A testing device and a testing method

Abstract

The present invention is applicable to the field of gas bearings, and discloses a testing device and a testing method. The testing device comprises a base, a fixed bracket assembly for supporting a cylinder, a detection assembly, a load loading assembly, a bearing air supply assembly and several groups of gas bearing screws. The gas bearing screws are installed at an air outlet, and the gas bearing screws are provided with throttle holes. Different groups of gas bearing screws have throttle holes of different diameters. The bearing air supply assembly is connected to the air inlet. The detection assembly comprises a flow meter, a pressure sensor and a tension pressure sensor. The flow meter is installed on the bearing air supply assembly. The pressure sensor measures the pressure change in the gas bearing cavity in real time. The tension pressure sensor measures the axial force of the piston under different working conditions. The load loading assembly comprises a first load applying assembly for applying a radial force to the piston and a second load applying assembly for applying an axial force to the piston. The testing device can test the performance of the gas bearing under different working conditions.

Description

Technical Field

[0001] The invention relates to the field of gas bearings, and in particular to a testing device and a testing method for measuring the gas bearing performance of a free piston Stirling generator. Background Art

[0002] There are two moving parts inside the free piston Stirling generator, the valve piston and the power piston. The friction and wear caused during operation and the working fluid pollution and gas path blockage caused by the generated debris are key issues affecting the stability and life of the generator. The reasons for the wear between the piston and the cylinder mainly exist in the following aspects: First, during the actual installation and operation, due to factors such as processing accuracy, coaxiality of the piston and the cylinder, the permanent magnet will be far away from the equilibrium position in the radial direction and will be subjected to a large radial force, causing the power piston and the cylinder to contact, increasing the friction during operation. On the other hand, due to material limitations, immature mechanical design and manufacturing process levels, the existing traditional flexible leaf spring structure limits the leaf spring's axis, radial stiffness, natural frequency, displacement stroke and effective operation times.

[0003] In order to solve the above problems, the free piston Stirling generator uses hydrostatic gas bearings to support the power piston. Hydrostatic gas bearings have the advantages of high precision and can effectively reduce the friction between the moving parts. Hydrostatic gas bearings mainly form a pressure gas film between the cylinder and the piston through the viscosity of the gas, thereby generating a certain support load. Its key parameters mainly include bearing capacity, flow, stiffness and stability.

[0004] To this end, many scholars have conducted extensive research on the static and dynamic characteristics of gas bearings. Most of them use simulation software to calculate the gas film flow field inside the gas bearing, and most of them focus on the analysis of gas bearings in rotor machinery. Some scholars also use the spring tension and compression balance principle to load the bearing, and use displacement sensors and flow meters to measure the size of the gas film gap and gas consumption, realizing the continuous measurement of the pressure distribution of the static pressure gas bearing. However, the current experimental tests focus on studying the performance of a single plane bearing. There is no experimental device specifically used to measure the characteristics of the free piston Stirling generator gas bearing, and it is impossible to realize the influence of different gas bearing structures, inflation pressures, radial forces, etc. on the performance of the generator rotor. Summary of the invention

[0005] The first object of the present invention is to provide a testing device, which aims to solve the technical problem that the existing testing devices cannot realize the influence of different gas bearing structures, inflation pressures, radial forces, etc. on the performance of the generator rotor.

[0006] To achieve the above object, the solution provided by the present invention is:

