Patent ID: 12247957

In the drawings,1000: pin-on-disk type friction pair;1010: acoustic emission sensor;1020: high-speed camera;1030: thermal infrared imager;1040: base;1050: L-shaped cantilever beam;1051: column;1052: horizontal beam;1100: disk specimen;1200: pin specimen;2000: clamping mechanism;3000: axial force loading mechanism;4000: rotating power mechanism;5000: current loading mechanism;5100: conductive terminal;5200: resistor;5300: power supply;5400: ammeter;5500: current;5600: Ampere force;6000: force measuring mechanism;7000: centering mechanism;7100: support platform;7110: rotating shaft;7111: first shaft section;7113: cross-shaped hinge shaft;71131: first hinge shaft;71132: second hinge shaft;7114: push rod;7120: first guide rail;7112: second shaft section;71121: annular boss;7200: rotating disk;7210: second guide rail;7300: pin member;7310: rod;7320: head;8000: magnetic field generating mechanism;9000: levelness calibration mechanism;9100: cylinder;9200: annular cylinder;9300: support frame; and9400: horizontal plate.

DESCRIPTION OF EMBODIMENTS

The present invention is further described in detail below with reference to the embodiments and drawings; however, the embodiments of the present invention are not limited thereto.

Embodiment

Referring toFIGS.2to18, a plurality of specific embodiments of a pin-on-disk type in-situ current-carrying friction testing system of the present invention are shown. The pin-on-disk type in-situ current-carrying friction testing system of the present invention includes a pin-on-disk type friction pair1000, a clamping mechanism2000, an axial force loading mechanism3000, a rotating power mechanism4000, a current loading mechanism5000, a force measuring mechanism6000, a support platform7100, a conductive terminal5100, and a magnetic field generating mechanism8000. The pin-on-disk type friction pair1000includes a disk specimen1100and a pin specimen1200, the disk specimen1100is horizontally arranged on the support platform7100, the clamping mechanism2000is used to clamp the pin specimen1200, the pin specimen1200is vertically arranged after being clamped, and a center line of the pin specimen1200is perpendicular to an end face of the pin specimen1100facing the pin specimen1200(an upper end face of the disk specimen1100inFIG.2). The axial force loading mechanism3000is used to push the pin specimen1200to move along an axial direction of the disk specimen1100, so as to control a pressure between the pin specimen1200and the disk specimen1100; the rotating power mechanism4000is used to control a relative rotary motion between the pin specimen1200and the disk specimen1100, so that dynamic friction is formed; the force measuring mechanism6000is used to measure a force between the pin specimen1200and the disk specimen1100; the current loading mechanism5000is used to load a current, after the current is loaded, the current flows through a contact surface between the pin specimen1200and the disk specimen1100, the current loading mechanism5000includes a conductive terminal5100, one end of the conductive terminal5100abuts against an annular sidewall of the disk specimen1100and is used to guide a current in the disk specimen1100to flow in a horizontal direction; the magnetic field generating mechanism8000is used to generate a magnetic field, and when the pin specimen1200and the disk specimen1100rotate relatively, the pin specimen1200, the conductive terminal5100, and the magnetic field generating mechanism8000are relatively stationary, and an Ampere force5600generated by a current5500flowing in a horizontal direction in the disk specimen1100under the action of the magnetic field faces the support platform7100, so that the disk specimen1100is tightly pressed on the support platform7100, and the purpose of fixing the disk specimen1100on the support platform7100is achieved.

The present invention is suitable for all conductive pin-on-disk type friction pairs1000. A force generated by a current in a magnetic field is utilized for clamping, which is simple to operate and will not damage the friction pairs. Especially for a sheet disk specimen1100, no radial clamping force is required, a contact area between the disk specimen1100and a support platform7100is large, and the force distribution is more uniform, which will not cause serious deformation of the disk specimen1100, so that the current-carrying friction performance of the disk specimen can be accurately measured.

In the present invention, the pin specimen1200and the disk specimen1100rotate relatively to form dynamic friction. In some embodiments, the disk specimen1100may be kept stationary, and the pin specimen1200may be driven to rotate by the rotating power mechanism4000. In other embodiments, as shown inFIG.2, the pin specimen1200may be kept stationary, and the disk specimen1100may be driven to rotate by the rotating power mechanism4000.

In the present invention, the force measuring mechanism6000may be configured based on a requirement. As shown inFIG.2, a two-dimensional force sensor capable of measuring a normal force and a lateral force between the disk specimen1100and the pin specimen1200is selected.

