Rotary friction power charging device

Abstract

The application relates to the technical field of tribology in mechanical engineering, in particular to a rotary friction electrification device, which comprises a rotating part, a transmission shaft, a conductive slip ring, a liquid pool, a friction part and a supporting part, wherein: one end of the transmission shaft is fixed with the rotating part, and the other end of the transmission shaft is fixed with the liquid pool; the inner cavity of the liquid pool is provided with a fixing seat for fixing a test piece; the rotor of the conductive slip ring is sleeved on the transmission shaft, and the stator of the conductive slip ring is fixed by the supporting part; the friction part is fixedly connected with the supporting part, and the friction part is arranged above the fixing seat; an auxiliary electrode is fixed to the friction part, a reference electrode is fixed to the inner cavity of the liquid pool, and a working electrode is connected to the fixing seat; the auxiliary electrode is electrically connected with an electrochemical workstation, the reference electrode and the working electrode are both electrically connected to the rotor of the conductive slip ring, and the stator of the conductive slip ring is electrically connected to the electrochemical workstation. The device of the application can avoid wire winding and reduce the influence of electromagnetic coupling on electrode potential.

Description

Technical Field

[0001] The present application relates to the technical field of tribology in mechanical engineering, and in particular to a rotary friction electrification device. Background Art

[0002] Triboelectrochemical phenomena occur when an external electric field is applied to a friction interface. This field influences the physical and chemical properties of the friction pair and the interface, as well as the surface properties and ambient atmosphere, thereby altering the friction coefficient and wear state. On a macroscale, a tribometer is typically used to measure the friction and load between two material surfaces during sliding. For example, a rotary tribometer can measure continuous friction and rotational speed data, making it suitable for evaluating the wear resistance and stability of materials under continuous rotation.

[0003] The power-on method of rotating friction motion faces a great challenge, mainly because when the test piece is connected to the working electrode, the rotational motion may cause the wire to tangle. In the related art, a friction and wear tester that can reduce the chance of wire tangling is provided. Figure 1 The related art employs a friction pair layout consisting of three evenly distributed ceramic balls 1 and a metal disk 9. The fixture holding the three ceramic balls 1 is fixed to the metal disk 8 and connected to the motor shaft 3 via a coupling 2. The auxiliary electrode is fixed to the flange and connected to the auxiliary electrode via a brush assembly 4, ensuring power is supplied to the rotating auxiliary electrode. In other words, the related art employs a top-mounted motor, which drives the three ceramic balls 1 to rotate, thereby enabling frictional charging of the ceramic balls 1 and the workpiece placed within the metal disk 8.

[0004] Although the method in the related art can solve the problem of wire winding to a certain extent, since its brushes are connected to the motor shaft, there may be coupling between the electrode field strength of the brushes and the auxiliary electrode, which will interfere with the accurate control of the working electrode potential.

[0005] Therefore, how to reduce the impact of electromagnetic coupling on the electrode potential while avoiding wire entanglement is an urgent problem that needs to be solved. Summary of the Invention

[0006] Based on this, it is necessary to provide a rotating friction charging device that can avoid wire entanglement and reduce the impact of electromagnetic coupling on the electrode potential to address the above technical problems.

[0007] In a first aspect, the present application provides a rotary friction electrification device, the device comprising a rotating portion, a transmission shaft, a conductive slip ring, a liquid pool, a friction portion, and a support portion, wherein:

[0008] One end of the transmission shaft is fixed to the rotating part, and the other end of the transmission shaft is fixed to the liquid pool;

[0009] The inner cavity of the liquid pool is provided with a fixing seat for fixing the test piece;

[0010] The rotor of the conductive slip ring is sleeved on the transmission shaft and fixed, and the stator of the conductive slip ring is fixed by the support part;

[0011] The friction portion is fixedly connected to the support portion, and the friction portion is placed above the fixing seat;

[0012] An auxiliary electrode is fixed to the friction part, a reference electrode is fixed to the inner cavity of the liquid pool, and a working electrode is connected to the fixing seat; the auxiliary electrode is electrically connected to the electrochemical workstation, the reference electrode and the working electrode are both electrically connected to the rotor of the conductive slip ring, and the stator of the conductive slip ring is electrically connected to the electrochemical workstation.

[0013] In one embodiment, the fixing seat is coaxially fixed to the bottom surface of the inner cavity of the liquid pool with the liquid pool, and the outer bottom end of the liquid pool is coaxially fixed to the transmission shaft.

[0014] In one embodiment, the friction part includes a friction ball, a ball holder and a joint, wherein:

[0015] The joint is fixed to the ball holder, the ball holder is fixed to the support portion, and the rubbing ball is fixed to the ball holder.

[0016] In one embodiment, the ball holder includes a base and a ball holder cage, wherein:

[0017] The friction ball is fixed to the base, the ball holder is arranged outside the friction ball, and the ball holder is detachably connected to the base;

[0018] One end of the ball cage is open away from the base, and the friction balls protrude from the open end of the ball cage.

[0019] In one embodiment, the end of the joint away from the base is connected to the force sensor, and the joint is capable of bearing a vertical load force provided externally.

[0020] In one embodiment, the support portion includes a fixed base and a support rod, wherein:

[0021] The support rod is fixed to the fixed base, the support rod is vertically arranged and higher than the top of the liquid pool;

[0022] The joint is connected to the support rod via a displacement assembly, and the displacement assembly can drive the joint to move closer to or away from the fixing seat in a vertical direction.

