2 are installed opposite to each other and are in the same hydraulic circuit. The cylinder rod of the hydraulic cylinder 1 and the cylinder rod of the hydraulic cylinder 2 are on the same axis. The side specimen 1 is connected to the cylinder rod of the hydraulic cylinder 1, and the side specimen 2 is connected to the cylinder rod of the hydraulic cylinder 2. The side specimen 1 and the side specimen 2 are pushed out or retracted simultaneously by the hydraulic cylinder 1 and the hydraulic cylinder 2 respectively. The center specimen is installed on the specimen seat, and the axes of the cylinder rods of the hydraulic cylinder 1 and the hydraulic cylinder 2 are perpendicular to the axis of the center specimen. The end face flow distribution pair simulation fixture is provided with a hydraulic cylinder three, an upper specimen and a lower specimen. The clamping structure of the end face flow distribution pair simulation fixture is similar to the end face flow distribution pair structure of the inclined plate type hydraulic pump motor and the inner curve type hydraulic pump motor. The upper specimen simulates the cylinder structure of the hydraulic pump motor, and the lower specimen simulates the flow plate structure of the hydraulic pump motor. The upper specimen is threadedly connected to the cylinder rod of the hydraulic cylinder three, and the thread rotation direction is opposite to the motor rotation direction. The lower specimen is installed on the specimen seat, and the cylinder rod of the hydraulic cylinder three coincides with the axis of the specimen seat.

2. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The clamping force of hydraulic cylinder 1 and hydraulic cylinder 2 is controlled by hydraulic pressure, and the hydraulic pressure is set to 10MPa to 30MPa; when the motor drives the central sample, the maximum speed is set to 1000rpm.

3. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that Both side specimen one and side specimen two are provided with arc-shaped notches to fit with the center specimen, and the materials of side specimen one and side specimen two, the inner diameter and roughness of the surface in contact with the center specimen are consistent with the actual inner curve hydraulic pump motor plunger; the material, outer diameter and roughness of the center specimen are consistent with the actual inner curve hydraulic pump motor roller, and the maximum diameter of the center specimen is 60 mm and the minimum diameter is 10 mm.

4. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The maximum clamping force of hydraulic cylinder three is set to 30MPa; when the motor drives the lower sample, the maximum speed is set to 2000rpm.

5. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The material, shape and surface roughness of the upper sample are consistent with the actual hydraulic pump motor cylinder body, and the material, shape and surface roughness of the lower sample are consistent with the actual hydraulic pump motor distribution plate. The maximum diameters of the upper and lower samples are both 80 mm.

6. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The coaxiality of the cylinder rod of hydraulic cylinder one and the cylinder rod of hydraulic cylinder two is 0.01mm, and the verticality of the cylinder rod of hydraulic cylinder one and the cylinder rod of hydraulic cylinder two to the rotation center of the central specimen is 0.05mm; the coaxiality of the cylinder rod of hydraulic cylinder three and the rotation axis of the specimen seat is 0.01mm, and the cylinder rod of hydraulic cylinder three cannot rotate.

7. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The side sample 1, the side sample 2, the center sample, the upper sample and the lower sample can all be replaced.

8. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The torque sensor calculates the friction coefficient between the friction pairs by detecting the rotation torque fluctuation of the sample seat. The no-load torque of the sample seat is T 0 When the clamping force of the fixture is F, the torque of the specimen holder is T 1 , the sample diameter is R, and the friction coefficient between the friction pairs is obtained .

9. The friction and wear test bench for simulating the friction pair of hydraulic pump and motor according to claim 1, It is characterized in that The bearing assembly consists of a thrust bearing and a self-aligning ball bearing, and can bear axial loads and radial loads.

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