[0007] A test device for measuring the performance of a gas bearing, wherein the gas bearing comprises a cylinder and a piston, wherein the piston is coaxially disposed in the cylinder, an air gap is left between the piston and the cylinder, and the piston can reciprocate in the cylinder, wherein the piston is provided with a gas bearing cavity, an air inlet and an air outlet, wherein the air inlet and the air outlet are respectively connected to the gas bearing cavity, wherein the test device comprises a base, a fixing bracket assembly disposed on the base for supporting the cylinder, a detection assembly, a load loading assembly, a bearing air supply assembly and a plurality of groups of gas bearing screws, wherein the gas bearing screws are used for being installed at the air outlet, wherein the gas bearing screws are provided with a throttle hole, wherein different groups of the gas bearing screws have throttle holes of different diameters, and wherein the shaft The bearing air supply assembly is used to connect with the air inlet, and the detection assembly includes a flow meter, a pressure sensor and a tension pressure sensor. The flow meter is installed on the bearing air supply assembly, and the pressure sensor is used to be installed on the piston and used to measure the pressure changes in the gas bearing cavity in real time. The tension pressure sensor is used to be installed on the piston and used to measure the axial force of the piston under different working conditions. The load applying assembly includes a first load applying assembly and a second load applying assembly. The first load applying assembly is used to connect with the piston and apply a radial force load to the piston. The second load applying assembly is used to connect with the tension pressure sensor and apply an axial force load to the piston.

[0008] Preferably, the first load applying assembly includes a load platform and a first counterweight block, the load platform is used to connect with the piston, a plurality of first counterweight blocks are provided, and the first load applying assembly applies different radial forces to the piston by configuring the first counterweight blocks of different masses or different quantities on the load platform.

[0009] Preferably, the second load applying assembly includes a supporting bracket installed on the base, a fixed pulley installed on the top of the supporting bracket, a traction rope and a second counterweight block, the traction rope is wound around the fixed pulley, and one end of the traction rope is connected to the tension and pressure sensor, and the other end is used to connect to the second counterweight block, and a plurality of second counterweight blocks are provided, and the second load applying assembly applies different axial forces to the piston by adding second counterweight blocks of different masses or different numbers.

[0010] Preferably, a slide groove is provided on the base, and a first bolt and a first nut are inverted at the bottom of the support bracket, the first bolt is adapted to the slide groove, and the support bracket is fixed to the base by the cooperation of the first bolt and the first nut.

[0011] Preferably, the pressure sensor is used to be installed at a first end of the piston, and the tension pressure sensor is used to be installed at a second end of the piston.

[0012] Preferably, the detection assembly further comprises a pressure sensor adapter and a gland connecting plate, the pressure sensor is threadedly connected to the piston via the pressure sensor adapter, and the tension pressure sensor is mounted on the piston via the gland connecting plate.

[0013] Preferably, the bearing air supply assembly includes an air supply system, an air supply pipe and an air supply adapter, the air supply pipe is connected to the air inlet of the piston through the air supply adapter, the bearing air supply system is connected to the air supply pipe, and the flow meter is installed on the air supply pipe.

[0014] Preferably, a pressure reducing valve is further provided between the bearing air supply assembly and the air supply pipe.

[0015] Preferably, a second bolt and a second nut are inverted at the bottom of the fixed bracket assembly, the second bolt is adapted to the slide groove, and the fixed bracket assembly is fixed to the base through the cooperation of the second bolt and the second nut.

[0016] Preferably, the fixed bracket assembly includes a first fixed bracket and a second fixed bracket arranged from bottom to top, the first fixed bracket is inverted with the second bolt and the second nut, the first fixed bracket is fixed to the base by the cooperation of the second bolt and the second nut, and the second fixed bracket cooperates with the first fixed bracket to fix the cylinder in the installation groove formed by the two.

[0017] A second object of the present invention is to provide a testing method based on the above-mentioned testing device, the testing method comprising:

[0018] Step S100, installing a set of gas bearing screws in the gas outlet of the piston, placing the piston in the cylinder, and fixing the cylinder on the base through the fixing bracket assembly, and then installing the pressure sensor and the tension pressure sensor on the piston;

[0019] Step S200, controlling the bearing air supply assembly to inflate air into the gas bearing cavity and maintaining the pressure in the gas bearing cavity unchanged;

[0020] Step S300, controlling the first load applying assembly to apply a radial force to the piston and keep it constant;

[0021] Step S400, controlling the second load applying assembly to apply an axial force to the piston, and gradually increasing the output load of the second load applying assembly until the piston slides;

[0022] Step S500, finding the point of maximum static friction force on the piston according to the force curve of the piston, and recording the pressure in the gas bearing cavity and the value displayed in the flow meter;

[0023] Step S600, replace the gas bearing screw in step S100, change the gas pressure in the gas bearing cavity in step S200, change the radial force applied to the piston by the first load application assembly in step S400, repeat steps S100 to S500, and obtain the performance rules of the gas bearing under different working conditions.

