Transmission shaft intermediate support assembly and transmission shaft system

Abstract

A transmission shaft intermediate support assembly and a transmission shaft system belong to the technical field of vehicle transmission and comprise an intermediate support, two ends of the intermediate support are respectively connected with a telescopic transmission shaft through a universal joint, one end of each telescopic transmission shaft far away from the intermediate support is connected with a universal joint, and the intermediate support and the telescopic transmission shafts at two ends of the intermediate support are integrated. The use of an intermediate transmission shaft is canceled, an intermediate transmission shaft assembly line and related dynamic balance equipment are canceled, the production investment is reduced, and meanwhile, under the cooperation of the universal joint and the telescopic transmission shaft, the angle and length adjustment is realized, so that the matching design error, the manufacturing and machining error and the assembly error of the whole vehicle can be avoided; abnormal abrasion of the middle bearing assembly is reduced, only the telescopic transmission shaft is adopted, the types of the transmission shafts are effectively reduced, product management is facilitated, meanwhile, due to the fact that the angle and the length can be adjusted, the connecting frame only needs to be designed into one or more sizes, and cost is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle transmission, and in particular to a transmission shaft intermediate support assembly and a transmission shaft system. Background Art

[0002] The drive shaft is a rotating body with high speed and few supports. The drive shaft is an important component for transmitting power in the automobile transmission system. Its function is to transmit the power of the engine to the wheels together with the gearbox and drive axle, so that the car can generate driving force. Trucks and dump trucks have a longer wheelbase. In order to increase the critical speed of the drive shaft, avoid resonance and consider the needs of the overall layout of the vehicle, 2 to 3 drive shafts are generally arranged. At this time, the drive shaft intermediate support is required.

[0003] In the current design scheme, the intermediate support of the transmission shaft is generally assembled at the output end of the intermediate transmission shaft. For example, the patent document with publication number CN211054921U discloses a transmission shaft intermediate support connection structure, including an adjustment hanger, a rotating shaft hanger and an intermediate support member, the intermediate support member is connected to the rotating shaft hanger, the transmission shaft is rotatably connected to the intermediate support member, the rotating shaft hanger is connected to the adjustment hanger, and the adjustment hanger is connected below the frame crossbeam.

[0004] The existing intermediate support connection structure of the transmission shaft, in which the intermediate support connection structure is assembled at the output end of the intermediate transmission shaft, includes an intermediate transmission shaft assembly process, which is complex and costly, and the adjustment of the size of the hanger is easily affected by changes in the vehicle frame height, suspension height, and drive axle input flange position, and needs to be designed into a variety of sizes, which increases the processing, procurement and storage costs, and is also prone to design, processing errors and assembly errors; in addition, due to the influence of vehicle matching design errors, manufacturing processing errors and assembly errors, after the intermediate transmission shaft is installed on the vehicle, it is often subjected to additional torque, resulting in abnormal wear of the intermediate support assembly. Summary of the invention

[0005] In order to solve the technical problems that the existing intermediate support connection structure in the above-mentioned background technology is assembled at the output end of the intermediate transmission shaft, the assembly process is complicated and costly, and is affected by changes in the vehicle frame height, suspension height, and drive axle input flange position, resulting in a large number of hanger sizes, difficult management, and prone to design and assembly errors, the present invention provides a transmission shaft intermediate support assembly and a transmission shaft system.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention provides a transmission shaft intermediate support assembly, comprising an intermediate support installed on a frame crossbeam, wherein two ends of the intermediate support are respectively connected to a telescopic transmission shaft through a universal joint, and one end of the telescopic transmission shaft away from the intermediate support is connected to a universal joint. The intermediate support and the telescopic transmission shafts at both ends thereof are integrated as a whole, thereby eliminating the use of the intermediate transmission shaft, and further eliminating the intermediate transmission shaft assembly line and related dynamic balancing equipment, thereby reducing production input. At the same time, with the cooperation of the universal joint and the telescopic transmission shaft, angle and length adjustment can be achieved, thereby avoiding vehicle matching design errors, manufacturing processing errors and assembly errors, reducing abnormal wear of the intermediate support assembly, and only using the telescopic transmission shaft effectively reduces the types of transmission shafts, which is beneficial to product management. At the same time, since the angle and length can be adjusted, the connecting frame only needs to be designed in one or several sizes, thereby effectively reducing the cost.