[0023] In one embodiment, the support portion further comprises a support frame, wherein:

[0024] The support frame is fixedly connected to the fixed base;

[0025] The support frame is fixedly connected to the stator of the conductive slip ring.

[0026] In one embodiment, the support frame includes support legs and a fixing ring, wherein:

[0027] The supporting legs are fixed to the fixing base, and at least two supporting legs are provided;

[0028] The fixing ring is sleeved on the outside of the conductive slip ring, and the fixing ring is fixedly connected to each of the supporting legs;

[0029] The support frame is no higher than the stator of the conductive slip ring.

[0030] In one embodiment, the fixing seat is an annular clamp, and the connecting ends of the annular clamp are connected by bolts.

[0031] In one embodiment, the liquid pool can contain electrolyte.

[0032] In the aforementioned rotary friction charging device, when a specimen is fixed to a fixed seat, the rotating portion, via the transmission shaft, can drive the rotor of the conductive slip ring, the liquid pool, and the fixed seat to rotate circumferentially. Simultaneously, the friction portion is positioned above the fixed seat, and when the specimen is driven to rotate, it can rub against the friction portion. Because the auxiliary electrode is fixed to the friction portion and does not participate in the rotation, the auxiliary electrode's wire does not participate in the rotational motion, thereby avoiding entanglement with other wires. Because the reference electrode is fixed in the inner cavity of the liquid pool, the working electrode is fixed to the fixed seat, and both the reference electrode and the working electrode are connected to the electrochemical workstation via the conductive slip ring, the stator of the conductive slip ring does not participate in the rotation, while the rotor of the conductive slip ring is driven to rotate by the transmission shaft. That is, the wires between the electrochemical workstation and the stator of the conductive slip ring also do not participate in the rotational motion, thereby avoiding the problem of wire entanglement. Furthermore, the wires connecting the reference electrode and the working electrode to the rotor of the conductive slip ring participate in the rotational motion synchronously and are independent of each other, thereby also avoiding the problem of wire entanglement.

[0033] Furthermore, in the device of the present application, the auxiliary electrode is fixed to the fixed friction part. Therefore, the auxiliary electrode is not directly connected to the motor shaft, and there will be no mutual coupling between the electric field of the auxiliary electrode and the electric field of the motor. Therefore, in the device of the present application, the electromotive force of the working electrode can be more accurately regulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of a friction charging device in related technology.

[0035] Figure 2 Schematic diagram of the overall structure of the friction charging device in the embodiment of the present application.

[0036] Figure 3 A schematic diagram showing the fixed state of the conductive slip ring and the fixing frame.

[0037] Figure 4 A schematic diagram showing the structure of the liquid pool and the fixed seat.

[0038] Figure 5 A schematic diagram showing the structure of the friction part.

[0039] Figure 6 A schematic diagram showing the principle of hydration.

[0040] Figure 7 Schematic diagram showing the principle of triboelectrochemical reaction.

[0041] Figure numerals: 1. rotating part; 2. transmission shaft; 3. conductive slip ring; 31. rotor; 32. stator; 33. anti-rotation plate; 4. liquid pool; 41. fixed seat; 5. test piece; 6. friction part; 61. ball holder; 611. base; 612. ball holder cage; 613. positioning hole; 62. friction ball; 63. joint; 7. supporting part; 71. fixed base; 72. supporting frame; 721. supporting leg; 722. fixing ring; 723. anti-rotation pin; 8A. auxiliary electrode; 8B. working electrode; 8C. reference electrode; 9. electrochemical workstation. DETAILED DESCRIPTION

[0042] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0043] In the description of the application, it should be understood that, if there are these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0044] In addition, if there are these terms "first", "second", these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0045] In this application, unless otherwise explicitly specified and limited, if there are terms such as "mounting", "connecting", "connecting", "fixing" and the like, these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0046] In this application, unless otherwise explicitly specified and limited, if there are similar descriptions such as "first feature on or under second feature", the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0047] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0048] See Figure 2-Figure 4 A rotary friction electrification device provided in one embodiment of the present application includes a rotating portion 1, a transmission shaft 2, a conductive slip ring 3, a liquid pool 4, a friction portion 6, and a support portion 7. One end of the transmission shaft 2 is fixed to the rotating portion 1, and the other end of the transmission shaft 2 is fixed to the liquid pool 4. A fixing seat 41 for fixing a test piece 5 is provided within the inner cavity of the liquid pool 4. The rotor 31 of the conductive slip ring 3 is sleeved and fixed to the transmission shaft 2, and the stator 32 of the conductive slip ring 3 is fixed to the support portion 7. The friction portion 6 is fixedly connected to the support portion 7 and is positioned above the fixing seat 41.

[0049] Furthermore, an auxiliary electrode 8A is fixed to the friction part 6, a reference electrode 8C is fixed to the inner cavity of the liquid pool 4, and a working electrode 8B is connected to the fixing seat 41; the auxiliary electrode 8A is electrically connected to the electrochemical workstation 9, the reference electrode 8C and the working electrode 8B are both electrically connected to the rotor 31 of the conductive slip ring 3, and the stator 32 of the conductive slip ring 3 is electrically connected to the electrochemical workstation 9.

