【作者】 张磊；

【导师】 李杰；

【作者基本信息】 吉林大学 ， 车辆工程， 2011， 博士

【摘要】 变速器的种类很多,包括：手动变速器,自动变速器,无级变速器,机械式自动变速器,以及双离合变速器。无论哪种类型的变速器,齿轮都是主要的传动部件,齿轮的承载能力与可靠性,直接关系着传动质量,进而影响整车性能。齿轮承载能力分析国家标准涉及到大量的系数,求解非常繁琐,而且在齿轮整个结构区域内无法获得位移场、温度场和应力场的变化。齿轮试验也只能得到齿轮的疲劳寿命和极限应力,对齿轮实际运转过程中的内部应力或温度则无法直接测量。为了保证齿轮不发生破坏,只能将齿轮设计得偏于保守。随着计算机和软件技术的高速发展,作为一种应用范围广泛的现代数值分析方法,有限元法已经在齿轮设计与分析中得到应用。应用有限法不仅能够实现接触、弯曲和胶合的承载能力分析,而且还能够优化齿轮齿形,实现齿轮的轻量化设计。本文在国家863高技术研究发展计划重点项目(2006AA110104)与吉林省科技发展计划项目(20076029)支持和资助下,根据汽车行业的特点,研究变速器齿轮承载能力分析经典方法和有限元法,通过对某型实际变速器的研究,探索相应的分析流程和规范。比较了各种类型变速器传动的优缺点,分析了变速器齿轮研究的背景和意义,以及国内外齿轮承载能力研究现状,针对齿轮常见的三种失效形式,即齿面剥落(点蚀)、轮齿折断、以及齿面胶合进行综述和分析,提出本文研究的内容。面向工程应用,对齿轮接触和弯曲承载能力分析标准GB/T3480-1997中载荷修正系数、计算应力修正系数、许用应力修正系数,计算应力和许用应力等各种系数与应力公式进行了系统分析和总结,应用APDL开发了齿轮接触与弯曲承载能力分析的计算机程序模块,既便于应用又为后续齿轮接触和弯曲有限元分析结果的验证提供了必要的依据。面向工程应用,对齿轮胶合承载能力分析的闪温法标准GB/Z6413.1与积分温度法标准GB/Z6413.2所包含的基本参数、瞬时温升及其修正系数、积分温升及其修正系数、闪温胶合准则和积分胶合准则等进行系统分析和总结,应用APDL开发了齿轮胶合承载能力分析的计算机程序模块,实现了对啮合齿面温度的快速、准确预测。建立了用于接触、弯曲和温度有限元分析的参数化三维齿轮实体几何模型,各主要啮合点的三维齿轮接触有限元模型,适用于不同啮合点、齿轮齿廓和旋向变化的三维齿轮弯曲有限元模型。面向工程应用,利用APDL开发了齿轮参数化实体几何模型和与齿轮啮合过程对应的接触和弯曲有限元模型自动化实现计算机程序模块,对齿轮瞬时温度分析有限元建模的基本参数进行了研究,通过对齿轮瞬时温度分析基本理论的分析,建立了齿轮瞬时温度分析的边界条件,随时间和位置变化移动热源载荷,提出了在ANSYS处理移动热源加载方法。应用APDL开发了齿轮瞬时温度分析有限元模型自动实现的计算机程序模块。以便能够准确预测齿轮的温度分布状态。根据汽车行业的特点,结合某变速器逆向设计的需要,应用开发的经典方法和有限元法自动实现模块,针对变速器齿轮承载能力分析遇到的问题,从接触、弯曲和胶合三个方面对变速器齿轮承载能力进行了研究与分析。本文的创新点为：(1)面向工程应用,对齿轮接触和弯曲承载能力分析标准GB/T3480-1997,胶合承载能力分析闪温法标准GB/Z6413.1-2003和积分温度法标准GB/Z6413.2-2003进行了分析和总结,应用APDL开发了齿轮接触、弯曲、闪温和积分温度承载能力分析的计算机程序模块,只要输入齿轮承载能力分析的原始数据,就可自动完成齿轮承载能力的经典分析,不但提高了计算效率和准确性,而且避免了以往使用简化公式或查阅图表所带来的误差。(2)依据齿轮啮合的几何位置关系,建立了各主要啮合点的三维齿轮接触有限元模型,可以全面分析齿轮啮合过程中接触状态的变化。针对三维齿轮弯曲有限元建模的啮合接触线和作用载荷确定的核心问题进行了研究,根据斜齿轮的载荷接触线分布原理,提出了便于工程应用的三维齿轮弯曲有限元模型接触线确定方法和载荷假设,不但适用于齿轮不同啮合位置、齿轮齿廓及齿轮旋向的变化,而且解决了多对齿轮啮合时的齿向载荷分布和齿间载荷分配问题。(3)提出了齿轮齿面区域平均换热系数、齿轮单个齿面区域平均摩擦热流密度及其确定方法,避免了以往采用恒定换热系数和摩擦热流密度的不足,使结果更接近于真实的轮齿温度分布状态。通过对齿面瞬时加热和温升机理的研究,将随齿轮啮合过程不断变化的摩擦热,转变为随时间和位置变化的移动函数热源载荷问题,提出在ANSYS中处理移动热源函数的加载方法,不但可以解齿轮任意啮合位置的齿面瞬时温升,而且对于求解各种平面和曲面类型的移动函数载荷问题都具有借鉴意义。(4)应用APDL开发了齿轮参数化实体几何模型、与齿轮啮合过程对应的接触和弯曲有限元模型、齿轮瞬时温度分析有限元模型自动实现的计算机程序模块,只要输入齿轮的原始数据,就能自动完成齿轮承载能力的有限元分析。结合某变速器逆向设计的需要,联合应用齿轮承载能力经典分析计算机程序模块,全面实现了变速器齿轮接触、弯曲和胶合承载能力的一体化经典分析和有限元分析,克服了以往只能实现某一种承载能力分析的不足。更多还原

【Abstract】 There are many different types of transmissions including:Manual Transmission, Automatic Transmission, Continuously Variable Transmission, Automated Mechanical Transmission, and Dual Clutch Transmission, while regardless of what type of transmissions, as the main components in the transmission, the strength and reliability of gears are directly related to the transmission quality, thus affecting the performance of the vehicle.The national standard for calculating gear load capacity includes large numbers of coefficients, the solution of which is very complicated, and the variation of displacement field, temperature field and stress field in the whole gears construction region can not be obtained. The gear fatigue life and permissible stress can just be obtained in gear test, while the stress and temperature in the process of gears rotating can not be directly measured. In order to ensure gears are not destroyed, gears have to be conservatively designed. With the rapid development of computer and software technology, as a numerical analysis method applied widely, finite element method has been applicable to the design and analysis of gears. The application of the method can not only achieve gear