Testing device for testing friction characteristic between materials under low-temperature vacuum condition

Abstract

The invention provides a testing device for testing friction characteristics between materials under a low-temperature vacuum condition, which comprises a load testing cylinder, a refrigeration assembly and a vacuum assembly are arranged on the load testing cylinder, a first friction piece and a second friction piece are arranged in the load testing cylinder, the first friction piece is connected with a driving mechanism, and the second friction piece is connected with a second friction piece. The second friction piece is connected with a pressure applying assembly, and the pressure applying assembly is used for making the second friction piece abut against the first friction piece. The driving mechanism drives the first friction piece to rotate, the pressure applying assembly provides pressure for the second friction piece and the first friction piece, so that the first friction piece and the second friction piece generate friction, and a vacuum and low-temperature environment can be formed in the load testing cylinder through the refrigeration assembly and the vacuum assembly; therefore, the change rule of the friction coefficient between the two materials along with relative speed, pressure, boundary temperature and vacuum conditions is explored.

Description

Technical Field

[0001] The invention belongs to the technical field of friction testing, and more specifically, relates to a testing device for testing friction characteristics between materials under low-temperature vacuum conditions. Background Art

[0002] When the mechanism moves, the relative speed and pressure between materials will change, and the friction coefficient is an important reference coefficient in structural mechanics modeling. When the relative speed and pressure between materials change, the friction coefficient between the two will change. There are many references to explore the changing law of the friction coefficient between materials, but there are few reports that comprehensively consider the impact of changes in environmental boundary conditions on the friction coefficient, especially those involving low temperature and vacuum conditions. Some products will encounter low temperature and vacuum environmental conditions during actual use. For example, the penetrating detection method in the field of deep space exploration needs to consider the changing law of the friction characteristics between the projectile and the star soil. However, the existing technology lacks relevant research that comprehensively considers the impact of low temperature and vacuum environments on the friction coefficient. Summary of the invention

[0003] In order to solve the problems in the prior art, the technical solution adopted by the present invention is: providing a test device for testing the friction characteristics between materials under low-temperature vacuum conditions, including a load test cylinder, on which a refrigeration component and a vacuum component are arranged, and a first friction part and a second friction part are arranged in the load test cylinder, the first friction part is connected to a driving mechanism, and the second friction part is connected to a pressure component, and the pressure component is used to make the second friction part abut against the first friction part.

[0004] Optionally, the refrigeration assembly includes a liquid nitrogen circuit channel arranged around the load test cylinder, and a liquid nitrogen input port and a liquid nitrogen output port are respectively arranged at two ends of the liquid nitrogen circuit channel.

[0005] Optionally, the pressure-applying assembly includes two fixed pulleys and a steel wire rope, the second friction member is slidably connected to the load testing cylinder, one end of the second friction member is connected to a force transmission rod, and a movable pulley is provided at one end of the force transmission rod away from the second friction member, the steel wire rope is wound around the fixed pulley and the movable pulley, and counterweight blocks are provided at both ends.

[0006] Optionally, the vacuum assembly includes a negative pressure mechanism and a vacuum port connected to the negative pressure mechanism, and the vacuum port is communicated with the interior of the load testing cylinder.

[0007] Optionally, the driving mechanism includes a motor, which is connected to a rotating shaft. The rotating shaft passes through the top plate and the bottom plate of the load testing cylinder and is coaxially fixedly connected to the first friction member. The rotating shaft is rotatably connected to the top plate and the bottom plate, and a sealing assembly is provided at the connection.

[0008] Optionally, the sealing assembly includes a magnetic flow seal and a sealing ring, wherein the magnetic flow seal is sleeved on the outside of the rotating shaft, and the sealing ring is arranged between the magnetic flow seal and the load testing cylinder.

[0009] Optionally, it further comprises a torque sensor fixing bracket fixed on the load testing cylinder, the torque sensor fixing bracket is provided with a torque sensor, and the torque sensor is connected to the rotating shaft.

