Rail transit grounding carbon brush device based on high-purity rare earth and graphite compound and method thereof

Abstract

The present application relates to the field of rail transit vehicle carbon brush technology, in particular to a rail transit grounding carbon brush device based on high-purity rare earth and graphite compound and a method thereof, comprising a grounding device, the grounding device comprising a brush holder, a pre-tightening piece arranged inside the brush holder and used for applying a pre-tightening force to the graphite carbon brush, a connecting piece connected to the bottom of the pre-tightening piece, and an electromagnetic driving piece used for regulating the pre-tightening force intensity of the pre-tightening piece through the connecting piece. The present application regulates the compression of the pressing plate on the first spring by constructing the linkage compensation structure of the electromagnetic driving piece, the connecting piece and the pre-tightening piece, so as to realize the automatic compensation of the pre-tightening force. The structure makes the contact pressure of the graphite carbon brush stable after wear, and avoids the poor conduction caused by insufficient pressure.

Description

Technical Field

[0001] This invention relates to the field of carbon brush technology for rail transit vehicles, and more specifically, to a grounding carbon brush device and method for rail transit vehicles based on high-purity rare earth and graphite compounds. Background Technology

[0002] The grounding carbon brush device for rail transit is a key component ensuring the electrical safety and equipment stability of vehicles. Installed on the bogie, this device establishes a low-resistance return path for traction current, leakage current, and lightning surge current through the sliding contact between the carbon brush and the grounding ring or track. Its core function is to prevent stray currents from corroding bearings and the car body structure, and to ensure potential equilibrium between the vehicle and the ground. The device consists of highly conductive and wear-resistant carbon materials, constant-voltage springs, and insulating components. It possesses self-lubricating properties, adapts to vehicle vibration, and effectively suppresses electromagnetic interference, making it a crucial guarantee for the safe and reliable operation of trains.

[0003] Patent application CN202322325699.6 discloses a carbon brush structure for rail transit vehicles, relating to the field of carbon brush structures for rail transit vehicles. The structure includes a carbon brush, a first support plate mounted on the top of the carbon brush, first springs mounted at both ends of the top of the first support plate, a second spring mounted in the middle of the top of the first support plate, a second support plate fixedly mounted on the top of the first and second springs, a top plate mounted on the top of the second support plate, and a third power supply hole opened inside the top plate through which the positive and negative terminals of the motor pass. Detection blocks are mounted on both sides of the carbon brush to automatically detect the service limit of the carbon brush.

[0004] However, existing grounding carbon brush devices for rail transit only use simple springs for pre-tensioning, without an automatic pre-tensioning force compensation structure. As the carbon brush wears down and shortens in length, the springs become loose and the contact pressure becomes unbalanced, which can easily lead to poor conductivity. Furthermore, the carbon brushes do not use high-purity rare earth-doped graphite-based composite materials, resulting in poor wear resistance and conductivity. In addition, there is no matching dust treatment structure, and the wear debris can easily accumulate and interfere with the operation of the equipment. Ultimately, this leads to a short service life for the carbon brushes and the entire device, making it difficult to meet the high reliability requirements of rail transit.

[0005] In view of this, we propose a grounding carbon brush device and method for rail transit based on high-purity rare earth and graphite compounds. Summary of the Invention

[0006] The purpose of this invention is to provide a grounding carbon brush device and method for rail transit based on high-purity rare earth and graphite compounds. By constructing a linkage compensation structure of electromagnetic drive components, connecting components and pre-tightening components, and adjusting the pressure plate to squeeze the first spring, automatic compensation of pre-tightening force is achieved, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A grounding carbon brush device for rail transit based on high-purity rare earth and graphite compounds includes a grounding device, which includes a brush holder, a pre-tightening member disposed inside the brush holder for applying pre-tightening force to the graphite carbon brush, a connector connected to the bottom of the pre-tightening member, and an electromagnetic drive member for adjusting the pre-tightening force intensity of the pre-tightening member through the connector.

[0009] The preload includes a lead screw, a pressure plate sleeved on the outside of the lead screw, a first spring disposed on the bottom surface of both ends of the pressure plate, and a positioning plate that slides on the outside of the lead screw and is used to accommodate the graphite carbon brush.

[0010] In the above configuration, after the bottom end of the graphite carbon brush rubs and wears against the contact element, the lead screw is driven to rotate and adjust the height of the pressure plate, squeezing the first spring to continuously apply preload to the graphite carbon brush.

[0011] The connector includes a rotating shaft, a ratchet rotatably connected to the top of the rotating shaft and connected to the lead screw, several pawls meshing with the ratchet, a sleeve sleeved on the outside of the rotating shaft, and two symmetrically threaded levers connected to the sleeve wall. The rotating shaft wall has two spiral grooves for the levers to slide.

[0012] In the above configuration, when the electromagnetic drive is energized and generates electromagnetic attraction to move the sleeve downward, the lever slides along the spiral groove and drives the rotating shaft to rotate. Through the meshing transmission of the ratchet and pawl, the lead screw rotates at a fixed angle, thereby keeping the preload of the preload constant.