contact bending and scuffing load capacity, but also optimize gear tooth profile and design light-weighted gears.The research has been supported by the National 863 High Technology Research and Development Plan Key Project (2006AA110101) and the Technology Development Program of Jilin Province (20076029). According to characteristics of the automotive industry, the classical method and the finite element method for load capacity of transmission gears were studied. By analyzing a certain type of actual transmission, the appropriate processes and norms were explored.Firstly, the study compared the advantages and disadvantages of various types of transmissions, automobile transmission gears background and significance, and the gear load capacity status at home and abroad were analyzed. Three common gear failure modes:flanks spalling (pitting), breakage, and scuffing were reviewed and analyzed. Main contents in this dissertation were described as follows.Oriented engineering application, factors including load factors, nominal stress factors, permissible stress factors, and stress formulas used for calculating stress and permissible stress in gear contact and bending load capacity standard GB/T 3480-1997 were systematically analyzed and summarized. Computer program modules for analyzing gear contact and bending load capacity were developed by using APDL, which was conveniently applied, and provided necessary basis for validating the results of the finite element model for analysis of gear contact and bending load capacity.Oriented engineering application, basic parameters, flash temperature and its factors, integral temperature and its factors, flash temperature scuffing risk and integral temperature scuffing risk in scuffing load capacity of flash temperature method standard GB/Z 6413.1-2003 and integral temperature method standard GB/Z 6413.2-2003 were systematically analyzed and summarized. Computer program modules for analyzing gear scuffing load capacity were developed by using APDL, which could predict the temperature of the engaging gears quickly and accurately.Corresponding to the research of the finite element method for analyzing gear contact and bending stress in the engagement gears and the development of relevant computer program modules, parametric three-dimensional model was developed for the finite element analysis on contact, bending, and scuffing. The contact finite element model of meshing points, the bending finite element model for meshing gears on different locations, gear tooth profile and the rotation were developed. Oriented engineering application, parametric geometric model for gears and computer program modules for automatically building contact and bending finite element models in meshing gears were developed by using APDL.The fundamental parameters of the finite element model for the analysis of gear contact temperature were made a research. By analyzing the theory of the gear contact temperature, the boundary conditions of the analysis of gear contact temperature and the moving heat load changing with the time and location were developed. The method of moving heat load in ANSYS was proposed. Computer program modules which could analyze the finite element model of gear contact temperature were developed to predict the profile of the gear temperature condition accurately by using APDL.Finally, in accordance with