Study On Improvement Of The Main Transmission System In 2800 Rough Mill

Rough mill 2800 is the key equipment of squeezing and extending in aluminum processing plant, which was designed and machined independently by our country in the last century. Because of the limited design capacity and now growing annual production, the main transmission is becoming vulnerable with the increasing loads, which leads to frequent failure in the system. By now, the main transmission system has the symptoms of deficient roll torque and overload current, and consequently production is compromised. For improving the roll capacity and enhancing competitive ability, the main transmission system needs to be improved according to the current situation. Concrete and comprehensive method is developed to analyze the bearing capacity of weak links which is caused by expansion of power in the main transmission system. Moreover, the method will provide reference to studies on characteristics of transmission system in like rough mills theoretically and practically.In this paper, key parts (herringbone gear , shaft, bearing, attachment bolts, coupling shaft, notch, palm end) of the main transmission system are analyzed by classic mechanics and computer simulation technology in line with design theory. Based on these analyses, reasonable improvements are proposed. Power of motor will be expanded from 6400KW with direct current to 7000 to 8000KW with alternating current so that roll torque will be strengthened to meet the need of production under the same rolling velocity. By decrease of thick of top,middle,down bush, the center distance of herringbone gear is cut down, number of gear is from 22 to 25 ,the accuracy manufacture of gear is from level 8 to level 7, modified of shape of gear; properly increase of geometry dimension of left notch is for enhance of strength, which is adapt to the increase of power motor.