A friction testing machine capable of monitoring boundary lubrication conditions

Abstract

This application relates to a friction testing machine capable of monitoring boundary lubrication conditions, comprising: a pressure applying device, a rotary drive device, a rolling clamp, a steel ball, and a turntable; wherein, the pressure applying device is located on one side of the rotary drive device along a first direction; the turntable is disposed at one end of the rotary drive device near the pressure applying device, and the rotary drive device is used to drive the turntable to rotate on a first plane; the rolling clamp is disposed at one end of the pressure applying device near the rotary drive device; the steel ball is rotatably clamped on the rolling clamp; the pressure applying device is configured to apply a loading force to the steel ball along the first direction, so that the steel ball abuts against the turntable; the first direction is perpendicular to the first plane. Thus, after the turntable contacts the steel ball, the turntable rotates, and the steel ball can also rotate around its own center, realizing the rolling of the steel ball on the turntable, thereby enabling the friction testing machine to perform rolling friction tests.

Description

Technical Field

[0001] This application relates to the field of friction and wear testing, and in particular to a friction testing machine capable of monitoring boundary lubrication conditions. Background Technology

[0002] In fields such as tribology theory and technology, mechanical surface / interface science and performance control, biotribology and biomechanics, micro / nano manufacturing theory and technology, and micro / nano optoelectronic testing theory and technology, experimental testing and characterization based on material properties are important research methods. The tribological properties of materials depend not only on their own physical and chemical properties, but also on their working environment and relative motion state.

[0003] In traditional friction and wear testing machines, a steel ball and a turntable form a friction pair. A rotating unit applies torque to the turntable, causing it to rotate, while a loading unit applies a vertical force to the steel ball, keeping it stationary. A computer collects friction data via a force sensor and plots a friction coefficient-time curve. However, these friction and wear testing machines can only perform sliding friction tests and cannot perform rolling friction tests. Summary of the Invention

[0004] Therefore, it is necessary to provide a friction testing machine that can monitor the boundary lubrication state, addressing the problem that the aforementioned friction and wear testing machines cannot perform rolling friction tests.

[0005] A friction testing machine capable of monitoring boundary lubrication conditions includes: a pressure application device, a rotary drive device, a rolling clamp, steel balls, and a turntable;

[0006] Wherein, the pressure-applying device is located on one side of the rotary drive device along the first direction; the turntable is disposed at one end of the rotary drive device near the pressure-applying device, and the rotary drive device is used to drive the turntable to rotate on the first plane; the rolling clamp is disposed at one end of the pressure-applying device near the rotary drive device; the steel ball is rotatably clamped on the rolling clamp;

[0007] The pressure device is configured to apply a loading force to the steel ball along the first direction so that the steel ball abuts against the turntable; the first direction is perpendicular to the first plane.

[0008] In one embodiment, the rolling clamp includes an assembly portion and at least three rotating members disposed on the assembly portion, the at least three rotating members being spaced apart at one end of the assembly portion; the spherical surface of the steel ball contacts the at least three rotating members.

[0009] In one embodiment, the rotating component is a deep groove ball bearing, and the outer wall surface of the deep groove ball bearing is in contact with the spherical surface of the steel ball.

[0010] In one embodiment, the pressure application device includes an electric cylinder, an electric cylinder connector, a spring, a spring connecting block, a force sensor, and a fixing block connected sequentially along the first direction;

[0011] The piston rod of the electric cylinder is connected to the electric cylinder connector. The spring connecting block has a groove at one end near the electric cylinder connector. One end of the spring is connected to the bottom wall of the groove, and the other end of the spring is connected to the electric cylinder connector. The rolling clamp is located at the end of the fixed block away from the force sensor.

[0012] In one embodiment, the pressure applying device is provided with a first guide rail on one side along the second direction, the first guide rail extends along the first direction, and two first sliders are provided on the first guide rail at intervals along the first direction, the two first sliders being connected to the spring connecting block and the fixing block respectively; the second direction is perpendicular to the first direction.

