混合润滑状态下齿轮接触刚度

Gear contact stiffness under mixed lubrication status

为研究混合润滑状态下齿轮的接触刚度,提出了一种计算齿轮接触刚度的方法。首先计算出齿轮啮合过程中运动参数和受力情况,然后采用混合弹流润滑方法求解得到不同时刻粗糙齿面啮合处的膜厚与压力分布,将结果代入接触刚度计算式,得到不同时刻齿轮啮合的接触刚度。讨论了不同工况对齿轮啮合接触刚度的影响,并将光滑表面接触刚度与粗糙表面接触刚度进行了对比。结果表明:转速和载荷对接触刚度影响很大,速度越快,接触刚度越小;载荷越大,接触刚度越大。

In gear transmission mechanism, stiffness is undoubtedly an important parameter, and considering the ubiquitous lubricant in mechanical system,it is necessary to study the contact stiffness under the condition of mixed lubrication. It is certain that the gear contact stiffness considering lubrication is the result of a multi-factor combination. In real working conditions,the gear contact stiffness is timevarying due to the variation of meshing force,the influence of rough interface and the presence of lubricant.In fact,the mixed lubrication solution is crucial. Once the film thickness and pressure distribution under mixed lubrication are known,the final result can be obtained by substituting the obtained results into the calculation expression. In order to study the contact stiffness of gears under mixed lubrication conditions,a calculation method is proposed. First,the motion parameters and normal contact force during the gear meshing process are determined. Second,the mixed elastohydrodynamic lubrication method is used to obtain the film thickness and pressure distribution on the meshing rough tooth surface at different moment.Finally, the obtained film thickness and pressure distribution are brought into the contact stiffness calculation formula to get the contact stiffness of gear at different times. The influence of different working conditions on the contact stiffness of gear is further discussed,and the contact stiffness of smooth surface is compared with that of rough surface. The results show that the speed and load have obvious influences on the contact stiffness. The higher the gear speed,the smaller the contact stiffness,and the smaller the applied load,the greater the contact stiffness of the gear.