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Selection and Optimization of High Line Thick Rolling Mill and Redesign of Main Reducer May 14, 2018

Optimization of roughing and middle-rolling mill selection in Henan Metallurgical High Line and remodeling of main reducer Ge Baowen Ma Fuyi Wu Baoxi Yu Baoshun (Anyang Iron & Steel Co., Ltd.) Inspected and improved the structure and important parameters of the main reducer, not only for the Anyang Steel High Line The reliable operation of the rough rolling mill has laid the foundation, and has created the conditions for the further development of the rolling process.

0 Foreword The Angang High-speed Line is the first high-speed wire rod production line in Henan Province that combines the introduction of the first set of key equipment and domestic equipment support. The whole line consists of rough rolling, medium rolling, pre-finishing rolling, finish rolling, and de-calibrating. Rolling mill composition. Among them, the key equipment for pre-finishing, finish rolling, and substracting three sets of units was introduced into MORGAN in the United States, while the equipment for rough rolling and medium rolling a total of 14 main trains was designed and manufactured by domestic equipment. The rough rolling mill (H-6V) 6 aircrafts, 8 stands (7H14V), each stand single-drag, flat/vertical alternate arrangement. In order to give full play to the advantages of advanced foreign technology and equipment, in the early stage of project implementation, we highlighted the selection and optimization of the rough rolling mill and the modified design of the main reducer, so that not only the main drive of the roughing and rolling mills The performance and life of the device have been further ensured, and it has also effectively promoted the technological level of Anyang Steel's high line and improved its product quality.

1 The selection of high-roughing medium and moderate rolling mills The optimization of flat/vertical two-roller alternating roughing and rolling mills usually adopts a closed type two-high rolling mill. The typical representative of this type of rolling mill is mainly the United States. The Morgan (MORGAN) model and Germany's color are commonly used in high- and medium-line rough rolling mills at home and abroad, and during the implementation phase of the Ansteel high-wire project, we have the structure of the two main models mentioned above. The characteristics and performance were analyzed and analyzed in a comprehensive and meticulous manner. After analysis, even though the American Morgan model and the German SMS model are similar in terms of roller bearings, radial adjustment, upper roller balance, and rack locking, the two The following differences are evident in the following aspects, and the comparative analysis is as follows: Rack format: The Morgan mill's rolling mill is a "closed-end, welding rack", and the arch of the mill is cut in whole blocks of thick steel. The frame is welded by beams and arches, which is a compact structure that reduces the weight of the rolling mill compared to that of the SMS archway.The second is to improve the processing and manufacturing process of the rolling mill. Arch defect easily occurs, and to ensure and enhance the strength of the steel mill.

Axial adjustment. The axial adjustment of the Morgan model adopts a nut, so that the rod is shortened or elongated, so that the jaws rotate around the fulcrum, and the bearing housing is pulled to move to one side or the other, thereby realizing the axial adjustment of the roller assembly in the frame. And positioning. Compared with the SMS model that achieves axial adjustment through the gasket, the first is to improve the accuracy of the adjustment.

The second is to speed up the adjustment. The third is to enhance the stability of the roll axial positioning.

Lifting institutions. The lifting mechanism of the Morgan model is only a set of motor-driven speed reducers, worm gears, and worms to drive the screw to rotate and lift, thereby completing the lifting of the assembly of the rack, and achieving even the connecting parts of the main shaft and the roll, after being put into production. During the period of ~8 years, Wang was still required by the king to decelerate its bearing capacity and had a long service life.: Outstanding resistance and disengagement, while the SMS-Machine's hoisting mechanism was composed of two sets, both to enhance the overall lifting mechanism and the spindle. The overall lifting mechanism is driven by a deceleration system consisting of a worm gear and a worm, so that the “L-shaped main lifting frame drives the rack and the main shaft to lift at the same time. The spindle lifting mechanism is driven by a hydraulic cylinder, and only the spindle is raised and lowered independently, so that the connection and disengagement of the spindle and the roller can be realized. Compared with the SMS-type lifting mechanism, it is clear that the Morgan-type lifting mechanism is compact and reliable.

The second is easy operation and simple maintenance. The third is to reduce the investment in the initial period of the seven sets of institutions and the cost of maintenance and repairs in the future.

Spindle connection. The connection between the main drive shaft and the roller of the Morgan model adopts the “card sleeve” type connection. There is a clamping mechanism in the sleeve of the connecting shaft that can be expanded and contracted. As long as the roll head is inserted into place, it can be automatically carded. tight. Compared with the SMS-type "end cap rotation and bolt" connection method of the SMS model, the Morgan card type "card sleeve" type connection method is particularly safe, fast, and agile.