[0024] The testing device provided by the present invention has the following advantages:

[0025] First, the testing device of the present invention can test the performance of the gas bearing under different working conditions, so as to determine whether the gas bearing meets the rigid requirement of actual supporting capacity under different working conditions.

[0026] Second, the testing device of the present invention utilizes the principle of static and dynamic friction to determine the floating state of the piston by measuring the friction force of the piston, thereby determining the performance of the gas bearing. The device is simple and reliable.

[0027] Thirdly, the test device of the present invention changes the amount of gas entering the gap cavity per unit time by installing a gas bearing screw with different throttle holes at the gas outlet during the test. The method is simple and effective.

[0028] The test method provided by the present invention utilizes the principle of static and dynamic friction, and determines the floating state of the piston by measuring the friction force of the piston, thereby determining the performance of the gas bearing. The test method is simple and effective, and the test method of the present invention can test the performance of the gas bearing under different working conditions, thereby determining whether the gas bearing meets the rigid requirement of actual support capacity under different working conditions. In addition, during the test, the test method of the present invention changes the amount of gas entering the gap cavity per unit time by installing a gas bearing screw with a throttle hole of different diameters at the gas outlet. The method is simple and effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 is a schematic diagram of the structure of a testing device provided by an embodiment of the present invention;

[0031] Figure 2is a schematic diagram of the structure of the testing device provided by an embodiment of the present invention in another direction;

[0032] Figure 3 is a cross-sectional view of a gas bearing provided by an embodiment of the present invention;

[0033] Figure 4 It is a flow chart of the testing method provided by the embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 1. Cylinder; 2. First fixed bracket; 3. Locking nut; 4. Pressure sensor adapter; 5. Pressure sensor; 6. Base; 7. Air supply pipe; 8. Air supply adapter; 9. Second fixed bracket; 10. Second bolt; 11. Second nut; 12. Support bracket; 13. Loading platform; 14. First counterweight; 15. Second counterweight; 16. Traction rope; 17. Fixed pulley; 18. Pressure cover connecting plate; 19. Pull pressure sensor; 20. Piston; 21. Sealing PTFE pad; 22. Gas bearing screw; 23. Gas bearing cavity; 24. Clearance cavity. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0039] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] like Figures 1 to 3 As shown, it is a test device of an embodiment of the present invention, which is used to measure the performance of a gas bearing, especially suitable for measuring the performance of a gas bearing of a free piston Stirling generator, to see whether the gas bearing performance meets the rigid requirement of actual support capacity. The gas bearing includes a cylinder 1 and a piston 20, the piston 20 is coaxially arranged in the cylinder 1, a gap cavity 24 is left between the piston 20 and the cylinder 1, and the piston 20 can reciprocate in the cylinder 1, and the piston 20 is provided with a gas bearing cavity 23, an air inlet and an air outlet, and the air inlet and the air outlet are respectively connected to the gas bearing cavity 23.

