车床主轴尾部安装有两个推力球轴承，如图所示。由于在加工零件时受到了很大的轴向载荷，另一方面主轴箱外面的推力球轴承３、４润滑条件差，因此容易损坏。人们在更换推力球轴承以后，常发现主轴轴向间隙无法调整到符合技术要求，只要主轴转动几分钟就会发现主轴箱前后冒烟； The lathe spindle is fitted with two thrust ball bearings at the tail end, as shown in the figure. Due to the large axial load on the machined part, on the other hand the thrust ball bearings 3, 4 on the outside of the headstock have poor lubrication conditions and therefore are easily damaged. After the replacement of thrust ball bearings, the spindle can often find the axial clearance can not be adjusted to meet the technical requirements, as long as the spindle rotates a few minutes you will find the front and rear spindle smoke;