An auxiliary spring that compensates for the height drop due to the creep of the rubber body in a mechanical transmission manner

Abstract

The present invention discloses an auxiliary spring that compensates for the height decrease due to the creep of a rubber body in a mechanical transmission manner, which includes a rigid core shaft, a rubber body vulcanized and bonded to the outer periphery of the core shaft, a metal outer sleeve vulcanized and bonded to the outer periphery of the rubber body, and a support plate horizontally installed on the top of the metal outer sleeve. A height lifting device is provided between the core shaft and the base. The lifting device includes a frame base, a lifting mechanism installed on the frame base, a torsion transmission mechanism, and a pressure storage mechanism. When the rubber body has crept and dropped to a set height, the carriage is in a heavy load condition, and the auxiliary spring encounters a downward overload impact, the support plate sinks and presses down the pressure storage mechanism, and the pressure storage mechanism temporarily stores the pressure. When the downward overload impact is released or the carriage heavy load is released, the pressure stored in the pressure storage mechanism causes the lifting mechanism to lift the auxiliary spring upward through the torsion transmission mechanism, thereby realizing the compensation for the decreased height of the auxiliary spring.

Description

Technical Field

[0001] The present invention relates to an air spring on a train bogie, and more particularly to an auxiliary spring that compensates for the height drop due to the creep of a rubber body in a mechanical transmission manner, belonging to the technical field of train vibration reduction. Background Art

[0002] The air spring mainly consists of an auxiliary spring at the lower part and a rubber airbag at the upper part.

[0003] The auxiliary spring has a rigid mandrel. The outer periphery of the mandrel is a rubber body that is vulcanized with the mandrel and accumulates outward and upward. The rubber body has multiple metal sleeves that are vulcanized with the rubber body from the inside to the outside; outside the rubber body is a metal outer sleeve that is vulcanized with the rubber body; the top of the metal outer sleeve is a support plate.

[0004] The top of the rubber airbag is an upper cover plate. A rubber airbag is formed by surrounding and sealing the outer periphery of the bottom surface of the upper cover plate and the outer periphery of the metal outer sleeve with an annular rubber capsule.

[0005] The bottom of the mandrel is the installation base of the air spring.

[0006] Normally, to save materials and for lightweight, the mandrel is a hollow body that penetrates up and down.

[0007] The air spring is installed on the bogie to support the train car body and is used for multi-directional vibration reduction of the car body during operation.

[0008] Since the auxiliary spring is located at the lower part of the rubber airbag, it bears all the loads above the rubber airbag.

[0009] Originally, when the rubber body encounters a load impact, the deformation generated can be restored, and people utilize this characteristic for vibration reduction between various components. However, when the rubber body is applied to the train auxiliary spring, due to the long-term heavy pressure of the car body and the characteristics of the rubber itself, the rubber body will produce creep that cannot restore its original shape. Especially under long-term repeated overload impacts, this creep change will be accelerated, causing the height of the auxiliary spring to gradually decrease, and thus the overall height of the auxiliary spring to become lower and lower. When the height of the auxiliary spring decreases, to ensure that the overall height of the air spring remains at the preset height, a differential pressure valve will be activated, and a pneumatic system dedicated to adjusting the overall height of the air spring will inflate and pressurize the rubber airbag to increase the height of the air spring to compensate for the height reduction due to the creep of the auxiliary spring. But compensating for the height by inflating and pressurizing the rubber airbag in this way increases the stiffness of the rubber airbag, affecting the vibration reduction effect of the train operation. At the same time, using such inflation and pressurization increases the expansion pressure on the rubber capsule, making it easier for the rubber capsule itself and its joints with the upper cover plate and the metal outer sleeve to burst, leading to operation failures and shortening the service life of the air spring.

