Tramcar suspension bush with damping function

Abstract

This invention discloses a tram suspension bushing with a buffer function, comprising an outer frame, a spindle located within the outer frame, and a rubber elastomer integrally vulcanized with both ends of the outer frame and the spindle. A helical buffer assembly is sleeved between the outer frame and the spindle. A helical strip is provided on the outer wall of the inner sleeve, and a helical groove adapted to the helical strip is formed on the inner wall of the outer sleeve. A gap exists between the groove wall and the outer wall of the helical strip, and damping grease is injected into the gap. Elastic reset components for promoting the return flow of damping grease are provided at both ends of the inner and outer sleeves. A heat-conducting medium is injected into the annular cavity formed by the groove and the inner wall of the outer frame. This invention adopts a damping pair structure with a three-headed helical strip and a helical groove to achieve omnidirectional buffering and vibration reduction, taking into account torsional, radial, and axial damping performance. It can better adapt to the complex impact conditions of trams and effectively improve the comfort and quietness of trams.

Description

Technical Field

[0001] This invention relates to the field of suspension bushing technology, and more specifically, to a tram suspension bushing with a cushioning function. Background Technology

[0002] Suspension bushings are the core elastic components that connect the suspension arms to the vehicle frame subframe. They mainly bear the functions of load-bearing, vibration damping, and positioning, and directly determine the ride comfort and handling stability of the entire vehicle.

[0003] With the popularization of new energy electric vehicles, the operating conditions of suspension bushings have changed significantly: the transient torque output of the drive motor is much greater than that of the traditional fuel engine, and strong circumferential torsional impacts are generated during rapid acceleration and regenerative braking. In order to meet the requirements of buffering and vibration reduction, bushing solutions with fluid damping have emerged in the industry. The damping performance is improved by the shear throttling of damping grease, but there are still shortcomings: For example, patent CN216975627U mainly relies on the compression and shearing of the first protrusion on the outer wall of the spindle assembly, the second protrusion on the inner wall of the outer sleeve, and the rubber damper to achieve axial stiffness improvement and soft / hard limiting. Although this structure can improve the shaft diameter ratio and axial limiting, it still mainly relies on the passive deformation of rubber and lacks a fluid damping structure for the transient torsional impact, radial impact, and axial movement of the tram. Furthermore, it does not consider the problems of damping medium segregation and backflow, as well as high-temperature attenuation. Most fluid damping bushings are designed only for radial impact, with weak circumferential torsional damping force. They cannot effectively attenuate the transient torque impact of the electric vehicle motor, which can easily cause vibration and abnormal noise in the suspension system, affecting the overall vehicle comfort. Existing structures are mostly passive damping cavities, lacking active reset pressure equalization structures. Under high-frequency reciprocating impact, damping grease tends to agglomerate to one side. After the impact disappears, the damping grease cannot quickly refill the gap, resulting in uneven distribution and easy occurrence of cavitation noise. After long-term operation, the damping performance continues to degrade. The viscosity of damping grease is highly sensitive to temperature. The heat generated during the damping shear process is difficult to dissipate quickly, especially in summer. High temperatures cause the viscosity of the damping grease to decrease, resulting in a significant reduction in damping force and insufficient buffering capacity.

[0004] In conclusion, the current suspension bushings still have defects and need to be improved. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0006] Therefore, the object of the present invention is to provide a tram suspension bushing with a buffer function, comprising an outer frame, a spindle located within the outer frame, and a rubber elastomer integrally vulcanized with both ends of the outer frame and the spindle. A helical buffer assembly is sleeved between the outer frame and the mandrel. The helical buffer assembly includes an outer sleeve that mates with the inner wall of the outer frame and an inner sleeve that mates with the outer wall of the mandrel. The outer wall of the inner sleeve is provided with a helical strip, and the inner wall of the outer sleeve is provided with a helical groove adapted to the helical strip. There is a gap between the groove wall and the outer wall of the helical strip, and damping grease is injected into the gap. Both ends of the inner sleeve and the outer sleeve are provided with elastic reset components for pushing the damping grease back. The outer cylindrical wall of the outer sleeve is provided with grooves, and the annular cavity formed by the grooves and the inner wall of the outer frame is filled with a heat-conducting medium.