[0013] In the technical solution of the present invention, the brush holder includes a frame beam and a sleeve fixedly connected to the bottom of the outer wall of the frame beam by bolts. The side wall of the frame beam is provided with a sliding groove and the bottom is provided with an airflow cavity. A guide plate is welded to the bottom of the front cavity of the airflow cavity on the frame beam. A filter screen is snapped into the end cavity of the airflow cavity on the frame beam. A dust collection groove is snapped and fixed to the bottom of the frame beam below the filter screen.

[0014] In the above setup, the frame beam serves as the main load-bearing foundation. Through the cooperation of various components, the device is installed, fixed, and guided, while also completing the directional guidance, filtration, and centralized collection of carbon brush shavings, ensuring the stable and precise operation of the device.

[0015] In the technical solution of the present invention, the pre-tightening component further includes two slide rods slidably connected to the pressure plate and sleeved in the first spring, a ring piece tightly sleeved on the top of the slide rod, a pair of limiting blocks elastically embedded in the positioning plate, a second spring disposed at the end of the limiting block, and a positioning screw sleeved in the second spring.

[0016] In the technical solution of the present invention, the upper and lower ends of the lead screw are respectively rotatably connected to the groove walls at the upper and lower ends of the slide groove. The bottom end of the slide rod is snapped and fixed to the top surface of the positioning plate. A positioning groove is provided through the top of the positioning plate. The limiting block is slidably connected to the round holes in the groove walls at the left and right ends of the positioning groove. The end of the limiting block is conical. One end of the second spring is bonded and fixed to the limiting block, and the other end is bonded and fixed to the hole wall of the round hole in the groove wall of the positioning groove. The positioning screw is threadedly connected to the outer wall of the positioning plate. After the positioning screw is fixed, its end abuts against the limiting block, thereby limiting the contraction range of the limiting block.

[0017] In the above configuration, the matching arrangement of each component of the pretensioner enables the transmission adjustment and constant compensation of the carbon brush pretension force, while also providing precise motion guidance and secure carbon brush mounting limit, ensuring stable application of pretension force and reliable carbon brush installation and operation.

[0018] In the technical solution of the present invention, the connecting member further includes a third spring disposed on the inner wall of the circular groove at the end of the pawl and the end of the rotating shaft, a connecting rod snapped and fixed to the top surface of the ratchet and coaxially connected to the bottom end of the lead screw, and a top cover snapped and fixed to the top of the rotating shaft and rotatably connected to the bottom surface of the internal partition of the frame beam. The two ends of the third spring are adhered and fixed to the inner wall of the circular groove at the end of the pawl and the end of the rotating shaft, and a rotating groove is provided on the bottom surface of the sleeve.

[0019] In the above configuration, the matching of each component of the connector enables precise conversion from vertical motion to rotational motion and unidirectional fixed-angle transmission, stably transmitting power to the lead screw and ensuring constant compensation of the preload of the preload component.

[0020] In the technical solution of the present invention, the electromagnetic drive component includes a cylindrical valve, a positioning cylinder sleeved on the outside of the cylindrical valve, a fourth spring disposed on the bottom surface of the cylindrical valve, a transmission rod disposed on the top of the cylindrical valve and having a T-shaped longitudinal section, and a magnetic coil sleeved on the outside of the positioning cylinder.

[0021] In the technical solution of the present invention, the cylindrical valve slides inside the positioning cylinder, the bottom end of the positioning cylinder is snapped and fixed to the inner bottom surface of the frame beam, the elastic force provided by the fourth spring pushes the transmission rod to move upward, the top end of the transmission rod is rotatably connected to the inside of the rotating groove, and the magnetic coil is fixedly connected to the front outer wall of the frame beam by bolts.

[0022] In the above configuration, the matching arrangement of each component of the electromagnetic drive realizes power triggering, execution and transmission, takes into account sliding guidance and automatic reset, and avoids linkage interference from manual operation, providing stable and controllable power support for constant preload compensation.

[0023] In the technical solution of the present invention, the graphite carbon brush includes a carbon brush body, three copper conductive ribs that are slidably embedded inside the carbon brush body and evenly distributed along the axial direction, a copper connecting piece welded to the top of the three copper conductive ribs and snapped and fixed to the top surface of the carbon brush body, and a wire welded to the top surface of the copper connecting piece.

[0024] In the technical solution of the present invention, the carbon brush body is integrally formed in a stepped cylindrical structure and is made of high-purity rare earth doped graphite-based composite material. The bottom end of the carbon brush body is provided with an arc-shaped contact surface, the top end of the carbon brush body is integrally formed with a connector strip, and the outer walls on the left and right sides of the top end of the carbon brush body are provided with conical grooves.

[0025] The above setup uses the carbon brush body as the basic carrier to reduce overall contact resistance, improve current conduction stability, realize current convergence and grounding output, and adapt to the mounting and positioning requirements.

[0026] On the other hand, the present invention also provides a grounding method for a rail transit carbon brush based on high-purity rare earth and graphite compounds, which includes the following steps using the above-mentioned rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds:

[0027] S1. First, install and position the carbon brush. Insert the graphite carbon brush vertically from top to bottom into the positioning groove of the positioning plate in the pre-tightening part. During the insertion process, the conical groove wall of the graphite carbon brush squeezes the limiting block, causing the limiting block to compress the second spring and retract into the round hole of the positioning groove wall.

