轻载装载机变速箱振动特性分析与试验

为了给装载机变速箱减振降噪提供依据，通过集中参数和有限元法相结合的方式对变速箱进行振动分析。综合考虑液力变矩器激励、齿轮系统内部激励等因素，建立装载机变速箱传动系统的弯-扭耦合动力学模型，求解得到各轴承的动态支反力；建立箱体有限元模型，进行模态分析，以轴承动态支反力为激励，在模态的基础上进行箱体谐响应分析，得到箱体在激励下的振动响应，选择箱体表面的振动测点，分析测点的振动加速度，找到并分析振动峰值及对应振型；最后进行变速箱振动试验，验证仿真的正确性。结果表明：传动系统的激励主要集中在输入和输出平行轴齿轮处，传动系统和箱体振动的峰值频率均和齿轮啮合频率相近，变速箱箱体振动较大的位置位于箱体的底部。试验与仿真对比，试验中存在和仿真相近的峰值频率，仿真和试验所得的振动加速度均方根误差值小于20%，验证了仿真的正确性。

Analysis and Test of Vibration Characteristics of Light Load Loader Gearbox

In order to provide basis for vibration and noise reduction of loader gearbox, the vibration analysis of gearbox was carried out by combining centralized parameters and finite element method. Considering the excitation of hydraulic torque converter and gear system internal excitation factors, a loader gearbox transmission system of bend-torsion coupling dynamic model was established, the dynamic reaction force of each bearing was solved. The casing finite element model was established for modal analysis, taking the bearing dynamic reaction force as the excitation, the modal harmonic response analysis was conducted on the basis of enclosure. The vibration response of the box under the excitation was obtained, the vibration measurement points on the surface of the box were selected, the vibration acceleration of the measurement points was analyzed, the vibration peak value and corresponding vibration mode were found and analyzed, and finally the gearbox vibration test was conducted to verify the correctness of the simulation. The results show that the excitation of the transmission system is mainly concentrated at the input and output parallel shaft gears, the vibration peak frequency of the transmission system and the box body is close to the meshing frequency of the gear, and the larger vibration of the box body is located at the bottom of the box body. Compared with the simulation, the peak frequency in the test is similar to that in the simulation, and the root mean square error of the vibration acceleration obtained by the simulation is less than 20%, which verifies the correctness of the simulation.