[0007] As a preferred technical solution: As described above, in a type of electric vehicle suspension bushing with a buffer function, the outer wall of the outer sleeve is interference-fitted with the inner wall of the outer frame, the inner wall of the inner sleeve is interference-fitted with the outer wall of the spindle, and the inner diameter of the outer sleeve is larger than the outer diameter of the inner sleeve.

[0008] With the above technical solution, there is also a gap between the outer sleeve and the inner sleeve. When the impact force causes the spindle 2 and the outer frame 1 to undergo radial relative displacement, the gap allows the outer sleeve and the inner sleeve to also undergo relative displacement. In addition, with the spiral damping structure composed of spiral strips, spiral grooves and damping grease, the impact can be absorbed and dissipated.

[0009] As described above, in a type of trolley suspension bushing with a buffer function, the cross-section of the spiral strip and the spiral groove are both trapezoidal. A rubber strip is vulcanized and fixed to the tooth tip of the spiral strip. Three ends of the spiral strip are evenly distributed on the circumferential surface of the inner sleeve. The staggered angle of the three ends of the spiral strip is 120°. The spiral strip and the inner sleeve are an integral structure.

[0010] Through the above technical solution, the rubber strip is designed so that under extreme impact conditions, the top of the spiral tooth contacts the bottom of the spiral groove first through the rubber strip, absorbing the hard impact energy and eliminating abnormal noise from metal collision. At the same time, it serves as a secondary limit to prevent the rubber elastomer from being damaged by overpressure.

[0011] As described above, a tram suspension bushing with a buffer function has a first extension portion extending axially at both ends of the outer sleeve, and a second extension portion extending axially at both ends of the inner sleeve. The first and second extension portions are cylindrical, and their end faces do not contact the rubber elastomer. Limiting steps are provided on the inner circular surface of the first extension portion and the outer circular surface of the second extension portion.

[0012] Through the above technical solution, the setting of the first extension and the second extension can increase the interference fit length between the outer sleeve and the outer frame, and also increase the interference fit length between the inner sleeve and the mandrel, thereby improving the overall clamping force and anti-torsion safety margin.

[0013] As described above, in a type of electric vehicle suspension bushing with a buffer function, the elastic reset component is located between the first extension and the second extension, and a cylindrical connecting groove is formed between the spiral buffer component, the inner wall of the first extension, the outer wall of the second extension, the end face of the outer sleeve, and the end face of the inner sleeve.

[0014] The spiral grooves are evenly distributed at three ends on the inner wall of the outer sleeve. The two ends of the spiral grooves extend axially along the inner wall of the outer sleeve, and the openings at both ends of the spiral grooves are connected to the connecting grooves.

[0015] Through the above technical solution, the connecting groove can connect the three-headed spiral grooves, and the inside of the connecting groove is also filled with damping grease. In this way, when the damping grease is actively pushed, the damping grease in the connecting groove can be evenly backfilled into the three-headed spiral groove, effectively solving the problems of damping grease agglomeration, cavitation noise, and long-term performance degradation.

[0016] As described above, a tram suspension bushing with a buffer function includes an elastic reset assembly comprising a fixed ring and a push plate, and a wave spring located between the fixed ring and the push plate. The fixed ring and the push plate each have an annular positioning groove on their opposite sides. Both ends of the wave spring are inserted into the annular positioning groove. The outer surface of the wave spring and the center hole are provided with rubber sleeves. Both ends of the rubber sleeves are integrally formed with the fixed ring and the push plate by vulcanization.

[0017] The above technical solution, with the rubber sleeve, can enclose the wave spring, providing isolation and protection, preventing the wave spring from being affected by complex external working conditions, and improving the service life of the wave spring.

