A shear-type elastic wheel for rail transit vehicles

Abstract

The invention discloses a shear-type elastic wheel for rail transit vehicles, comprising a wheel hoop, a wheel center disc, a pressure plate and two elastic discs, wherein the elastic disc comprises an inner annular metal disc and an outer annular metal disc, an elastic body is arranged between the inner metal disc and the outer metal disc, the two elastic discs are symmetrically arranged on both sides of the inner space of the wheel hoop with a V-shaped axial cross section, the wheel center disc and the pressure plate are respectively fastened by bolts on the outer sides of the two elastic discs, the inner metal discs of the two elastic discs are fixed to the wheel hoop, the outer metal disc of the elastic disc located on one side of the wheel center disc is fixed to the wheel center disc, and the outer metal disc of the elastic disc located on one side of the pressure plate is fixed to the pressure plate, the elastic body of the elastic disc is divided into an inner layer elastic body and an outer layer elastic body, the inner layer elastic body and the outer layer elastic body have a stiffness difference, an annular metal partition is arranged between the inner layer elastic body and the outer layer elastic body, and when used, the force between the wheel hoop and the wheel center disc can be transmitted by twisting the elastic body.

Description

Technical Field

[0001] The invention relates to a shear-type elastic wheel for a rail transit vehicle, belonging to the technical field of rail transit. Background Art

[0002] One of the functions of elastic wheels for rail transit vehicles is to enable the force applied by the wheel core to be flexibly transmitted to the wheel tread during starting and braking, so that the force of the wheel tread on the track surface has a continuous increase process. Although this process is extremely short, it can well maintain the viscosity between the wheel and the rail, and prevent the wheel from slipping suddenly due to force, causing damage to the wheel and the track. The second function of elastic wheels for rail transit vehicles is to effectively reduce noise and vibration.

[0003] The application number is CN201310700423, and the name is an invention patent of a shear-type elastic wheel for rail transit vehicles. The scheme is: a wheel hoop with mounting ring grooves on both sides, a wheel center with a notch and a pressure ring and two elastic discs, the pressure ring is arranged at the notch of the wheel center and connected to the wheel center fastener, the elastic disc is an elastic body with inner metal plates and outer metal plates embedded on both sides, the inner protrusions on the sides of the two elastic discs are respectively matched and buckled with the inner grooves corresponding to the wheel hoop connecting disc, and the outer protrusions are respectively matched and buckled with the outer grooves corresponding to the side of the wheel center and the outer grooves corresponding to the side of the pressure ring, and the two elastic discs are symmetrically pressed between the wheel center and the wheel hoop and between the pressure ring and the wheel hoop, and there is an outer radial gap between the outer periphery of the elastic disc and the outer hole wall of the wheel hoop. There is an inner radial gap h2 between the inner periphery of the elastic disc and the wheel center shaft neck and the pressure ring shaft neck, and the angle α between the elastic disc and the vertical section is 0-20°.

[0004] The above scheme represents the mainstream design of the prior art elastic wheel, namely: there is an elastic disk on each side of the wheel, and the inner and outer sides of each elastic disk are respectively provided with an annular inner metal plate and an outer metal plate, and a vulcanized rubber layer is provided between the inner metal plate and the outer metal plate, the outer metal plate is rigidly connected to the wheel core, and the inner metal plate is rigidly connected to the wheel rim where the wheel tread is located. When in use, the driving force or braking resistance is transmitted between the wheel core and the wheel rim by the shear force of the rubber layer between the inner metal plate and the outer metal plate.

[0005] The elastic wheel designed in the above prior art has the following defects:

[0006] 1. The rubber layer between the inner metal plate and the outer metal plate is a single-layer design. No matter how large the force is, there is only one linear shear force transmission mode. In actual operation, when not climbing a slope, overloading, or braking at high speed, the force that needs to be transmitted is generally relatively small, and there is no need for a rubber layer with greater rigidity to transmit the force. If a rubber layer with greater rigidity transmits the force, the time for the wheel tread to continuously increase the force on the track surface will be very short, and the wheel will still slip.