[0028] S2. After the graphite carbon brush is inserted into place, the limiting block is reset and inserted into the conical groove under the elastic restoring force of the second spring, thereby achieving axial limiting of the graphite carbon brush. Then, tighten the positioning screw so that the end of the positioning screw abuts against the limiting block, limiting the retraction stroke of the limiting block and completing the mounting and fixing of the graphite carbon brush.

[0029] S3. Next, perform initial pressure adjustment. Install the grounding device as a whole at the axle-end grounding bracket of the rail transit vehicle, so that the bottom end of the graphite carbon brush abuts against the contact surface. During the contact process, the graphite carbon brush drives the positioning plate to move up and squeeze the first spring. Then, manually rotate the lead screw from the top of the lead screw to adjust the vertical height of the pressure plate outside the lead screw. By adjusting the compression of the first spring by the pressure plate, the contact pressure between the graphite carbon brush and the friction disc is precisely adjusted to 0.3-0.5MPa.

[0030] S4. After the device is put into use, the bottom end of the graphite carbon brush will continuously rub against the contact surface, causing wear. The length of the graphite carbon brush will shorten, causing the positioning plate to move downward under the elastic restoring force of the first spring, reducing the compression of the first spring. The contact pressure between the graphite carbon brush and the friction disc will be lower than the lower limit of 0.3MPa. At this time, the magnetic coil in the electromagnetic drive component will be energized and generate electromagnetic attraction. Under the action of electromagnetic attraction, the column valve will overcome the elastic restoring force of the fourth spring and drive the transmission rod to move vertically downward along the positioning cylinder.

[0031] S5. When the transmission rod moves downward, its top end drives the sleeve in the connecting part to move vertically downward synchronously through the rotating groove. During the downward movement of the sleeve, the lever on its tube wall slides along the spiral groove on the shaft wall and drives the shaft to rotate around its own axis. The rotation of the shaft drives the ratchet at its top end to rotate synchronously. The ratchet meshes with the pawl and drives the connecting rod to rotate at a fixed angle. The connecting rod drives the screw to rotate synchronously at a fixed angle, causing the pressure plate to move vertically downward along the screw and squeeze the first spring again. This restores the contact pressure between the graphite carbon brush and the friction disc to the set range of 0.3-0.5MPa, realizing automatic constant compensation of the preload.

[0032] S6. When the bottom of the graphite carbon brush is worn down to near the bottom of the internal copper conductive rib, stop the device and replace the graphite carbon brush. First, loosen the positioning screw so that the end of the positioning screw is no longer in contact with the limit block. Then, pull out the graphite carbon brush vertically to complete the disassembly.

[0033] S7. After disassembly, manually rotate the lead screw again from the top to move the pressure plate vertically upward along the lead screw to reset it, in preparation for the installation of the new graphite carbon brush.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. This rail transit grounding carbon brush device and method based on high-purity rare earth and graphite compounds, by constructing a linkage compensation structure of electromagnetic drive components, connectors and pre-tightening components, and regulating the pressure plate to squeeze the first spring, achieves automatic compensation of pre-tightening force. This structure ensures that the contact pressure of the graphite carbon brush remains stable at 0.3-0.5MPa after wear, avoiding poor conductivity caused by insufficient pressure. At the same time, it avoids the problems of easy failure of motors under the vibration conditions of rail transit and the need for complex electrical control adaptation, ensuring the continuity and stability of grounding conductivity, and making the structure more suitable for the complex operating environment of rail transit.

[0036] 2. The grounding carbon brush device and method for rail transit based on high-purity rare earth and graphite compounds. The graphite carbon brush adopts high-purity rare earth doped graphite-based composite material, with built-in copper conductive ribs and a dust treatment structure for the brush holder. This not only improves the wear resistance and conductivity of the carbon brush, but also realizes the centralized collection of wear debris. Combined with the simple structure without motor, it further extends the overall service life of the device and meets the lightweight and high reliability requirements of rail transit. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0038] Figure 2 This is a cross-sectional view of the overall structure of the present invention;

[0039] Figure 3 This is a cross-sectional schematic diagram of the brush holder structure in this invention;

[0040] Figure 4 This is a schematic diagram of the pre-tightening component in the present invention;

[0041] Figure 5 This is a partial structural breakdown diagram of the pretensioner in this invention;

[0042] Figure 6 This is a schematic diagram of the connector structure in this invention;

[0043] Figure 7 This is a cross-sectional schematic diagram of the connector structure in this invention;

[0044] Figure 8 This is a cross-sectional schematic diagram of the electromagnetic drive component in this invention;

[0045] Figure 9 This is a structural breakdown diagram of the carbon brush body in this invention;

[0046] Explanation of reference numerals in the attached figures:

[0047] 100. Grounding device; 110. Brush holder; 111. Frame beam; 1110. Slide groove; 112. Sleeve; 113. Guide plate; 114. Filter screen; 115. Dust collection trough; 120. Pre-tightening component; 121. Lead screw; 122. Pressure plate; 123. Slide rod; 124. Ring plate; 125. First spring; 126. Positioning plate; 1260. Positioning groove; 127. Limiting block; 128. Second spring; 129. Positioning screw; 130. Connecting component; 131. Rotating shaft; 1310. Spiral groove; 13 2. Ratchet; 133. Pawl; 134. Third Spring; 135. Connecting Rod; 136. Top Cover; 137. Sleeve; 1370. Rotating Slot; 138. Lever; 140. Electromagnetic Drive Component; 141. Cylindrical Valve; 142. Positioning Cylinder; 143. Fourth Spring; 144. Transmission Rod; 145. Magnetic Coil; 150. Graphite Carbon Brush; 151. Carbon Brush Body; 1510. Connecting Strip; 1511. Conical Slot; 152. Copper Conductive Rib; 153. Copper Connecting Plate; 154. Wire. Detailed Implementation

