【作者】 刘超；

【导师】 潘运平；

【作者基本信息】 武汉理工大学 ， 机械工程， 2024， 硕士

【摘要】 随着汽车工业的快速发展,消费者对汽车的舒适性要求不断提高,驱动桥作为汽车重要组成部分,对驱动桥的振动噪声控制成为提升整车NVH(噪声、振动和粗糙度)性能的关键因素。本文以某公司研制的前置后驱商用驱动桥为研究对象,针对其在50km/h匀速行驶工况下噪声过大这一现象,对驱动桥振动噪声进行分析,并通过噪声台架试验验证。根据分析结果给出相应的改进措施,以提高驱动桥NVH性能。本文主要的研究内容如下:首先,探讨了驱动桥产生振动和噪声的原理及其传播途径;研究了驱动桥运行过程中受到的内、外部激励。以此为基础,综合考虑驱动桥准双曲面齿轮的齿侧间隙、啮合刚度、传动误差以及轴承的非线性接触力等变量,构建了驱动桥准双曲面齿轮系统的非线性动力学方程组,为研究驱动桥齿轮系统振动奠定基础。其次,采用四阶龙格-贝塔算法对驱动桥齿轮系统动力学方程求解,从而获得齿轮系统中轴承的详细动态响应。研究结果表明齿轮系统的振动特性主要受到二阶扭矩和齿轮啮合冲击的显著影响;利用CATIA对驱动桥中准双曲面齿轮进行切齿加工仿真得到了准双曲面齿轮模型,进而创建了驱动桥齿轮-轴承系统原型进行动力学仿真研究,通过对比轴承处振动加速度从而验证齿轮系统动力学理论模型。再次,对驱动桥0～2000Hz的主振型及其固有频率进行分析。结果显示路面激励不会导致桥壳产生共振现象;基于模态分析结果采用模态叠加法,将轴承的动态响应作为边界条件,对驱动桥壳进行频率响应分析得到桥壳振动特性;以桥壳振动作为边界条件,对驱动桥噪声进行了数值模拟,结果指出,噪声主要辐射区域位于桥壳的后盖,并且在一阶齿轮啮合频率下,桥壳辐射出的声压值最大;采用声-固耦合的直接边界元法对驱动桥的隔音性能进行了分析,结果表明在400～1300Hz的频率范围内桥壳在个别频率下的隔音性能较差。最后,对驱动桥进行台架试验测量驱动桥噪声以此验证噪声数值模拟;研究了齿侧间隙、时变啮合刚度对所建立的齿轮系统动力学模型的振动影响规律并提出齿轮系统减震措施;并针对驱动桥后盖辐射噪声大对齿轮系统参数、桥壳后盖分别进行优化,优化后桥壳较原来其噪声辐射有明显的改善。更多还原

【Abstract】 With the rapid development of the automotive industry,consumers’demands for vehicle comfort have continuously increased.As an essential component of a vehicle,controlling the vibration and noise of the drive axle becomes a key factor in enhancing the overall NVH(Noise,Vibration,and Harshness)performance of the vehicle.This article focuses on a front-engine rear-drive commercial drive axle developed by a certain company.It addresses the issue of excessive noise at a constant speed of 50km/h,analyzes the vibration and noise of the drive axle,and validates the findings through noise test bench experiments.Based on the analysis results,corresponding improvement measures are proposed to enhance the drive axle’s NVH performance.The main research contents of this thesis are as follows:Firstly,the principles of vibration and noise generation in the drive axle and their propagation paths were discussed,as well as the internal and external excitations experienced by the drive axle during operation.On this basis,taking into account variables such as tooth side clearance,meshing stiffness,transmission errors,and the nonlinear contact forces of bearings in the quasi-hyperbolic gear of the drive axle,a set of nonlinear dynamic equations for the quasi-hyperbolic gear system of the drive axle was constructed.This laid the foundation for studying the vibration of the drive axle gear system.Secondly,the fourth-order Runge-Kutta algorithm was employed to solve the dynamic equations of the drive axle gear system,thereby obtaining a detailed dynamic response of the bearings within the gear system.The study results indicated that the vibration characteristics of the gear system were significantly influenced by second-order torque and gear mesh impact.Utilizing CATIA,a simulation of gear cutting for the quasi-hyperbolic gears within the drive axle was performed,resulting in a quasi-hyperbolic gear model.Subsequently,a prototype of the drive axle gear-bearing system was created for dynamic simulation studies.The dynamic theory model of the gear system was validated by comparing the vibration acceleration at the bearings.Thirdly,the main vibration shape and natural frequency of the drive axle within0～2000Hz are analyzed.The results show that road excitation will not cause the resonance phenomenon of the axle housing.Based on the modal analysis results,the modal superposition method is used,and the dynamic response of the bearing is used as the boundary condition.The frequency response analysis of the drive axle housing is performed to obtain the vibration characteristics of the axle housing.Based on the axle housing Using vibration as the boundary condition,a numerical simulation of the drive axle noise was carried out.The results pointed out that the main noise radiation area is located at the back cover of the axle housing,and at the first-order gear meshing frequency,the sound pressure value radiated by the axle housing is the largest;using sound-The solid-coupled direct boundary element method analyzed the sound insulation performance of the drive axle.The results showed that the sound insulation performance of the axle housing at individual frequencies was poor in the frequency range of 400～1300Hz.Finally,a bench test was conducted on the drive axle to measure the noise of the drive axle to verify the noise numerical simulation;the influence of tooth side clearance and time-varying meshing stiffness on the vibration of the established gear system dynamics model was studied,and gear system vibration reduction measures were proposed.;In view of the large radiation noise from the drive axle back cover,the gear system parameters and the axle housing back cover were optimized respectively.After the optimization,the noise radiation of the axle housing was significantly improved compared with the original one.更多还原