基于非线性动力学模型高速球轴承摩擦力矩研究

Study on Friction Moments of High Speed Ball Bearings Based on Nonlinear Dynamic Model

针对钢球滚动周期内钢球滑滚比实时变化,采用粗糙摩擦系数与滑滚比关系方程实时修正钢球与滚道的摩擦系数。针对高速轻载时钢球粗糙摩擦牵引和润滑牵引显著增大且赫兹接触力明显减小,建立考虑钢球摩擦牵引和润滑牵引的高速球轴承非线性动力学模型。基于该模型结合经典的六类摩擦力矩经验公式计算轴承总摩擦力矩。根据不同载荷下钢球角速度和轴承摩擦力矩证明了该模型是有效的,进而研究了轴承高低速、轻重载和初始接触角对轴承摩擦力矩的影响规律,揭示了不同工况和初始接触角时六类摩擦力矩的影响权重和诱因。分析结果表明:在轻重载条件下,低速时,差动滑动摩擦力矩主要影响总摩擦力矩,高速时,润滑黏度摩擦力矩主要影响总摩擦力矩。在较大径轴向载荷作用下,高速轴承产生较大的自旋摩擦力矩,其次是润滑黏度摩擦力矩。

In view of the real-timely variation of slide-to-roll ratio of balls,the relation of asperity friction coefficient with the slide-to-roll ratio is adopted to adjust the asperity friction between balls and raceways.At high speeds and light loads,asperity friction traction and lubricant traction of balls are intensified significantly and the Hertz contact force is decreased markedly,which is emphasized to develop a nonlinear dynamic model of high speed ball bearings.Then,combining this model with these classic empirical formulas of six kinds of friction moments to calculate the total friction moment.This model is proved to be effective according to the angular velocity of steel ball and the friction moment of bearing under different loads.Subsequently,the effects of high and low speeds,light and heavy loads,and initial contact angles on friction moments are analyzed,and the influence weights and inducements of six kinds of friction moments under different working conditions and initial contact angles are revealed.The results show that under the condition of light and heavy loads,differential sliding friction moment mainly affects the total friction moment at low speeds,while viscous friction moment mainly contributes to the total friction moment at high speeds.Moreover,under combined loads,spinning friction crucially effects the total friction moment for high speed bearings,and the next is viscous friction moment.