滚动轴承游隙振荡的试验研究

Experimental research on clearance oscillation phenomenon of rolling bearings

在进行某型航空发动机模拟试验时,发现了一种鲜见报道的转子-轴承系统振动幅值长周期变化现象。为探究该现象的成因,利用某型航空发动机模拟试验器对该现象进行了长时间测试和验证,试验揭示了该现象受转速、滑油流量和温度、载荷、轴承状态和游隙等因素的影响规律。在大量试验后,分解了试验器和轴承,并更换新轴承进行了重复试验。试验结果表明,该轴承的振动幅值长周期变化现象是轴承游隙引起的热-构耦合现象。其机理是游隙较大的轻载轴承打滑发热,引发轴承游隙周期性变化,导致转子振动出现振荡现象,该研究称其为滚动轴承的游隙振荡现象。该现象对轴承的散热状态和径向载荷较为敏感,主要发生在轴承工作载荷远远低于轴承额定载荷的情况下,可以通过改变供油条件或适当增加不平衡载荷的方式消除该现象。

A rarely recorded phenomenon of long-period vibration amplitude variation of rotor bearing systems was found on an aeroengine simulate rotor system.In order to analyze this phenomenon,a vibration displacement sensor and a vibration speed sensor were used to carry out a long period test.The influence caused by speed,oil,temperature,load,bearing state,and clearance was analyzed.After the experiments,the bearings were disassembled and replaced with new bearings for experiments.The experiment results show that the long-period vibration amplitude variation of the bearing may be a thermal structural coupling phenomenon of the bearing.The source of the phenomenon is the periodic change of the bearing clearance caused by the sliding and heating of the light load bearing.The clearance oscillation phenomenon is sensitive to the heat dissipation state and radial direction of the bearing.This phenomenon mainly occurs when the working load of the bearing is far lower than the rated load of the bearing.This phenomenon can be eliminated by changing the lubricate oil supply(damaging the heat dissipation balance)or appropriately increasing the unbalanced load.