Spindle bracket. The spindle bracket of the Morgan model is neither in contact with the spindle (during operation) nor does it move up and down as the spindle moves up and down. Although this type of bracket cannot balance the weight of the spindle, it has been proved that for high wire rough rolling speeds The lower, medium-roller spindle with a small hinge connection does not affect its connection function. However, the carriage of the sMachine type spindle not only bears the spindle load when in contact with the spindle during operation, but also moves up and down as the spindle moves up and down. The over design of this function has led to the increase of the weight of the bracket of this model and the complication of the structure.

From the above analysis, the Morgan model has unique advantages in improving the rigidity of the rolling mill, reducing the weight of the equipment, simplifying the equipment structure, improving the use performance, and saving the investment in the project. Therefore, the model is the preferred target of the Anyang Steel High-Line. At the same time, the model was further improved. First, a hydraulic motor was added to the pressing device, which not only improved the adjustment accuracy and speed, but also made the overload protection performance of the rolling mill simpler and more reliable. The rate has also been further improved. The second is to add a hydraulic balancing device on the upper roller, which facilitates the roll change operation and reduces the operating cost, thereby further improving and promoting the development of the process performance of the Morgan roughing and medium rolling mills.

2 High Line Coarse and Medium Rolling Main Reducer Modified Design In the main rolling mill drive, the role of the main reducer is to turn the higher speed of the motor into the required rotation speed of the roll, and its performance will directly affect the production of the entire line. According to the investigation of the operating conditions, the manufacturing drawings of the domestic high-coarse rough-rolled main reducer are mainly supplied directly by Morgan Stanley and Siemag Germany. The main reducer produced in this country is therefore highly numerous in China. The problems reflected by the line manufacturers are: The frequent occurrence of tooth breakage or broken shaft accidents in the main reducer has led to several months of failed shutdown of the individual high-line production lines that have been put into production (due to the failure to prepare the main speed reducer in time. The accident machine's broken teeth and broken shaft accidents have been plagued for a long time. For this reason, these plants have only 14 sets of main reducers of different sizes and flat/vertical forms to shorten the processing time of the accident. It can be seen that the main deceleration The existence of machine failure not only seriously threatens the normal operation of wire rod production, but also occupies and consumes large amounts of funds and manpower.

In view of the above situation, at the stage of implementation of the technical transformation of Ansteel High-speed Line, the first one compares the drawings and related materials of Morgan S.K. and Siemag Germany, and the other is the broken teeth of the domestic rough rolling mill. Broken shaft accidents were investigated. As a result, it was found that Morgan designed the gear parameters to be too small, and the transmission structure design was unreasonable. The design strength and rigidity of the box were large and the cabinet was relatively bulky. Simmark's drawings are the opposite. Although the choice of gear parameters can be basic, but the design of the box stiffness, bearing structure and lubrication scheme is not proper. Overall, the existing problems can be summarized as follows: Gear Design There is a problem with the parameters, the tooth type selection is incompatible with domestic processing capacity, and the safety factor is too small.

The choice of gear material is unreasonable, the strength is low, and the impact resistance and fatigue toughness are poor.

The shaft of the speed reducer and the rigidity of the box body are poor, which can not meet the requirement of high precision of hard tooth surface contact.

The precision of processing and manufacturing does not meet the requirements of the drawings, and the final inspection did not adopt special technological measures (tooth shape, tooth profile modification, tooth surface magnetic particle inspection, etc.).

There is a problem with lubrication, and the choice of space piping and fuel injection methods cannot reasonably and effectively meet the working requirements of gears and bearings.

Based on the above analysis, combined with the experience of other domestic high-line manufacturers, we decided to integrate the advantages of the models of the main reducer of Morgan and Simecker, and redesigned the original organic type. The main contents are as follows: "Spiral bevel gear selection of new The Kleinberger tooth profile is a contour spiral bevel gear that extends an epicycloid.

The primary module of the cylindrical helical gear was increased from the original 8 to 10, and the final module was increased from the original 16 to 22. It was replaced by the “overlay arrangement”.

The rigidity ensures the meshing stability of the high-precision gears.

The lubricating oil path and fuel injection method inside the box have been completely modified to meet the needs of lubrication of gears and bearings. Through the above-mentioned retrofit design, it further ensures that the gear transmission is “smooth in operation.” 3 Conclusions The rough rolling mill of Ansteel High Line has now been in operation for three years. There has never been a case of vicious equipment accidents, especially 14 masters. The operation condition of the reducer is good, and the phenomenon of broken teeth, broken shaft and poor lubrication of the system is completely eliminated, and no accidental kit has been equipped for the reason that the main reducer breaks the teeth and breaks the shaft accident so far, which is similar to the domestic ones. In fact, it is unique, and it has even been adopted by several new high-tech lines in China. Practice has proved that the optimization of the selection of the rough rolling mill at Angang Steel and the modified design of the main reducer are not only feasible but also feasible. Effectively, it can be regarded as a model of success in our country's similar units, so it has extensive promotion and reference value.