热膨胀对自密封滑动轴承润滑液泄漏的影响分析

Analysis of Thermal Expansion Effects on Leakage in Self - sealed Journal Bearings

本文以支承HDD主轴的自密封滑动轴承为对象,通过一个简化模型研究了因热膨胀导致的润滑液泄漏问题。分析表明,轴承的存油空间（包括间隙、油孔、油槽等）的容积膨胀率αT与润滑液的体膨胀系数αoil不匹配是造成温度变化时润滑液泄漏的重要原因。为减少泄漏,一方面应选用低膨胀液体作为润滑剂,另一方面应通过轴承设计以控制存油空间的膨胀率。控制αT的措施包括:（1）以线膨胀系数不同的材料制作滑动轴承摩擦副的不同零件（如轴套和外圈）;（2）根据轴承尺寸及材料、润滑液类型确定适当的轴承间隙比;（3）尽可能减少油孔、油槽等除轴承间隙之外的存油空间。

This paper, based on a simplified model, researched the problem of liquid lubricant leakage caused by thermal expansion effects in self- sealed journal bearings used in HDD spindles. The theoretical analysis indicated that the mismatch between the thermal expansion coefficient (TEC) of oil - containing - space (including the bearing clearance, oil holes and grooves) in bearing, aT and that of the liquid lubricant, aoil was a significant factor inducing leakage when bearing temperature varied. Hence measures such as selecting liquids with a low TEC as lubricant and properly designing the bearings should be taken to match the aT and the aoil. A number of useful techniques were presented including (1) using materials with different TEC on different bearing parts, (2) carefully determining the ratio of bearing clearance according to the configuration of dimension, materials and lubricant type of bearing and (3) decreasing the additional volume, such as oil holes and grooves in bearing structures to control the TEC of oil - containing - space in bearings.