[0010] Optionally, it further includes a mobile platform, the load test cylinder is fixedly arranged on the mobile platform, a support seat is arranged at the bottom of the mobile platform, the mobile platform is provided with an encoder fixing frame, an encoder is arranged on the encoder fixing frame, and the encoder is used to measure the rotation speed of the driving mechanism.

[0011] Optionally, a temperature sensor and a gauge are provided on the load test cylinder, which are used to detect the internal temperature and vacuum degree of the load test cylinder respectively.

[0012] The beneficial effect of the test device for testing the friction characteristics between materials under low-temperature vacuum conditions provided by the present invention is that: compared with the prior art, the present invention includes a load test cylinder, a refrigeration component and a vacuum component are arranged on the load test cylinder, a first friction member and a second friction member are arranged in the load test cylinder, the first friction member is connected to a driving mechanism, the second friction member is connected to a pressure component, and the pressure component is used to make the second friction member abut against the first friction member. The first friction member is driven to rotate by the driving mechanism, and the pressure of the second friction member and the first friction member is provided by the pressure component, so that the first friction member and the second friction member rub against each other, and a vacuum and low-temperature environment can be formed in the load test cylinder by the refrigeration component and the vacuum component, so as to explore the variation law of the friction coefficient between the two materials with the relative speed, pressure, boundary temperature and vacuum conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, 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 these drawings without paying creative labor.

[0014] Figure 1 A schematic diagram of the structure of a test device provided in an embodiment of the present invention;

[0015] Figure 2 A schematic diagram of the friction characteristic interface of a test device provided in an embodiment of the present invention;

[0016] Among them, the reference numerals in the figure are:

[0017] 1. Support seat; 2. Encoder fixing bracket; 3. Mobile platform; 4. Encoder; 5. Locking assembly; 6. Load test tube; 7. Liquid nitrogen circuit channel; 8. Magnetic flow seal; 9. Liquid nitrogen output port; 10. Torque sensor; 11. Motor; 12. Torque sensor fixing bracket; 13. First friction member; 14. Second friction member; 15. Vacuum extraction port; 16. Wire rope; 17. Fixed pulley; 18. Counterweight; 19. Temperature sensor; 20. Liquid nitrogen input port; 21. Gauge; 22. Sealing ring; 23. Input shaft; 24. Output shaft. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0020] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying 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 one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] Please also read Figure 1 and Figure 2 Now, the experimental device for testing the friction characteristics between materials under low-temperature vacuum conditions provided by an embodiment of the present invention is described.

[0023] A test device for testing friction characteristics between materials under low-temperature vacuum conditions includes a load test cylinder 6, on which a refrigeration component and a vacuum component are arranged, and a first friction member 13 and a second friction member 14 are arranged in the load test cylinder 6, the first friction member 13 is connected to a driving mechanism, and the second friction member 14 is connected to a pressure component, and the pressure component is used to make the second friction member 14 abut against the first friction member 13.

[0024] The present invention drives the first friction member 13 to rotate through a driving mechanism, provides pressure between the second friction member 14 and the first friction member 13 through a pressure-applying component, causes the first friction member 13 and the second friction member 14 to rub against each other, and forms a vacuum and low-temperature environment in the load test tube 6 through a refrigeration component and a vacuum component, thereby exploring the variation law of the friction coefficient between the two materials with relative speed, pressure, boundary temperature and vacuum conditions.

[0025] In some embodiments of the present invention, see Figure 1 The refrigeration assembly includes a liquid nitrogen circuit channel 7 which is arranged around the load test cylinder 6, and a liquid nitrogen input port 20 and a liquid nitrogen output port 9 are respectively arranged at two ends of the liquid nitrogen circuit channel 7.

