轴承预紧力研究方法总结讲义资料.pptx

研究方向
怎样选择预紧方式
怎样确定预计力大小
预紧力对轴承、轴系刚度的影响
滚动轴承预紧的意义和预紧力的估算及调整（2004）李红光
滚动轴承预紧方式：
定位预紧
向一个轴承的内圈或外圈施加轴向力后，将内、外圈保持相对固定0
the expected life of the bearing is about 12,000 h. For a fixed rotation speed, when the life of calculation is larger than 12,000 h, the maximum corresponding preload is the variable preload. Thus, the variable preload at low speed is obtained from the calculated results
for high speed
For a fixed rotation speed, when the temperature rise of the ball bearing is limited to 25 °C by machine tool industry standard, the maximum corresponding preload in Fig. 6 can be chosen as the variable preload. When the spindle speed reaches 6000 rpm, the temperature rise will exceed 25 °C while the preload is reduced to a lower level. From the rolling bearing analysis theory [1] . Harris, Rolling Bearing Analysis (third ed.), John Wiley and Sons, New York (1991).[1], the spin–roll ratio is increased by decreasing the preload. As the spin–roll ratio increases, the bearing produces more friction and hence heat generation. Meanwhile, it is observed from our experiment that the preload less than 1000 N cannot eliminate clearance effectively and thus decrease the rigidity and increase the friction and wear resulting from excessive sliding. Therefore, the preload of 1000 N can be determined for high speed range over 6000 rpm. The variable preloads with the rotation speed during high speed range (3000–7000 rpm) can be obtained, as listed in Table 8.
Speed (rpm)
Variable preload (N)
≤4000
2000
≤5000
1000
≤6000
1000
≤7000
1000
Variable preloads for high speed range.
of spindle behavior between variable preload and constant preload
Based on the analysis above, the variable preload for the entire speed range can be obtained from Tables 8 and 11. A preload of 2000 N is selected as the constant preload according to the medium preload. The temperature rises of bearing under variable preload and the constant pressure preload were simul