[0050] In an embodiment of the present application, the rotating part 1 serves as a driving source of the rotating friction charging device; when the specimen 5 is fixed on the fixed seat 41, the rotating part 1 can drive the rotor 31 of the conductive slip ring 3, the liquid pool 4 and the fixed seat 41 to rotate circumferentially through the transmission shaft 2; at the same time, the friction part 6 is placed above the fixed seat 41, and the specimen 5 can achieve friction with the friction part 6 when being driven to rotate. Since the auxiliary electrode 8A is fixed to the friction portion 6, and the friction portion 6 does not participate in the rotation, the wire of the auxiliary electrode 8A does not participate in the rotational motion, thereby avoiding entanglement with the other wires; since the reference electrode 8C is fixed in the inner cavity of the liquid pool 4, the working electrode 8B is fixed to the fixing seat 41, and the reference electrode 8C and the working electrode 8B are both connected to the electrochemical workstation 9 through the conductive slip ring 3; therefore, during the rotation process, the stator 32 of the conductive slip ring 3 does not participate in the rotation, and the rotor 31 of the conductive slip ring 3 is driven to rotate by the transmission shaft 2; that is, the wire between the electrochemical workstation 9 and the stator 32 of the conductive slip ring 3 does not participate in the rotational motion, thereby avoiding the problem of wire entanglement; and, the wires connecting the reference electrode 8C and the working electrode 8B to the rotor 31 of the conductive slip ring 3 participate in the rotational motion synchronously, and the wires of the two are independent of each other, thereby also avoiding the problem of wire entanglement.

[0051] Furthermore, in the device of the present application, the auxiliary electrode 8A is fixed to the friction part 6, and therefore, it is not directly connected to the motor main shaft, and there will be no mutual coupling between the electric field of the auxiliary electrode 8A and the electric field of the motor. Therefore, in the device of the present application, the electromotive force of the working electrode 8B can be more accurately regulated.

[0052] In one possible implementation, the rotating part 1 can be a rotating platform of an existing rotating test equipment, and the transmission shaft 2 is fixed coaxially with the rotating platform and perpendicular to the rotating platform. For example, the rotating part 1 can be a rotating platform of a friction and wear testing machine.

[0053] In another possible implementation, rotating unit 1 can be an independent rotating platform driven by a drive motor. For example, rotating unit 1 can also consist of a drive motor, a reducer, a coupling, and a rotating table. The output shaft of the drive motor is coaxially fixed to the input shaft of the reducer, the output shaft of the reducer is coaxially fixed to the rotating table via a coupling, and the transmission shaft 2 is coaxially fixed to the rotating table. This allows the drive unit, through transmission shaft 2, to drive components fixed to transmission shaft 2 to achieve rotational motion.

[0054] It should be noted that the rotational motion of the rotating part 1 can be variable speed or uniform speed, that is, the circumferential rotational speed of the rotating part 1 is controllable and adjustable.

[0055] Furthermore, the support portion 7 includes a fixed base 71 and a support frame 72; wherein the fixed base 71 is used to support the rotating friction charging device, and the support frame 72 is used to fix the stator 32 of the conductive slip ring 3, so that when the transmission shaft 2 rotates, the stator 32 and the rotor 31 of the conductive slip ring 3 can remain relatively stable.

[0056] Specifically, in one embodiment, referring to Figure 2 and Figure 3 When the rotating unit 1 is a rotating platform of a friction and wear testing machine, the fixed base 71 is the frame of the friction and wear testing machine. When the rotating unit 1 is a rotating platform driven by an independent drive motor, the fixed base 71 can be a hollow cavity with an open top end and a closed bottom end. The rotating unit 1 is fixedly connected to the bottom end of the fixed base 71 within the hollow cavity of the fixed base 71, so that the top end of the rotating platform protrudes from the open top end of the fixed base 71.

[0057] In one embodiment, referring to Figure 2 and Figure 3The support frame 72 is fixedly connected with the fixed base 71, and the support frame 72 is fixedly connected with the stator 32 of the conductive slip ring 3, so that the stator 32 of the conductive slip ring 3 can be kept in a stable state. Specifically, the support frame 72 includes a support leg 721 and a fixing ring 722, and the support leg 721 is fixedly connected with the fixed base 71, for example, by welding or bolt connection. The fixing ring 722 is sleeved on the stator 32 of the conductive slip ring 3, and the fixing ring 722 is fixedly connected with the outer wall of the stator 32 of the conductive slip ring 3. Specifically, the outer wall of the stator 32 of the conductive slip ring 3 is fixedly provided with a rotation-stopping piece 33, and the inner side of the fixing ring 722 is provided with a rotation-stopping pin 723. The stator 32 of the conductive slip ring 3 is fixed by the fixing ring 722 through the plug-in cooperation or threaded connection of the rotation-stopping pin 723 and the rotation-stopping piece 33, so as to prevent the stator 32 of the conductive slip ring 3 from rotating. This fixing mode effectively guarantees the stability of the stator 32 of the conductive slip ring 3, and ensures the accuracy and reliability in the experiment. The length of the rotation-stopping pin 723 can be adjusted by adjusting the bolt.

[0058] Further, referring to Figure 2 and Figure 3 , the support leg 721 is provided with at least two, and each support leg 721 is fixedly connected with the fixing ring 722. Each support leg 721 is uniformly arranged along the circumference of the stator 32 of the conductive slip ring 3, so that the stator 32 of the conductive slip ring 3 can obtain more stable support and fixing effect. The fixing ring 722 can be a rectangular ring structure or a circular ring structure, which is not limited in the embodiments of the present application. It should be noted that, in order to further improve the support effect of the stator 32 of the conductive slip ring 3, the setting height of the fixing ring 722 is not higher than the top end of the stator 32 of the conductive slip ring 3, that is, the setting height of the fixing ring 722 is not higher than the end of the conductive slip ring 3 away from the fixed base 71.