[0008] Preferably, the intermediate support includes a first connecting flange, a second connecting flange and a buffer seat, and the first connecting flange and the second connecting flange both contain an inserting portion, and the inserting portions of the first connecting flange and the second connecting flange are inserted together in the buffer seat and connected to the bearing in the buffer seat, and the first connecting flange and the second connecting flange are axially fixed by connecting bolts and locking nuts, so that the first connecting flange and the second connecting flange are installed in the buffer seat with the bearing, which has the ability to transmit power and can also play a buffering role.

[0009] Preferably, the first connecting flange includes a first flange plate and a first plug-in part that are fixedly connected, and the second connecting flange includes a second flange plate and a second plug-in part that are fixedly connected. The second plug-in part is inserted in the first plug-in part, and the outer wall of the first plug-in part is connected to the bearing in the buffer seat. The connecting bolt passes through the interior of the second plug-in part and is connected to the clamping nut. The arrangement of the plug-in part enables power transmission between the first connecting flange and the second connecting flange, while ensuring the connection between the connecting flange, the bearing and the buffer plate. The overall structure is compact, which reduces the installation space occupied by the vehicle chassis.

[0010] Preferably, first anti-skid grooves are provided on the inner wall of the first plug-in part and the outer wall of the second plug-in part, and the first anti-skid grooves can cooperate with each other to limit relative rotation between the two plug-in parts, thereby ensuring the effectiveness of power transmission.

[0011] Preferably, a second anti-slip groove is provided at the end of the second plug-in part and at the inner wall position where the first flange contacts the end of the second plug-in part. The second anti-slip groove can be used to limit the relative rotation between the two. The setting of the first anti-slip groove and the second anti-slip groove can effectively ensure the effectiveness of power transmission.

[0012] Preferably, the first flange and the second flange are both connected to the universal joint, and the surfaces of the first flange and the second flange are provided with a third anti-slip groove to increase the friction between the universal joint and the universal joint, and cooperate with the use of bolts to ensure the connection firmness between the universal joint and the corresponding flange and the effectiveness of power transmission.

[0013] Preferably, the buffer seat includes a support and a buffer plate, the support is connected to the frame crossbeam through a connecting frame, the buffer plate is installed on the support, the bearing is arranged in the bearing seat, and a retaining ring and a dust ring are respectively provided at both ends of the bearing. The bearing seat is arranged in the buffer plate, the dust ring is used to block large dust and particles for the maintenance-free deep groove ball bearing, and the retaining ring is used to limit the axial position of the maintenance-free deep groove ball bearing.

[0014] Preferably, the buffer seat includes a support and a buffer plate, the support is connected to the frame crossbeam through a connecting frame, the buffer plate is installed on the support, the bearing is arranged in the bearing seat, and a retaining ring and a dust ring are respectively provided at both ends of the bearing in sequence, the bearing seat is arranged in the buffer plate, the buffer plate, the support and the bearing seat are fixed as a whole, and the buffer plate, the support and the bearing seat are fixed as a whole to avoid wear of the buffer plate due to relative movement between the buffer plate, the support and the bearing seat, and the buffer plate plays a role of buffering and vibration isolation when the vehicle bounces.

[0015] Preferably, the first mounting hole and the second mounting hole are both circular hole structures, which effectively avoids the risk of abnormal stress on the buffer disk caused by improper assembly of the oblong hole structure and improves the overall service life of the intermediate support assembly.

[0016] The present invention also provides a transmission shaft system, including a transmission shaft intermediate support assembly and a plurality of transmission shafts, wherein the intermediate support is fixedly connected to a frame crossbeam through a connecting frame, and both ends of the intermediate support are respectively connected to the transmission shaft through a telescopic transmission shaft, thereby eliminating the use of the intermediate transmission shaft and reducing production input. At the same time, with the cooperation of the universal joint and the telescopic transmission shaft, angle and length adjustment can be achieved, thereby avoiding vehicle matching design errors, manufacturing errors and assembly errors, and reducing abnormal wear of the intermediate support assembly.

