计及齿面摩擦的直齿轮动力学分析

Dynamic analysis for spur gears considering friction effect

建立了考虑齿面摩擦影响的六自由度非线性直齿轮动力学模型,以FZG试验专用A型齿轮为研究对象,计算了实际时变啮合刚度,基于混合润滑模型分析了不同齿面粗糙度对应的时变摩擦系数,利用数值仿真方法研究了齿面粗糙度改变对齿轮啮合力、摩擦力、轴承力以及动传动误差等信号的时频特征的影响,并利用FZG试验台对A型齿轮具有完好齿面和损伤齿面两种状态下的多个振动加速度时频信号进行比较分析,验证了仿真结果。结果表明:齿面摩擦力会抑制啮合线方向的振动,齿面粗糙度增大会减小动传动误差,但加剧摩擦力方向振动,从而导致系统振动幅值增加,结论对齿面微损伤的故障诊断有实用参考意义。

A 6-DOF nonlinear dynamic model for a spur gear with consideration of friction was established. Taking a A-type gear in FZG test rig as an example, its realistic time-varying mesh stiffness was calculated, its time-varying friction coefficient was analyzed based on a mixed lubrication model. For three gear systems with various tooth surface roughness, the dynamic responses of the gear meshing, such as, normal load, friction force, bearing force and dynamic transmission error （DTE） were comparatively investigated in time and frequency domain with numerical simulation method, and the vibration tests on different gear pairs with the perfect and damaged tooth surface were conducted to validate the analysis results finally. The results showed that the tooth friction reduces vibration in line of action （ LOA ） , increase in tooth surface roughness reduces DTE but exacerbates vibration in off-line-of-action （OLOA）, hence the system vibration amplitude increases. The results provided a reference for fault diagnosis of a micro-damaged tooth surface.