[0041] See also Figure 1-Figure 3 The test device of the embodiment of the present invention includes a base 6, a fixed bracket assembly arranged on the base 6 for supporting the cylinder 1, a detection assembly, a load loading assembly, a bearing air supply assembly and a plurality of groups of gas bearing screws 22, the gas bearing screws 22 are used to be installed at the gas outlet of the piston 20, the gas bearing screws 22 are provided with throttle holes, and different groups of gas bearing screws 22 have throttle holes of different diameters, the bearing air supply assembly is used to be connected to the air inlet of the piston 20 to provide working gas for the gas bearing, the detection assembly includes a flow meter (not shown), a pressure sensor 5 and a tension pressure sensor 19, the flow meter is installed at the bearing On the air supply assembly, the pressure sensor 5 is installed on the piston 20 for measuring the pressure changes in the gas bearing chamber 23 in real time. The tension pressure sensor 19 is installed on the piston 20 for measuring the axial force of the piston 20 under different working conditions. The load applying assembly includes a first load applying assembly and a second load applying assembly. The first load applying assembly is connected to the piston 20 for applying a radial force load to the piston 20. The second load applying assembly is connected to the tension pressure sensor 19 for applying an axial force load to the piston 20 (i.e., applying the load required to measure the friction force of the piston 20 to the piston 20).

[0042] The specific steps of measuring the performance of a gas bearing by the testing device of the embodiment of the present invention are as follows:

[0043] Step S100, install one set of gas bearing screws 22 in the gas outlet of the piston 20, place the piston 20 in the cylinder 1, and fix the cylinder 1 on the base 6 through the fixing bracket assembly, and then install the pressure sensor 5 and the tension pressure sensor 19 on the piston 20;

[0044] Step S200, controlling the bearing air supply assembly to inflate the gas bearing chamber 23, and maintaining the pressure in the gas bearing chamber 23 unchanged;

[0045] Step S300, controlling the first load applying assembly to apply radial force to the piston 20 and keep it constant;

[0046] Step S400, controlling the second load applying assembly to apply an axial force to the piston 20, and gradually increasing the output load of the second load applying assembly until the piston 20 slides;

[0047] Step S500, according to the force curve of the piston 20, find the point of maximum static friction force on the piston 20, and record the pressure in the gas bearing cavity 23 and the value displayed in the flow meter.

[0048] Step S600, replace the gas bearing screw 22 in step S100 to change the diameter of the throttle hole, change the gas pressure in the gas bearing chamber 23 in step S200, change the radial force applied to the piston 20 by the first load application assembly in step S400, repeat steps S100 to S500, and obtain the maximum static friction force on the piston 20 under different working conditions, so as to judge the "floating" state of the piston 20 and obtain the performance law of the gas bearing.

[0049] The testing device according to the embodiment of the present invention has the following advantages:

[0050] First, the testing device of the embodiment of the present invention can test the performance of the gas bearing under different working conditions, so as to determine whether the gas bearing meets the rigid requirement of actual supporting capacity under different working conditions.

[0051] Second, the testing device of the embodiment of the present invention utilizes the principle of static and dynamic friction and determines the floating state of the piston 20 by measuring the friction force of the piston 20, thereby determining the performance of the gas bearing. The device is simple and reliable.

[0052] Third, during testing, the test device of the embodiment of the present invention changes the amount of gas entering the gap cavity 24 per unit time by installing a gas bearing screw 22 with throttle holes of different diameters at the gas outlet. The method is simple and effective.

[0053] Preferably, in order to prevent gas leakage from the thread gap, a sealing polytetrafluoroethylene gasket 21 is provided at each gas bearing screw 22 .

[0054] Preferably, a slide groove is provided on the base 6, and a second bolt 10 and a second nut 11 are inverted at the bottom of the fixed bracket assembly, the second bolt 10 is adapted to the slide groove, and the fixed bracket assembly is fixed to the base 6 by the cooperation of the second bolt 10 and the second nut 11. In other words, the position of the fixed bracket on the base 6 is adjustable, which is conducive to adjusting the positional relationship between the gas bearing and the test device, making the test more convenient.

[0055] Furthermore, the fixed bracket assembly includes a first fixed bracket 2 and a second fixed bracket 9 arranged from bottom to top, the first fixed bracket 2 is inverted with a second bolt 10 and a second nut 11, the first fixed bracket 2 is fixed to the base 6 by the cooperation of the second bolt 10 and the second nut 11, the second fixed bracket 9 and the first fixed bracket 2 cooperate with each other to fix the cylinder 1 in the installation groove formed by the two, and the adjustment method and fixing method of the fixed bracket assembly are cleverly designed and easy to adjust.