[0017] It can be seen from the above technical solutions that the advantages of the present invention are:

[0018] 1. The intermediate support and the telescopic transmission shafts at both ends are an integral whole, eliminating the use of the intermediate transmission shaft, and then eliminating the intermediate transmission shaft assembly line and related dynamic balancing equipment, reducing production input. At the same time, with the cooperation of the universal joint and the telescopic transmission shaft, the angle and length adjustment can be achieved, thereby avoiding vehicle matching design errors, manufacturing errors and assembly errors, reducing abnormal wear of the intermediate support assembly, and only using telescopic transmission shafts, effectively reducing the types of transmission shafts, which is beneficial to product management. At the same time, due to the ability to adjust the angle and length, the connecting frame only needs to be designed in one or several sizes, effectively reducing costs.

[0019] 2. The first connecting flange and the second connecting flange are connected by an inserting part. The setting of the inserting part enables power transmission between the first connecting flange and the second connecting flange, while ensuring the connection between the connecting flange and the bearing and the buffer plate. The overall structure is compact, which reduces the installation space occupied by the vehicle chassis.

[0020] 3. A first anti-slip groove is provided on the inner wall of the first plug-in part and the outer wall of the second plug-in part, and a second anti-slip groove is provided on the end of the second plug-in part and the inner wall position where the first flange contacts the end of the second plug-in part. The anti-slip groove can be used to limit the relative rotation between the first plug-in part and the second plug-in part, thereby effectively ensuring the effectiveness of power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the intermediate support assembly of the transmission shaft according to one or more embodiments of the present invention;

[0023] Figure 2 is a schematic cross-sectional structure diagram of a transmission shaft intermediate support assembly according to one or more embodiments of the present invention;

[0024] Figure 3 It is a schematic diagram of the overall structure of the intermediate support according to one or more embodiments of the present invention;

[0025] Figure 4 It is a schematic diagram of an exploded structure of an intermediate support according to one or more embodiments of the present invention;

[0026] Figure 5 A schematic cross-sectional structure diagram of an intermediate support according to one or more embodiments of the present invention;

[0027] Figure 6 is a schematic cross-sectional structure diagram of a bearing according to one or more embodiments of the present invention;

[0028] Figure 7 for Figure 6 A schematic diagram of a local enlarged structure at the position of structure A shown;

[0029] Figure 8 A schematic diagram of the structure of a support according to one or more embodiments of the present invention;

[0030] Fig. 9 A schematic diagram of the structure of a connecting frame according to one or more embodiments of the present invention;

[0031] The components represented by the reference numerals in the figure are:

[0032] 1. Frame beam; 2. Connecting frame; 21. First mounting hole; 22. Weight reduction groove; 3. Intermediate support; 31. First connecting flange; 311. First plug-in part; 32. Second connecting flange; 321. Second plug-in part; 33. Buffer seat; 331. Support; 3311. Second mounting hole; 332. Buffer plate; 333. Bearing; 3331. Cassette combination sealing unit; 334. Dust ring; 335. Retaining ring; 336. Pressure plate; 337. Bearing seat; 34. Connecting bolt; 35. Pressing nut; 36. First anti-skid groove; 37. Second anti-skid groove; 38. Third anti-skid groove; 4. First telescopic transmission shaft; 41. First universal joint; 42. First telescopic spline pair; 5. Second telescopic transmission shaft; 51. Second universal joint; 52. Second telescopic spline pair. DETAILED DESCRIPTION