[0059] Further, referring to Figure 4 , the liquid pool 4 is a hollow cavity with an open upper end. The cross section of the liquid pool 4 can be rectangular or circular. The outer side of the closed end of the liquid pool 4 is coaxially fixed with the end of the transmission shaft 2 away from the rotating part 1, so that the liquid pool 4 can keep concentric stability when rotating with the transmission shaft 2, and will not be affected by uneven centrifugal force. At the same time, the fixed seat 41 is fixed in the hollow cavity of the liquid pool 4, and the fixed seat 41 is fixedly connected with the inner side of the closed end of the liquid pool 4, that is, the fixed seat 41 is fixedly connected with the bottom end of the liquid pool 4 in the hollow cavity of the liquid pool 4. The fixed seat 41 can be a ring-shaped clamp, and the fixed seat 41 is fixedly connected with the bottom end of the liquid pool 4 by bolt connection.

[0060] Specifically, referring to Figure 4The connecting ends of the annular clamp are connected by bolts, that is, the tightness of the clamp can be adjusted by adjusting the degree of screwing the bolts in and out. In the embodiment of the present application, the test piece 5 targeted by the rotary friction charging is a metal test piece 5. The test piece 5 is embedded in the liquid pool 4 and is located in the middle of the fixed seat 41. By adjusting the bolts of the annular clamp, the annular clamp clamps the test piece 5, thereby stably fixing the test piece 5 to the fixed seat 41.

[0061] In one embodiment, referring to Figure 4 A groove for fixing the reference electrode 8C may be provided on the inner wall of the hollow cavity of the liquid pool 4, and the reference electrode 8C may be snapped into the groove for fixation; the reference electrode 8C is electrically connected to an output end of the rotor 31 of the conductive slip ring 3 through a wire, and the wire connecting the reference electrode 8C may be fixed accordingly along a path extending to the rotor 31 of the conductive slip ring 3, such as by bonding or bundling, which is not specifically limited in the embodiments of the present application; as long as the wire can maintain a stable state relative to the transmission shaft 2 when the transmission shaft 2 drives the rotor 31 of the conductive slip ring 3 and the liquid pool 4 to rotate.

[0062] Furthermore, the working electrode 8B can be fixed to the fixing base 41, such as by bundling or welding. The working electrode 8B can also be fixed between the specimen 5 and the fixing base 41, that is, the specimen 5 and the working electrode 8B are clamped by the fixing base 41, so that the specimen 5 and the working electrode 8B are fixed to the fixing base 41. The working electrode 8B is electrically connected to an output end of the rotor 31 of the conductive slip ring 3 through a wire, and the wire connecting the working electrode 8B can be fixed accordingly along a path extending to the rotor 31 of the conductive slip ring 3, such as by bonding or bundling. This is not specifically limited in the embodiments of the present application. As long as the wire can maintain a stable state relative to the transmission shaft 2 when the transmission shaft 2 drives the rotor 31 of the conductive slip ring 3 and the liquid pool 4 to rotate.

[0063] Furthermore, the liquid pool 4 may contain an electrolyte, which can serve as a lubricant during friction. Furthermore, the presence of the electrolyte can form a hydrated adsorption layer on the surface of the specimen 5, thereby reducing electrostatic interactions between the friction surfaces of the specimen 5. The effects of the electrolyte will be explained in more detail below, and the principles of its implementation are omitted here. The electrolyte can be a water-based electrolyte, an oil-based electrolyte, or a mixture of grease or other similar liquids.

[0064] Furthermore, the support portion 7 also includes a support rod; the support rod is used to fix the friction portion 6; when the transmission shaft 2 drives the fixed seat 41 of the fixed specimen 5 to rotate, thereby realizing rotational friction between the specimen 5 and the friction portion 6, the support rod can support the friction portion 6, so that the friction portion 6 can maintain a relatively stable position.

[0065] In one possible implementation, the support rod can be an independent support member, one end of the support rod is bent and fixedly connected to the fixed base 71, so that the bent end of the support rod and the fixed base 71 can be placed on the same horizontal plane; the other end of the support rod is arranged parallel to the transmission shaft 2, that is, the vertical part of the support rod and the transmission shaft 2 are both arranged perpendicular to the horizontal plane where the fixed base 71 is located.

[0066] In another possible implementation, the support rod may also be a cantilever of the friction and wear testing machine, and the friction portion 6 is connected to the cantilever of the support rod, thereby fixing the friction portion 6 .

[0067] It should be noted that the joint 63 is connected to the support rod, and the displacement assembly can drive the joint to move closer to or away from the fixing seat 41 in the vertical direction, so that the friction part 6 can adjust its position on the support rod along the direction of approaching or moving away from the fixing seat 41.

[0068] In one embodiment, referring to Figure 5 The friction part 6 includes a friction ball 62, a ball holder 61, and a joint 63; wherein the joint 63 is fixed to the support part 7, and the joint 63 is fixedly connected to the ball holder 61, for forming a stable support for the ball holder 61; the ball holder 61 is used to fix the friction ball 62, so that the friction ball 62 can be aligned with the specimen 5 fixed on the fixing seat 41, thereby realizing the rotational friction between the friction ball 62 and the specimen 5.

