油膜轴承倾斜承载对冷连轧机启动的影响

Influence of misaligned journal bearings on the start-up process of tandem cold rolling mills

针对某CVC带钢冷连轧机启动阶段支持辊油膜轴承静压承载能力不足的问题,应用流体润滑理论,建立了轴承倾斜工作下静压承载能力的全润滑系计算模型,分析了轧机压下倾斜、油泵功率和节流器液阻对轴承静压承载性能的影响.计算结果表明,压下倾斜过大会造成轴套与衬套的轴线出现倾斜,进而导致轴承的静压承载能力急剧下降,是造成轴承寿命缩短、连轧机启动频繁失败的根本原因.在实际生产中,限定了轧机压下倾斜设定值上限,增大了润滑油黏度,从而有效提高了轴承的承载能力,机组启动成功率显著提高.

In order to solve the poor load capacity of oil film bearings during the start-up process of tandem cold rolling mills, based on the hydrostatic bearing theory, a load bearing capacity model for oil film was established. The influences of screw-down tilting, hydraulic pump power and restrictor＇ s hydraulic resistance on the hydrostatic pressure bearing-spindle system were calculated. The results show screw-down tilting is the basic reason of the problem. When there is an obliquity between the shaft sleeve and bush which is caused by screw-down tilting, the load capacity of the bearing drops suddenly. Minimizing the obliquity between the shaft sleeve and bush is essential to keep the kelmet working constantly. The results of calculation have already served as the guidance to make relative measures and achieved good effect.