[0033] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0034] Example 1

[0035] In a typical embodiment of the present invention, Figure 1-Figure 9As shown, a transmission shaft intermediate support assembly is proposed, including: an intermediate support 3, a first telescopic transmission shaft 4 and a second telescopic transmission shaft 5, one end of the intermediate support 3 is connected to the first telescopic transmission shaft 4 through a connecting flange, the other end of the intermediate support 3 is connected to the second telescopic transmission shaft 5 through a connecting flange, the intermediate support 3 is fixedly connected to the frame crossbeam 1 through a connecting frame 2, and the two ends of the intermediate support 3 are respectively connected to the transmission shaft system of the vehicle through the first telescopic transmission shaft 4 and the second telescopic transmission shaft 5. The intermediate support 3, the first telescopic transmission shaft 4 and the second telescopic transmission shaft 5 are used as a whole, and the use of the intermediate transmission shaft is eliminated, thereby eliminating the intermediate transmission shaft assembly line and related dynamic balancing equipment, etc., reducing production investment, such as Figure 2 As shown, both ends of the first telescopic transmission shaft 4 are connected to the transmission shaft system and the intermediate support 3 through the first universal joint 41, and both ends of the second telescopic transmission shaft 5 are connected to the transmission shaft system and the intermediate support 3 through the second universal joint 51, and the first telescopic transmission shaft 4 can be adjusted in length through its own first telescopic spline pair 42, and the second telescopic transmission shaft 5 can also be adjusted in length through its own second telescopic spline pair 52, so that with the cooperation of the universal joint and the telescopic spline pair, the angle and length can be adjusted, thereby avoiding vehicle matching design errors, manufacturing errors and assembly errors. Only telescopic transmission shafts are used, which effectively reduces the types of transmission shafts and is beneficial to product management. At the same time, the connecting frame 2 only needs to be designed in one or several sizes, which effectively reduces the cost.

[0036] like Figure 3-Figure 5 As shown, the intermediate support 3 includes a first connecting flange 31, a second connecting flange 32, a buffer seat 33, a connecting bolt 34 and a clamping nut 35. The first connecting flange 31 and the second connecting flange 32 both have an inserting portion. The inserting portions of the first connecting flange 31 and the second connecting flange 32 are inserted together in the buffer seat 33 and connected to the bearing 333 in the buffer seat 33. At the same time, the first connecting flange 31 and the second connecting flange 32 are axially fixed together by the connecting bolt 34 and the clamping nut 35, as shown in FIG. Figure 2 As shown, the first connecting flange 31 is connected to the first telescopic transmission shaft 4 through the first universal joint 41, the second connecting flange 32 is connected to the second telescopic transmission shaft 5 through the second universal joint 51, and the first connecting flange 31 and the second connecting flange 32 are connected to the transmission system through the first telescopic transmission shaft 4 and the second telescopic transmission shaft 5.

[0037] like Figure 4As shown, the first connecting flange 31 includes a first flange plate and a first plug-in portion 311, the first plug-in portion 311 is a hollow columnar structure, the first plug-in portion 311 is fixedly connected to the first flange plate by welding or integral molding, the first plug-in portion 311 is coaxially arranged with the first flange plate, and the first plug-in portion 311 and the first flange plate have a through hole at the center position allowing the connecting bolt 34 to be installed; the second connecting flange 32 includes a second flange plate and a second plug-in portion 321, the second plug-in portion 321 is a hollow columnar structure, the second plug-in portion 321 is fixedly connected to the second flange plate by welding or integral molding, the second plug-in portion 321 is coaxially arranged with the second flange plate, and the second plug-in portion 321 and the second flange plate have a through hole at the center position allowing the connecting bolt 34 to be installed.

[0038] like Figure 5 As shown, the inner diameter of the first inserting part 311 is the same as the outer diameter of the second inserting part 321, the second inserting part 321 is inserted into the first inserting part 311, the outer wall of the first inserting part 311 is connected to the bearing 333 in the buffer seat 33, and the connecting bolt 34 passes through the inside of the second inserting part 321 and is threadedly connected to the clamping nut 35.

[0039] like Figure 4 and Figure 5 As shown, a first anti-skid groove 36 is provided on the inner wall of the first plug-in part 311 and the outer wall of the second plug-in part 321. The first anti-skid groove 36 is arranged along the circumferential direction of the corresponding plug-in part and extends along the axial direction of the corresponding plug-in part. The first plug-in part 311 and the second plug-in part 321 are cooperated through the first anti-skid groove 36 to limit the relative rotation between the two and ensure the effectiveness of power transmission; the end of the second plug-in part 321 and the inner wall position where the first flange and the end of the second plug-in part 321 contact are provided with a second anti-skid groove 37 to limit the relative rotation between the two through the cooperation of the second anti-skid groove 37. The effectiveness of power transmission is effectively guaranteed by the arrangement of the first anti-skid groove 36 and the second anti-skid groove 37.