[0010] In addition to the above problems, the creep of the auxiliary spring rubber body will also cause the following adverse consequences:

[0011] 1. As the creep of the auxiliary spring rubber body becomes more and more serious, the elasticity of the auxiliary spring becomes worse and worse. This is also one of the important reasons why the vibration damping effect of high-speed trains is much worse than at the beginning after a certain number of years of use.

[0012] 2. In the airless state, the lower part of the hanging airbag will interfere with other components on the bogie, affecting the safe operation of the vehicle.

[0013] Through retrieval, no special research on the above problems has been found at present. However, our company believes that effectively solving the problem of the height reduction of the air spring caused by the creep of the auxiliary spring rubber body is of great significance for the train to maintain a good vibration damping effect for a long time and extend its service life, and a series of related researches have been carried out for this purpose.

[0014] The research of the present invention is suitable for eliminating the adverse effects caused by creep of the air springs of trains operating in all regions (including freezing regions). Summary of the Invention

[0015] The technical problem to be solved by the present invention is: how to timely implement height compensation for the height reduction of the air spring caused by the creep of the auxiliary spring rubber body.

[0016] In view of the above problems, the technical solution proposed by the present invention is:

[0017] An auxiliary spring that compensates for the height drop caused by the creep of the rubber body in a mechanical transmission manner, including a rigid core shaft, a rubber body vulcanized and bonded to the outer periphery of the core shaft, a metal outer sleeve vulcanized and bonded to the outer periphery of the rubber body, and a support plate horizontally installed on the top of the metal outer sleeve. A height lifting device is provided between the core shaft and the base. The lifting device includes a frame seat, a lifting mechanism installed on the frame seat, a torque transmission mechanism, and a pressure storage mechanism. When the rubber body has crept down to the set height, the carriage is in a heavy load condition, and the auxiliary spring encounters a downward overload impact, the support plate sinks and presses the pressure storage mechanism, and the pressure storage mechanism temporarily stores the pressure. When the downward overload impact is released or the heavy load of the carriage is released, the pressure stored in the pressure storage mechanism makes the lifting mechanism lift the auxiliary spring upward through the torque transmission mechanism.

[0018] Further, the lifting mechanism includes a lifting lead screw vertically installed on the frame seat and a worm gear fixedly installed on the lifting lead screw. The lifting lead screw supports the bottom of the core shaft and can rise on the frame seat when the lifting lead screw rotates.

[0019] Further, the torque transmission mechanism includes a worm and a ratchet fixed on the worm. The worm is horizontally arranged, and the worm teeth of the worm mesh with the worm wheel teeth of the worm wheel. Both sides of the frame base are respectively provided with side walls, and the two side walls are provided with symmetrically arranged worm mounting holes. The two ends of the worm are respectively rotatably mounted in the worm mounting holes of the two side walls.

[0020] Further, the pressure storage mechanism includes a compression spring, a pressure rod, and a pawl. The compression spring presses on the base. The pressure rod is vertically sleeved in the hollow mandrel, with its lower end pressing on the compression spring and its upper end located below the support plate. The pawl is arranged at the lower part of the pressure rod that can cooperate with the worm. The pawl and the ratchet are in an upward-pushing rotational fit. When the pressure rod is pressed down, the pawl slides downward along the sliding surface of the ratchet teeth. When the pressure rod rises, it can drive the pawl, and the top end of the pawl pushes upward against the pushing surface of the ratchet teeth to drive the ratchet to rotate.

[0021] Further, there are four lifting lead screws, which are arranged in a matrix to support the auxiliary spring. The worm wheels assembled on each lifting lead screw are at the same height. There are two worms, and the worm teeth are arranged at both ends of the worms. The two worms are parallelly arranged between the left two worm wheels and the right two worm wheels among the four worm wheels arranged in a matrix. There are two ratchets, which are respectively arranged in the middle of the two worms. The pressure rod is located between the two ratchets, and there are two pawls, which respectively cooperate with the two ratchets on both sides of the pressure rod.