[0007] 2. The forces (driving force and braking resistance) of the wheel during operation are entirely dependent on the shear force provided by the rubber layer between the inner metal plate and the outer metal plate throughout the entire process. In particular, the long-term and repeated provision of shear force for the extreme driving force and resistance can easily cause the rubber layer to creep and lose its elasticity. Summary of the invention

[0008] The technical problem to be solved by the present invention is mainly: how to make the elastic wheel maintain the viscosity between the tread surface and the track surface under non-limit force (driving force and braking force) to prevent the wheel from slipping.

[0009] In view of the above problems, the technical solution proposed by the present invention is:

[0010] A shear-type elastic wheel for rail transit vehicles comprises a wheel hoop, a wheel center disc, a pressure plate and two elastic discs, the elastic disc comprising an inner annular metal disc and an outer annular metal disc, an elastic body being arranged between the inner metal disc and the outer metal disc, the two elastic discs being symmetrically arranged on both sides of the inner space of the wheel hoop with a V-shaped axial cross section, the wheel center disc and the pressure plate being fastened by bolts on the outer sides of the two elastic discs respectively, the inner metal disc of the two elastic discs being fixed to the wheel hoop, the outer metal disc of the elastic disc located on one side of the wheel center disc being fixed to the wheel center disc, and the outer metal disc of the elastic disc located on one side of the pressure plate being fixed to the pressure plate, the elastic body of the elastic disc being divided into an inner layer elastic body and an outer layer elastic body, the inner layer elastic body and the outer layer elastic body having a stiffness difference, an annular metal partition being arranged between the inner layer elastic body and the outer layer elastic body, and when in use, the force between the wheel hoop and the wheel center disc can be transmitted by twisting the elastic body.

[0011] Furthermore, the stiffness of the inner layer elastic body is smaller than the stiffness of the outer layer elastic body.

[0012] Furthermore, the inner elastomer and the outer elastomer are both rubber bodies, the inner elastomer is bonded to the inner metal disc and the metal partition respectively by vulcanization, and the outer elastomer is bonded to the outer metal disc and the metal partition respectively by vulcanization.

[0013] Furthermore, the inner metal disk of the two elastic disks is an annular common inner disk shared by the two elastic disks.

[0014] Furthermore, the inner edge of the annular common inner disk is an annular stop disk extending centripetally, and a stop notch is provided on the stop disk, and the stop notch has a clockwise stop edge and a counterclockwise stop edge; a stop block 1 is provided in the stop notch, and its two ends are respectively connected to the inner edges of two metal partitions, and there is a distance between the stop block 1 and the clockwise stop edge and the counterclockwise stop edge; a stop block 2 is provided in the stop notch, and its two ends are respectively connected to the inner edges of two outer metal disks, and there is a distance between the stop block 2 and the clockwise stop edge and the counterclockwise stop edge; the stop block 2 is located on the inner side of the stop block 1, and the width of the stop block 2 is smaller than the width of the stop block 1. When the wheel center disk rotates, the stop block 1 touches the clockwise stop edge or the counterclockwise stop edge before the stop block 2.

[0015] Furthermore, the inner metal disc is fixed to the wheel hoop in such a way that the outer circumference of the common inner disc is press-fitted into the inner circumference of the wheel hoop in an interference fit manner.

[0016] Furthermore, the outer periphery of the common inner disk has an axially arranged limiting protrusion, and the inner periphery of the wheel hoop has an axially arranged limiting groove. When the common inner disk is installed in the inner space of the wheel hoop, the limiting protrusion is inserted into the limiting groove in a transition fit or interference fit manner.

[0017] Furthermore, a plurality of limiting holes are circumferentially provided on the opposite sides of the wheel center disc and the pressure plate, and a plurality of limiting columns are provided on the outer side of the outer metal disc. When the outer metal disc on one side of the wheel center disc is fixed to the wheel center disc, and the outer metal disc on the side of the pressure plate is fixed to the pressure plate, the limiting columns are inserted into the limiting holes in a transition fit manner.

[0018] Furthermore, the two ends of stop block one are fixedly connected to the inner edges of the metal partitions of the two elastic disks by welding, and the two ends of stop block two are fixedly connected to the inner edges of the outer metal disks of the two elastic disks by welding.

[0019] Furthermore, a positioning notch 1 is provided on the inner ring edges of the metal partitions of the two elastic disks, and the two ends of the stop block 1 are respectively welded in the positioning notch 1 of the inner ring edges of the two metal partitions; a positioning notch 2 is provided on the inner ring edges of the outer metal disks of the two elastic disks, and the two ends of the stop block 2 are respectively welded in the positioning notch 2 of the inner ring edges of the two outer metal disks.