[0018] As described above, in a type of tram suspension bushing with a buffer function, the push plate is annular, and the side of the push plate abuts against the limiting step. The push plate has a rubber sleeve integrally formed by vulcanization. Both the outer and inner circular surfaces of the rubber sleeve have a set of sealing lips integrally formed. The sealing lip on the outer circular surface of the rubber sleeve is sealed and fitted with the inner wall of the first extension, and the sealing lip on the inner circular surface of the rubber sleeve is sealed and fitted with the outer wall of the second extension.

[0019] Through the above technical solution, the sealing lip can improve the sealing performance between the push plate and the first extension and the second extension. In this way, the push plate can prevent the damping grease from leaking towards the wave spring side during the movement. At the same time, the inner circle of the first extension and the outer circle of the second extension are coated with polytetrafluoroethylene coating, which can reduce reciprocating sliding friction and improve the wear resistance life of the sealing lip.

[0020] As described above, in a type of tram suspension bushing with a buffer function, the inner side of the rubber elastomer is provided with a groove that matches the size of the fixing ring, and the fixing ring is embedded in the fixing ring and vulcanized and fixed together with the rubber elastomer.

[0021] With the above technical solution, the fixing ring is fixed to the rubber elastomer, so that the entire elastic reset component and the rubber elastomer are integrated into one unit. This allows the assembly of the elastic reset component and the rubber elastomer to be completed in one go, reducing assembly steps.

[0022] As described above, a type of tram suspension bushing with a buffer function has a set of symmetrically distributed countersunk holes on the outer frame wall at the groove. The countersunk holes are connected to an annular cavity, and a sealing post with an interference fit is inserted into the countersunk hole. A sealing ring is provided on the step of the countersunk hole.

[0023] With the above technical solution, the countersunk hole design ensures that after the sealing post is inserted into the countersunk hole, the bottom end of the sealing post fits tightly against the sealing ring, which can improve the sealing effect and prevent the heat transfer medium from leaking out of the countersunk hole. Beneficial effects

[0024] This invention employs a damping pair structure with a three-headed spiral strip and a spiral groove. Under circumferential torsion conditions, the tooth surfaces of the three spiral strips synchronously shear the damping grease, resulting in a large effective shearing area, which can significantly reduce the transient torque impact generated by the rapid acceleration and regenerative braking of the tram motor. Under radial displacement and axial movement conditions, the spiral tooth surface synchronously squeezes the damping grease, forcing the damping grease to flow through the gap, achieving omnidirectional buffering and vibration reduction. It takes into account the torsional, radial and axial damping performance, which can better adapt to the complex impact conditions of trams and effectively improve the comfort and quietness of trams.

[0025] This invention provides elastic reset components at both ends of the spiral strip and the spiral groove. When an impact occurs, the damping grease is squeezed and pushes the elastic reset components to store energy. After the impact disappears, the elastic reset components rebound and push the damping grease back into the spiral gap. This fundamentally avoids the problems of axial aggregation of damping grease and abnormal noise due to gap cavitation, and ensures that the damping performance does not decay under long-term high-frequency operation.

[0026] This invention features grooves on the mating surfaces of the outer sleeve and the outer frame, filled with a thermally conductive medium. This fills the microscopic air gaps in the metal interference fit surfaces, significantly reducing interfacial thermal resistance. The heat generated by damping shear can be quickly conducted to the outer frame and suspension arms for dissipation, effectively reducing the steady-state operating temperature of the damping grease, delaying its high-temperature aging, minimizing the damping force attenuation under high summer temperatures, and improving performance stability.

[0027] This invention features a spiral buffer assembly with inner and outer sleeves between the outer frame and the mandrel. By shearing and throttling the energy through the damping grease in the gap between the spiral strip and the spiral groove, it achieves multi-directional buffering in the circumferential, radial, and axial directions. The elastic reset components at both ends can push the damping grease backflow, reducing segregation and cavitation noise. The heat-conducting medium in the groove of the outer sleeve helps dissipate heat and improves damping stability. Attached Figure Description

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein Figure 1 This is a perspective view of the present invention; Figure 2 This is a three-dimensional sectional view of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is a perspective view of the outer frame and outer sleeve of the present invention; Figure 5 This is a perspective view of the mandrel and inner sleeve of the present invention; Figure 6 This is a side view of the outer sleeve and spiral groove of the present invention; Figure 7 This is a side view of the inner sleeve and spiral strip of the present invention; Figure 8 This is an exploded perspective view of the elastic reset component of the present invention.