[0056] Specifically, the first fixing bracket 2 and the second fixing bracket 9 are locked by the locking nut 3 .

[0057] Furthermore, two groups of fixed bracket assemblies are provided, which are respectively fixed at the two ends of the cylinder 1, so that the forces at both ends of the cylinder 1 and the piston 20 are more balanced.

[0058] It can be understood that the fixed bracket assembly in this embodiment is a structure that is closed up and down, and the specific structure of the fixed bracket assembly is not limited to the above structure, as long as the cylinder 1 can be fixed for easy measurement. For example, the fixed bracket assembly can be set to a structure that is closed left and right.

[0059] Preferably, the bearing air supply assembly includes an air supply system, an air supply pipe 7 and an air supply adapter 8. The air supply pipe 7 is connected to the air inlet of the piston 20 through the air supply adapter 8. The bearing air supply system is connected to the air supply pipe 7. The flow meter is installed on the air supply pipe 7. The flow meter adopts an ALICAT 20 series standard mass flow meter with a reading accuracy of ±0.5%.

[0060] Furthermore, a pressure reducing valve is provided between the bearing air supply assembly and the air supply pipe 7, and the pressure entering the gas bearing cavity 23 is controlled by the pressure reducing valve. The pressure range of the pressure reducing valve is (0.005-0.6) MPa, the sensitivity is 0.2%, and the accuracy is ±0.5%.

[0061] Preferably, the pressure sensor 5 is installed at the first end of the piston 20, and the tension pressure sensor 19 is used to be installed at the second end of the piston 20. The two are separately arranged at the two ends of the piston 20 without affecting each other, which can improve the measurement accuracy.

[0062] Preferably, the pressure sensor 5 is connected to the piston 20 in a threaded manner through the pressure sensor adapter 4, and the connection method is simple and easy to install.

[0063] Preferably, the tension pressure sensor 19 is installed on the piston 20 through the gland connecting plate 18, and the connection method is simple and easy to install.

[0064] Preferably, the first load applying assembly includes a load platform 13 and a first counterweight block 14, the load platform 13 is connected to the second end of the piston 20, and a plurality of first counterweight blocks 14 are provided. The masses of different first counterweight blocks 14 can be the same or different. The first load applying assembly applies different radial forces to the piston 20 by configuring first counterweight blocks 14 of different masses on the load platform 13. The first load applying assembly has a simple structure and is convenient for adjusting the radial force applied to the piston 20.

[0065] Specifically, the load platform 13 is connected to the piston 20 via screws.

[0066] Preferably, the second load applying assembly includes a supporting bracket 12 installed on the base 6, a fixed pulley 17 installed on the top of the supporting bracket 12, a traction rope 16 and a second counterweight 15, the traction rope 16 is wound around the fixed pulley 17, and one end of the traction rope 16 is connected to the tension pressure sensor 19, and the other end is used to connect to the second counterweight 15. There are several second counterweights 15, and the masses of different second counterweights 15 can be the same or different. The second load applying assembly applies different axial forces to the piston 20 by adding second counterweights 15 of different masses. The first load applying assembly has a simple structure and is easy to adjust the axial force applied to the piston 20.

[0067] Preferably, a first bolt and a first nut are inverted at the bottom of the support bracket 12, and the first bolt is adapted to the slide groove on the base 6. The support bracket 12 is fixed to the base 6 by the cooperation of the first bolt and the first nut. That is to say, the position of the support bracket 12 on the base 6 is adjustable, specifically, it can be adjusted according to the position of the cylinder 1 relative to the base 6. The adjustment method and fixing method of the support bracket 12 are cleverly designed and easy to adjust.

[0068] The first load applying assembly and the second load applying assembly of the test device of the embodiment of the present invention are installed on the same side of the piston 20. The test device can satisfy the function and influence of radial force on the equipment used for gas bearings by applying load on one side of the piston 20. In particular, when used to measure the performance of the gas bearing of the free piston Stirling generator, the performance of the gas bearing is tested by adding radial force at one end of the piston 20, which is closer to the actual operating conditions of the generator.

