新改进的Ф300mm穿孔机是中信重工与某钢管厂联合设计的新型穿孔机,由中信重工负责制造。原设计的顶杆小车中的推力调心滚子轴承使用寿命短,不仅影响穿孔工作的正常进行,而且增加了产品成本。因此,在重新设计时,对原穿孔机结构进行了相应的改进设计。1原设计存在的不足(1)推力调心滚子轴承无预紧力原顶杆小车结构如图1所示,推力调心滚子轴承无安装预紧力,即使 The newly improved Ф300mm piercing machine is a new type of piercing machine jointly designed by CITIC Heavy Industry and a steel pipe factory and is manufactured by CITIC Heavy Industries. The original design of the mandrel thrust spherical roller bearings in the life of a short life, not only affect the normal perforating work, but also increased product costs. Therefore, in the redesign, the original piercing machine structure has been improved accordingly. 1 The original design of the existing deficiencies (1) Thrust Spherical Roller Bearings no preload The structure of the original trolley shown in Figure 1, the thrust spherical roller bearings without preload, even if