[0013] In one embodiment, the rolling clamp and the fixing block are detachably connected;

[0014] The rolling clamp is provided with a first step, and the fixing block is provided with a second step that cooperates with the first step; the first step and the second step are connected by fasteners.

[0015] In one embodiment, the rotary drive device includes a motor, a first coupling, a torque sensor, a second coupling, and a rotary shaft connected sequentially along the first direction;

[0016] The output shaft of the motor is connected to the first coupling; an electric slip ring and a bearing assembly are sequentially fitted on the rotating shaft along the first direction, with the electric slip ring located on the side of the bearing assembly closer to the motor; the turntable is fixed to the end of the rotating shaft away from the motor, and an insulating gasket is provided between the turntable and the rotating shaft to electrically isolate the turntable and the rotating shaft.

[0017] In one embodiment, the friction testing machine further includes a signal acquisition and processing module, which includes a processing unit and a resistance measurement unit and an acquisition unit electrically connected to the processing unit; wherein, the first signal terminal of the resistance measurement unit is electrically connected to the rolling fixture, the second signal terminal of the resistance measurement unit is electrically connected to the outer ring of the electric slip ring, and the inner ring of the electric slip ring is electrically connected to the turntable; the first acquisition terminal of the acquisition unit is electrically connected to the force sensor, and the second acquisition terminal of the acquisition unit is electrically connected to the torque sensor.

[0018] In one embodiment, the friction testing machine further includes an upper housing and a lower housing connected to each other, the pressure applying device is disposed in the upper housing, and the rotation driving device is disposed in the lower housing;

[0019] The lower housing is provided with a first fixed frame, and the motor, the torque sensor, the slip ring and the bearing assembly are all fixedly connected to the first fixed frame; the upper housing is provided with a second fixed frame, and the electric cylinder and the first guide rail are both fixedly connected to the second fixed frame.

[0020] In one embodiment, the first fixing frame includes a top plate, a second guide rail, and an assembly frame; the second guide rail extends along a third direction and is fixed to the top plate, and the assembly frame is connected to the second guide rail via a second slider; the third direction is perpendicular to the first direction and the second direction.

[0021] The aforementioned friction testing machine incorporates a rolling clamp at one end of the pressure application device, on which a steel ball is rotatably held. When the turntable contacts the steel ball, its rotation causes the ball to rotate around its center, enabling the machine to perform rolling friction tests. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a friction testing machine provided in one embodiment of this application;

[0024] Figure 2 for Figure 1 A schematic diagram of the structure of some components of the friction testing machine;

[0025] Figure 3 for Figure 1 A schematic diagram of signal acquisition and processing in a friction testing machine;

[0026] Figure 4 for Figure 2 An assembly diagram of the fixed block, rolling clamp, and steel ball in the process;

[0027] Figure 5 for Figure 4 A schematic diagram of the assembly of the rolling clamp and the steel ball;

[0028] Figure 6 for Figure 2 Front view of the first fixed bracket and pressure application device in the middle;

[0029] Figure 7 for Figure 6 Side view;

[0030] Figure 8 for Figure 2 Front view of the second fixed bracket and rotary drive device;

[0031] Figure 9 for Figure 8 Side view;

[0032] Figure 10 for Figure 2 An assembly diagram of the rotating shaft, bearing assembly, insulating gaskets, and turntable.

[0033] Figure 11 This is a schematic diagram of the assembly of a sliding clamp and a fixed frame provided in an embodiment of this application.

