Stable supporting structure of large mechanical transmission shaft

Abstract

The stable supporting structure comprises a bakelite tile and a bakelite tile seat which are coaxially matched and sleeved together and used for bearing and fixing a shifting fork connecting shaft, the bakelite tile seat is made of bakelite materials and directly matched with the connecting shaft, abrasion of the shaft in the operation process is reduced, and the stability of the shaft is improved. The depth of the bakelite tilting fillet is half of the diameter of the shifting fork connecting shaft, it is guaranteed that the connecting shaft is still in close fit when receiving lateral load in operation, and the stabilizing effect is achieved preliminarily. Upper lead seats are arranged on the two sides of the middle of the bakelite tile seat respectively, supporting springs are vertically arranged below the bottom faces of the upper lead seats respectively, and the supporting springs are vertically arranged in vertical guide grooves in the base respectively.

Description

Technical Field

[0001] The present invention relates to a stable support structure for a large mechanical transmission shaft. Background Art

[0002] In recent years, China's steel industry has developed rapidly, and large rolling mills have been continuously applied in production. With the development of different varieties of steel, the center distance requirements of the rolls during the production process can be adjusted at any time. Correspondingly, higher requirements are imposed on the transmission shaft connecting the rolling mill and the reducer. At present, universal shafts are mostly used. To ensure continuous production, the service life of the universal shaft is becoming increasingly important.

[0003] The fork-type universal coupling is easy to install and has the advantages of large torque transmission, compact structure, and large angular compensation amount, etc., and is widely used in the transmission of large rolling mills in the steel industry. However, with the development of different steel varieties, the center distance of the rolls changes continuously, and the large swing during operation leads to a significant reduction in the service life of the transmission shaft. The various forms of vibration phenomena that occur during the rolling process are random and transient. Its occurrence intensity and frequency are related to the rolling process and its operation time, and are also related to the coefficients such as the stiffness and damping of the transmission system itself. From the perspective of dynamics, the general causes can be divided into the following three types: free vibration. After the rolling mill is disturbed and its equilibrium state is destroyed, the vibration maintained by the elastic restoring force of the system, that is, due to the existence of damping in the system, and only energy consumption exists, without energy supply, the vibration will gradually decay. Forced vibration. When the natural frequency of the rolling mill shafting is equal to the external excitation response frequency, forced vibration will occur. Self-excited vibration. A periodic oscillation excited by an alternating force generated by the rolling mill system itself under certain conditions without external excitation. Production accidents caused by the torsional vibration of the main drive system of the rolling mill occur frequently at home and abroad, which seriously restricts the development of the modern steel industry. Through the kinematic analysis of the fork-type universal coupling, it can be seen that the torsional vibration during the working process generates dynamic loads, resulting in cracks at the mating parts at both ends of the coupling, increased wear of the shock-absorbing slider, and frequent fracture of the positioning pin shaft.

[0004] Searching the literature shows that for cross-type universal couplings, the balance bracket method is adopted. However, there is currently no effective solution to the large swing and high load of the fork-type universal coupling. The method of improving the service life of the fork-type coupling by erecting a stabilizing device has not been designed and applied. Summary of the Invention

[0005] The purpose of the present invention is to provide a stable support structure for a large mechanical transmission shaft, so that the transmission shaft runs smoothly during operation, reduces the instantaneous load borne by the mating parts, and solves the bottleneck problem of frequent fractures of the transmission shaft of large rolling mills in steel plants, resulting in accidents.

[0006] The technical solution adopted by the present invention is a stable support structure for a large-scale mechanical transmission shaft, including a bakelite tile and a bakelite tile seat that are coaxially fitted together, which is used to support and fix the fork connecting shaft. The bakelite tile seat is made of bakelite material and directly cooperates with the connecting shaft to reduce the wear of the shaft during operation. The depth of the bakelite tile seat is half the diameter of the fork connecting shaft to ensure that the connecting shaft remains tightly fitted when receiving lateral loads during operation, thereby initially achieving a stabilizing effect; upper guide seats are respectively arranged on both sides of the middle of the bakelite tile seat, and support springs are respectively vertically arranged under the bottom surface of the upper guide seat, and the support springs are respectively vertically arranged in vertical guide grooves in the base.

