【作者】 廖红；

【导师】 徐劲力；

【作者基本信息】 武汉理工大学 ， 机械工程， 2016， 硕士

【摘要】 齿轮-转子-轴承系统因具备高能量密度,高效率,低振动,低噪声等特点,而被广泛应用于汽车传动系统,其工作性能对整车NVH性能有至关重要的影响。因此,如何建立更为有效的动力学模型以准确地预测其动态特性,是当前工程领域亟待解决的难题之一。本文选取汽车主减速器中准双曲面齿轮副、转轴和圆锥滚子轴承构成的齿轮-转子-轴承系统作为研究对象,综合考虑齿轮、轴承与转轴的振动耦合等多种影响因素,构建了更为精确有效的非线性动力学模型,应用现代分析技术全面深入地研究了系统动力学行为以及振动噪声的产生机理。具体研究工作如下:首先,考虑了齿轮动态啮合力对转轴振动的影响,基于连续质量的梁振动理论,建立了转轴弯-扭振动数学模型。综合考虑了发动机输出扭矩、路面阻力等外部激励,以分段非线性函数表示的齿轮动态啮合力、齿面摩擦阻力和以非线性幂函数表示的轴承动态支承力等系统内部激励,以及转轴弯曲效应对齿轮振动的影响,构建了集中参数的准双曲面齿轮弯-扭-轴-摆振动数学模型。考虑了柔性转轴对轴承振动的影响,建立了轴承振动分析模型。其次,采用4-5阶自适应步长的Runge-Kutta数值方法求解了控制微分方程,获取了系统多种稳态响应,基于时域、频域及相空间分析技术,探讨了一系列动力学参数对系统动态特性及分岔与混沌的影响。同时采用多尺度法获得了系统主共振和次共振的近似解析解及失稳边界条件。再次,构建了准双曲面齿轮CAE仿真模型,研究了齿轮的固有特性及齿面接触特性。同时基于齿轮-转子-轴承系统的Romax Designer虚拟样机,得到了齿轮与轴承的动态响应。最后,基于主减速器振动测试以及车内噪声的试验数据,探讨了负载扭矩、齿侧间隙等参数对主减速器振动的影响,获得了最佳齿侧间隙,并验证了轴承支承刚度优化后减振降噪的实际效果。同时,将试验数据和仿真结果的进行对比分析,验证了理论模型及计算结果。基于理论建模、仿真分析和试验验证的并行研究路线,为主减速器动态设计与优化提供了理论依据。更多还原

【Abstract】 Since the geared rotor-bearing system has the characteristics of higher energy density,higher efficiency,lower vibration and noise,it is widely used in vehicles.And its work performance has a crucial effect on the vehicle NVH performance.Therefore,how to establish an effective dynamic model is one of the most important topics to be solved urgently in the current engineering application,for the accurate prediction of its dynamic characteristics.In this thesis,the research object is the geared rotor-bearing system consisted of hypoid gear pair,shafts and tapered roller bearings from an automobile main reducer.Considering the coupled vibration of gears,bearings and shafts,and other various factors,the nonlinear dynamic model of a geared rotor-bearing system is established.The modern analytical techniques are applied to study the dynamic behavior of the system in depth,and reveal the underlying vibration and noise physics of the hypoid geared rotor system.The major works of this dissertation are as follows.Firstly,considering the effect of dynamic mesh force on shaft vibration,the lateral-torsional vibration mathematical model of the shaft is obtained,based on the vibration theory of continuous beam.And then,the pinion and gear coupled dynamic model of lateral-torsional-axial-pendulant degree of freedom is established by lumped parameter method.This model takes into account synthesized engine output torque,road resistance and other external excitation,piecewise-nonlinear dynamic mesh force,tooth friction drag,and bearing dynamic load expressed as a non-linear power function and other internal excitation,and the dynamic bending deformation of the shaft.Besides,the bearing vibration analysis model in view of the flexible rotor effect is proposed.Secondly,an adaptive step size control for Runge-Kutta algorithm is performed for solving the differential equations,and a variety of steady state response is presented.Then,a series of important dynamic and geometric influence on dynamic behavior,bifurcation and chaos characteristics are examined by using multiple analysis techniques based on time domain,frequency domain and phase space.Simultaneously,by applying the method of multiple scales to the reduced system,the first approximation steady state solutions and their boundary condition of instability for the primary resonance and secondary resonance of the system are obtained.Thirdly,the 3-D finite element model of pinion and gear is presented by employing CAE software,then its inherent characteristics and tooth contact pattern are investigated.Simultaneously,an entire geared rotor-bearing model based on the virtual prototype technology of Romax Designer software is introduced to characterize the potential interaction between dynamic bearing load and gear tooth contact force,so the steady state response analysis of gear and bearing are conducted.Finally,the experimental correlation process for main reducer is presented under different operating conditions.The housing surface acceleration of main reducer and sound pressure level inside the vehicle are measured.The influence of load torque and backlash on the vibration of hypoid geared rotor-bearing system are analyzed and discussed,so the best backlash is identified.In addition,the actual effect of bearing stiffness optimized on vibration and noise reduction is verified.The comparison of dynamic simulation results and experimental measurements plays a significant role in validation for the proposed analytical models and procedures.Therefore,the parallel research line based on theoretical modeling,simulation analysis and experimental verification for a geared rotor-bearing system dynamics provides a theoretical basis for the main reducer dynamic design and optimization.更多还原