[0034] Figure label:

[0035] 1-Friction testing machine; 10-Pressure application device; 11-Electric cylinder; 12-Electric cylinder connector; 13-Spring; 14-Spring connecting block; 141-Groove; 15-Force sensor; 16-Fixing block; 161-Second step; 17-First guide rail; 18-First slider; 20-Rotary drive device; 21-Motor; 22-First coupling; 23-Torque sensor; 24-Second coupling; 25-Rotating shaft; 26-Electric slip ring; 27-Bearing assembly; 271-Angular contact ball bearing; 272-Bearing housing; 273-Bearing cover; 28-Insulation 31-Shim; 31-Rolling clamp; 311-Assembly part; 312-Rotating part; 313-First step; 32-Sliding clamp; 40-Steel ball; 50-Turntable; 60-Signal acquisition and processing module; 61-Processing unit; 62-Resistance measurement unit; 63-Acquisition unit; 71-Lower housing; 72-Upper housing; 73-First fixing frame; 731-Top plate; 732-Second guide rail; 733-Assembly frame; 734-Second slider; 74-Second fixing frame; 75-Fixing plate; 76-Handwheel; 77-First connecting part; 78-Second connecting part. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0042] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0043] This application provides a friction testing machine capable of monitoring boundary lubrication conditions, referring to... Figure 1 , Figure 2 and Figure 3 As shown, the friction testing machine 1 includes: a pressure application device 10, a rotary drive device 20, a rolling clamp 31, a steel ball 40, and a turntable 50.

[0044] The pressure applying device 10 is located on one side of the rotary drive device 20 along the first direction a. A turntable 50 is disposed at the end of the rotary drive device 20 near the pressure applying device 10, and the rotary drive device 20 drives the turntable 50 to rotate on the first plane. A rolling clamp 31 is disposed at the end of the pressure applying device 10 near the rotary drive device 20. A steel ball 40 is rotatably clamped on the rolling clamp 31. The pressure applying device 10 is configured to apply a loading force to the steel ball 40 along the first direction a, so that the steel ball 40 abuts against the turntable 50. The first direction a is perpendicular to the first plane.

[0045] In this embodiment, the first plane is a horizontal plane, and the first direction 'a' is a vertical direction. The pressure applying device 10 is located directly above the rotary drive device 20, and the pressure applying device 10 is used to apply a vertically downward loading force to the steel ball 40. The steel ball 40 is rotatably held by the rolling clamp 31. Here, it can be understood that after the steel ball 40 is held by the rolling clamp 31, the steel ball 40 can rotate around its own center, but the steel ball 40 cannot be displaced relative to the rolling clamp 31.

[0046] The aforementioned friction testing machine 1, by setting a rolling clamp 31 at one end of the pressure application device 10, allows the steel ball 40 to be rotatably clamped on the rolling clamp 31. Thus, after the turntable 50 contacts the steel ball 40, the turntable 50 rotates, and the steel ball 40 also rotates around its own center, achieving rolling of the steel ball 40 on the turntable 50, thereby enabling the friction testing machine 1 to perform rolling friction tests.

[0047] In one embodiment, reference Figure 4 As shown, the rolling clamp 31 includes an assembly portion 311 and at least three rotating members 312 disposed on the assembly portion 311, the at least three rotating members 312 being spaced apart at one end of the assembly portion 311. The spherical surface of the steel ball 40 contacts the at least three rotating members 312.

[0048] In the embodiments of this application, reference is made to Figure 5 As shown, the portion of the rolling clamp 31 near the steel ball 40 is an assembly part 311. The assembly part 311 has an inverted trapezoidal cross-section and contains three rotating parts 312. Two rotating parts 312 are positioned on one side of the inverted trapezoid, and one rotating part 312 is positioned on the other side. The three rotating parts 312 form a clamping area within which the steel ball 40 is located. It should be noted that the term "clamping" in this text does not mean that the steel ball 40 is prevented from falling vertically after being clamped by the rolling clamp 31. Rather, it is equivalent to limiting the position of the steel ball 40 on the surface of the turntable 50 to prevent displacement of the steel ball 40 relative to the rolling clamp 31. This arrangement ensures that the steel ball 40 can rotate while simplifying the structure of the rolling clamp 31, making it easy to manufacture and assemble.

[0049] In another example, the number of rotating parts 312 can be four, five, or more. This application does not limit the number of rotating parts 312.