characteristics of the automotive industry and the need of reversal design of transmissions, the automatic finite element model was developed and applied. Moreover, aiming at the problem in analyzing load capacity of transmission gears, the load capacity of transmission gears in terms of contact, bending and scuffing was studied and analyzed.The creative contents in this dissertation are:(1) Oriented engineering application, the national standards were analyzed and summarized as follows:gear contact and bending load capacity of standard GB/T 3480-1997, scuffing load capacity of flash temperature method standard GB/Z 6413.1-2003 and integral temperature method GB/Z 6413.2-2003. By using APDL, computer program modules which could analyze the load capacity of gear contact, bending, flash integral and temperature integral were developed. Just applying the original datas of gear load capacity, the analysis of gear load capacity could be automatically completed. This method could not only improve efficiency and accuracy, but also avoid the errors caused by using simplified formulas or charts.(2)Based on the geometric relationship among gears, the finite element model of main meshing points for the engagement gears was developed in order to make a comprehensive analysis of gear contact states in the process of gears meshing. The most important question determined by the gear contact line and the load in the finite element model of gear bending was considered. According to the load distribution principle of helical gear contact line, the convenient method for engineering application to determine the contact line and the load assumptions for gear bending finite element model was put forward, which could not only be appropriate for meshing gears on different locations, gear tooth profile and the rotation, but also solve the problem of the face load and transverse load in the process of multi-tooth gears meshing.(3) Gear tooth average heat transfer coefficients, the average single gear tooth heat flux and their determination methods were proposed, which could avoid the weakness of using constant heat transfer coefficients and heat flux, making the results more close to the real distribution of gears temperature. Through the research of the tooth heating and the mechanism of transient temperature, the friction heat continuously varying during gears meshing was converted into a mobile function of heat load changing with time and location. The method dealing with loading moving heat function was proposed in ANSYS, which not only solved flash temperature on gears teeth, but also made a significance in solving various types of moving load function problems.(4) By using APDL, computer program modules for automatically building parametric gear solid geometry model, contact and bending finite element model corresponding to the process of gears meshing and contact temperature finite element model were developed. Just applying the original gear datas, the analysis of gear loading capacity could be automatically completed. Combined with the reverse design of a transmission and the computer program modules for classical analysis, the integration of classical analysis and finite element analysis of transmission gears contact, bending and scuffing load capacity was fulfilled, and the lack that only a certain load capacity could be analyzed in the past was overcame.更多还原