含侧隙齿轮副的动载荷分析

DYNAMIC LOAD ANALYSIS OF SPUR GEAR PAIRS WITH BACKLASH

以振动理论为基础 ,提出一种考虑齿轮拍击振动的齿轮动载荷的数值计算方法。建立计算动载荷的齿轮冲击模型 ,在模型中考虑了齿轮正、反冲击时实际的啮合刚度 ,并给出啮合柔度的计算方法。分析在考虑静态传递误差、啮合刚度、侧隙、摩擦力及外部扭矩变化等多种激励时 ,作用在轮齿上的动态载荷以及整个齿轮上的综合动态载荷的计算公式。最后通过实例分析作用在轮齿上的动态载荷。

The determination of gear dynamic load is very important and difficult in gear design. Here, based on the vibration theory, a two-degrees-of-freedom (d.o.f.) non-linear model was established for the dynamic analysis of a spur gear pair. A new method with a computer program suggested is developed to investigate dynamic load acted on gear teeth and gears when backlashes and friction are considered, which means impact and rattle may occur when some conditions are met. The dynamic gear load was introduced directly into the governing equations of motion, and the dynamic tooth load acted on each tooth in contact were obtained by solving the compatibility equations of tooth deformation. An impact model of gear meshing was developed to include the complex excitations, such as the time-varying mesh stiffness, the static transmission errors, and the friction between gear teeth. In this model the stiffness of gear tooth engagement when contact of working and non-working sides of gear tooth occurs was considered respectively. After that, the validity of the approach is demonstrated with numerical examples. It is concluded from the results of analysis that the friction between meshing teeth has a more important effect on teeth separation and gear dynamic load than the stiffness of shafts. The theory presented is general and applicable to spur gears including high contact ratio gears.