[0069] Specifically, refer to Figure 5 The ball holder 61 includes a base 611 and a ball holder cage 612. The ball 62 is fixed to the base 611, and the ball holder cage 612 is provided to cover the outside of the ball 62. The end of the ball holder cage 612 away from the base 611 is open, and the ball 62 protrudes from the open end of the ball holder cage 612. The ball holder cage 612 is detachably connected to the base 611. The specific connection method is that the ball holder cage 612 is a cage with a circular cross-section, and the outer wall of the ball holder cage 612 near the end of the base 611 is provided with an external thread. The base 611 is provided with a hole for installing the ball holder cage 612, and the hole is provided with an internal thread. The external thread of the ball holder 61 matches the internal thread of the hole of the base 611, and the ball holder cage 612 is connected to the base 611 by screwing, and the detachable effect can be achieved.

[0070] Further, when the support rod is an independent support, the joint 63 is fixedly connected with the support rod; and the joint 63 can bear the vertical load force provided from outside; that is, the joint 63 can bear the pressure in the direction of the vertical fixed base 41 and transmit the pressure to the rubbing ball 62. The end of the joint 63 away from the base 611 is connected with the force sensor, and the vertical load force applied on the joint 63 can be measured through the sensor, so that the size of the load force applied on the joint 63 can be better monitored.

[0071] Specifically, referring to Figure 5 A positioning hole 613 is formed in the base 611, and the reference electrode 8C is fixed in the positioning hole 613, so that the reference electrode 8C has better stability. Further, the reference electrode 8C can be one of a graphite electrode, an Ag / AgCl electrode or a calomel electrode, and the specific type of the reference electrode 8C is not limited in the embodiment of the application. The nearest distance between the axis of the positioning hole 613 and the rubbing ball 62 can be [0.5mm-2mm]. In one possible implementation, the nearest distance between the axis of the positioning hole 613 and the rubbing ball 62 can be any one of 0.5mm, 1mm and 2mm; and preferably, the nearest distance is 1mm, so that the reference electrode 8C can provide a constant and accurate reference potential for the rubbing ball 62. The reference electrode 8C is not only used for accurately controlling the potential of the test piece 5 (i.e., the working electrode 8B), but also protects the test piece 5 from being excessively oxidized or reduced by avoiding applying too high a potential, thereby ensuring the accuracy of the electrochemical measurement and the repeatability of the experiment.

[0072] The above describes the friction charging device provided by the embodiment of the application from the perspective of structure; the following describes the effect of the friction charging device provided by the embodiment of the application from the perspective of use method and principle of friction charging of the test piece 5. In addition, the concepts of super-slip and liquid super-slip involved in the following description are described first. Super-slip: refers to the sliding friction state between the surfaces in relative motion, in which the sliding friction coefficient is 0.01 or below. The friction coefficient of general oil lubrication is about 0.05-0.10. Liquid super-slip: refers to the super-slip state achieved by a liquid lubricant.

[0073] Perform preliminary preparations: fix the specimen 5 made of metal or semiconductor material in the liquid pool 4. Since the specimen 5 is connected to the working electrode 8B, the specimen 5 itself can serve as the working electrode 8B; install and fix the specimen 5 through the fixing seat 41. For the friction part 6, the auxiliary electrode 8A is fixed on the base 611 made of metal or other conductive material, and the friction ball 62 can be made of polymer material. Therefore, the base 611 and the friction ball 62 made of conductive material are equivalent to the auxiliary electrode 8A. The reference electrode 8C is directly fixed in the liquid pool 4, and an electrolyte is added to the liquid pool 4 so that the reference electrode 8C is partially or completely immersed in the electrolyte; and the specimen 5, the base 611 and the friction ball 62 are completely immersed in the electrolyte. Among them, the distance between the reference electrode 8C and the specimen 5 is less than or equal to 1.5 mm, and preferably can be 1 mm.

[0074] When installing the specimen 5 on the fixing seat 41, first rotate the connecting bolts of the fixing seat 41 forward to loosen the fixing seat 41, and then place the specimen 5 into the fixing seat 41, or place the specimen 5 and the working electrode 8B into the fixing seat 41 together, wherein the specimen 5 is placed between the fixing seat 41 and the specimen 5; then, reverse the connecting bolts of the fixing seat 41 so that the fixing seat 41 clamps the specimen 5, or clamps the specimen 5 and the working electrode 8B, to ensure that the specimen 5 is fixed in the liquid pool 4. This fixing method ensures the stability and safety of the specimen 5 during the experiment.

[0075] After the test piece 5 is fixed, the height of the friction part 6 is adjusted so that the friction ball 62 is located above the test piece 5 and just contacts the surface of the test piece 5. The rotational friction motion between the friction ball 62 and the test piece 5 is realized by the friction and wear testing machine, that is, the rotating part 1 drives the rotor 31 of the conductive slip ring 3 and the liquid pool 4 to rotate through the transmission shaft 2. The test piece 5 fixed by the fixing seat 41 in the liquid pool 4 rotates synchronously. That is, while the friction ball 62 remains fixed, the test piece 5 rotates, thereby realizing rotational friction between the two.

