中文摘要：

为定量解明中厚板轧机压下螺纹副回松机理和铜螺母螺牙顶端塑性压缩变形鼓包现象，制作中厚板轧机螺纹副1／8实物模型，进行螺纹副压下螺钉回松量测试、振动试验和铜螺母螺牙塑性压扁及顶端鼓包的有限元数值分析。轧机压下螺纹副采用大间隙中径定位力学约束。在轧制及间歇振动及咬、甩钢载荷工况下，由于螺纹副力学约束定位而侧隙控制的不可靠性，每当发生压下螺钉与平衡机构之间的不同步运动场合，诱发压下螺钉回松或螺牙顶端产生塑性压扁鼓包现象。提出主／副复合螺母结构，副螺母靠螺牙背面对压下螺钉实现几何约束以取代中径定位力学约束，有效地防止螺纹副动态侧隙的发生而分离，实现压下螺钉自平衡，减小压下螺钉的回松量，防止铜螺母螺牙产生塑扁鼓包。同时，减缓铜螺母的磨损，成倍增加螺纹副工作寿命．

英文摘要：

A 1/8 mill screw pair experiment model of heavy and medium plate mill is made to analyse the rapping mechanism and the forming reason of plastic bulge quantitatively. Based on the experiment model, a series of experiments are done like rapping distance testing, vibration experiment and FEM numerical simulation of the copper nut tooth plastic bulge. The mill screw pair is oriented on medium radius, which is force constraint and is unreliable. There is time difference between the mill screw and balance mechanism when bite and toss of steel, which is the main reason for the forming of rapping and plastic bulge. Compound nut is provided, which can take place of force constraint with geometric constraint which depends on the rear of nut tooth. In the compound nut, the back side of slave nut tooth is the working face. The results of 1/8 model experiment show that it can control screw-pair dynamic gap, realize self-balance of screw, reduce the effect of mill screw-pairs rapping and prevent the emergence of a plastic bulge of copper nut tooth with compound nut. At the same time, adopting compound nut can reduce the abrasion of copper nut effectively and elongate the nut lifetime.