[0048] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0049] Please see Figures 1-3 As shown, this embodiment provides a technical solution:

[0050] A grounding carbon brush device for rail transit based on high-purity rare earth and graphite compounds includes a grounding device 100. The grounding device 100 includes a brush holder 110, a pre-tightening member 120 disposed inside the brush holder 110 for applying pre-tightening force to a graphite carbon brush 150, a connector 130 connected to the bottom of the pre-tightening member 120, and an electromagnetic drive member 140 for adjusting the pre-tightening force intensity of the pre-tightening member 120 through the connector 130.

[0051] Specifically, the brush holder 110 includes a frame beam 111 and a sleeve 112 that is fixedly connected to the bottom of the outer wall of the frame beam 111 by bolts. The side wall of the frame beam 111 has a sliding groove 1110 and the bottom has an airflow cavity. A guide plate 113 is welded to the bottom of the front opening of the airflow cavity on the frame beam 111. A filter screen 114 is snapped into the end opening of the airflow cavity on the frame beam 111. A dust collection groove 115 is snapped and fixed to the bottom of the frame beam 111 below the filter screen 114.

[0052] Furthermore, the frame beam 111 serves as the main load-bearing structure of the brush holder, providing a foundation for the installation and arrangement of various components. The sleeve 112 assists the brush holder in achieving adaptation and fixation with the external structure, improving the installation stability of the device. The slide groove 1110 provides motion guidance for the transmission components of the pre-tightening parts, ensuring their operating accuracy. The airflow cavity provides a flow channel for the abrasive dust generated by the carbon brush operation, realizing the directional guidance of dust. The guide plate 113 guides the airflow and dust in the airflow cavity, causing them to move towards the filter screen. The filter screen 114 filters and intercepts the dust flowing in the airflow cavity, preventing the dust from spreading outward. The dust collection trough 115 collects the carbon brush abrasive dust intercepted by the filter screen, realizing the centralized collection and cleaning of dust.

[0053] In the above setup, the frame beam 111 serves as the main load-bearing foundation. Through the cooperation of various components, the device is installed and fixed, and the transmission is guided. At the same time, the carbon brush shavings are directionally guided, filtered, and collected in a centralized manner, ensuring the stable and accurate operation of the device.

[0054] Please see Figures 4-5As shown, in this embodiment, the preload 120 includes a lead screw 121, a pressure plate 122 sleeved on the outside of the lead screw 121, first springs 125 disposed on the bottom surfaces of both ends of the pressure plate 122, and a positioning plate 126 sliding on the outside of the lead screw 121 and used to accommodate the graphite carbon brush 150. After the bottom end of the graphite carbon brush 150 rubs and wears against the contact element, the lead screw 121 is driven to rotate and adjust the height of the pressure plate 122, squeezing the first springs 125 to continuously apply preload force to the graphite carbon brush 150.

[0055] Specifically, the pretensioner 120 also includes two slide rods 123 that are slidably connected to the pressure plate 122 and sleeved in the first spring 125, a ring piece 124 tightly sleeved on the top of the slide rod 123, a pair of limiting blocks 127 that are elastically embedded in the positioning plate 126, a second spring 128 provided at the end of the limiting block 127, and a positioning screw 129 sleeved in the second spring 128.

[0056] Furthermore, the upper and lower ends of the lead screw 121 are rotatably connected to the upper and lower end walls of the slide groove 1110, respectively. The bottom end of the slide rod 123 is snapped and fixed to the top surface of the positioning plate 126. A positioning groove 1260 is provided through the top of the positioning plate 126. The limiting block 127 is slidably connected to the round holes in the left and right end walls of the positioning groove 1260. The end of the limiting block 127 is conical. One end of the second spring 128 is bonded and fixed to the limiting block 127, and the other end is bonded and fixed to the hole wall of the round hole in the positioning groove 1260. The positioning screw 129 is threadedly connected to the outer wall of the positioning plate 126. After the positioning screw 129 is fixed, its end abuts against the limiting block 127, thereby limiting the contraction range of the limiting block 127.

[0057] Furthermore, the lead screw 121 adjusts the vertical height of the pressure plate 122 by rotation, providing transmission power for preload adjustment; the pressure plate 122 transmits preload pressure by vertically moving and squeezing the first spring 125; the first spring 125 outputs stable elastic pressure through elastic restoring force, continuously preloading the graphite carbon brush 150; the positioning plate 126 provides a space for the graphite carbon brush 150, and also supports various limiting and guiding components.