[0076] Furthermore, the triboelectric device in the embodiment of the present application allows for control of the load applied to the joint 63, adjustment of the rotational speed of the rotating portion 1, and adjustment of the rotation radius of the specimen 5 relative to the friction ball 62 (the horizontal distance between the axis of the specimen 5 and the axis of the friction ball 62). Liquid lubricant is added to the liquid reservoir 4, and the electrochemical workstation 9 is activated. The input voltage is set to generate a voltage between the working electrode 8B and the auxiliary electrode 8A, thereby generating a voltage between the specimen 5 and the friction ball 62. Simultaneously, the reference electrode 8C maintains a constant potential in the electrolyte, controlling the electrode potential.

[0077] The experimental process for rotary triboelectric charging is as follows: start the electrochemical workstation 913, apply a negative voltage of -2V, and simultaneously operate the friction and wear tester to apply a load at the joint 63 of the friction part 6; then set the rotation speed and rotation radius of the rotating part 1. After setting the rotation speed of the tester's rotating platform, the drive shaft 2 will drive the conductive slip ring 3 rotor 31, the liquid pool 4, and the test piece 5 fixed in the liquid pool 4 to rotate at a uniform speed. This causes the friction ball 62 and the test piece 5 to undergo a rotational friction motion at the set voltage. During this process, the sensor collects the rotational motion signal in real time, the friction and wear tester's electronic equipment begins to record the friction force and / or friction coefficient during the rotational friction motion, and the electrochemical workstation 9 records the current during the friction motion in real time until the friction coefficient is observed to gradually decrease to a super-slip state and remain stable.

[0078] In the related art, the layout of three ceramic balls and a circular ring disk is used. This requires extremely high alignment of the three balls' centers of gravity and the center of the ring, and thus the alignment effect cannot be guaranteed. If the three ceramic balls and the center of the ring cannot be accurately aligned, eccentricity will cause multiple wear marks on the surface of the ring disk, which is not conducive to surface analysis of the specimen after the friction test. In the device of the present application, however, there is only one rubbing ball 62. The difficulty of aligning the rubbing ball 62 with the specimen 5 is significantly reduced, making it easier to achieve the alignment effect, thereby ensuring more accurate results of rotational friction tests conducted based on the device of the present application.

[0079] Furthermore, in related art, the structure leaves the brushes exposed, and dust and moisture in the air can affect the resistivity between the brushes and the motor shaft. This can cause instability in the applied voltage, regardless of whether power is supplied by a DC power supply or an electrochemical workstation, resulting in poor repeatability of experimental results. In the device of the present application, the stator 32 of the conductive slip ring 3 also serves as a protective device, reducing the ingress of dust and moisture in the air into the brushes between the rotor 31 and stator 32 of the conductive slip ring 3. This improves the stability of the voltage applied to the working electrode 8B and the reference electrode 8C, thereby enhancing the reproducibility of experimental results.

[0080] Furthermore, in related art, the structure is configured such that the graphite electrode (reference electrode 8C) is placed directly above the workpiece (working electrode 8B). As a result, graphite chips from the graphite electrode, which oxidize and peel off, remain directly on the workpiece surface, severely contaminating the ball-disk contact area and interfering with the friction test results. In contrast, in the apparatus of the present application, the working electrode 8B and the reference electrode 8C are effectively connected to the rotating specimen 5 and an auxiliary position nearby (the inner wall of the liquid pool 4), respectively. In other words, in the apparatus of the present application, the reference electrode 8C does not interfere with the surface of the specimen 5 (working electrode 8B), thereby achieving more accurate experimental results.

[0081] Reference Figure 6 During the test, the sudden drop in the friction coefficient and its subsequent stabilization reflect two main processes: First, the surface of specimen 5 becomes negatively charged after a negative voltage is applied, attracting positive charges from strong hydration, forming a hydrated adsorption layer on the surface of specimen 5. This hydration effect reduces friction, resulting in the sudden decrease in the friction coefficient. Second, triboelectrochemical reactions lead to slow anodic oxidation of the ball holder 61 and slow cathodic precipitation of the electrolyte solution. These reactions form a triboelectrochemical reaction film on the surface of specimen 5, causing the friction coefficient to gradually decrease and then stabilize. The synergistic coupling of these two factors creates a super-slip or ultra-low friction state between specimen 5 and the friction ball 62.

[0082] In an electrochemical system, when a voltage is applied to charge the surface of specimen 5 (positive or negative), water molecules are attracted to the charged surface due to their polarity (oxygen atoms are negatively charged, hydrogen atoms are positively charged). These water molecules are arranged in an orderly fashion, forming a structure known as a "hydration layer." This layer is primarily composed of water molecules, interconnected by hydrogen bonds and forming hydrogen bonds with charged groups or atoms on the surface. The ordered structure of the hydration layer significantly reduces direct contact between the two friction surfaces, thereby reducing friction and wear. This hydration layer acts as a "lubricating pad," allowing the surfaces to slide against each other with minimal resistance. Furthermore, the hydration layer forms a "buffer layer" between the two surfaces, effectively reducing adhesion caused by chemical bonds and physical adsorption. The formation of the hydration adsorption layer is accompanied by the attraction and accumulation of positive and negative charges. These charges further reduce the electrostatic interactions between the friction surfaces (the contact surface between specimen 5 and the counter-friction ball 62) through a shielding effect.

[0083] At the same time, the hydration layer provides load-bearing capacity through its thickness and density. Between the two interacting surfaces (the contact surface of the specimen 5 and the counter-ball 62), this layer of hydrated water molecules can support loads normal to the surfaces, reducing direct contact and the associated mechanical wear. The load-bearing capacity of the hydration layer depends on its integrity and stability, which is generally determined by the applied electric field strength and the thickness of the hydration layer.