In the present invention, there are many specific options for the magnetic field generating mechanism8000. For example, a magnetic field may be generated by a current, or other methods in the prior art can be used to generate a magnetic field. The specific magnetic field intensity and direction may be selected based on a requirement, and the magnetic field generating mechanism8000with an adjustable magnetic field intensity is preferred to adjust a pressure of the disk specimen1100on the support platform7100to prevent the disk specimen1100from sliding relative to the support platform7100.

In the present invention, when the disk specimen1100is driven to rotate by the rotating power mechanism4000, if a center of the disk specimen1100is not concentric with a rotating shaft of the rotating power mechanism4000, the disk specimen1100is in an eccentric rotation state, which increases a static friction force between the disk specimen1100and the support platform7100and is not beneficial to the fixation of the disk specimen1100, and the disk specimen is likely to fall off particularly when rotating at a high speed. Therefore, in some embodiments, a centering mechanism7000is further provided for coaxially arranging a center line of the disk specimen1100and a rotating shaft7110of the support platform7100, that is, a center line of the disk specimen1100is coincident with a center line of the rotating shaft7110. There are many specific centering mechanisms7000. As shown inFIGS.3to7, the centering mechanism7000includes a support platform7100, a rotating disk7200, and a plurality of pin members7300. A rotating shaft7110extending along a center line of the support platform7100is provided in a middle of the support platform. A plurality of first guide rails7120penetrating through the support platform7100are arranged on the support platform7100in a circular array around the rotating shaft7110, the rotating disk7200is annular with a hollow center, the rotating disk7200is coaxially sleeved on an outer wall of the rotating shaft7110, a plurality of the second guide rails7210penetrating through the rotating disk7200are arranged on the rotating disk7200in a circular array around the rotating shaft7110, the pin members7300, the first guide rails7120and the second guide rails7210correspond to each other one by one, that is, each pin member7300corresponds to one first guide rail7120and one second guide rails7210, and the first guide rail7120and the second guide rail7210are tapered notches, that is, a distance between a wall surface of a notch of a guide rail and a center line of the rotating shaft7110increases or decreases progressively from one end of the guide rail to the other end of the guide rail. The pin member7300includes a rod7310and two heads7320at two ends of the rod7310, the rod7310of each pin member7300is inserted into a corresponding first guide rail7120and second guide rail7210, the two heads7320at two ends of the rod7310are positioned at two sides of the support platform7100and the rotating disk7200, and a size of the head7320is greater than a width of the notches of the first guide rail7120and the second guide rail7210. When the support platform7100and the rotating disk7200rotate relatively, the first guide rail7120guides the pin member7300to move in a first direction, the second guide rail7210guides the pin member7300to move in a second direction, the first direction and the second direction are both in a same plane, and an included angle between the first direction and the second direction is an acute angle or an obtuse angle, that is, the first direction and the second direction are neither parallel nor perpendicular. Therefore, when the rotating disk7200is rotated, all pin members7300move synchronously along the first guide rail7120of the support platform7100, so that the center line of the disk specimen1100is coincident with the center line of the rotating shaft7110.

In some embodiments, to increase a friction force between the disk specimen1100and the support platform7100, a contact surface between the support platform7100and the disk specimen1100may be roughened, for example, one side of the support platform7100facing the disk specimen1100is a rough surface.

In actual testing, there is a case where two planes (a top plane and a bottom plane) of the disk specimen1100are not parallel, for which, it is necessary to adjust a levelness of the disk specimen1100facing a plane of the pin specimen1200, i.e., to adjust a top plane of the disk specimen1100inFIG.2to be completely horizontal. Therefore, some modifications may be made to the rotating shaft7110to adjust an inclination angle of the support platform7100. In some embodiments, as shown inFIGS.8to10, the rotating shaft7110includes a first shaft section7111, a second shaft section7112, a cross-shaped hinge shaft7113, and a plurality of push rods7114, the cross-shaped hinge shaft7113is fixedly connected by a first hinge shaft71131and a second hinge shaft71132which are perpendicular to each other, the first shaft section7111is hinged to the first hinge shaft71131, and the second shaft section7112is hinged to the second hinge shaft71132, so that the first shaft section7111and the second shaft section7112can rotate in multiple directions, an annular boss71121is arranged on a peripheral sidewall of the second shaft section7112, a plurality of push rods7114are circumferentially arranged along the annular boss71121, each push rod7114passes through the annular boss71121and is threadedly connected to the annular boss71121, and center lines of all the push rods7114are parallel to a center line of the second shaft section7112. Therefore, an included angle between a center line of the support platform7100and a center line of the second shaft section7112, that is, the inclination angle of the support platform7100can be adjusted by the push rod7114, so as to adjust a levelness of the disk specimen1100facing an end face of the rotating shaft7110.

