机械工程毕业设计 四辊初轧轧机的压下机构设计.doc

PAGE PAGE 39摘 要本次设计的课题是四辊初轧轧机的压下机构设计，主要是对四辊初轧机压下机构的压下螺丝、压下螺母、压下止推轴承进行了改造设计。通过对四辊轧机压下机构的改造设计，电机通过两级圆柱齿轮减速和一级蜗杆蜗轮减速传动压下螺丝。压下螺丝和压下螺母选择了合理的机构，压下螺丝传动端选择了花键的结构形式，承载能力大；传动端花键采用了连续压力油润滑，能将润滑油输送到压下螺丝的各个润滑点，便于操作；压下螺丝的止推端部做成凹形，这时，凸形球面止推轴承处于压缩应力状态，可以提高了压下止推轴承的强度。压下螺母为整体螺母，整体螺母加工制造较为简单，工作可靠。压下螺母中油孔的设计有利于螺纹的润滑，能有效的提高其使用寿命。本课题根据螺纹的自锁条件进行了梯型螺纹设计，通过螺纹的自锁设计并增大压下螺丝球面止推轴颈有效防止了压下螺丝的自动旋松，提高了轧制时的辊缝精度。压下螺丝的止推轴承是推力圆锥滚子止推轴承，推力圆锥滚子轴承比铜垫滑动止推轴承提高承载能力35%左右，在轧制时轧辊弯曲时能实现压下螺丝自位调心。最后本设计讨论了压下螺丝阻塞事故的动力学机理，提出了操作注意事项。关键词：四辊轧机；压下机构；压下螺丝；压下螺母；压下止推轴承AbstractThis designs topic is four roller preliminary rolling mills screw design, which mainly about four roller blooming mill screw housing pin, depressed nut, and depressed thrust bearing to carry on the transformation design. Through to four high rolling mill screw transformation design, motor through two level of cylindrical gears deceleration and first-level worm bearing adjuster worm gear reduction gear housing pin. The housing pin and depressed the nut to choose the reasonable organization, the housing pin transmission end has chosen the spline structural style, has big bearing capacity; The transmission end spline has used the continual pressure oil lubrication, can transport the lubricating oil to housing pins each lubrication points, is advantageous for the operation; The housing pin stops pushes the nose to make the cup, by now, the convexity spherical surface thrust bearing was at the elastic strain condition, might enhance has depressed thrust bearings intensity. The depressed nut is the overall nut, the overall nut processing manufacture is simpler, operation reliable. The oil hole of the depressesd nut to be advantageous to the thread lubrication, can effectively enhanced its service life. This topic has carried on the ladder thread design according to the thread self-locking condition, designed and increases the housing pin spherical surface thrust journal through the thread self-locking to prevent the housing pin to turn on lathe the pine au