[0022] Further, a lower limit position for generating the maximum vertical overload impact before creep occurs is set below the support plate, and the upper end surface of the pressure rod is at the height of this lower limit position.

[0023] Further, a pawl installation space is arranged inside the lower end of the pressure rod, and windows for the top end of the pawl to protrude are arranged on both sides of the installation space.

[0024] Further, the frame base includes an upper layer plate with a horizontally arranged top and a lower layer plate with a horizontally arranged bottom. The upper and lower ends of the lifting lead screw respectively have external threads, and the upper layer plate and the lower layer plate are respectively provided with threaded holes that cooperate with the external threads at the upper and lower ends of the lifting lead screw. There is a compensation space between the lower layer plate and the base, and the height of the compensation space is equal to or greater than the compensation height for the auxiliary spring.

[0025] Further, through holes are arranged on the lower layer plate, and the compression spring presses on the base through the through holes.

[0026] Further, before the rubber body generates creep, the worm teeth of the worm mesh with the worm wheel teeth at the upper end near the worm wheel, and the length of the worm wheel teeth downward at this meshing position is greater than or equal to the height that the lifting lead screw is about to rise.

[0027] Beneficial effects:

[0028] 1. In the process of continuous creep of the rubber body of the auxiliary spring, the lifting device of the present invention can automatically and continuously implement height compensation. Moreover, since the device is a pure mechanical transmission without involving liquid, it is not affected by freezing weather, so that the air spring can always maintain an ideal height. There is no need to additionally inflate and pressurize the rubber airbag to implement height compensation. This is beneficial to maintaining the elastic stiffness of the rubber airbag in the most ideal state, and can reduce the risk of the rubber airbag bursting, which is beneficial to extending the service life of the rubber airbag.

[0029] 2. Due to the setting of the compression spring, it objectively bears part of the overload impact load, reduces the ultimate pressure that the rubber body of the auxiliary spring originally has to bear, and can effectively delay the creep process of the rubber body.

[0030] 3. It can prevent the lower part of the hanging airbag from interfering with other parts on the bogie when it is deflated, thus affecting the safe operation of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic cross-sectional view of the air spring.

[0032] Figure 2 The figure is a top view of the lifting device after removing the upper plate.

[0033] Figure 3 for Figure 1 A partial schematic diagram of .

[0034] Figure 4 for Figure 3 A partial schematic diagram of the present invention, in which the elastic member shown is a tension spring.

[0035] Figure 5 for Figure 1 The schematic diagram of the air spring without the rubber airbag shows the state of the entire lifting device when the pressure rod is not in contact with the support plate, and no force is generated between the pawl and the ratchet wheel.

[0036] Figure 6 for Figure 1 The schematic diagram of the air spring without the rubber airbag shows that after the auxiliary spring encounters a downward overload impact under a heavy load condition, the pressure rod is pressed down by the support plate until the top pressure end of the pawl has pressed against the pushing surface of the ratchet teeth.

[0037] Figure 7 It is a cross-sectional schematic diagram showing that the upper end surface of the pressure rod is located at the lower limit position.

[0038] In the figure: 1. Air spring; 2. Rubber airbag; 3. Auxiliary spring; 31. Core shaft; 32. Rubber body; 33. Metal outer sleeve; 34. Support plate; 4. Lifting device; 41. Mounting base; 411. Upper plate; 412. Lower plate; 413. Through hole; 414. Threaded hole; 415. Side wall; 416. Compensation space; 42. Lifting lead screw; 421. Worm gear; 4211. Worm gear teeth; 422. External thread; 43. Worm; 44. Worm teeth; 45. Ratchet; 451. Sliding surface; 452. Pushing surface; 46. Pawl; 461. Pressing end; 462. Elastic member; 47. Compression spring; 48. Pressing rod; 481. Upper end surface; 482. Installation space; 483. Window; 49. Lower limit; 5. Base. Detailed implementation manners

[0039] The present invention will be further described below in conjunction with embodiments and the drawings:

[0040] As Figure 1 shown, the auxiliary spring 3 is a main component of the air spring 1. It is located below the rubber airbag 2 and together with the rubber airbag 2 constitutes the air spring 1. The bottom of the auxiliary spring 3 has a base 5 for installing the entire air spring. The air spring is installed on the bogie through the base 5 to support the car body of the train and play a role in vertical and horizontal vibration reduction during operation.