[0007] The support spring is installed on both sides instead of in the middle. The purpose is that when the deadweight of the connecting shaft is fully applied to the bakelite tile seat, the deadweight and the spring deformation support force do not act in the same plane, so that the support springs on both sides bend inward after being stressed; the connecting shaft is subjected to a centripetal force on both sides in the radial direction. When the connecting shaft is running, the centrifugal inertia force is generated. The radial force generated by the spring and the lateral load offset each other, further reducing the left and right shaking of the connecting shaft; to ensure the smooth operation of the fork connecting shaft, the spring support is adopted. The torsional vibration generated by the fork connecting shaft during operation is dynamically reduced by the elastic force generated by the compression deformation of the spring. The center distance of the coupling can be adjusted at any time, and the installation is adopted as an upper and lower distribution. By adjusting the height of the spring, the center distance of the universal shaft is adjusted. In order to ensure that two shafts can be supported at the same time, the stabilizing device needs to be designed into two layers. At the same time, it is convenient to replace the fork coupling. The upper and lower layers of the stabilizing device must be designed to be detachable and removable; during operation, the center distance of the upper and lower shafts needs to be adjusted at any time according to production requirements, so a high-strength spring is used to support the bakelite tile seat, and the fork coupling is supported by the elastic force generated by the compression deformation of the spring. Dynamic adjustment of the position of the supporting bakelite shingle seat is achieved through the expansion and contraction of the spring.

[0008] The torsional vibration of the rolling mill is a complex nonlinear vibration. The reasons that affect its vibration can be divided into external reasons and internal reasons. The internal reason is determined by the structural form and structural parameters of the rolling mill, which reflects the influence of the system structure itself on the dynamic load. External factors include temperature environment, rolling conditions, etc., including unknown factors such as field control and time-varying stiffness. Therefore, many factors should be considered when designing the rolling mill so that it has a wide range of applications and meets the rolling bearing capacity of the rolling system under certain vibration. External factors should be considered while strengthening the real-time control and monitoring of the site to minimize the torsional vibration degree of the rolling process and protect the normal operation of the rolling mill. A set of shock-absorbing and stabilizing devices is designed to reduce the moment of inertia and dynamic load. The stabilizing device is installed in the middle position of the coupling. Under the premise of meeting the fatigue strength safety factor verification and torsional stiffness verification, the stabilizing device effectively reduces the shaking, ensures the optimization of stability and the precision of the rolled products, and the universal coupling will not resonate.

[0009] The stable support structure of the present invention is mainly divided into two parts: the upper shaft support and the lower shaft support. Such a design is based on the installation distribution of the fork-type universal shaft, and the upper and lower parts are designed accordingly. At the same time, the installation structures of the upper and lower parts facilitate the disassembly, assembly and maintenance of the universal shaft. By using the stabilizing device, the impact load during the operation of the connecting shaft is greatly reduced, and the service life of the equipment is improved. Ultimately, spare parts and human resources are saved significantly, and production capacity is released at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a three-dimensional structure schematic diagram of the present invention.

[0011] In the figure: 1. Lower lead screw seat; 2. Base; 3. Support spring; 4. Upper lead screw seat; 5. Upper base; 6. Bakelite tile seat; 7. Bakelite tile. EMBODIMENT

[0012] A stable support structure for a large mechanical transmission shaft, as Figure 1 shown, includes a bakelite tile 7 and a bakelite tile seat 6 that are coaxially and telescopically sleeved together for carrying and fixing the fork connecting shaft. The bakelite tile seat 6 is made of bakelite and directly cooperates with the connecting shaft to reduce the wear of the shaft during operation. The depth of the bakelite tile seat 6 is half of the diameter of the fork connecting shaft to ensure that the connecting shaft remains in close cooperation when receiving lateral loads during operation, initially achieving a stabilizing effect. On both sides of the middle of the bakelite tile seat, upper lead screw seats 4 are respectively arranged. Below the bottom surface of the upper lead screw seats 4, support springs 3 are respectively arranged vertically. The support springs 3 are respectively arranged vertically in the vertical guide grooves in the base 2. A lower lead screw seat 1 is arranged inside the lower end of the base 2, and an upper base 5 is arranged on the top surface of the base 2.

[0013] There may be several situations where torsional vibration occurs during the operation of the fork connecting shaft: when the rolling mill bites and casts steel, the torque is very large, resulting in torsional vibration; vibration caused by the periodic change of the load during the rolling process; torsional vibration occurs when the natural frequency of the rolling mill machinery is in a multiple relationship with the electrical frequency of the transmission system. During the movement of the fork coupling, due to revolution, a centrifugal inertial force is generated. This centrifugal inertial force causes lateral vibration, resulting in additional lateral loads on the plugs and fixing pins at both ends.

Claims

1. A stable support structure for a large mechanical transmission shaft, Characterized in that: It includes a bakelite tile and a bakelite tile seat that are coaxially and cooperatively sleeved together, used to carry and fix the shift fork connecting shaft. The bakelite tile seat is made of bakelite material and directly cooperates with the connecting shaft to reduce the wear of the shaft during operation. The depth of the bakelite tile seat is half of the diameter of the shift fork connecting shaft, ensuring that the connecting shaft remains in close fit when receiving lateral loads during operation, initially achieving a stable effect; on both sides of the middle of the bakelite tile seat, upper lead seats are respectively arranged. Below the bottom surfaces of the upper lead seats, support springs are respectively vertically arranged. The support springs are respectively vertically arranged in the vertical guide grooves in the base.

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