Theoretical And Experimental Studies On Two Dimensional Mini-size Controllable Roll System Of Aluminum Foil Mills

Abstract Abstract In order to meet the great need of providing extremely thin and wide-strip aluminunt foil products. based on the existing precision and strip-shape controllable characteristics. modern aluminum foil mills will develop to be of smaller roll diameter, wider roll body and higher working speed. The typical kind of mills is 2350 aluminum foil middle and final mills introduced from British DAVY Corporation in the middle of 1 990s. However, from its pilot to now, mill has to run at lower speed. there are frequent occurrences of the shortened longevity and burning damage accidents of work roll thrust bearing of 2350 aluminum foil mill. The result is dozens of millions of economic losses every year and hardship of production. At present. the theory and method about how to solve shortened longevity of mill thrust bearing and its burning damage accidents are very few in professional and technical realm. hence it has been paid great attention and studied b multitude domestic and foreign scholars and experts. About the puzzle of mill bearing shortened longevity and burning damage accidents, several typical viewpoints are as followed: some German experts think that the mal-condition case of roll system results in the destruction of bearing seal system and subsequently impurity goes into it some Russian experts think that radial gap is altered because of contact deformation between bearing chock and external ring; and a number of domestic researchers consider that it is a kind of random action. Starting from the concept of roll system behavior, which forms another side of the contradiction of mill bearing shorten longevity and its burning damage, this paper has presented that the roll system action at mini-size uncontrollable status is the reason that makes bearing overload and load non-uniform, mill run at lower speed. So further research of theory and industrial experiment has been carried out. With the theor~?of mechanism and dynamics, the dynamic restrain behavior of work roll system of 2350 aluminum foil mill has been analyzed. It has been found that biggish impact force existing between pair components for the gap of pair with open restrain (restrain with gap). the instability of roll system with lower natural frequency and the disturbed perfect state lead to the overload, non-uniform load and mill vibration at lower natural frequency. The paper gives a new concept of open and enclosed compound restrain (pair). With this new concept, the roll system is reconstructed to keep the pair ?11] ? components in perfect state. Thus the impact force is cleared and the system runs in a stable status. According to the theory of 2-0 mini-size roll system behavior of aluminum foil mill, the theoretical modal of axial load was set up. The software program 3-DECBBEM and corresponding suppoiting programs, which are specialized in calculating load 3-D distribution of bearing, are used to calculate the load size and distribution of angle contact bail beating and 4-row short cylinder roller beating when the chock of 2350 aluminum foil mill is given variant restrains. The effect of 2-0 mini-size roll system behavior on bearing load characteristics is analyzed, and the bearing capacity and the external ring thermal deformation which effects on its rotating are also analyzed. Bas...