In addition, a level bubble is used to calibrate the levelness, requiring repeated adjustment of each push rod7114, which is time-consuming. Therefore, the present invention also provides a new levelness calibration mechanism9000that can quickly calibrate the levelness of the disk specimen1100. As shown inFIGS.11to14, the levelness calibration mechanism9000includes a cylinder body9100, an annular cylinder9200, a support frame9300, and a horizontal plate9400, the annular cylinder9200is carried in the cylinder body9100by the support frame9300, the annular cylinder9200and the cylinder body9100are coaxially arranged, and the second shaft section7112can be inserted into the annular cylinder9200and is in clearance fit with the annular cylinder. The horizontal plate9400is fixedly attached to the cylinder body9100in a detachable manner, such as in a threaded connection, such that the horizontal plate9400can move along a center line of the annular cylinder9200, and the center line of the annular cylinder9200is perpendicular to the horizontal plate9400and faces an end face of the annular cylinder9200. During the use, as shown inFIG.15, the second shaft section7112is inserted into the annular cylinder9200, so that the annular cylinder9200abuts against the annular boss71121, and then the horizontal plate9400is connected to the cylinder body9100. In this way, an end face of the disk specimen1100facing away from the rotating shaft7110can be attached to the horizontal plate9400, so that the end face of the disk specimen1100abutting against the horizontal plate9400is perpendicular to the center line of the second shaft section7112, and then the push rod7114is rotated to fix the support platform7100.

In the present invention, an intensity of a current flowing along a horizontal plane of the disk specimen1100may be increased by preventing the current from flowing along the rotating shaft7110, which is beneficial to enhancing a friction force between the disk specimen1100and the support platform7100, so as to avoid relative sliding between the disk specimen and the support platform. In some embodiments, an insulating component (7100,7200) may be provided to prevent the current from flowing along the support platform7100. The form and position of the insulating component may be set based on a requirement. For example, the support platform7100and the rotating disk7200are made of insulating materials, and the insulating part and the rotating disk may serve as the insulating component.

In the present invention, the conductive terminal5100may be a brush, and a number of the brushes may be selected based on a requirement, such as one, two, or more. When two or more conductive terminals5100are used, all the conductive terminals5100are arranged in parallel along a circumference of the disk specimen1100, each conductive terminal5100needs to be connected in series with a resistor5200to avoid short circuit of the conductive terminals5100. As shown inFIGS.16and17, to distribute the current uniformly among the conductive terminals5100, a resistor5200with an adjustable resistance value, i.e., a varistor, may be selected, and each varistor is connected in series with an ammeter5400to observe a current of each branch. When at least two conductive terminals5100are used, one magnetic field generating mechanism8000may be arranged, or each conductive terminal5100may be respectively matched with one magnetic field generating mechanism8000.

In the present invention, other in-situ testing equipment (1010,1020,1030) may be additionally arranged based on a requirement. For example, in some embodiments, as shown inFIG.18, an acoustic emission sensor1010, a high-speed camera1020, and a thermal infrared imager1030are further provided, the high-speed camera1020may be used to capture transient phenomena of electric arcs, the thermal infrared imager1030may be used to collect temperature information near a current-carrying friction pair, the acoustic emission sensor1010may collect acoustic signals generated when a material surface is damaged, the acoustic emission sensor1010may be used to monitor the wear of bearings, engines and tools, and the level of damage to buildings. These scenarios involve the generation of cracks, material breakage, and breaking of atomic bonds, which are similar to friction and wear. Therefore, the integration of the acoustic emission sensor1010, the high-speed camera1020, the thermal infrared imager and other in-situ testing equipment may help to more thoroughly study the current-carrying friction failure mechanism.

In some embodiments, to adjust a speed of a relative sliding between the disk specimen1100and the pin specimen1200, an L-shaped cantilever beam1050may be provided to carry the pin specimen1200and drive the pin specimen1200to rotate along a column1051positioned outside the disk specimen1100and extending in a vertical direction, thereby changing a distance between the pin specimen1200and a center of the disk specimen1100. As shown inFIG.2, the rotating power mechanism4000is carried in the base1040, the L-shaped cantilever beam1050includes a column1051and a horizontal beam1052, one end of the column1051is connected to the base1040, the other end is connected to the horizontal beam1052, the horizontal beam1052can rotate around a central axis of the column1051, and the pin specimen1200is carried on the horizontal beam1052. When the horizontal beam1052rotates around the central axis of the vertical column1051, a distance between a center line of the pin specimen1200and a center line of the rotating shaft7110changes accordingly, thereby adjusting a linear velocity of the pin specimen1200relative to the disk specimen1100.

The above descriptions are merely preferred specific embodiments of the present invention, however, the protection scope of the present invention is not limited thereto, and any modifications and substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by examples of the present invention shall fall within the protection scope of the present invention.