考虑内圈挡边表面波纹度的圆锥滚子轴承振动特征研究

Investigation for Vibrations of Tapered Roller Bearing Considering the Surface Waviness on the Rib of the Inner Race

表面波纹度是圆锥滚子轴承滚道表面的主要形状误差之一。针对圆锥滚子轴承内圈挡边表面波纹度诱发的时变激励机理和动力学建模的问题,考虑流体动力润滑油膜与轴承轴向和径向变形耦合激励作用的影响,提出考虑时变激励的圆锥滚子轴承挡边表面波纹度动力学模型,并通过试验结果验证模型的有效性;研究内圈挡边表面波纹度时变激励下的圆锥滚子轴承的振动响应特征;分析内圈挡边表面波纹度幅值和阶次对圆锥滚子轴承振动响应特征的影响规律,解决圆锥滚子内圈挡边波纹诱发的时变激励及其动力学建模问题,为获得准确的含内圈挡边表面波纹度的圆锥滚子轴承的动力学响应特征提供新的手段和方法。结果显示,轴承的振动水平随着内圈挡边表面波纹度幅值的增大逐渐加剧;内圈挡边表面波纹度会改变轴承振动加速度响应频谱的峰值频率;当内圈挡边表面波纹度的阶次为滚动体数目的整数倍时,圆锥滚子轴承振动值将出现峰值。因此,控制内圈挡边表面波纹度的幅值与阶次将有利于抑制圆锥滚子轴承的振动水平。

Surface waviness is one of main geometrical errors on the components of tapered roller bearings. A clear understanding of mechanics and dynamic modelling methods is very helpful for predicting accurate vibrations of the bearings. To overcome this problem, a dynamic model considering time-varying excitation for a tapered roller bearing with surface waviness on the rib of the inner race is developed, which can formulate the elastohydrodynamic lubrication and coupling excitation between axial and radial deflections. An experimental study is also conducted to validate the proposed model. Vibration characteristics of a tapered roller bearing considering the surface waviness on the rib of the inner race are predicted. Influences of the amplitude and wave number of the surface waviness on the bearing vibrations are discussed. It seems that the proposed model can provide a new method for modeling vibrations of the bearing with the surface waviness on the rib of the inner race. In addition, the results show that the vibration level of the bearing increases with the amplitude of the surface waviness; the peak frequency in the spectrum of the bearing acceleration will be affected by the surface waviness; a peak value of the vibration response of the bearing will be generated when the wave number is the integral multiple of the number of the rollers. Therefore, the surface waviness with a reasonable amplitude and wave number will be useful for decreasing the vibration level of the tapered roller bearings.