[0058] Furthermore, the slide rod 123 provides precise guidance for the movement of the pressure plate 122 and the extension and retraction of the first spring 125, preventing skewing and jamming; the ring plate 124 axially limits the slide rod 123 to prevent it from coming out of the pressure plate 122; the limiting block 127, in conjunction with the second spring 128 and the positioning screw 129, limits and fixes the graphite carbon brush 150; the positioning screw 129 limits the contraction range of the limiting block 127 to prevent the graphite carbon brush 150 from loosening. In actual use, a thin-film pressure sensor is installed inside the pre-tightening member 120 between the bottom surface of the pressure plate 122 and the top of the first spring 125. The thin-film pressure sensor has an annular gasket structure and is sleeved on the slide rod 123. The sensitive element of the sensor is in direct contact with the end of the first spring 125, converting the compression reaction force of the first spring 125 into a voltage signal output.

[0059] In the above configuration, the matching arrangement of each component of the pretensioner 120 realizes the transmission adjustment and constant compensation of the carbon brush pretension force, and has both precise motion guidance and carbon brush stable clamping limit, ensuring stable application of pretension force and reliable installation and operation of carbon brush.

[0060] Please see Figures 6-7 As shown, in this embodiment, the connector 130 includes a rotating shaft 131, a ratchet 132 rotatably connected to the top of the rotating shaft 131 and driven by the lead screw 121, a plurality of pawls 133 meshing with the ratchet 132, a sleeve 137 sleeved on the outside of the rotating shaft 131, and two symmetrically threaded levers 138 connected to the wall of the sleeve 137. The shaft wall of the rotating shaft 131 is provided with two spiral grooves 1310 for the levers 138 to slide.

[0061] Specifically, when the sleeve 137 moves down, the lever 138 slides along the spiral groove 1310 and drives the rotating shaft 131 to rotate. Through the meshing transmission of the ratchet 132 and the pawl 133, the lead screw 121 rotates at a fixed angle, thereby keeping the preload of the preload of the preload 120 constant.

[0062] Furthermore, the connector 130 also includes a third spring 134 disposed on the inner wall of the circular groove at the end of the pawl 133 and the end of the rotating shaft 131, a connecting rod 135 snapped and fixed to the top surface of the ratchet 132 and coaxially connected to the bottom end of the lead screw 121, and a top cover 136 snapped and fixed to the top of the rotating shaft 131 and rotatably connected to the bottom surface of the inner partition of the frame beam 111. The two ends of the third spring 134 are adhered and fixed to the inner wall of the circular groove at the end of the pawl 133 and the end of the rotating shaft 131. A rotating groove 1370 is provided on the bottom surface of the sleeve 137.

[0063] Furthermore, the rotating shaft 131, as the core transmission shaft of the connecting piece 130, provides a mounting base for the ratchet 132 and the pawl 133, and realizes power transmission through its own rotation. The spiral groove 1310 on its shaft wall provides sliding guidance for the lever 138 and converts the vertical movement of the sleeve 137 into its own rotational movement. The ratchet 132 is rotatably connected to the top of the rotating shaft 131 and meshes with the pawl 133 to realize unidirectional fixed angle transmission and avoid reverse power transmission. The pawl 133, together with the third spring 134, realizes unidirectional rotation limit of the ratchet 132, ensuring accurate power transmission from the rotating shaft 131 to the lead screw 121.

[0064] Furthermore, the sleeve 137, as the receiving component of the driving power, transmits the vertical downward movement force of the transmission rod 144 to the lever 138. The rotating groove 1370 on its bottom surface realizes the rotational connection with the transmission rod 144, allowing the sleeve 137 to rotate relative to the transmission rod 144. The lever 138 converts the vertical linear motion of the sleeve 137 into the rotational motion of the rotating shaft 131, realizing the precise conversion of the motion mode.

[0065] In the above configuration, the matching arrangement of each component of the connector 130 enables precise conversion from vertical motion to rotational motion and unidirectional fixed-angle transmission, stably transmitting power to the lead screw 121 and ensuring constant compensation of the preload force of the preload component 120.

[0066] Please see Figure 8 As shown, in this embodiment, the electromagnetic drive component 140 includes a cylindrical valve 141, a positioning cylinder 142 sleeved on the outside of the cylindrical valve 141, a fourth spring 143 disposed on the bottom surface of the cylindrical valve 141, a transmission rod 144 disposed on the top of the cylindrical valve 141 and having a T-shaped longitudinal cross section, and a magnetic coil 145 sleeved on the outside of the positioning cylinder 142.

[0067] Specifically, the column valve 141 slides inside the positioning cylinder 142, the bottom end of the positioning cylinder 142 is snapped and fixed to the inner bottom surface of the frame beam 111, the elastic force provided by the fourth spring 143 pushes the transmission rod 144 to move upward, the top end of the transmission rod 144 is rotatably connected to the inside of the rotating groove 1370, and the magnetic coil 145 is fixedly connected to the front outer wall of the frame beam 111 by bolts.

[0068] Furthermore, the column valve 141, as the core actuator of the electromagnetic drive 140, receives electromagnetic attraction and drives the transmission rod 144 to complete vertical reciprocating motion; the positioning cylinder 142 provides precise guidance for the sliding of the column valve 141, and at the same time provides a mounting and positioning base for the magnetic coil 145; the fourth spring 143 provides upward reset power for the column valve 141 and the transmission rod 144 through elastic restoring force.

[0069] Furthermore, the transmission rod 144 realizes the vertical power transmission between the column valve 141 and the connector 130, and can rotate relative to the sleeve 137. When the screw 121 is manually rotated to make the pressure plate 122 move vertically upward along the screw 121 to reset, it will drive the sleeve 137 of the connector 130 to rotate synchronously, while the transmission rod 144 remains stationary. Therefore, it will not affect the structure and subsequent use of the electromagnetic drive component 140.