[0020] Beneficial effects:

[0021] 1. It can prolong the time for the wheel tyre to be stressed, so that the viscous force between the tread and the track surface can be avoided during the driving and braking process, thus preventing the wheel from slipping.

[0022] 2. It can avoid the extreme stretching of the inner and outer elastomers, avoid accelerating the creep process of the rubber body, and enable the rubber body to maintain good elasticity for a long time.

[0023] 3. It can achieve better vibration and noise reduction effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional schematic diagram of the shear-type elastic wheel for rail transit vehicles;

[0025] Figure 2 It is a schematic axial cross-sectional view of the shear-type elastic wheel for rail transit vehicles;

[0026] Figure 3 for Figure 2 Schematic diagram of the decomposition;

[0027] Figure 4 is a three-dimensional schematic diagram of the wheel center disk;

[0028] Figure 5 is a three-dimensional schematic diagram of the pressure plate;

[0029] Figure 6 It is a three-dimensional schematic diagram of the common inner disk and the elastic disks on both sides thereof after being pressed into the wheel hoop;

[0030] Figure 7 is a three-dimensional schematic diagram of the wheel hoop;

[0031] Figure 8 It is a three-dimensional schematic diagram of the common inner disk and the elastic disks on both sides thereof, and mainly shows the first positioning notch, the second positioning notch and the stop notch;

[0032] Fig. 9 The figure is a three-dimensional schematic diagram of the common inner plate and the elastic plates on both sides thereof, and mainly shows the setting positions of the stop block 1, the stop block 2 and the stop notch;

[0033] Fig.10 For the Fig. 9 A partial schematic diagram is also provided.

[0034] In the figure: 1. wheel hoop; 101. limiting groove; 2. wheel center plate; 3. pressure plate; 4. elastic plate; 5. outer metal plate; 501. positioning notch two; 502. stop block two; 6. metal partition; 601. positioning notch one; 602. stop block one; 7. inner elastic body; 8. outer elastic body; 9. common inner plate; 901. limiting protrusion; 902. stop plate; 903. stop notch; 9031. clockwise stop edge; 9032. counterclockwise stop edge; 10. limiting hole; 11. limiting column. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings:

[0036] like Figure 1As shown in FIG. 8 , a shear-type elastic wheel for rail transit vehicles comprises a wheel rim 1, a wheel center disc 2, a pressure plate 3 and two elastic plates 4, the elastic plate 4 comprising an inner annular metal plate and an outer annular metal plate 5, an elastic body being arranged between the inner metal plate and the outer metal plate 5, the two elastic plates 4 having a V-shaped axial cross section and being symmetrically arranged on both sides of the inner space of the wheel rim 1, the wheel center disc 2 and the pressure plate 3 being fastened by bolts on the outer sides of the two elastic plates 4 respectively, the inner metal plates of the two elastic plates 4 being fixed to the wheel rim 1, the outer metal plate 5 of the elastic plates 4 located on one side of the wheel center disc 2 being fixed to the wheel center disc 2, and the outer metal plate 5 of the elastic plates 4 located on one side of the pressure plate 3 being fixed to the pressure plate 3, the improvement of which is that the elastic body of the elastic plate 4 is divided into an inner layer elastic body 7 and an outer layer elastic body 8, the inner layer elastic body 7 and the outer layer elastic body 8 having a stiffness difference, an annular metal partition plate 6 being arranged between the inner layer elastic body 7 and the outer layer elastic body 8, when in use, the force between the wheel rim 1 and the wheel center disc 2 can be transmitted by twisting the elastic body. Specifically, during operation, when the wheel axle outputs driving force to the wheel center disc 2, the wheel center disc 2 and the pressure plate 3 fixed thereto simultaneously apply driving force to the outer metal discs 5 fixed thereto, and the outer metal disc 5 transmits the driving force to the metal partition 6 through the outer elastic body 8 in the form of shear force, and the metal partition 6 transmits the driving force to the inner metal disc through the inner elastic body 7 in the form of shear force, and the inner metal disc transmits the driving force to the wheel hoop 1 fixed thereto, and the wheel hoop 1 transmits the driving force to the rail through its tread. During the transmission of the driving force, the inner elastic body 7 and the outer elastic body 8 will be twisted and stretched, which will play a transmission buffering role in the transmission of the driving force. Since the elastomer is divided into an inner layer of elastomer 7 and an outer layer of elastomer 8 with different stiffness, the layer of elastomer with the lower stiffness must be the one with the largest stretching amplitude during the driving force transmission process. Thus, in the general case that the train is not climbing a slope, is overloaded, or is accelerating rapidly, the layer of elastomer with the lower stiffness combined with the outer layer of elastomer 8 (the outer layer of elastomer 8 will also be slightly stretched) is sufficient to meet the requirements of buffering the driving force transmission, and the elastomer with the lower stiffness has a better buffering effect. When the train is climbing a slope, overloaded, or accelerating rapidly, the layer of elastomer with the higher stiffness can be stretched to a greater extent to meet the requirements of buffering the driving force transmission when the train is climbing a slope, overloaded, or accelerating rapidly. Thus, compared with the prior art, in both cases, the stretching amplitude of the rubber body is actually increased, and the time for the increase of the driving force on the wheel rim 1 is prolonged, so that the viscous force between the tread and the track surface can be avoided during the driving process, thereby preventing the wheel from slipping. Based on the same principle as above, when the braking resistance exerted on the wheel center disc 2 is transmitted to the wheel rim 1, the force increase time of the wheel rim 1 can also be prolonged, so that the viscous force between the tread and the track surface can be avoided during the braking process, thereby preventing the wheel from slipping.