[0026] Specifically, the load test cylinder 6 is a cylindrical structure, the liquid nitrogen circuit channel 7 is spirally wound inside the side wall of the load test cylinder 6, the liquid nitrogen input port 20 is set at the lower end of the liquid nitrogen circuit channel 7, and the liquid nitrogen output port 9 is set at the upper end of the liquid nitrogen circuit channel 7. Liquid nitrogen circulation can quickly reduce the temperature inside the load test cylinder 6, and is injected from the liquid nitrogen input port 20 and flows out from the liquid nitrogen output port 9. Liquid nitrogen can be used to cool the inside of the load test cylinder 6, creating a low-temperature environment, which is convenient for testing the friction characteristics of different friction materials in a low-temperature environment.

[0027] In some embodiments of the present invention, see Figure 1 The pressure-applying assembly includes two fixed pulleys 17 and a steel wire rope 16. The second friction member 14 is slidably connected to the load test tube 6. One end of the second friction member 14 is connected to a force transmission rod. A movable pulley is provided at the end of the force transmission rod away from the second friction member 14. The steel wire rope 16 is wound around the fixed pulley 17 and the movable pulley, and counterweights 18 are provided at both ends.

[0028] The counterweight 18 and the steel wire rope 16 can provide leftward pressure to the force transmission rod, which transmits force to the second friction member 14, thereby applying pressure to the first friction member 13. By changing the weight of the counterweight 18, the pressure between the first friction member 13 and the second friction member 14 can be adjusted.

[0029] In some embodiments of the present invention, the vacuum assembly includes a negative pressure mechanism and a vacuum port 15 connected to the negative pressure mechanism, and the vacuum port 15 is connected to the inside of the load test cylinder 6. The negative pressure mechanism can be a vacuum pump group, and the vacuum degree inside the load test cylinder 6 can be adjusted through the vacuum port 15.

[0030] In some embodiments of the present invention, see Figure 1 The driving mechanism includes a motor 11, which is connected to a rotating shaft. The rotating shaft passes through the top plate and the bottom plate of the load test cylinder 6 and is coaxially fixedly connected to the first friction member 13. The rotating shaft is rotatably connected to the top plate and the bottom plate, and a sealing assembly is provided at the connection.

[0031] In some embodiments of the present invention, see Figure 1 The sealing assembly includes a magnetic flow seal 8 and a sealing ring 22 . The magnetic flow seal 8 is sleeved on the outside of the rotating shaft, and the sealing ring 22 is arranged between the magnetic flow seal 8 and the load test cylinder 6 .

[0032] In some embodiments of the present invention, see Figure 1 The rotating shaft includes an input shaft 23 and an output shaft 24. The motor 11 is coaxially fixedly connected to the first friction member 13 through the input shaft 23, and the input shaft 23 is rotatably connected to the magnetic flow seal 8 located at the top. The lower end of the first friction member 13 is fixedly connected to the output shaft 24, and the output shaft 24 is rotatably connected to the magnetic flow seal 8 located at the bottom.

[0033] In some embodiments of the present invention, see Figure 1 , further comprising a torque sensor fixing frame 12 fixed on the load test cylinder 6, on which a torque sensor 10 is arranged, and the torque sensor 10 is connected to the rotating shaft.

[0034] Specifically, the output end of the motor 11 is connected to the input end of the torque sensor 10, and the output end of the torque sensor 10 is coaxially installed with the magnetic flow seal 8. The torque M under stable friction can be recorded by the torque sensor 10.

[0035] In some embodiments of the present invention, see Figure 1 , further comprising a mobile platform 3, a load test cylinder 6 fixedly arranged on the mobile platform 3 through a locking assembly 5, a support seat 1 arranged at the bottom of the mobile platform 3, an encoder fixing frame 2 arranged on the mobile platform 3, an encoder 4 arranged on the encoder fixing frame 2, and the encoder 4 is used to measure the rotation speed of the rotating shaft. Specifically, the locking assembly 5 can be a bolt or the like.

[0036] In some embodiments of the present invention, see Figure 1 A temperature sensor 19 and a gauge 21 are provided on the load test cylinder 6 to detect the internal temperature and vacuum degree of the load test cylinder 6 respectively.