[0041] As Figure 1 shown, an auxiliary spring that compensates for the height drop due to the creep of the rubber body in a mechanical transmission manner includes: a rigid core shaft 31, a rubber body 32 vulcanized and bonded to the outer periphery of the core shaft 31, a metal spacer sleeve that is vulcanized and integrated with the rubber body in multiple layers from the inside to the outside, a metal outer sleeve 33 vulcanized and bonded to the outer periphery of the rubber body, and a support plate 34 horizontally installed on the top of the metal outer sleeve 33; the core shaft 31 is a hollow body that penetrates up and down, and the support plate 34 is hermetically fixed to the metal outer sleeve 33 (such as by adding a gasket) to ensure the airtightness of the rubber airbag 2. A height lifting device 4 is provided between the core shaft 31 and the base 5. The lifting device 4 includes a mounting base 41, a lifting mechanism, a torque transmission mechanism, and a pressure storage mechanism installed on the mounting base 41. When the rubber body 32 undergoes creep and has dropped to the set height, the car body is in a heavy load condition, and the auxiliary spring 3 encounters a downward overload impact, the support plate 34 sinks, contacts and presses the pressure storage mechanism, and the pressure storage mechanism temporarily stores the pressure. When the downward overload impact is removed or the heavy load of the car body is removed, the pressure stored in the pressure storage mechanism makes the lifting mechanism lift the auxiliary spring 3 upward through the torque transmission mechanism, so that the auxiliary spring 3 is lifted to compensate for the height drop of the auxiliary spring 3 caused by the creep of the rubber body. Here, the removal of the heavy load means that part or all of the personnel or goods loaded in the car body are unloaded.

[0042] Since this device does not involve liquids and is a pure mechanical transmission, it is not affected by freezing weather and can be applied to all regions with different temperatures.

[0043] As shown Figure 1 —3, the lifting mechanism includes a lifting lead screw 42 vertically installed on the frame base 41 and a worm gear 421 fixedly installed on the lifting lead screw 42. The lifting lead screw 42 supports the bottom of the mandrel 31. When the lifting lead screw 42 rotates, it can rise on the frame base 41.

[0044] As a way of installing the lifting lead screw 42, an upper plate 411 is horizontally arranged at the top of the frame base 41 and a lower plate 412 is horizontally arranged at the lower part. The upper end and the lower end of the lifting lead screw 42 respectively have external threads 422. Threaded holes 414 that cooperate with the external threads 422 at the upper end and the lower end of the lifting lead screw 42 are respectively provided on the upper plate 411 and the lower plate 412. There is a compensation space 416 between the lower plate 412 and the base 5. The height of the compensation space 416 is equal to or greater than the compensation height for the auxiliary spring. Before the rubber body generates creep, the lower end of the lifting lead screw 42 is located in the compensation space 416.

[0045] The torque transmission mechanism includes a worm 43 and a ratchet wheel 45 fixed on the worm 43. The worm 43 is horizontally arranged. The worm teeth 44 of the worm 43 mesh with the worm gear teeth 4211 of the worm gear 421; both sides of the frame base 41 respectively have side walls 415. The two side walls 415 have symmetrically arranged worm installation holes. The two ends of the worm 43 are respectively rotatably installed in the worm installation holes of the two side walls 415. When the ratchet wheel 45 drives the worm 43 to rotate, the worm teeth 44 of the worm 43 push the worm gear teeth 4211 of the worm gear 421 to make the worm gear 421 and the lifting lead screw 42 rotate, so that the lifting lead screw 42 moves up and down on the frame base 41. The present invention only allows the lifting lead screw 42 to rise, so the ratchet wheel 45 is designed to rotate only in a specific direction.