[0029] In the diagram: 1. Outer frame; 2. Mandrel; 3. Rubber elastomer; 4. Outer sleeve; 5. Inner sleeve; 6. Spiral strip; 7. Spiral groove; 8. Rubber strip; 9. First extension; 10. Second extension; 11. Limiting step; 12. Fixing ring; 13. Wave spring; 14. Push plate; 15. Rubber sleeve; 16. Rubber sheath; 17. Sealing lip; 18. Groove; 19. Trench; 20. Countersunk hole; 21. Sealing post; 22. Connecting groove. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] like Figures 1-8As shown, this embodiment of the invention discloses a tram suspension bushing with a buffer function, including an outer frame 1, a spindle 2 located inside the outer frame 1, and a rubber elastomer 3 integrally formed by vulcanization at both ends of the outer frame 1 and the spindle 2. A spiral buffer assembly is fitted between the outer frame 1 and the mandrel 2. The spiral buffer assembly includes an outer sleeve 4 that mates with the inner wall of the outer frame 1 and an inner sleeve 5 that mates with the outer wall of the mandrel 2. A spiral strip 6 is provided on the outer wall of the inner sleeve 5, and a spiral groove 7 adapted to the spiral strip 6 is opened on the inner wall of the outer sleeve 4. There is a gap between the groove wall of the spiral groove 7 and the outer wall of the spiral strip 6, and damping grease is injected into the gap. Both ends of the inner sleeve 5 and the outer sleeve 4 are equipped with elastic reset components for pushing the damping grease back. A groove 19 is provided on the outer circular wall of the outer sleeve 4, and a heat-conducting medium is injected into the annular cavity formed by the groove 19 and the inner wall of the outer frame 1.

[0033] Specifically, when a circumferential torsion condition occurs: When the tram's motor outputs transient torque and regenerative braking generates reverse torque, the spindle 2 drives the inner sleeve 5 to undergo a small-angle circumferential twist relative to the outer frame 1 and outer sleeve 4. The side slope of the spiral strip 6 and the side wall of the spiral groove 7 undergo relative misalignment. The damping grease in the gap is squeezed by the tooth surface and forced to flow at high speed along the tooth gap. The viscous shearing action of the damping grease converts the mechanical energy of the impact into heat energy dissipation, thereby attenuating the torque impact.

[0034] When radial impact occurs: When the wheel passes over potholes and speed bumps, the radial impact force causes the spindle 2 and the outer frame 1 to undergo radial relative displacement. The gap between the tooth tip of the spiral strip 6 and the bottom of the spiral groove 7 is compressed, and the damping grease in the gap is squeezed and forced to flow laterally along the annular gap at the tooth tip, dissipating the impact energy through the throttling effect.

[0035] At the same time, the rubber elastomers 3 at both ends undergo radial elastic deformation, providing corresponding elastic buffering and absorbing part of the impact energy. In this way, the overall buffering and vibration reduction effect is improved through the dual vibration reduction effect of rubber elastic buffering and fluid damping dissipation.

[0036] When axial movement occurs: When the suspension is subjected to axial impact in the front-to-back direction, the inner sleeve 5 and the outer sleeve 4 undergo axial relative misalignment. The end face of the spiral strip 6 and the end wall of the spiral groove 7 compress the damping grease, generating axial damping force to attenuate axial movement. Combined with the axial elastic limit of the rubber elastomers 3 at both ends, axial buffering and vibration reduction are achieved to avoid abnormal noise from axial impact.

[0037] When the above conditions occur, the damping grease will be squeezed and sheared, and then the damping grease will flow along the gap and squeeze the elastic reset component. Through the rebound force of the elastic reset component, the damping grease can be actively pushed to flow back, so that the damping grease can be quickly and evenly backfilled into the gap between the spiral strip 6 and the spiral groove 7.