[0040] It is understandable that in other embodiments, the first anti-slip groove 36 and the second anti-slip groove 37 can also be set to structures such as transmission teeth, as long as efficient power transmission can be guaranteed between the first connecting flange 31 and the second connecting flange 32. No excessive restrictions are made here.

[0041] The first flange and the second flange are both connected to the universal joint, and the surfaces of the first flange and the second flange are both provided with a third anti-slip groove 38. Figure 4As shown, the first flange and the second flange are both provided with bolt holes for bolt installation, and the third anti-slip grooves 38 are provided around the bolt holes of the first flange and the second flange to increase the friction between the universal joint and the universal joint, and cooperate with the use of bolts to ensure the connection firmness between the universal joint and the corresponding flange and the effectiveness of power transmission.

[0042] The buffer seat 33 includes a support 331, a buffer plate 332, a bearing 333, a dust ring 334, a retaining ring 335, a pressure plate 336 and a bearing seat 337, wherein the support 331 supports the entire assembly and is connected to the frame crossbeam 1 through the connecting frame 2. Figure 8 As shown, the support 331 is a U-shaped structure, and a second mounting hole 3311 is opened at the top of the support 331. The second mounting hole 3311 is a circular hole structure for installing bolts, and then fixedly connected with the pressure plate 336 and the connecting frame 2 through bolts; the bearing 333 is installed in the bearing seat 337, and is fixedly installed on the support 331 through the bearing seat 337. The buffer plate 332 is arranged between the bearing seat 337 and the support 331. The buffer plate 332 is a rubber disc structure. The buffer plate 332, the support 331 and the bearing seat 337 are vulcanized into a whole to avoid relative movement between the buffer plate 332, the support 331 and the bearing seat 337 to cause wear of the buffer plate 332. The buffer plate 332 plays a role of buffering and vibration isolation when the vehicle bounces.

[0043] The bearing 333 is a maintenance-free deep groove ball bearing to reduce the number of maintenance and reduce maintenance costs. Two dust rings 334 and two retaining rings 335 are provided. A retaining ring 335 and a dust ring 334 are provided at both ends of the bearing 333 respectively. The dust ring 334 is used to block large dust and particles for the maintenance-free deep groove ball bearing, and the retaining ring 335 is used to limit the axial position of the maintenance-free deep groove ball bearing; the pressure plate 336 is arranged on the upper part of the support 331 to cover the upper opening of the support 331, so as to assist the fixed installation of the buffer disk 332, such as Figure 7 As shown, the bearing 333 is sealed by a box-type combined sealing unit 3331, which can effectively prevent muddy water from entering the bearing and grease from flowing out of the bearing, effectively ensuring the lubrication of the bearing and increasing the life of the bearing.

[0044] like Fig. 9 As shown, the bottom and side of the connecting frame 2 are provided with a first mounting hole 21, and the first mounting hole 21 is a circular hole structure for the installation of bolts. The bottom of the connecting frame 2 is fixedly connected to the pressure plate 336 and the support 331 in sequence by bolts, and the side of the connecting frame 2 is fixedly connected to the frame crossbeam 1 by bolts. The connecting frame 2 is provided with a weight reduction groove 22 to achieve lightweight connection The frame 2 reduces the overall weight of the connecting frame 2, and reinforcing ribs are welded and fixed on both sides of the connecting frame 2 to increase the overall rigidity of the connecting frame 2 and reduce the deformation of the connecting frame 2.

[0045] The first mounting hole 21 and the second mounting hole 3311 are both circular hole structures, which effectively avoids the risk of abnormal stress on the buffer plate 332 caused by improper assembly of the oblong hole structure and improves the overall service life of the intermediate support assembly.