[0070] Furthermore, the magnetic coil 145 is sleeved on the outside of the positioning cylinder 142 and fixed to the front outer wall of the frame beam 111 by bolts, serving as the power triggering component of the electromagnetic drive component 140. The grounding device 100 has an external control module, which receives the voltage signal from the thin-film pressure sensor in the pre-tightening component 120 and compares it with a preset threshold. When the detected pressure value is lower than the voltage threshold corresponding to 0.3MPa, the control module controls the magnetic coil 145 to be energized to generate electromagnetic attraction, providing driving force for the column valve 141 to overcome the elastic force of the fourth spring 143 and move downward, driving the sleeve 137 to move downward to compensate for the pre-tightening force, until the pressure is restored to the set range of 0.3-0.5MPa and then the energization is stopped, thereby realizing closed-loop precise control of the contact pressure.

[0071] In the above configuration, the matching arrangement of each component of the electromagnetic drive 140 realizes power triggering, execution and transmission, takes into account sliding guidance and automatic reset, and avoids linkage interference from manual operation, providing stable and controllable power support for constant preload compensation.

[0072] Please see Figure 9 As shown, in this embodiment, the graphite carbon brush 150 includes a carbon brush body 151, three copper conductive ribs 152 that are slidably embedded inside the carbon brush body 151 and evenly distributed along the axial direction, a copper connecting piece 153 that is welded to the top of the three copper conductive ribs 152 and snapped and fixed to the top surface of the carbon brush body 151, and a wire 154 that is welded to the top surface of the copper connecting piece 153.

[0073] Specifically, the carbon brush body 151 has a stepped cylindrical structure and is integrally formed using high-purity rare earth doped graphite-based composite material. The bottom of the carbon brush body 151 is provided with an arc-shaped contact surface, and the top of the carbon brush body 151 is integrally formed with a connector strip 1510. Conical grooves 1511 are opened on the outer walls on the left and right sides of the top of the carbon brush body 151.

[0074] Furthermore, the carbon brush body 151, serving as the basic supporting structure of the graphite carbon brush 150, provides an installation carrier for each component through an integrated stepped cylindrical structure made of high-purity rare earth-doped graphite-based composite material. The arc-shaped contact surface at the bottom enables frictional conductivity with the contact element. The carbon brush body 151 uses high-purity flake graphite as the matrix, doped with 3%-8% by mass of a composite rare earth component of high-purity cerium oxide and lanthanum oxide, and supplemented with conductive carbon black and high-temperature resistant resin binder. It is integrally formed through vacuum mixing, isothermal molding, and high-temperature sintering carbonization processes. The high-purity rare earth elements can finely... Graphite grains are sculpted and the lattice arrangement is optimized to improve the material's self-lubricating properties, wear resistance, and electrical conductivity, while reducing contact resistance and frictional temperature rise, enabling it to withstand the harsh operating conditions of high current, strong vibration, and high-frequency friction in rail transit. Copper conductive ribs 152 effectively reduce the overall contact resistance of the carbon brush, improving the efficiency and stability of current conduction. Copper connecting pieces 153 enable the current to converge from multiple conductive ribs and provide a welding connection base for the conductors 154. The conductors 154 serve as the core carrier for current conduction, enabling the electrical connection between the graphite carbon brush 150 and the external grounding system.

[0075] The above configuration, based on the carbon brush body 151, reduces the overall contact resistance, improves the stability of current conduction, realizes current convergence and grounding output, and adapts to the mounting and positioning requirements.

[0076] The grounding method of the rail transit grounding carbon brush based on high-purity rare earth and graphite compounds of the present invention, using the above-mentioned rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds, includes the following steps:

[0077] S1. First, install and position the carbon brush. Insert the graphite carbon brush 150 vertically from top to bottom into the positioning groove 1260 of the positioning plate 126 in the pre-tightening member 120. During the insertion process, the wall of the tapered groove 1511 of the graphite carbon brush 150 presses against the limiting block 127, causing the limiting block 127 to compress the second spring 128 and retract into the round hole in the wall of the positioning groove 1260.

[0078] S2. After the graphite carbon brush 150 is inserted into place, the limiting block 127 is reset and inserted into the tapered groove 1511 under the elastic restoring force of the second spring 128, thereby achieving axial limiting of the graphite carbon brush 150. Then, the positioning screw 129 is tightened so that the end of the positioning screw 129 abuts against the limiting block 127, limiting the retraction stroke of the limiting block 127, and completing the mounting and fixing of the graphite carbon brush 150.

[0079] S3. Next, perform initial pressure adjustment. Install the grounding device 100 as a whole at the axle-end grounding bracket of the rail transit vehicle, so that the bottom end of the graphite carbon brush 150 contacts the contact surface. During the contact process, the graphite carbon brush 150 drives the positioning plate 126 to move upward and squeeze the first spring 125. Then, manually rotate the lead screw 121 from the top of the lead screw 121 to adjust the vertical height of the pressure plate 122 outside the lead screw 121. By adjusting the compression of the first spring 125 by the pressure plate 122, the contact pressure between the graphite carbon brush 150 and the friction disc is precisely adjusted to 0.3-0.5MPa.