[0046] The pressure storage mechanism includes a compression spring 47, a pressure rod 48 and a pawl 46. The compression spring 47 is pressed on the base 5. The pressure rod 48 is vertically sleeved in the hollow mandrel 31. Its lower end presses on the compression spring 47 and its upper end is located below the support plate 34. The pawl 46 is arranged at the lower part of the pressure rod 48 that can cooperate with the ratchet wheel 45 of the worm 43. The pawl 46 and the ratchet wheel 45 are in an upward-pushing rotational fit. When the pressure rod 48 is pressed down, the pawl 46 slides downward across the sliding surface 451 of the ratchet teeth of the ratchet wheel 45. When the pressure rod 48 rises, it can drive the pawl 46, and the top pressing end 461 of the pawl 46 pushes upward against the pushing surface 452 of the ratchet teeth of the ratchet wheel 45 to drive the ratchet wheel 45 to rotate.

[0047] There are four lifting lead screws 42, which are arranged in a matrix to support the auxiliary spring 3. The worm wheels 421 assembled on each lifting lead screw 42 are at the same height. There are two worm shafts 43, and the worm teeth are arranged at both ends of the worm shaft 43. The two worm shafts 43 are arranged in parallel between the left two worm wheels 421 and the right two worm wheels 421 among the four worm wheels 421 arranged in a matrix. There are two ratchets 45, which are respectively arranged in the middle of the two worm shafts 43. The pressure rod 48 is located between the two ratchets 45. There are two pawls 46, which are respectively engaged with the two ratchets 45 on both sides of the pressure rod 48.

[0048] As Figure 5 , 7 shown, a lower limit 49 for generating the maximum vertical overload impact before creep is provided below the support plate 34, and the upper end surface 481 of the pressure rod 48 is at the height of the lower limit 49. With this setting, even when encountering an overload impact under a heavy load condition before the rubber body 32 of the auxiliary spring generates creep, the support plate 34 can only touch the upper end surface 481 of the pressure rod 48 and will not press down the pressure rod 48 to make it move downward.

[0049] A pawl installation space 482 is provided inside the lower end of the pressure rod 48. The installation space 482 has windows 483 on both sides of the pressure rod 48 for the top pressing ends 461 of the pawls 46 to protrude. Under the action of the elastic member 462 inside the installation space 482, the top pressing ends 461 of the pawls 46 always automatically pop out of the windows 483 and are in a state where they can slide downward along the sliding surface 451 of the ratchet teeth of the ratchet 45 and push upward against the pushing surface 452 of the ratchet teeth of the ratchet 45.

[0050] A through hole 413 is provided in the center of the lower layer plate 412 of the frame base 41, and the compression spring 47 presses on the base 5 through the through hole 413.

[0051] Before the rubber body 32 generates creep, the worm teeth 44 of the worm shaft 43 are engaged with the worm wheel teeth 4211 at the upper end near the worm wheel 421, and the length of the worm wheel teeth 4211 downward at this engagement position is greater than or equal to the height that the lifting lead screw 42 will rise. As the lifting lead screw 42 rises, the engagement position between the worm teeth 44 and the worm wheel teeth 4211 will gradually move downward.

[0052] As Figure 1 —7 shows, it can be seen from the above settings of the present invention that:

[0053] Before the rubber body 32 generates creep, even when the carriage reaches a heavy load state and encounters the maximum downward load impact, the support plate 34 will not press down the pressure rod 48 to make it move downward.