[0038] When the damping grease is subjected to compression and shearing for a long time, or under high temperature conditions in summer, the temperature of the damping grease itself will rise. The heat of the damping shear is quickly conducted through the outer sleeve 4. The heat-conducting medium on the outer wall of the outer sleeve 4 fills the microscopic air gap of the metal interference fit surface, so that the heat is quickly conducted from the outer sleeve 4 to the outer frame 1, and then dissipated into the external environment through the connection surface between the outer frame 1 and the suspension swing arm.

[0039] The damping grease is made of wide-temperature-range silicon, with an operating temperature range of -40℃ to 120℃. This avoids the problem of excessively hard bushings caused by excessively high viscosity of the damping grease in low-temperature winter conditions.

[0040] The preferred thermal conductive medium is automotive-grade phase change thermal grease. Phase change thermal grease is solid at room temperature and melts to fill gaps after reaching the working temperature. It does not flow or migrate at high temperatures and has far superior vibration resistance and anti-aging properties compared to ordinary silicone grease, with the best long-term stability.

[0041] In one specific embodiment of the present invention, the outer wall of the outer sleeve 4 is interference-fitted with the inner wall of the outer frame 1, the inner wall of the inner sleeve 5 is interference-fitted with the outer wall of the mandrel 2, and the inner diameter of the outer sleeve 4 is larger than the outer diameter of the inner sleeve 5.

[0042] Specifically, such as Figure 2 and Figure 3 As shown, flat keys can be machined on the inner wall of the outer sleeve 4 and the outer wall of the inner sleeve 5 (not shown in the figure). Corresponding keyways are machined on the outer circular wall of the outer frame 1 and the inner circular wall of the inner sleeve 5 (not shown in the figure). In this way, the flat keys and keyways cooperate with each other to avoid loosening due to long-term alternating torsional impact, ensuring the accuracy and long-term consistency of the helical damping, and also playing a guiding role, making it easier for the helical strip 6 and the helical groove 7 to be aligned during installation.

[0043] In one specific embodiment of the present invention, the cross sections of the spiral strip 6 and the spiral groove 7 are both trapezoidal. The tooth tip of the spiral strip 6 is vulcanized and fixed with a rubber strip 8. The spiral strip 6 has three ends evenly distributed on the circumferential surface of the inner sleeve 5. The staggered angle of the three spiral strips 6 is 120°. The spiral strip 6 and the inner sleeve 5 are an integral structure. The spiral groove 7 has three ends evenly distributed on the inner wall of the outer sleeve 4.

[0044] Specifically, such as Figures 2-7 As shown, the three-head design of the spiral strip 6 and spiral groove 7 allows the three spirals to work synchronously, resulting in an effective shear area three times that of the single-head structure. This provides stronger damping force and ensures that the circumferential force is completely balanced, preventing the generation of eccentric load moments.

[0045] Furthermore, the tooth tips and roots of the spiral bar 6 are rounded to avoid stress concentration; the trapezoidal teeth increase the shear contact area while making the damping grease flow more smoothly, the damping characteristics more linear, and reducing step impact.

[0046] A polytetrafluoroethylene coating is sprayed onto the side of the trapezoidal teeth to reduce wear under long-term alternating motion, ensure clearance stability, and delay the decay of damping performance; at the same time, it avoids abnormal metal friction noise under extreme working conditions.

[0047] In one specific embodiment of the present invention, the outer sleeve 4 has a first extension 9 extending axially at both ends, and the inner sleeve 5 has a second extension 10 extending axially at both ends. The first extension 9 and the second extension 10 are cylindrical. The end faces of the first extension 9 and the second extension 10 do not contact the rubber elastomer 3. The inner circular surface of the first extension 9 and the outer circular surface of the second extension 10 are provided with a limiting step 11.