[0046] Example 2

[0047] In another typical embodiment of the present invention, a transmission shaft system is proposed, which is installed on the chassis of a car to transmit power from a power system. The transmission shaft system includes: a transmission shaft intermediate support assembly and a plurality of transmission shafts. The intermediate support assembly is arranged between two designated adjacent transmission shafts. The intermediate support assembly includes an intermediate support 3. The intermediate support 3 is fixedly connected to the frame crossbeam 1 through a connecting frame 2. The two ends of the intermediate support 3 are respectively connected to the transmission shaft of the vehicle's transmission shaft system through a first telescopic transmission shaft 4 and a second telescopic transmission shaft 5 to realize power transmission.

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A transmission shaft intermediate support assembly, comprising: The intermediate support (3) is installed on the frame crossbeam (1), characterized in that the two ends of the intermediate support (3) are respectively connected to a telescopic transmission shaft through a universal joint, and the end of the telescopic transmission shaft away from the intermediate support (3) is connected to the universal joint.

2. The transmission shaft intermediate support assembly according to claim 1, characterized in that: The intermediate support (3) comprises a first connecting flange (31), a second connecting flange (32) and a buffer seat (33). The first connecting flange (31) and the second connecting flange (32) both comprise an inserting portion. The inserting portions of the first connecting flange (31) and the second connecting flange (32) are inserted together in the buffer seat (33) and connected to a bearing (333) in the buffer seat (33). The first connecting flange (31) and the second connecting flange (32) are axially fixed by connecting bolts (34) and clamping nuts (35).

3. The transmission shaft intermediate support assembly according to claim 2, characterized in that: The first connecting flange (31) includes a first flange plate and a first inserting portion (311) which are fixedly connected, and the second connecting flange (32) includes a second flange plate and a second inserting portion (321) which are fixedly connected, the second inserting portion (321) is inserted into the first inserting portion (311), the outer wall of the first inserting portion (311) is connected to the bearing (333) in the buffer seat (33), and the connecting bolt (34) passes through the interior of the second inserting portion (321) and is connected to the clamping nut (35).

4. The transmission shaft intermediate support assembly according to claim 3, characterized in that: A first anti-slip groove (36) is provided on the inner wall of the first inserting portion (311) and the outer wall of the second inserting portion (321).

5. The transmission shaft intermediate support assembly according to claim 3, characterized in that: A second anti-slip groove (37) is provided at the end of the second inserting portion (321) and at the inner wall position where the first flange plate contacts the end of the second inserting portion (321).

6. The transmission shaft intermediate support assembly according to claim 3, characterized in that: The first flange and the second flange are both connected to the universal joint, and the surfaces of the first flange and the second flange are both provided with a third anti-slip groove (38).

7. The transmission shaft intermediate support assembly according to claim 2, characterized in that: The buffer seat (33) comprises a support seat (331) and a buffer plate (332), the support seat (331) is connected to the frame crossbeam (1) through a connecting frame (2), the buffer plate (332) is installed on the support seat (331), the bearing is arranged in a bearing seat (337), a retaining ring (335) and a dust ring (334) are arranged at both ends of the bearing (333), the bearing seat (337) is arranged in the buffer plate (332), and the buffer plate (332), the support seat (331) and the bearing seat (337) are fixed as a whole.

8. The transmission shaft intermediate support assembly according to claim 7, characterized in that: The bottom and side of the connecting frame (2) are both provided with a first mounting hole (21), the top of the support (331) is provided with a second mounting hole (3311), the bottom of the connecting frame (2) is fixedly connected to the support (331) by bolts, and the connecting frame (2) is provided with a weight-reducing groove (22) and a reinforcing rib.

9. The transmission shaft intermediate support assembly according to claim 8, characterized in that: The first mounting hole (21) and the second mounting hole (3311) are both circular hole structures.

10. A transmission shaft system, characterized in that: It comprises a transmission shaft intermediate support assembly as described in any one of claims 1 to 9 and a plurality of transmission shafts, wherein the intermediate support (3) is fixedly connected to the frame crossbeam (1) via a connecting frame (2), and the two ends of the intermediate support (3) are respectively connected to the transmission shaft via a telescopic transmission shaft.

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