[0069] See also Figure 4 , the embodiment of the present invention also provides a testing method, including:

[0070] Step S100, install the selected gas bearing screw 22 in the gas outlet of the piston 20, place the piston 20 in the cylinder 1, and fix the cylinder 1 on the base 6 through the fixing bracket assembly, and then install the pressure sensor 5 and the tension pressure sensor 19 on the piston 20;

[0071] Step S200, controlling the bearing air supply assembly to inflate the gas bearing chamber 23, and maintaining the pressure in the gas bearing chamber 23 unchanged;

[0072] Step S300, controlling the first load applying assembly to apply radial force to the piston 20 and keep it constant;

[0073] Step S400, controlling the second load applying assembly to apply an axial force to the piston 20, and gradually increasing the output load of the second load applying assembly until the piston 20 slides;

[0074] Step S500, according to the force curve of the piston 20, find the point of maximum static friction force on the piston 20, and record the pressure in the gas bearing cavity 23 and the value displayed in the flow meter.

[0075] Step S600, replace the gas bearing screw 22 in step S100, thereby changing the diameter of the throttling hole, changing the gas pressure in the gas bearing chamber 23 in step S200, changing the radial force applied to the piston 20 by the first load application assembly in step S400, repeating steps S100 to S500, measuring the force on the piston 20 under different gas bearing apertures, different inflation pressures, and different radial forces of the piston 20, and obtaining the maximum static friction force on the piston 20 under different working conditions, thereby judging the "floating" state of the piston 20 and obtaining the performance law of the gas bearing.

[0076] Step S400, change the gas bearing screw 22 in step S100, replace it with a gas bearing screw 22 with a different inner hole diameter, change the gas pressure in the gas bearing chamber 23 in step S100, change the radial force applied to the piston 20 by the first load application assembly in step S200, repeat steps S100 to S300, and obtain the maximum static friction force under different working conditions, so as to judge the "floating" state of the piston 20 and obtain the performance law of the gas bearing.

[0077] The testing method of the embodiment of the present invention utilizes the principle of static and dynamic friction, and determines the floating state of the piston 20 by measuring the friction of the piston 20, so as to determine the performance of the gas bearing. The testing method is simple and effective. Moreover, the testing method of the embodiment of the present invention can test the performance of the gas bearing under different working conditions, so as to determine whether the gas bearing meets the rigid requirement of actual support capacity under different working conditions. In addition, the testing method of the embodiment of the present invention changes the amount of gas entering the gap cavity 24 per unit time by installing a gas bearing screw 22 with throttle holes of different diameters at the gas outlet during the test. The method is simple and effective.

[0078] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A test device for measuring the performance of a gas bearing, wherein the gas bearing comprises a cylinder and a piston, wherein the piston is coaxially disposed in the cylinder, an air gap is left between the piston and the cylinder, and the piston can reciprocate in the cylinder, wherein the piston is provided with a gas bearing cavity, an air inlet and an air outlet, wherein the air inlet and the air outlet are respectively connected to the gas bearing cavity, and wherein: The testing device includes a base, a fixed bracket assembly arranged on the base for supporting the cylinder, a detection assembly, a load loading assembly, a bearing air supply assembly and several groups of gas bearing screws, the gas bearing screws are used to be installed on the air outlet, the gas bearing screws are provided with throttle holes, and different groups of gas bearing screws have throttle holes of different diameters, the bearing air supply assembly is used to be connected to the air inlet, the detection assembly includes a flow meter, a pressure sensor and a tension pressure sensor, the flow meter is installed on the bearing air supply assembly, the pressure sensor is used to be installed on the piston, and is used to measure the pressure change in the gas bearing cavity in real time, the tension pressure sensor is used to be installed on the piston, and is used to measure the axial force of the piston under different working conditions, the load loading assembly includes a first load applying assembly and a second load applying assembly, the first load applying assembly is used to be connected to the piston, and is used to apply a radial force load to the piston, and the second load applying assembly is used to be connected to the tension pressure sensor, and is used to apply an axial force load to the piston.