[0048] Specifically, such as Figures 3-5 As shown, there is a gap between the first extension 9 and the second extension 10 and the rubber elastomer 3. This way, the deformation of the rubber elastomer 3 under load will not be transmitted to the outer sleeve 4 and the inner sleeve 5 through the extension, avoiding eccentricity and skewness of the outer sleeve 4 and the inner sleeve 5. It also avoids nonlinear changes in the helical fit clearance due to rubber deformation interference, ensuring the stability and consistency of damping performance under full load conditions. Furthermore, the elastic reset component and the rubber elastomer 3 are independent of each other, which facilitates assembly.

[0049] In one specific embodiment of the present invention, the elastic reset component is located between the first extension 9 and the second extension 10, and a cylindrical connecting groove 22 is formed between the spiral buffer component, the inner wall of the first extension 9, the outer wall of the second extension 10, the end face of the outer sleeve 4, and the end face of the inner sleeve 5.

[0050] The spiral groove 7 extends axially along the inner wall of the outer sleeve 4 at both ends, and the groove openings at both ends of the spiral groove 7 are connected to the connecting groove 22.

[0051] Specifically, such as Figure 3 , Figure 4 and Figure 7 As shown, after the bushing is assembled, damping grease is injected into the gap between the spiral strip 6 and the spiral groove 7, as well as into the connecting groove 22. By setting the connecting grooves 22 at both ends, the ends of the three spiral grooves 7 can be connected, and the pressure at both ends of the spiral grooves 7 is balanced, preventing the damping grease from accumulating on one side.

[0052] When the damping grease is squeezed and sheared, the damping grease between the spiral strip 6 and the spiral groove 7 will move towards the connecting groove 22 on one side. This increases the pressure inside the connecting groove 22, and the elastic reset component will be compressed under the pressure. When the damping grease stops moving, under the rebound force of the elastic reset component, it will actively push the damping grease in the connecting groove 22 to move, thereby pushing the damping grease to be evenly refilled into the gap between the spiral strip 6 and the spiral groove 7.

[0053] Furthermore, the openings at both ends of the spiral groove 7 are located at the axial ends of the outer sleeve 4. During assembly, the three-headed spiral strip 6 is aligned with the opening of the three-headed spiral groove 7, and the spiral strip 6 can be screwed into the spiral groove 7.

[0054] In one specific embodiment of the present invention, the elastic reset assembly includes a fixed ring 12 and a push plate 14, and a wave spring 13 located between the fixed ring 12 and the push plate 14. The fixed ring 12 and the push plate 14 are each provided with an annular positioning groove on their opposite sides. Both ends of the wave spring 13 are inserted into the annular positioning groove. The outer surface of the wave spring 13 and the center hole are provided with rubber sleeves 15. Both ends of the rubber sleeves 15 are vulcanized and integrally formed with the fixed ring 12 and the push plate 14.

[0055] The inner side of the rubber elastomer 3 is provided with a groove 18 that matches the size of the fixing ring 12. The fixing ring 12 is embedded in the fixing ring 12 and is vulcanized and fixed together with the rubber elastomer 3.

[0056] Specifically, such as Figure 2 , Figure 3 and Figure 8 As shown, the elastic reset component is integrated on the rubber elastomer 3. When the bushing is assembled, the outer sleeve 4 is inserted into the outer frame 1 and pressurized, the inner sleeve 5 is fitted onto the mandrel 2 and pressurized, and then the mandrel 2 is inserted into the outer frame 1 and rotated to push it in, thereby causing the spiral strip 6 and the spiral groove 7 to engage. Next, rubber elastomers 3 are inserted into the left end of the mandrel 2 and the outer sleeve 4 and vulcanized for fixation. At the same time, damping grease is injected into the right end of the mandrel 2 and the outer sleeve 4, so that the damping grease is evenly filled into the gap between the spiral strip 6 and the spiral groove 7. Finally, rubber elastomers 3 are inserted into the right end of the mandrel 2 and the outer sleeve 4 and vulcanized for fixation. When the two rubber elastomers 3 are installed, the elastic reset components on them can be installed precisely between the first extension 9 and the second extension 10. This makes the overall assembly process simple and facilitates mass production and vehicle application.