[0080] S4. After the device is put into use, the bottom end of the graphite carbon brush 150 continuously rubs against the contact surface, causing wear. The length of the graphite carbon brush 150 shortens, causing the positioning plate 126 to move downward under the elastic restoring force of the first spring 125, reducing the compression of the first spring 125. The contact pressure between the graphite carbon brush 150 and the friction disc is lower than the lower limit of 0.3MPa. At this time, the magnetic coil 145 in the electromagnetic drive component 140 is energized and generates electromagnetic attraction. Under the action of electromagnetic attraction, the column valve 141 overcomes the elastic restoring force of the fourth spring 143, driving the transmission rod 144 to move vertically downward along the positioning cylinder 142.

[0081] S5. When the transmission rod 144 moves downward, its top end drives the sleeve 137 in the connector 130 to move vertically downward synchronously through the rotating groove 1370. During the downward movement of the sleeve 137, the lever 138 on its tube wall slides along the spiral groove 1310 on the shaft wall of the rotating shaft 131 and drives the rotating shaft 131 to rotate around its own axis. The rotation of the rotating shaft 131 drives the ratchet 132 at its top end to rotate synchronously. The ratchet 132 meshes with the pawl 133 and drives the connecting rod 135 to rotate at a fixed angle. The connecting rod 135 drives the screw 121 to rotate synchronously at a fixed angle, so that the pressure plate 122 moves vertically downward along the screw 121 and squeezes the first spring 125 again. This restores the contact pressure between the graphite carbon brush 150 and the friction disc to the set range of 0.3-0.5MPa, realizing automatic constant compensation of the preload.

[0082] S6. When the bottom end of the graphite carbon brush 150 is worn down to near the bottom end of the internal copper conductive rib 152, stop the device and replace the graphite carbon brush 150. First, loosen the positioning screw 129 so that the end of the positioning screw 129 is disengaged from the limit block 127. Then, pull out the graphite carbon brush 150 in the vertical direction to complete the disassembly.

[0083] S7. After disassembly, manually rotate the lead screw 121 again from the top of the lead screw 121 to make the pressure plate 122 move vertically upward along the lead screw 121 to reset, in preparation for the installation of the new graphite carbon brush 150.

[0084] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the specification and its equivalents.

Claims

1. A grounding carbon brush device for rail transit based on high-purity rare earth and graphite compounds, comprising a grounding device, characterized in that: The grounding device includes a brush holder, a pre-tightening element disposed inside the brush holder for applying pre-tightening force to the graphite carbon brush, a connector connected to the bottom of the pre-tightening element, and an electromagnetic drive element that adjusts the pre-tightening force intensity of the pre-tightening element through the connector. The preload includes a lead screw, a pressure plate sleeved on the outside of the lead screw, a first spring disposed on the bottom surface of both ends of the pressure plate, and a positioning plate that slides on the outside of the lead screw and is used to accommodate the graphite carbon brush. After the bottom end of the graphite carbon brush rubs and wears against the contact part, the lead screw is driven to rotate and adjust the height of the pressure plate, squeezing the first spring to continuously apply preload to the graphite carbon brush. The connector includes a rotating shaft, a ratchet rotatably connected to the top of the rotating shaft and connected to the lead screw, several pawls meshing with the ratchet, a sleeve sleeved on the outside of the rotating shaft, and two symmetrically threaded levers connected to the sleeve wall. The rotating shaft wall has two spiral grooves for the levers to slide. When the electromagnetic drive is energized, it generates electromagnetic attraction to move the sleeve downward. The lever slides along the spiral groove and drives the rotating shaft to rotate. Through the meshing of the ratchet and pawl, the lead screw rotates at a fixed angle, thereby keeping the preload of the preload constant.

2. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 1, characterized in that: The brush holder includes a frame beam and a sleeve that is fixedly connected to the bottom of the outer wall of the frame beam by bolts. The side wall of the frame beam has a sliding groove and the bottom has an airflow cavity. A guide plate is welded to the bottom of the front cavity of the airflow cavity on the frame beam. A filter screen is snapped into the end cavity of the airflow cavity on the frame beam. A dust collection groove is snapped and fixed to the bottom of the frame beam below the filter screen.

3. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 2, characterized in that: The pretensioning component also includes two slide rods slidably connected to the pressure plate and sleeved in the first spring, a ring plate tightly sleeved on the top of the slide rod, a pair of limiting blocks elastically embedded in the positioning plate, a second spring set at the end of the limiting block, and a positioning screw sleeved in the second spring.

4. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 3, characterized in that: The upper and lower ends of the lead screw are rotatably connected to the groove walls at the upper and lower ends of the slide groove, respectively. The bottom end of the slide rod is snapped and fixed to the top surface of the positioning plate. A positioning groove is formed through the top of the positioning plate. The limiting block is slidably connected to the round holes in the groove walls at the left and right ends of the positioning groove. The end of the limiting block is conical. One end of the second spring is bonded and fixed to the limiting block, and the other end is bonded and fixed to the hole wall of the round hole in the positioning groove. The positioning screw is threaded and connected to the outer wall of the positioning plate. After the positioning screw is fixed, its end abuts against the limiting block, thereby limiting the contraction range of the limiting block.

5. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 4, characterized in that: The connector also includes a third spring disposed on the inner wall of the circular groove at the end of the pawl and the end of the rotating shaft, a connecting rod snapped and fixed to the top surface of the ratchet and coaxially connected to the bottom end of the lead screw, and a top cover snapped and fixed to the top of the rotating shaft and rotatably connected to the bottom surface of the internal partition of the frame beam. The two ends of the third spring are bonded and fixed to the inner wall of the circular groove at the end of the pawl and the end of the rotating shaft, and a rotating groove is provided on the bottom surface of the sleeve.

6. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 5, characterized in that: The electromagnetic drive component includes a cylindrical valve, a positioning cylinder sleeved on the outside of the cylindrical valve, a fourth spring disposed on the bottom surface of the cylindrical valve, a transmission rod disposed on the top of the cylindrical valve with a T-shaped longitudinal section, and a magnetic coil sleeved on the outside of the positioning cylinder.

7. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 6, characterized in that: The columnar valve slides inside the positioning cylinder, the bottom end of the positioning cylinder is snapped and fixed to the inner bottom surface of the frame beam, the elastic force provided by the fourth spring pushes the transmission rod to move upward, the top end of the transmission rod is rotatably connected to the inside of the rotating groove, and the magnetic coil is fixedly connected to the front outer wall of the frame beam by bolts.

8. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 7, characterized in that: The graphite carbon brush includes a carbon brush body, three copper conductive ribs that are slidably embedded inside the carbon brush body and evenly distributed along the axial direction, a copper connecting piece welded to the top of the three copper conductive ribs and snapped and fixed to the top surface of the carbon brush body, and a wire welded to the top surface of the copper connecting piece.

9. The rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds according to claim 8, characterized in that: The carbon brush body has a stepped cylindrical structure and is integrally molded using high-purity rare earth doped graphite-based composite material. The bottom of the carbon brush body has an arc-shaped contact surface, and the top of the carbon brush body has an integrally molded insert strip. Conical grooves are opened on the outer walls of the left and right sides of the top of the carbon brush body.

10. A grounding method for a rail transit carbon brush based on high-purity rare earth and graphite compounds, using the rail transit grounding carbon brush device based on high-purity rare earth and graphite compounds as described in claim 9, characterized in that... Includes the following steps: S1. First, install and position the carbon brush. Insert the graphite carbon brush vertically from top to bottom into the positioning groove of the positioning plate in the pre-tightening part. During the insertion process, the conical groove wall of the graphite carbon brush squeezes the limiting block, causing the limiting block to compress the second spring and retract into the round hole of the positioning groove wall. S2. After the graphite carbon brush is inserted into place, the limiting block is reset and inserted into the conical groove under the elastic restoring force of the second spring, thereby achieving axial limiting of the graphite carbon brush. Then, tighten the positioning screw so that the end of the positioning screw abuts against the limiting block, limiting the retraction stroke of the limiting block and completing the mounting and fixing of the graphite carbon brush. S3. Next, perform initial pressure adjustment. Install the grounding device as a whole at the axle-end grounding bracket of the rail transit vehicle, so that the bottom end of the graphite carbon brush abuts against the contact surface. During the contact process, the graphite carbon brush drives the positioning plate to move up and squeeze the first spring. Then, manually rotate the lead screw from the top of the lead screw to adjust the vertical height of the pressure plate outside the lead screw. By adjusting the compression of the first spring by the pressure plate, the contact pressure between the graphite carbon brush and the friction disc is precisely adjusted to 0.3-0.5MPa. S4. After the device is put into use, the bottom end of the graphite carbon brush will continuously rub against the contact surface, causing wear. The length of the graphite carbon brush will shorten, causing the positioning plate to move downward under the elastic restoring force of the first spring, reducing the compression of the first spring. The contact pressure between the graphite carbon brush and the friction disc will be lower than the lower limit of 0.3MPa. At this time, the magnetic coil in the electromagnetic drive component will be energized and generate electromagnetic attraction. Under the action of electromagnetic attraction, the column valve will overcome the elastic restoring force of the fourth spring and drive the transmission rod to move vertically downward along the positioning cylinder. S5. When the transmission rod moves downward, its top end drives the sleeve in the connecting part to move vertically downward synchronously through the rotating groove. During the downward movement of the sleeve, the lever on its tube wall slides along the spiral groove on the shaft wall and drives the shaft to rotate around its own axis. The rotation of the shaft drives the ratchet at its top end to rotate synchronously. The ratchet meshes with the pawl and drives the connecting rod to rotate at a fixed angle. The connecting rod drives the screw to rotate synchronously at a fixed angle, causing the pressure plate to move vertically downward along the screw and squeeze the first spring again. This restores the contact pressure between the graphite carbon brush and the friction disc to the set range of 0.3-0.5MPa, realizing automatic constant compensation of the preload. S6. When the bottom of the graphite carbon brush is worn down to near the bottom of the internal copper conductive rib, stop the device and replace the graphite carbon brush. First, loosen the positioning screw so that the end of the positioning screw is no longer in contact with the limit block. Then, pull out the graphite carbon brush vertically to complete the disassembly. S7. After disassembly, manually rotate the lead screw again from the top to move the pressure plate vertically upward along the lead screw to reset it, in preparation for the installation of the new graphite carbon brush.

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