[0037] Here are further improvements.

[0038] Preferably, the rigidity of the inner elastic body 7 is smaller than that of the outer elastic body 8, which is more conducive to the subsequent setting of the stretching limit of the inner elastic body 7 and the outer elastic body 8. Of course, the rigidity of the outer elastic body 8 can also be smaller than that of the inner elastic body 7.

[0039] Preferably, the inner elastic body 7 and the outer elastic body 8 are both rubber bodies, the inner elastic body 7 is bonded to the inner metal disc and the metal partition 6 respectively by vulcanization, and the outer elastic body 8 is bonded to the outer metal disc and the metal partition 6 respectively by vulcanization. Of course, using other elastic bodies or even steel springs can also solve the corresponding problems, but the effect is not as good as using rubber bodies.

[0040] The inner metal disks of the two elastic disks 4 are an annular common inner disk 9 shared by the two elastic disks 4. In the prior art, the two elastic disks 4 generally have their own inner metal disks, which increases the complexity of setting and assembly, while the present application adopts the common inner disk 9 to actually integrate the two elastic disks 4 into one, which is convenient for manufacturing and installation, and is more in line with the design requirements of the present application, as described below.

[0041] like Figure 2 , 9As shown in Figures 10, the inner edge of the annular common inner disk 9 is an annular stop disk 902 extending centripetally, and a stop notch 903 is provided on the stop disk 902, and the stop notch 903 has a clockwise stop edge 9031 and a counterclockwise stop edge 9032; a stop block 602 is provided in the stop notch 903, and the two ends are respectively connected to the inner edges of the two metal partitions 6, and the stop block 602 is spaced from the clockwise stop edge 9031 and the counterclockwise stop edge 9032; There is a stop block 2 502 in the opening 903, with both ends connected to the inner edges of the two outer metal plates 5 respectively, and there is a distance between the stop block 2 502 and the clockwise stop edge 9031 and the counterclockwise stop edge 9032; the stop block 2 502 is located on the inner side of the stop block 1 602, and the width of the stop block 2 502 is smaller than the width of the stop block 1 602. When the wheel center disk 2 rotates, the stop block 1 602 touches the clockwise stop edge 9031 or the counterclockwise stop edge 9032 before the stop block 2 502. In this way, when the driving force or resistance is not particularly large, the tensile deformation of the inner elastomer 7 combined with the outer elastomer 8 is sufficient to effectively realize the buffering transmission of the force, and the stop block 602 will not touch the clockwise stop edge 9031 or the counterclockwise stop edge 9032; when the force to be transmitted is large enough to a certain value, the inner elastomer 7 is stretched to the protected limit, and the stop block 602 touches the clockwise stop edge 9031 or the counterclockwise stop edge 9032 to prevent the inner elastomer 7 from continuing to stretch and being damaged. When the stopper 602 touches the clockwise stop edge 9031 or the counterclockwise stop edge 9032, the force that continues to increase continues to stretch the outer elastic body 8 with high rigidity, and the stretching of the outer elastic body 8 satisfies the transmission of force under conditions such as heavy load, climbing, rapid acceleration, and sudden braking. When such force increases to the stretching protection value of the outer elastic body 8, the stopper 502 touches the clockwise stop edge 9031 or the counterclockwise stop edge 9032 to prevent the outer elastic body 8 from continuing to stretch and being damaged. From then on, the force that continues to increase is rigidly transmitted by the stopper 602 and the stopper 502, but this situation rarely occurs.