[0054] After creep occurs in the rubber body 32 of the auxiliary spring 3, the height of the auxiliary spring 3 decreases. The pressure rod 48 is supported on the base 5 or the pedestal 41 that does not change in height by the compression spring 47. The support plate 34 fixed to the top end of the auxiliary spring 3 will approach the upper end surface 481 of the pressure rod 48 downward as the height of the auxiliary spring 3 decreases. In this case, when the carriage reaches the heavy-load state and encounters the maximum downward load impact, the support plate 34 will contact and press down the pressure rod 48, causing the pressure rod to slide downward against the upward elastic force of the compression spring 47. The pressing ends 461 of the pawls 46 ejected from the two side windows at the lower part of the pressure rod 48 will respectively slide downward past the sliding surfaces 451 of the teeth of the two side ratchets 45. When the downward load impact ends and the pressure rod 48 stops sliding downward, the pressing ends 461 of the pawls 46 will be inserted into the spaces between two adjacent teeth under the action of the elastic member 462, and the pressing ends 461 will press against the pushing surfaces 452 of the teeth of the ratchet 45 upward under the restoring force of the compression spring 47 pushing the pressure rod 48 upward. At this time, if the restoring force of the compression spring 47 used is large enough, at the moment when the downward impact load is removed, the force that makes the pressing end 461 of the pawl 46 push the tooth of the ratchet 45 is sufficient to drive the lifting lead screw 42 to rotate and rise through the torsion transmission mechanism set as above. Because the force that the pressing end 461 of the pawl 46 pushes the tooth of the ratchet 45 can be amplified and transformed through multiple stages of the torsion transmission mechanism set as above, the upward force formed by the lifting lead screw 42 can be hundreds or even thousands of times the restoring force of the compression spring 47. If the restoring force of the compression spring 47 used is relatively small, after the heavy load of the carriage is removed, the restoring force of the compression spring 47 will drive the lifting lead screw 42 to rotate and rise through the above mechanism, realizing the height compensation for the auxiliary spring 3.

[0055] During the long service life of the air spring, creep will continuously occur in the rubber body 32 of its auxiliary spring 3, and the device of the present invention will continuously and automatically implement height compensation, enabling the air spring to always maintain an ideal height. At the same time, due to the setting of the compression spring 47, it objectively bears part of the overload impact load, reduces the ultimate pressure that the rubber body 32 of the auxiliary spring 3 originally had to bear, and can effectively delay the creep process of the rubber body.

[0056] The above embodiments are only used to describe the present invention more clearly and should not be regarded as limiting the protection scope covered by the present invention. Any modification in an equivalent form should be regarded as falling within the protection scope covered by the present invention.

Claims

1. An auxiliary spring that compensates for the height drop due to the creep of the rubber body in a mechanical transmission manner, comprising a rigid mandrel (31), a rubber body (32) vulcanized and bonded to the outer periphery of the mandrel (31), a metal outer sleeve (33) vulcanized and bonded to the outer periphery of the rubber body, a support plate (34) horizontally installed on the top of the metal outer sleeve (33), and there is a spacing between the mandrel (31) and the metal outer sleeve (33), characterized in that: A height-lifting device (4) is arranged between the mandrel (31) and the base (5). The lifting device (4) includes a frame base (41), a lifting mechanism, a torsion transmission mechanism, and a pressure storage mechanism installed on the frame base (41). When the rubber body (32) has creeped and dropped to the set height, the carriage is in a heavy-load condition, and the auxiliary spring (3) encounters a downward overload impact, the support plate (34) sinks to contact and press down the pressure storage mechanism, and the pressure storage mechanism temporarily stores the pressure. When the downward overload impact is released or the heavy load of the carriage is released, the pressure stored in the pressure storage mechanism makes the lifting mechanism lift the auxiliary spring (3) upward through the torsion transmission mechanism; the lifting mechanism includes a lifting screw rod (42) vertically installed on the frame base (41) and a worm gear (421) fixedly installed on the lifting screw rod (42). The lifting screw rod (42) supports the bottom of the mandrel (31), and the lifting screw rod (42) can rise on the frame base (41) when rotating; the torsion transmission mechanism includes a worm (43) and a ratchet wheel (45) fixed on the worm (43). The worm (43) is horizontally arranged, and the worm teeth (44) of the worm (43) are engaged with the worm gear teeth (4211) of the worm gear (421); the pressure storage mechanism includes a compression spring (47), a pressure rod (48), and a pawl (46). The compression spring (47) presses on the base (5). The pressure rod (48) is vertically sleeved in the hollow mandrel (31). Its lower end presses on the compression spring (47), and its upper end is located below the support plate (34). The pawl (46) is arranged at the lower part of the pressure rod (48) that can cooperate with the worm (43). The pawl (46) and the ratchet wheel (45) are in a top-up rotational fit. When the pressure rod (48) is pressed down, the pawl (46) slides downward along the sliding surface (451) of the teeth of the ratchet wheel (45). When the pressure rod (48) rises, it can drive the pawl (46), and the top end (461) of the pawl (46) pushes up the pushing surface (452) of the teeth of the ratchet wheel (45) to drive the ratchet wheel (45) to rotate; a lower limit (49) of the maximum vertical overload impact before creep is set below the support plate (34), and the upper end surface (481) of the pressure rod (48) is at the height of the lower limit (49); before the rubber body (32) has creeped, the worm teeth (44) of the worm (43) are engaged with the worm gear teeth (4211) near the upper end of the worm gear (421), and the length of the worm gear teeth (4211) downward at this engagement position is greater than or equal to the height that the lifting screw rod (42) is going to rise.