[0050] In one embodiment, the rotating component 312 is a deep groove ball bearing, and the outer wall surface of the deep groove ball bearing is in contact with the spherical surface of the steel ball 40. Deep groove ball bearings have advantages such as simple structure and ease of use, and can simultaneously withstand radial and axial loads. Therefore, in this embodiment, the deep groove ball bearing can, on the one hand, apply the vertical loading force from the rolling clamp 31 to the steel ball 40, and on the other hand, cause the steel ball 40 to rotate. It is understood that a fixed shaft can be provided on the assembly part 311, and the deep groove ball bearing is assembled on the fixed shaft.

[0051] In one embodiment, reference Figure 6 and Figure 7 As shown, the pressure application device 10 includes an electric cylinder 11, an electric cylinder connector 12, a spring 13, a spring connecting block 14, a force sensor 15, and a fixing block 16 connected in sequence along the first direction a.

[0052] Specifically, the electric cylinder 11 is located at the top. The piston rod of the electric cylinder 11 is connected to one end of the electric cylinder connector 12, and the other end of the electric cylinder connector 12 is connected to the spring 13. The end of the spring 13 away from the motor 21 is connected to the spring connecting block 14, and the end of the spring connecting block 14 away from the motor 21 is connected to the force sensor 15. The end of the force sensor 15 away from the motor 21 is connected to the fixing block 16. The spring 13 serves two purposes: firstly, it transmits the vertical loading force applied by the electric cylinder 11; secondly, it buffers the vertical loading force, preventing excessive force from damaging components such as the force sensor 15, the fixing block 16, the rolling clamp 31, or the steel ball 40. The force sensor 15 is used to detect the vertical loading force borne by the steel ball 40, facilitating the calculation of the coefficient of friction.

[0053] Specifically, refer to Figure 6 As shown, a groove 141 is provided at one end of the spring connecting block 14 near the electric cylinder connecting member 12. The spring 13 is located in the groove 141, with one end of the spring 13 connected to the bottom wall of the groove 141 and the other end of the spring 13 connected to the electric cylinder connecting member 12. The rolling clamp 31 is located at the end of the fixed block 16 away from the force sensor 15. In this embodiment, the force sensor 15 is an S-type sensor, which has advantages such as high accuracy, good measurement range, and convenient installation. It is understood that the force sensor 15 can also be other types of sensors, and this embodiment does not limit this.

[0054] In one embodiment, the pressure applying device 10 is provided with a first guide rail 17 along one side of the second direction b. The first guide rail 17 extends along the first direction a, and two first sliders 18 are provided on the first guide rail 17, which are spaced apart along the first direction a. The two first sliders 18 are respectively connected to the spring connecting block 14 and the fixing block 16. The second direction b is perpendicular to the first direction a.

[0055] By setting the first guide rail 17 and the first slider 18, the loading force applied by the electric cylinder 11 can always act on the steel ball 40 in the vertical direction, avoiding the loading force applied by the electric cylinder 11 from generating a component force in other directions, making the value of the vertical loading force borne by the steel ball 40 more accurate, and improving the test accuracy of the friction testing machine 1.

[0056] In one embodiment, reference Figure 4 and Figure 5 As shown, the rolling clamp 31 and the fixing block 16 are detachably connected. The rolling clamp 31 is provided with a first step 313, and the fixing block 16 is provided with a second step 161 that cooperates with the first step 313. The step surfaces of the first step 313 and the second step 161 are interlocked. After they are tightly interlocked, the first step 313 and the second step 161 are connected by fasteners.

[0057] In this way, on the one hand, it facilitates the repair or replacement of the rolling clamp 31 when it is damaged; on the other hand, it also facilitates the replacement of different types of clamps. For example, refer to Figure 11 As shown, when a sliding test is required, the rolling clamp 31 can be removed, and the sliding clamp 32 can be assembled with the fixed block 16. It can be understood that the connection method between the sliding clamp 32 and the fixed block 16 is the same as the connection method between the rolling clamp 31 and the fixed block 16.

