【作者】 卢福；

【导师】 陈占福；

【作者基本信息】 上海交通大学 ， 机械设计及理论， 2010， 硕士

【摘要】 CVC轧机是一种轧辊凸度连续可变的,具有良好板形控制能力的新型轧机,是由德国SMS公司在1984年推出的。宝钢2050机组是成套引进SMS公司技术与装备的现代化热连轧板带生产线,在1989年建成投产。2050热轧精轧机组是四辊CVC轧机,带S形曲线的工作辊装配有轴向移动装置,通过改变工作辊的凸度来调节辊缝大小。工作辊上的四列滚子轴承主要承受弯辊力和轴向力,而支撑辊上的油膜轴承主要承受轧制力和绝大部分弯曲力矩。随着轧制负荷和轧制速度的不断增加,轧机的动态冲击、振动、磨损等对构件的影响显得日益重要,极大地影响着轧机辊系的稳定性。本文以宝钢热轧厂2050CVC轧机辊系在生产中出现的问题为切入点,以优化轧机辊系结构和提高辊系稳定性为目的,系统总结了CVC轧机的应用和技术特点,针对生产实践中存在的问题提出了一些有助于改善辊系稳定性的措施,主要论述了如下内容:1、介绍了CVC轧机的工作原理和结构特点,分析了其弯辊装置和轴向横移装置的典型结构,指出轧辊轴线交叉是轧机产生轴向力的主要原因,并提出了如何解决轧机轴向力过大所引起的一系列故障的措施。2、介绍了2050CVC轧机精轧工作辊原组合轴承的结构特点及产生的问题,提出了采用大锥角四列圆锥滚子轴承作为新的轴承设计方案,并校核了新设计轴承的寿命。综合运用SolidWorks、HyperMesh和MSC.Marc进行工作辊轴承和轴承座的有限元分析,得出了滚动轴承中各滚子所受载荷的变化规律。最后,对滚动轴承动态运行行为进行实验研究,获得了组合轴承列间载荷分布和轴向力的特点,为新轴承方案的实施提供了实验依据。3、介绍了宝钢2050精轧CVC轧机工作辊轴向横移及锁紧机构的机械结构及液压控制系统,系统论述了CVC轧机常见的机械和液压故障,并采用故障树分析方法对CVC辊系的常见故障进行了定性分析。故障树关系模型的建立极大地提高了故障诊断和改进使用维修方案的效率,节省了停机维修时间。4、介绍了宝钢2050支撑辊系的结构特点和油膜轴承的密封结构形式,制定了避免油膜轴承进水的相关技术措施,设计了一种用于阻止水直接冲击密封装置的防水罩。该技术措施在轧线上取得了显著的成效,能够保证在极短的时间内判定进水点及其原因,基本避免了大量水夹带氧化铁皮侵入系统所出现的进水现象。更多还原

【Abstract】 CVC mill, launched by German company SMS in 1984, is a new kind of mill which has a continuously variable roll crown and a good shape controlling capability. Founded and put into operation in 1989, Baosteel 2050 unit is a wholesale introduction of SMS technology and equipment of the modern hot continuous rolling strip production line. Hot Rolling Finishing Mill 2050 is a four-high CVC mill with S-shaped curve of the working rolls equipped by axial movable devices. It adjusts the roll gap by changing crown of the working rolls. Four-row roller bearings on the working rolls mainly bear roll-bending force and axial force, while the oil film on the backup roll mainly bear rolling force and most of the bending moment. With the rolling load and rolling speed increasing, effects of the mill’s dynamic impact, vibration and wear on the components become increasingly important. It greatly affects the stability of roll system.Making the problems in the 2050CVC roll system of Baosteel Hot Rolling Plant the breakthrough point, and with the purpose of optimizing roll system structure and improving the stability, this paper systematically summarizes applications and technical characteristics of the CVC mill, and raise up some help to improve the stability of roll system based on the practical problems during production, mainly discussed the following:1. This chapter introduces the working principle and structural characteristic of CVC mill; studies the typical structure of roll-bending and axial movable devices; points out that roll axis crossing is the main reason for producing axial force; and proposes the measures of solving a series of failures caused by too large mill axial force.2. This chapter introduces the structural feature and problems of original combined bearing used in 2050CVC finishing mill work roll; proposes using a large cone angle four-row tapered roller bearing as a new bearing design; and checks the life of new bearing. Changing regularity of load on each roller has been obtained by the finite element analysis on work roll bearings and bearing chock using SolidWorks, HyperMesh and MSC.Marc comprehensively. Finally, features of column load distribution of combined bearing and axial force have been obtained by experimental studying on dynamic operation behavior of rolling bearing. It also provides an experimental basis for implementation of the new bearing design.3. This chapter introduces the work roll axial sliding, locking mechanism and hydraulic control system of Baosteel 2050CVC finishing mill; systematically discusses the common mechanical and hydraulic failure of CVC mill, and analysis such common failures using fault tree analysis method. The establishment of fault tree relation model has greatly improved the efficiency of fault diagnosis and maintenance programs mend, saves the repairing down time.4. This chapter introduces the structural features of Baosteel 2050 backup roll unit and the sealing structure of film bearing; Develops relevant technical measures to avoid influent water in oil film bearing, and designs a waterproof cover to avoid direct impact of water on seal device. This technical measure has achieved remarkable effect in the rolling line which can guarantee to determine influent water spots and its causes in a very short period of time. It essentially avoids the occasional phenomenon of influent water caused by intrusion of a large number of water entrained oxide scale.更多还原