[0057] The wave spring 13 has no rigid or rubber connection with the fixed ring 12 or the push plate 14, and is an independent floating part. This ensures that the wave spring 13 can contract and extend stably, thereby achieving the rapid reset of the push plate 14.

[0058] The push plate 14 is located in the connecting groove 22 on the side away from the wave spring 13. When the pressure inside the connecting groove 22 increases, it will push the push plate 14 to move and compress the wave spring 13. When the damping grease stops moving, it will be quickly reset by the push plate 14 under the action of the rebound force of the wave spring 13. The push plate 14 can actively push the damping grease to flow back evenly.

[0059] In one specific embodiment of the present invention, the push plate 14 is annular, and the side of the push plate 14 abuts against the limiting step 11. A rubber sleeve 16 is integrally formed on the surface of the push plate 14 by vulcanization. A set of sealing lips 17 is integrally formed on both the outer and inner circular surfaces of the rubber sleeve 16. The sealing lips 17 on the outer circular surface of the rubber sleeve 16 are sealed and fitted with the inner wall of the first extension 9, and the sealing lips 17 on the inner circular surface of the rubber sleeve 16 are sealed and fitted with the outer wall of the second extension 10.

[0060] Specifically, such as Figure 2 , Figure 3 and Figure 8 As shown, the setting of the limiting step 11 allows the push plate 14 to abut against the limiting step 11 when the elastic reset assembly is installed between the first extension 9 and the second extension 10. Then, as the rubber elastomer 3 is continuously pushed in, the rubber elastomer 3 will squeeze the wave spring 13 through the fixing ring 12. In this way, after the assembly is completed, the wave spring 13 can maintain a pre-compression of 10%-15%, which eliminates the assembly gap and ensures the initial reset thrust.

[0061] One or two rectangular grooves are provided on the outer and inner circular surfaces of the rubber sleeve 16 between the two sealing lips 17. A polytetrafluoroethylene (PTFE) guide ring is inserted into the rectangular groove. The PTFE guide ring is in close contact with the inner circular surface of the first extension 9 and the outer circular surface of the second extension 10. The guide ring is slightly higher than the sealing lip 17 by about 0.05-0.1 mm. The guide ring bears all the radial support force and guide function, ensuring that the push plate 14 always moves axially without deviation.

[0062] The sealing lip 17 only slightly contacts the inner circular surface of the first extension 9 and the outer circular surface of the second extension 10, serving only a sealing function and not bearing radial load, thus greatly reducing wear and extending service life.

[0063] In one specific embodiment of the present invention, a set of symmetrically distributed countersunk holes 20 are provided on the wall of the outer skeleton 1 at the groove 19. The countersunk holes 20 are connected to the annular cavity. A sealing post 21 with interference fit is inserted into the countersunk hole 20. A sealing ring is provided on the step of the countersunk hole 20.

[0064] Specifically, such as Figure 3 and Figure 4As shown, after the outer sleeve 4 is inserted into the outer frame 1 and interference fits, the heat transfer medium is injected into the countersunk hole 20 on one side of the outer frame 1. The heat transfer medium can flow in the groove 19 and squeeze the internal air out of the countersunk hole 20 on the other side. When the heat transfer medium begins to overflow evenly from the countersunk hole 20 on the other side, the injection is stopped. Then, the sealing column 21 is inserted into the two countersunk holes 20 and interference fits are performed. The injected heat transfer medium can improve the heat transfer efficiency of the outer sleeve 4 and the outer frame 1.

[0065] In the description of this specification, terms such as "connection," "installation," and "fixation" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meanings of the above terms within this invention based on the specific circumstances.