[0037] The test device provided by the present invention can be used to test and analyze the changes of the interface friction characteristics of two materials under different temperatures and different vacuum conditions with the interface pressure and interface relative speed. According to the research requirements, a suitable counterweight is selected to obtain the relative pressure of the friction characteristic interface, and liquid nitrogen is introduced to cool the internal environment of the load test cylinder 6. At the same time, the vacuum pump group is started to evacuate the load test cylinder 6, and the internal temperature and vacuum degree of the load test cylinder 6 are obtained in real time through the temperature sensor 19 and the gauge 21. After the test environment conditions are reached, the motor 11 is started. After the speed of the motor 11 is stable, the speed of the motor 11 is obtained through the high-precision encoder 4. The high-precision torque sensor 10 records the torque M under stable friction, and the force F can be calculated through the counterweight. When the arc length L of the action interface is much smaller than the radius of gyration R of the first friction member 13, the arc length of the action interface can be approximately equivalent to a plane, and then the interface friction coefficient μ under this test condition is calculated. The test device provided by the present invention can be used to test and analyze the changes in the interface friction characteristics of two materials under different temperatures and different vacuum conditions as the interface pressure and interface relative velocity change. The maximum relative velocity can reach 2m / s, the minimum boundary temperature can reach -90°C, and the minimum vacuum degree can reach 0.0005Pa.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A test device for testing the friction characteristics between materials under low temperature and vacuum conditions, characterized by: It includes a load testing cylinder, on which a refrigeration component and a vacuum component are arranged, and a first friction member and a second friction member are arranged in the load testing cylinder, the first friction member is connected to a driving mechanism, and the second friction member is connected to a pressure component, and the pressure component is used to make the second friction member abut against the first friction member.

2. The test device for testing the friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: The refrigeration assembly comprises a liquid nitrogen circuit channel which is arranged around the load test cylinder, and a liquid nitrogen input port and a liquid nitrogen output port are respectively arranged at two ends of the liquid nitrogen circuit channel.

3. The test device for testing the friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: The pressure-applying assembly includes two fixed pulleys and a steel wire rope. The second friction member is slidably connected to the load test cylinder. One end of the second friction member is connected to a force transmission rod. A movable pulley is provided at one end of the force transmission rod away from the second friction member. The steel wire rope is wound around the fixed pulley and the movable pulley, and counterweight blocks are provided at both ends.

4. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: The vacuum assembly comprises a negative pressure mechanism and a vacuum port connected to the negative pressure mechanism, and the vacuum port is communicated with the interior of the load testing cylinder.

5. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: The driving mechanism includes a motor, which is connected to a rotating shaft. The rotating shaft passes through the top plate and the bottom plate of the load testing cylinder and is coaxially fixedly connected to the first friction member. The rotating shaft is rotatably connected to the top plate and the bottom plate, and a sealing assembly is provided at the connection.

6. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 5, characterized in that: The sealing assembly comprises a magnetic flow seal and a sealing ring. The magnetic flow seal is sleeved on the outer side of the rotating shaft, and the sealing ring is arranged between the magnetic flow seal and the load testing cylinder.

7. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 5, characterized in that: It also includes a torque sensor fixing frame fixed on the load testing cylinder, the torque sensor fixing frame is provided with a torque sensor, and the torque sensor is connected to the rotating shaft.

8. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: It also includes a mobile platform, the load test cylinder is fixedly arranged on the mobile platform, a support seat is arranged at the bottom of the mobile platform, the mobile platform is provided with an encoder fixing frame, an encoder is arranged on the encoder fixing frame, and the encoder is used to measure the rotation speed of the driving mechanism.

9. The test device for testing friction characteristics between materials under low temperature vacuum conditions as claimed in claim 1, characterized in that: The load test cylinder is provided with a temperature sensor and a gauge, which are used to detect the internal temperature and vacuum degree of the load test cylinder respectively.

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