[0042] The above-mentioned stop block 1 602 and stop block 2 502 are fixed before the elastomer is vulcanized.

[0043] like Figure 6 , 7 As shown in FIG. 9 , the inner metal disc is fixed to the wheel hoop 1, and the outer circumference of the common inner disc 9 is pressed into the inner circumference of the wheel hoop 1 in an interference fit manner. In this way, the installation of the two elastic discs 4 can be completed with just one press fit.

[0044] The outer periphery of the common inner disk 9 is provided with an axially arranged limiting protrusion 901, and the inner periphery of the wheel hoop 1 is provided with an axially arranged limiting groove 101. When the common inner disk 9 is installed in the inner space of the wheel hoop 1, the limiting protrusion 901 is inserted into the limiting groove 101 in a transition fit or interference fit manner, thereby ensuring that there is no slippage between the common inner disk 9 and the wheel hoop 1.

[0045] A plurality of limiting holes 10 are provided circumferentially on the sides facing each other of the wheel center disc 2 and the pressure plate 3, and a plurality of limiting posts 11 are provided on the outer side of the outer metal disc 5. When the outer metal disc 5 located on one side of the wheel center disc 2 is fixed to the wheel center disc 2, and the outer metal disc 5 located on one side of the pressure plate 3 is fixed to the pressure plate 3, the limiting posts 11 are inserted into the limiting holes 10 in a transition fit manner. Thus, the wheel center disc 2 and the pressure plate 3 fixed thereto can rigidly transmit the force to the outer metal disc 5.

[0046] like Figure 8 , 9 As shown in Figures 10, the two ends of the stopper 1 602 are fixedly connected to the inner edges of the metal partitions 6 of the two elastic disks 4 by welding, and the two ends of the stopper 2 502 are fixedly connected to the inner edges of the outer metal disks 5 of the two elastic disks 4 by welding. Further, a positioning notch 1 601 is provided on the inner edges of the metal partitions 6 of the two elastic disks 4, and the two ends of the stopper 1 602 are respectively welded in the positioning notch 1 601 of the inner edges of the two metal partitions 6; a positioning notch 2 501 is provided on the inner edges of the outer metal disks 5 of the two elastic disks 4, and the two ends of the stopper 2 502 are respectively welded in the positioning notch 2 501 of the inner edges of the two outer metal disks 5. In this way, it is possible to avoid the stopper 1 602 and the stopper 2 502 from falling off during acceptance due to loose welding.

[0047] The above implementation modes are limited to explaining the present invention. Without departing from the principle of the present invention, several improvements or modifications made by others should be deemed to fall within the protection scope of the present invention.

Claims

1. A shear-type elastic wheel for a rail transit vehicle, comprising a wheel hoop (1), a wheel center disc (2), a pressure plate (3) and two elastic plates (4), the elastic plate (4) having an annular inner metal plate and an annular outer metal plate (5), an elastic body being provided between the inner metal plate and the outer metal plate (5), the two elastic plates (4) having a V-shaped axial cross section and being symmetrically mounted on both sides of an inner space of the wheel hoop (1), the wheel center disc (2) and the pressure plate (3) being respectively fastened by bolts on the outer sides of the two elastic plates (4), the inner metal plates of the two elastic plates (4) being fixed to the wheel hoop (1), the outer metal plate (5) of the elastic plate (4) located on one side of the wheel center disc (2) being fixed to the wheel center disc (2), and the outer metal plate (5) of the elastic plate (4) located on one side of the pressure plate (3) being fixed to the pressure plate (3), characterized in that: The elastic body of the elastic disk (4) is divided into an inner elastic body (7) and an outer elastic body (8), the inner elastic body (7) and the outer elastic body (8) have a difference in rigidity, an annular metal partition (6) is provided between the inner elastic body (7) and the outer elastic body (8), and when in use, the acting force can be transmitted between the wheel hoop (1) and the wheel center disk (2) by twisting the elastic body.