[0066] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tram suspension bushing with a buffer function, comprising an outer frame (1), a spindle (2) located inside the outer frame (1), and a rubber elastomer (3) integrally formed by vulcanization at both ends of the outer frame (1) and the spindle (2). Its features are: A spiral buffer assembly is sleeved between the outer frame (1) and the mandrel (2). The spiral buffer assembly includes an outer sleeve (4) that mates with the inner wall of the outer frame (1) and an inner sleeve (5) that mates with the outer wall of the mandrel (2). A spiral strip (6) is provided on the outer wall of the inner sleeve (5). A spiral groove (7) adapted to the spiral strip (6) is opened on the inner wall of the outer sleeve (4). There is a gap between the groove wall of the spiral groove (7) and the outer wall of the spiral strip (6). Damping grease is injected into the gap. Both ends of the inner sleeve (5) and the outer sleeve (4) are provided with elastic reset components for pushing the damping grease back. The outer wall of the outer sleeve (4) is provided with a groove (19), and a heat-conducting medium is injected into the annular cavity formed by the groove (19) and the inner wall of the outer frame (1).

2. The tram suspension bushing with buffer function according to claim 1, characterized in that: The outer wall of the outer sleeve (4) is interference-fitted with the inner wall of the outer frame (1), the inner wall of the inner sleeve (5) is interference-fitted with the outer wall of the mandrel (2), and the inner diameter of the outer sleeve (4) is larger than the outer diameter of the inner sleeve (5).

3. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The cross-sections of the spiral strip (6) and the spiral groove (7) are both trapezoidal. The tooth tip of the spiral strip (6) is fixed with a rubber strip (8) by vulcanization. The spiral strip (6) has three heads evenly distributed on the circumference of the inner sleeve (5). The staggered angle of the three spiral strips (6) is 120°. The spiral strip (6) and the inner sleeve (5) are an integral structure.

4. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The outer sleeve (4) has a first extension (9) extending axially at both ends, and the inner sleeve (5) has a second extension (10) extending axially at both ends. The first extension (9) and the second extension (10) are cylindrical. The end faces of the first extension (9) and the second extension (10) do not contact the rubber elastomer (3). The inner circular surface of the first extension (9) and the outer circular surface of the second extension (10) are provided with a limiting step (11).

5. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The elastic reset component is located between the first extension (9) and the second extension (10), and a cylindrical connecting groove (22) is formed between the spiral buffer component, the inner wall of the first extension (9), the outer wall of the second extension (10), the end face of the outer sleeve (4), and the end face of the inner sleeve (5).

6. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The elastic reset assembly includes a fixed ring (12) and a push plate (14), and a wave spring (13) located between the fixed ring (12) and the push plate (14). The fixed ring (12) and the push plate (14) have annular positioning grooves on their opposite sides. Both ends of the wave spring (13) are inserted into the annular positioning grooves. The outer surface of the wave spring (13) and the center hole are provided with rubber sleeves (15). Both ends of the rubber sleeves (15) are vulcanized and integrally formed with the fixed ring (12) and the push plate (14).

7. A tram suspension bushing with a buffer function according to claim 5, characterized in that: The spiral groove (7) has three ends evenly distributed on the inner wall of the outer sleeve (4). The two ends of the spiral groove (7) extend axially along the inner wall of the outer sleeve (4), and the openings of both ends of the spiral groove (7) are connected to the connecting groove (22).

8. A tram suspension bushing with a buffer function according to claim 6, characterized in that: The push plate (14) is annular, and the side of the push plate (14) abuts against the limiting step (11). The push plate (14) is integrally vulcanized with a rubber sleeve (16). The outer and inner circular surfaces of the rubber sleeve (16) are integrally formed with a set of sealing lips (17). The sealing lips (17) on the outer circular surface of the rubber sleeve (16) are sealed and fitted with the inner wall of the first extension (9), and the sealing lips (17) on the inner circular surface of the rubber sleeve (16) are sealed and fitted with the outer wall of the second extension (10).

9. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The inner side of the rubber elastomer (3) is provided with a groove (18) that matches the size of the fixing ring (12). The fixing ring (12) is embedded in the fixing ring (12) and is vulcanized and fixed as a whole with the rubber elastomer (3).

10. A tram suspension bushing with a buffer function according to claim 1, characterized in that: The outer skeleton (1) wall at the groove (19) has a set of symmetrically distributed countersunk holes (20). The countersunk holes (20) are connected to the annular cavity. A sealing column (21) with an interference fit is inserted into the countersunk hole (20). A sealing ring is provided on the step of the countersunk hole (20).

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