[0058] In one embodiment, reference Figure 8 and Figure 9 As shown, the rotary drive device 20 includes a motor 21, a first coupling 22, a torque sensor 23, a second coupling 24, and a rotary shaft 25 connected sequentially along the first direction a.

[0059] Among them, motor 21 is located at the bottom, and the output shaft of motor 21 is connected to the first coupling 22. The end of the first coupling 22 away from motor 21 is connected to torque sensor 23. The end of torque sensor 23 away from motor 21 is connected to second coupling 24. The end of second coupling 24 away from motor 21 is connected to rotating shaft 25. The first coupling 22 and the second coupling 24 can be double free couplings, which can ensure more accurate measurement and compensate for radial and axial deviations. In addition, an electric slip ring 26 and a bearing assembly 27 are sequentially fitted on the rotating shaft 25 along the first direction a, with the electric slip ring 26 located on the side of the bearing assembly 27 closer to motor 21. Turntable 50 is fixed to the end of rotating shaft 25 away from motor 21. Specifically, refer to... Figure 10 As shown, an insulating gasket 28 is provided between the turntable 50 and the rotating shaft 25. The insulating gasket 28 is fixed to the end of the rotating shaft 25 away from the motor 21 by bolts, and the turntable 50 is connected to the insulating gasket 28. The function of the insulating gasket 28 is to electrically isolate the turntable 50 and the rotating shaft 25.

[0060] Specifically, the bearing assembly 27 includes a bearing housing 272, a bearing cap 273, and a pair of angular contact ball bearings 271. The pair of angular contact ball bearings 271 are mounted at both ends of the rotating shaft 25. The races of the angular contact ball bearings 271 have an angle with the internal steel balls. Used in pairs, they can withstand radial and axial loads and restrict axial displacement of the rotating shaft 25. The inner rings of the angular contact ball bearings 271 are interference-fitted with the rotating shaft 25 and can be positioned via the shoulders of the rotating shaft 25, preventing axial movement of the angular contact ball bearings 271 and facilitating installation. The bearing cap 273 is bolted to the bearing housing 272 and serves as a dust cover. The outer rings of the angular contact ball bearings 271 are mounted in the bearing housing 272 with an transition fit. By restricting the installation position of the angular contact ball bearings 271, the bearing housing 272 further ensures the perpendicularity of the rotating shaft 25, thereby achieving precise torque transmission.

[0061] In one embodiment, reference Figure 3 As shown, the friction testing machine 1 also includes a signal acquisition and processing module 60, which includes a processing unit 61 and a resistance measurement unit 62 and an acquisition unit 63 electrically connected to the processing unit 61. The first signal terminal of the resistance measurement unit 62 is electrically connected to the rolling clamp 31, the second signal terminal of the resistance measurement unit 62 is electrically connected to the outer ring of the slip ring 26, and the inner ring of the slip ring 26 is electrically connected to the turntable 50. During operation, the inner ring of the slip ring 26 and the turntable 50 rotate simultaneously, while the outer ring of the slip ring 26 does not rotate, preventing the wires between the slip ring 26 and the resistance measurement unit 62 from becoming entangled on the slip ring 26. Thus, the rolling clamp 31, the steel ball 40, the turntable 50, the slip ring 26, and the resistance measurement unit 62 form a circuit, allowing the resistance measurement unit 62 to measure the resistance value between the steel ball 40 and the turntable 50 in real time.

[0062] The first acquisition terminal of the acquisition unit 63 is electrically connected to the force sensor 15, and the second acquisition terminal of the acquisition unit 63 is electrically connected to the torque sensor 23. In this way, the acquisition unit 63 can acquire the values ​​of the force sensor 15 and the torque sensor 23 in real time. It can be understood that after the processing unit 61 acquires the resistance value measured by the resistance measurement unit 62 and the force data acquired by the acquisition unit 63, it can perform data processing and calculation to obtain the coefficient of friction. The acquisition unit 63 can be a data acquisition card, the resistance measurement unit 62 can be a resistance measurement board, and the processing unit 61 can be a computer.