[0084] During the experiment, the shear force mainly acts in the horizontal direction of the hydration layer, e.g. Figure 6 As shown in Figure 2, when one surface moves relative to another, the hydration layer must adjust its structure to accommodate the motion, reducing direct friction between the surfaces through internal sliding. The ordered structure of the hydration layer makes shearing between the surfaces easier than in direct metal-to-metal contact because the interactions between water molecules in the hydration layer are much weaker than the interactions between metal atoms.

[0085] During the experiment, shear forces acted primarily horizontally across the hydration layer. When one surface moves relative to another, the hydration layer must adjust its structure to accommodate the motion, reducing direct friction between the surfaces through internal sliding. The ordered structure of the hydration layer makes shearing between the surfaces easier than in direct metal-to-metal contact, because the interactions between water molecules in the hydration layer are much weaker than those between metal atoms.

[0086] Furthermore, the triboelectrochemical reaction is described as follows:

[0087] Triboelectrochemical reactions are complex phenomena involving electrochemical and mechanical interactions at tribointerfaces. These reactions are enhanced by friction and relative motion. In tribopairs involving metal surfaces, applying voltage can promote or modify the electrochemical properties of the materials, thereby affecting friction and wear behavior.

[0088] Reference Figure 7 In an electrochemical tribosystem, an oxidation reaction occurs on the surface of an anode connected to the positive electrode of a power source. This oxidation reaction involves the loss of electrons from surface metal atoms, converting them into metal ions. These metal ions may dissolve in the surrounding electrolyte or react with ambient oxygen to form metal oxides. This process forms an oxide film or thin layer on the metal surface, which may provide lubrication or prevent further chemical reactions.

[0089] In the system, the surface that acts as the cathode undergoes a reduction reaction, and the metal ions in the electrolyte may be reduced on the surface and deposited into metal elements, forming a protective layer or lubricating layer. In some cases, water electrolysis may occur at the cathode, producing hydrogen ( ), this hydrogen generation may affect the lubrication effect.

[0090] The friction-shear effect is a phenomenon in which the relative motion of the frictional contact generates shear stress, which affects the electrochemical reaction. Shear forces can first alter the surface microstructure, making certain areas more susceptible to oxidation or reduction. In some cases, shear can cause the protective film to break, exposing new material surfaces and restarting the electrochemical reaction process. Furthermore, shear forces can promote the transfer of substances between surfaces, increase local temperature and energy, and accelerate the kinetics of electrochemical reactions. Wear particles generated during the friction process may act as bridges in the electrochemical reaction, promoting electron transfer or changing the surface chemical composition.

[0091] As the electrochemical reaction proceeds, the metal atoms on the surface of the anode, exposed to a positive voltage, lose electrons and oxidize, forming a metal oxide layer. In tribology, this oxide layer is generally considered to possess lubricating properties because its relatively low hardness allows it to act as a solid lubricant. Simultaneously, the electrolyte solution undergoes a reduction reaction on the surface of the workpiece, acting as the cathode, resulting in the formation of a mixed triboelectrochemical reaction film at the contact interface. This film, due to its unique chemical and structural properties, can significantly reduce the coefficient of friction. Certain oxides can act as a sliding layer during the friction process, while the reduction deposition of metals may improve the surface microtopography and reduce surface roughness. As this reaction film forms and stabilizes, the friction coefficient gradually decreases and stabilizes. This stability is primarily due to the reaction film mechanically and chemically stabilizing the contact interface, providing more uniform and predictable friction behavior.

[0092] The in-situ generated triboelectrochemical reaction film in this experiment has a thickness of about 100-200 nm, is amorphous as a whole, has an elastic modulus of about 50 GPa, and a hardness of about 1 GPa.

[0093] The rotary triboelectric charging device provided in the embodiments of the present application effectively transmits current and voltage from a fixed position in the electrochemical workstation to the rotating reference electrode 8C and specimen 5 (working electrode 8B) in the liquid reservoir 4. This device effectively avoids the entanglement and twisting of the wires connecting the electrochemical workstation and the electrodes during rotation. In the device of the embodiments of the present application, the auxiliary electrode 8A is connected to the base 611, ensuring a uniform and stable voltage between the ball holder 61 and the specimen 5, allowing it to be used as the voltage between the triboelectric ball 62 and the specimen 5, thereby ensuring the accuracy and rationality of the applied electric field and the charging position.

[0094] The rotating triboelectric device provided in the embodiments of the present application can effectively control the voltage intensity at the rotating friction interface between the friction ball 62 and the specimen 5 through an applied electric field. By applying positive or negative voltages of varying magnitudes, the present application investigates their effects on frictional properties, aiming to achieve ultra-low friction and liquid super-lubricity on non-insulating surfaces. To address the technical challenges associated with electrification during rotational motion, the present application utilizes a clever structural design of the friction portion 6 and the use of a conductive slip ring 3, effectively connecting the working electrode 8B and the reference electrode 8C, respectively, to the rotating specimen 5 and its adjacent auxiliary location (the inner wall of the liquid reservoir 4). The present application's solution successfully achieves ultra-low friction (friction coefficient as low as 0.02) in electrolyte solutions on metal surfaces and super-lubricity (friction coefficient as low as below 0.01) in electrolyte solutions on semiconductor material surfaces. The triboelectric device provided in this application overcomes the ultra-low friction phenomenon that previous technologies could not achieve at the macroscale, expands the application scope of electronically controlled friction research, and provides a new solution for friction control of industrial materials.

