【作者】 孙建国；

【导师】 林腾蛟；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2008， 硕士

【摘要】 齿轮传动因具有传动效率高、恒功率等特点,广泛应用于机械、电子、化工、冶金、交通等诸多领域。随着近代工业技术的高速发展,对齿轮传动的减振降噪提出了更高的要求。通过齿轮热弹接触分析、齿轮修形、冲击动力仿真以提高齿轮传动的动力学性能已成为当前高性能齿轮设计的热点。论文课题来源于国家科技支撑计划项目及重庆市自然科学基金项目。将齿轮啮合原理、传热学、接触力学、结构动力学等相结合,对运转过程中的齿轮副进行热弹变形分析及啮合冲击特性研究。本文的主要研究工作如下:①运用齿轮啮合原理的运动学法,推导了渐开线齿轮齿廓方程,并对不同几何参数的渐开线齿轮副进行了接触有限元建模。②基于赫兹接触理论,分析了齿轮副齿面接触压力的变化规律;应用ANSYS软件对运转过程中的齿轮副进行了接触有限元分析,得出了轮齿接触力、接触变形及啮合刚度的变化规律。③分析了齿轮啮合过程中主、被动轮轮齿相对滑动速度,计算了轮齿边界对流换热系数及齿面摩擦热流量,并以多齿对模型分析了齿轮的本体温度场;将温度场、位移场及应力场耦合分析,计算齿轮副的热弹变形,得出齿轮副热弹变形量要比冷态时变形量略小,接触应力较冷态时稍大。④在轮齿接触有限元分析的基础上,进行了轮齿的修形研究,得到了齿轮副在没有考虑温度影响与考虑温度影响时的修形曲线;利用ANSYS软件对啮入、啮出位置时标准渐开线齿轮副和修形齿轮副进行了接触分析,修形后轮齿接触应力明显减小。⑤建立了标准渐开线齿轮和修形齿轮的动力接触有限元分析模型,利用ANSYS/LS-DYNA软件仿真,得到了啮合过程中齿轮副动态接触力及动态应力变化规律,修形后的齿轮接触特性明显改善。⑥通过Visual Basic及ANSYS/APDL语言开发了齿轮热弹接触分析及动力接触有限元分析程序;程序能建立任何模数、齿数、螺旋角及变位系数的齿轮副有限元模型;可以方便地借助ANSYS软件的二次开发实现齿轮副的静力接触、动力接触以及齿轮本体温度场分析。更多还原

【Abstract】 Gear transmission is widely applied in machines, electronic, chemical, metallurgy, traffic and so on because of its high transmission efficiency and constant power. Along with the rapid development of modern industrial technology, the requirement of vibration and noise reduction is becoming even higher. The design method based on thermo-elastic contact analysis, gear modification, and impact dynamic simulation is widely used to improve the dynamic performance of gear transmission.The thesis subject is supported by National Project of Scientific and Technical Supporting Programs and Chongqing Natural Science Foundation. Combining with principle of gear engagement, theory of heatl transfer, contact mechanics, and structural dynamics, the thermo-elastic deformation and meshing impact characteristics in meshing process are studied.The research work presented in this thesis can be summarized as follows:1) Using the kinematics of gear engagement principle, the tooth profile equation of involute gear is derived, and contact finite element models of involute gear pair with different geometric parameters are established.2) Based on Hertz theory, the contact pressure on tooth surface is analyzed. The software of ANSYS is used to analyze the contact performance of gear transmission, and then the changes along the contact path of gear tooth contact force, contact deformation and engagement stiffness are obtained.3) The relative sliding velocity between the tooth flanks is analyzed, then the convection heat transfer coefficient and tooth surface heat flux are calculated. Using above results, the body temperature of gear is studied based on multi-tooth pair model. Coupled with the temperature field, displacement field and stress field, the thermo-elastic deformation of gear pair is obtained. The results indicate the value of gear thermo-elastic deformation is a little smaller than the value of deformation in the cold state and the contact stress is a little larger than the cold state.4) Based on finite element analysis of tooth contact problem, the gear modification is studied, and the curves of gear modification which without temperature effect and with temperature effect are obtained. The contact finite element analysis of standard involute gear pair and modified gear pair in the meshing in and meshing out position is compared by the software of ANSYS. It shows the contact stress of modification gear pair is significantly reduced.5) The dynamic contact finite element model of standard involute gear pair and modified gear pair are established. By using the software of ANSYS/LS-DYNA, the dynamic contact force and dynamic stress of gear pair in meshing process are calculated, the contact characteristics of modified gear pair are improved significantly.6) By the language of Visual Basic and ANSYS/APDL, a finite element anlysis program is compiled to analyze the thermo-elastic contact and dynamic contact problem of gears. Using this program, the finite element model of gear pair with different module, teeth number, helical angle and modification coefficient can be built quickly, and the static/dynamic contact analysis and body temperature calculation can be completed conveniently by the help of the secondary development of ANSYS.更多还原