2. The testing device according to claim 1, characterized in that: The first load applying assembly includes a load platform and a first counterweight block, the load platform is used to connect with the piston, a plurality of first counterweight blocks are provided, and the first load applying assembly applies different radial forces to the piston by configuring the first counterweight blocks of different masses or different quantities on the load platform.

3. The testing device according to claim 1, characterized in that: The second load applying assembly includes a supporting bracket installed on the base, a fixed pulley installed on the top of the supporting bracket, a traction rope and a second counterweight block, the traction rope is wound around the fixed pulley, and one end of the traction rope is connected to the tension and pressure sensor, and the other end is used to connect to the second counterweight block. There are several second counterweight blocks, and the second load applying assembly applies different axial forces to the piston by adding second counterweight blocks of different masses or different quantities.

4. The testing device according to claim 3, characterized in that: A slide groove is provided on the base, and a first bolt and a first nut are inverted on the bottom of the support bracket. The first bolt is adapted to the slide groove, and the support bracket is fixed to the base through the cooperation of the first bolt and the first nut.

5. The testing device according to claim 1, characterized in that: The pressure sensor is used to be installed at the first end of the piston, and the tension pressure sensor is used to be installed at the second end of the piston.

6. The testing device according to claim 5, characterized in that: The detection assembly also includes a pressure sensor adapter and a gland connecting plate. The pressure sensor is threadedly connected to the piston via the pressure sensor adapter, and the tension pressure sensor is installed on the piston via the gland connecting plate.

7. The testing device according to claim 1, characterized in that: The bearing air supply assembly includes an air supply system, an air supply pipe and an air supply adapter. The air supply pipe is connected to the air inlet of the piston through the air supply adapter. The bearing air supply system is connected to the air supply pipe, and the flow meter is installed on the air supply pipe.

8. The testing device according to claim 7, characterized in that: A pressure reducing valve is also provided between the bearing air supply assembly and the air supply pipe.

9. The testing device according to claim 4, characterized in that: A second bolt and a second nut are inverted at the bottom of the fixed bracket assembly, the second bolt is adapted to the slide groove, and the fixed bracket assembly is fixed to the base through the cooperation of the second bolt and the second nut.

10. The testing device according to claim 9, characterized in that: The fixing bracket assembly includes a first fixing bracket and a second fixing bracket arranged from bottom to top, the first fixing bracket is inverted with the second bolt and the second nut, the first fixing bracket is fixed to the base through the cooperation of the second bolt and the second nut, and the second fixing bracket cooperates with the first fixing bracket to fix the cylinder in the installation groove enclosed by the two.

11. A testing method based on the testing device according to claim 1, characterized in that: The test method includes: Step S100, installing a set of gas bearing screws in the gas outlet of the piston, placing the piston in the cylinder, and fixing the cylinder on the base through the fixing bracket assembly, and then installing the pressure sensor and the tension pressure sensor on the piston; Step S200, controlling the bearing air supply assembly to inflate air into the gas bearing cavity and maintaining the pressure in the gas bearing cavity unchanged; Step S300, controlling the first load applying assembly to apply a radial force to the piston and keep it constant; Step S400, controlling the second load applying assembly to apply an axial force to the piston, and gradually increasing the output load of the second load applying assembly until the piston slides; Step S500, finding the point of maximum static friction force on the piston according to the force curve of the piston, and recording the pressure in the gas bearing cavity and the value displayed in the flow meter; Step S600, replace the gas bearing screw in step S100, change the gas pressure in the gas bearing cavity in step S200, change the radial force applied to the piston by the first load application assembly in step S400, repeat steps S100 to S500, and obtain the performance rules of the gas bearing under different working conditions.

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