2. The auxiliary spring for compensating the height reduction due to the creep of the rubber body in a mechanical transmission manner according to claim 1, characterized in that: Both sides of the frame base (41) respectively have side walls (415). The two side walls (415) are provided with symmetrically arranged worm installation holes, and both ends of the worm (43) are respectively rotatably installed in the worm installation holes of the two side walls (415).

3. The auxiliary spring for compensating the height decrease due to the creep of the rubber body in a mechanical transmission manner according to claim 1, characterized in that: There are four lifting lead screws (42), which are arranged in a matrix to support the auxiliary spring (3). The worm wheels (421) assembled on each lifting lead screw (42) are at the same height; there are two worm shafts (43), and the worm teeth are arranged at both ends of the worm shaft (43). The two worm shafts (43) are arranged in parallel between the left two worm wheels (421) and the right two worm wheels (421) among the four worm wheels (421) arranged in a matrix. There are two ratchets (45), which are respectively arranged in the middle of the two worm shafts (43); the pressure bar (48) is located between the two ratchets (45), and there are two pawls (46), which are respectively engaged with the two ratchets (45) on both sides of the pressure bar (48).

4. The auxiliary spring for compensating the height reduction due to the creep of the rubber body in a mechanical transmission manner according to claim 3, characterized in that: A pawl installation space (482) is provided inside the lower end of the pressure bar (48). Windows for the top pressure ends (461) of the pawls (46) to protrude are provided on both sides of the pressure bar (48) in this installation space (482).

5. The auxiliary spring for compensating the decreased height due to the creep of the rubber body in a mechanical transmission manner according to claim 1, wherein: The frame base (41) includes an upper layer plate (411) horizontally arranged at the top and a lower layer plate (412) horizontally arranged at the bottom. The upper and lower ends of the lifting lead screw (42) respectively have external threads (422). Threaded holes (414) that cooperate with the upper end external thread (422) and the lower end external thread (422) of the lifting lead screw (42) are respectively provided on the upper layer plate (411) and the lower layer plate (412). There is a compensation space (416) between the lower layer plate (412) and the base (5), and the height of the compensation space (416) is equal to or greater than the compensation height for the auxiliary spring.

6. The auxiliary spring for compensating the height reduction due to the creep of the rubber body in a mechanical transmission manner according to claim 5, characterized in that: A through hole (413) is provided on the lower layer plate (412), and the compression spring (47) presses on the base (5) through the through hole (413).

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