2. The shear-type elastic wheel for rail transit vehicles according to claim 1, characterized in that: The rigidity of the inner layer elastic body (7) is smaller than the rigidity of the outer layer elastic body (8).

3. The shear-type elastic wheel for rail transit vehicles according to claim 2, characterized in that: The inner layer elastomer (7) and the outer layer elastomer (8) are both rubber bodies. The inner layer elastomer (7) is bonded to the inner metal disc and the metal partition (6) respectively by vulcanization, and the outer layer elastomer (8) is bonded to the outer metal disc and the metal partition (6) respectively by vulcanization.

4. The shear-type elastic wheel for rail transit vehicles according to any one of claims 1 to 3, characterized in that: The inner metal disks of the two elastic disks (4) are an annular common inner disk (9) shared by the two elastic disks (4).

5. The shear-type elastic wheel for rail transit vehicles according to claim 4, characterized in that: The inner edge of the annular common inner disk (9) is an annular stop disk (902) extending centripetally, and a stop notch (903) is provided on the stop disk (902), and the stop notch (903) has a clockwise stop edge (9031) and a counterclockwise stop edge (9032); a stop block (602) is provided in the stop notch (903), and the two ends of the stop block (602) are respectively connected to the inner edges of the two metal partitions (6), and the stop block (602) is spaced from the clockwise stop edge (9031) and the counterclockwise stop edge (9032); 3) having a second stop block (502) with two ends respectively connected to the inner edges of the two outer metal disks (5), and a spacing between the second stop block (502) and the clockwise stop edge (9031) and the counterclockwise stop edge (9032); the second stop block (502) is located on the inner side of the first stop block (602), and the width of the second stop block (502) is smaller than the width of the first stop block (602). When the wheel center disk (2) rotates, the first stop block (602) touches the clockwise stop edge (9031) or the counterclockwise stop edge (9032) before the second stop block (502).

6. The shear-type elastic wheel for rail transit vehicles according to claim 4, characterized in that: The inner metal disc is fixed to the wheel hoop (1) by pressing the outer circumference of the common inner disc (9) into the inner circumference of the wheel hoop (1) in an interference fit manner.

7. The shear-type elastic wheel for rail transit vehicles according to claim 6, characterized in that: The outer circumference of the common inner disk (9) has an axially arranged limiting protrusion (901), and the inner circumference of the wheel hoop (1) has an axially arranged limiting groove (101). When the common inner disk (9) is installed in the inner space of the wheel hoop (1), the limiting protrusion (901) is inserted into the limiting groove (101) in a transition fit or interference fit manner.

8. The shear-type elastic wheel for rail transit vehicles according to claim 1, characterized in that: A plurality of limiting holes (10) are circumferentially provided on the opposite sides of the wheel center disc (2) and the pressure disc (3), and a plurality of limiting posts (11) are provided on the outer side of the outer metal disc (5). When the outer metal disc (5) on one side of the wheel center disc (2) is fixed to the wheel center disc (2), and when the outer metal disc (5) on one side of the pressure disc (3) is fixed to the pressure disc (3), the limiting posts (11) are inserted into the limiting holes (10) in a transition fit manner.

9. The shear-type elastic wheel for rail transit vehicles according to claim 5, characterized in that: The two ends of the first stopper block (602) are fixedly connected to the inner edges of the metal partitions (6) of the two elastic disks (4) by welding, and the two ends of the second stopper block (502) are fixedly connected to the inner edges of the outer metal disks (5) of the two elastic disks (4) by welding.

10. The shear-type elastic wheel for rail transit vehicles according to claim 9, characterized in that: A positioning notch 1 (601) is provided on the inner circumference of the metal partitions (6) of the two elastic disks (4), and the two ends of the stop block 1 (602) are respectively welded in the positioning notch 1 (601) of the inner circumference of the two metal partitions (6); a positioning notch 2 (501) is provided on the inner circumference of the outer metal disks (5) of the two elastic disks (4), and the two ends of the stop block 2 (502) are respectively welded in the positioning notch 2 (501) of the inner circumference of the two outer metal disks (5).

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