[0063] In this embodiment, the fixing block 16 and the insulating pad 28 can be made of insulating materials such as polyoxymethylene, polyvinyl chloride, polyethylene, polytetrafluoroethylene, and neoprene rubber.

[0064] In one embodiment, reference Figure 1 , Figure 2 and Figure 3 As shown, the friction testing machine 1 also includes an upper housing 72 and a lower housing 71 connected to each other. The pressure applying device 10 is disposed in the upper housing 72, and the rotation driving device 20 is disposed in the lower housing 71. The upper housing 72 and the lower housing 71 can be a housing structure composed of plate-like structural members.

[0065] Specifically, a first fixed frame 73 is provided inside the lower housing 71, and the motor 21, torque sensor 23, slip ring 26, and bearing assembly 27 are all fixedly connected to the first fixed frame 73. The first fixed frame 73 can be a rigid frame structure. A first connecting member 77 and a second connecting member 78 can be provided on the first fixed frame 73. The first connecting member 77 is used to fix the torque sensor 23 to the first fixed frame 73, and the second connecting member 78 is used to fix the slip ring 26 to the first fixed frame 73. In addition, a fixed plate 75 is provided on the top of the lower housing 71, and the bearing assembly 27 is mounted on the fixed plate 75. The above arrangement can ensure the loading perpendicularity of the rotary drive device 20, prevent the rotary drive device 20 from radially moving, and ensure the measurement accuracy of the friction testing machine 1.

[0066] In addition, a second fixing frame 74 is provided inside the upper housing 72. The electric cylinder 11 and the first guide rail 17 are both fixed on the second fixing frame 74. The second fixing frame 74 can be a rigid frame structure.

[0067] In one embodiment, the first fixing frame 73 includes a top plate 731, a second guide rail 732, and an assembly frame 733. The top plate 731 is fixed to the upper housing 72, and the second guide rail 732 extends along a third direction c and is fixed to the top plate 731. A second slider 734 is connected to the assembly frame 733 and is connected to the second guide rail 732. Simultaneously, the electric cylinder 11 and the first guide rail 17 are both fixed to the assembly frame 733. Thus, the assembly frame 733 slides on the second guide rail 732, simultaneously moving the pressure application device 10 along the third direction c. Furthermore, a handwheel 76 is provided on the second guide rail 732; rotating the handwheel 76 controls the sliding of the assembly frame 733. This allows adjustment of the eccentricity between the steel ball 40 and the turntable 50 according to experimental needs.

[0068] Understandably, a locking device can be installed on the handwheel 76. During the experiment, the locking device can be locked to prevent the assembly frame 733 from sliding on the second guide rail 732, thereby causing the pressure device 10 to move in the third direction c. The fixed connection point between the electric cylinder 11 and the assembly frame 733 can be minimized with respect to the end of the piston rod of the electric cylinder 11 (the end of the piston rod near the steel ball 40). This ensures the stability and verticality of the pressure device 10 to the greatest extent.

[0069] The friction testing machine 1 provided in this embodiment is used as follows:

[0070] Step 1: Place the turntable 50 and steel ball 40 required for the experiment in an ultrasonic cleaner and clean them for 10 minutes. Then, apply the grease sample to be tested onto the turntable 50 and fix the turntable 50 to the insulating pad 28. Fix the steel ball 40 to the rolling clamp 31. Rotate the handwheel 76 to move the electric cylinder 11 to the designated experimental position and record the current value.

[0071] Step 2: Set the required load value, movement speed, and movement time for the experiment. Control the electric cylinder 11 and motor 21 to perform the corresponding actions.

[0072] Step 3: The acquisition unit 63 acquires data from the torque sensor 23 and the force sensor 15 in real time and transmits the acquired data to the processing unit 61. The film thickness of the lubricating grease under test changes with friction, causing a change in contact resistance. The resistance measurement unit 62 acquires the contact resistance value in real time and transmits the acquired data to the processing unit 61. Based on the acquired data, the processing unit 61 calculates the final experimental data.