[0095] The mechanism of the super-lubricity achieved by the present invention is primarily attributed to the synergistic coupling of strong hydration and the triboelectrochemical reaction film. This system can achieve an ultra-low friction state in boundary lubrication, mixed lubrication, and hydrodynamic lubrication stages, significantly reducing the friction coefficient and wear rate by more than an order of magnitude. This super-lubricity is not only stable and reliable, but the in-situ formed triboelectrochemical reaction film also possesses moderate mechanical strength. This enables the rotary triboelectrification device provided by the embodiments of the present application, or the test piece 5 / component constructed based on the rotary triboelectrification device provided by the present application, to be applied in environments such as high-end equipment manufacturing, deep-sea components, and marine systems.

[0096] It should be emphasized that this application not only covers a three-electrode point-contact rotary friction electric control system composed of a test specimen 5 made of a metal / alloy / semiconductor material, a metal or alloy base 611, a friction ball 62 made of a polymer material, and a liquid lubricant such as an electrolyte solution, but also protects similar two-electrode rotary friction electric control systems; that is, in the rotary friction charging device provided in the embodiment of this application, the above-mentioned rotary friction test process can also be achieved in the absence of a reference electrode 8C. In addition, the present invention also includes corresponding test specimens 5, ball holders 61, friction balls 62, and lubricants made of other materials, as well as applications covering various friction interface forms such as point contact, line contact, and surface contact.

[0097] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in 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.

[0098] The above embodiments merely illustrate several implementation methods of the present application. 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 a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A rotary friction electrification device, characterized in that: The device comprises a rotating part (1), a transmission shaft (2), a conductive slip ring (3), a liquid pool (4), a friction part (6) and a support part (7), wherein: One end of the transmission shaft (2) is fixed to the rotating part (1), and the other end of the transmission shaft (2) is fixed to the liquid pool (4); The inner cavity of the liquid pool (4) is provided with a fixing seat (41) for fixing the test piece (5); The rotor (31) of the conductive slip ring (3) is sleeved on the transmission shaft (2) and fixed, and the stator (32) of the conductive slip ring (3) is fixed by the support portion (7); The friction portion (6) is fixedly connected to the support portion (7), and the friction portion (6) is placed above the fixing seat (41); The friction part (6) is fixed with an auxiliary electrode (8A), the inner cavity of the liquid pool (4) is fixed with a reference electrode (8C), and the fixing seat (41) is connected with a working electrode (8B); the auxiliary electrode (8A) is electrically connected to an electrochemical workstation, the reference electrode (8C) and the working electrode (8B) are both electrically connected to the rotor (31) of the conductive slip ring (3), and the stator (32) of the conductive slip ring (3) is electrically connected to the electrochemical workstation (9).

2. The device according to claim 1, characterized in that The fixing seat (41) is coaxially fixed to the liquid pool (4) on the bottom surface of the inner cavity of the liquid pool (4), and the outer bottom end of the liquid pool (4) is coaxially fixed to the transmission shaft (2).

3. The device according to claim 1, characterized in that The friction part (6) includes a friction ball (62), a ball holder (61) and a joint (63), wherein: The joint (63) is fixed to the ball holder (61), the ball holder (61) is fixed to the support portion (7), and the rubbing ball (62) is fixed to the ball holder (61).

4. The device according to claim 3, characterized in that The ball holder (61) comprises a base (611) and a ball holder cage (612), wherein: The rubbing ball (62) is fixed to the base (611), the ball support cage (612) is arranged outside the rubbing ball (62), and the ball support cage (612) is detachably connected to the base (611); The ball cage (612) is open at one end away from the base (611), and the rubbing ball (62) protrudes from the open end of the ball cage (612).

5. The device according to claim 4, characterized in that One end of the joint (63) away from the base (611) is connected to a force sensor, and the joint (63) is capable of receiving a vertical load force provided externally.

6. The device according to claim 4 or 5, characterized in that The support portion (7) comprises a fixed base (71) and a support rod, wherein: The support rod is fixed to the fixed base (71), the support rod is vertically arranged and is higher than the top of the liquid pool (4); The joint (63) is connected to the support rod via a displacement assembly, and the displacement assembly can drive the joint (63) to move closer to or away from the fixing seat (41) in a vertical direction.

7. The device according to claim 6, characterized in that The support portion (7) further includes a support frame (72), wherein: The support frame (72) is fixedly connected to the fixed base (71); The support frame (72) is fixedly connected to the stator (32) of the conductive slip ring (3).

8. The device according to claim 7, characterized in that The support frame (72) includes support legs (721) and a fixing ring (722), wherein: The supporting legs (721) are fixed to the fixing seat (41), and at least two supporting legs (721) are provided; The fixing ring (722) is sleeved on the outside of the conductive slip ring (3), and the fixing ring (722) is fixedly connected to each of the supporting legs (721); The support frame (72) is no higher than the stator (32) of the conductive slip ring (3).

9. The device according to any one of claims 1 or 2, characterized in that The fixing seat (41) is an annular clamp, and the connecting ends of the annular clamp are connected by bolts.

10. The device according to claim 1 or 2, characterized in that The liquid pool (4) can accommodate electrolyte.

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