[0073] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," "ideal embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0074] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A friction testing machine capable of monitoring boundary lubrication conditions, characterized in that, include: Pressure application device, rotary drive device, rolling clamp, steel balls and turntable; Wherein, the pressure-applying device is located on one side of the rotary drive device along the first direction; the turntable is disposed at one end of the rotary drive device near the pressure-applying device, and the rotary drive device is used to drive the turntable to rotate on the first plane; the rolling clamp is disposed at one end of the pressure-applying device near the rotary drive device; the steel ball is rotatably clamped on the rolling clamp; The pressure-applying device is configured to apply a loading force to the steel ball along the first direction, so that the steel ball abuts against the turntable; the first direction is perpendicular to the first plane; The pressure application device includes an electric cylinder, an electric cylinder connector, a spring, a spring connecting block, a force sensor, and a fixing block connected in sequence along the first direction; The piston rod of the electric cylinder is connected to the electric cylinder connector. The spring connecting block has a groove at one end near the electric cylinder connector. One end of the spring is connected to the bottom wall of the groove, and the other end of the spring is connected to the electric cylinder connector. The rolling clamp is located at the end of the fixed block away from the force sensor. The pressure applying device is provided with a first guide rail on one side along the second direction. The first guide rail extends along the first direction, and two first sliders are provided on the first guide rail at intervals along the first direction. The two first sliders are respectively connected to the spring connecting block and the fixing block; the second direction is perpendicular to the first direction. The rotary drive device includes a motor, a first coupling, a torque sensor, a second coupling, and a rotary shaft connected sequentially along the first direction; The output shaft of the motor is connected to the first coupling; an electric slip ring and a bearing assembly are sequentially sleeved on the rotating shaft along the first direction, with the electric slip ring located on the side of the bearing assembly closer to the motor; the turntable is fixed to the end of the rotating shaft away from the motor, and an insulating gasket is provided between the turntable and the rotating shaft to electrically isolate the turntable and the rotating shaft; The friction testing machine also includes a signal acquisition and processing module, which includes a processing unit and a resistance measurement unit and an acquisition unit electrically connected to the processing unit; The first signal terminal of the resistance measuring unit is electrically connected to the rolling clamp, the second signal terminal of the resistance measuring unit is electrically connected to the outer ring of the slip ring, and the inner ring of the slip ring is electrically connected to the turntable; the first acquisition terminal of the acquisition unit is electrically connected to the force sensor, and the second acquisition terminal of the acquisition unit is electrically connected to the torque sensor.

2. The friction testing machine according to claim 1, characterized in that, The rolling clamp includes an assembly part and at least three rotating members disposed on the assembly part, the at least three rotating members being spaced apart at one end of the assembly part; the spherical surface of the steel ball is in contact with the at least three rotating members.

3. The friction testing machine according to claim 2, characterized in that, The rotating component is a deep groove ball bearing, and the outer wall surface of the deep groove ball bearing is in contact with the spherical surface of the steel ball.

4. The friction testing machine according to claim 1, characterized in that, The rolling clamp and the fixing block are detachably connected; The rolling clamp is provided with a first step, and the fixing block is provided with a second step that cooperates with the first step; the first step and the second step are connected by fasteners.

5. The friction testing machine according to claim 1, characterized in that, The friction testing machine also includes an upper housing and a lower housing connected to each other, the pressure applying device is disposed in the upper housing, and the rotation driving device is disposed in the lower housing; The lower housing is provided with a first fixed frame, and the motor, the torque sensor, the electric slip ring and the bearing assembly are all fixedly connected to the first fixed frame; the upper housing is provided with a second fixed frame, and the electric cylinder and the first guide rail are both fixedly connected to the second fixed frame.

6. The friction testing machine according to claim 5, characterized in that, The first fixing frame includes a top plate, a second guide rail, and an assembly frame; the second guide rail extends along a third direction and is fixed to the top plate, and the assembly frame is connected to the second guide rail via a second slider; the third direction is perpendicular to the first direction and the second direction.

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