汽车门锁闭锁器小模数齿轮副啮合性能的有限元研究

发布时间：2019-06-20 14:14

【摘要】：汽车门锁闭锁器中传动用的小模数齿轮副多数是将塑料齿轮与金属齿轮配对使用,且多以金属齿轮为主动轮。此类齿轮副不仅拥有塑料齿轮的重量轻、能够吸振、自润滑等优势,还可以运用金属材料良好的导热性能改善其散热。然而塑料弹性模量低,热传导性差,热膨胀系数大；塑料齿轮在设计、应用上还没有一个统一的参照标准,而依据金属齿轮又会带来较大的差异性；针对此类齿轮副的分析研究也相对较少。所以,对此类齿轮副啮合性能进行系统而有效的分析,有着较高的理论和实践意义,对于应用此类齿轮副的企业具也有较高的经济效应,对齿轮副设计准则与研究方法的提出也具有重要意义。为此,本文以某汽车门锁闭锁器中的小模数齿轮副为研究对象,首先在CAXA电子图版中建立齿轮副模型,之后运用有限元分析理论和ANSYS12.0有限元分析软件对齿轮副的啮合性能进行较为全面的分析与研究。主要工作如下： (1)齿轮副的接触有限元分析：建立齿轮副精确的接触压力模型,研究齿轮副在一个啮合周期内的接触应力及应变分布,总结应力与应变在一个啮合周期内的分布规律；得到齿轮副最大接触应力为4.197MPa、应变为7.035μm,且最大应力与应变都发生在齿轮副在节点啮合时等结论。 (2)塑料齿轮的本体温度场有限元分析：详细地讨论了齿轮副传动过程中热量的产生和传播,系统地介绍了传热学的一些定义和热力学有限元分析的基本方程；计算得出了齿轮副的摩擦热流量；建立了塑料齿轮的单齿有限元模型；得到塑料齿轮在工作时的最高温度为42.447℃、温升达到7.447℃、最高温度出现在节圆附近、金属齿轮分配的摩擦热量占总摩擦热流量的绝大部分(如在节点处啮合时达到91%)等结论。 (3)在接触分析与热性能分析的基础上,对齿轮副在节点啮合时进行热-结构耦合性能分析,并讨论塑料材料的热膨胀系数与弹性模量(随温度升高而降低)对齿轮副啮合性能的影响；得到接触应力在考虑两种因素的耦合分析中最大(10.449MPa)、在仅考弹性模量影响的耦合分析最小(3.950MPa)、影响齿轮副耦合性能的主要因素是塑料齿轮的热膨胀系数等结论。 (4)塑料齿轮的接触疲劳寿命有限元分析：探讨了塑料齿轮的失效形式和破坏机理；分析了齿轮副在节点处啮合时的接触疲劳寿命,得到塑料齿轮轮齿的疲劳寿命为52130次(小于实际要求的60000次),而累计疲劳系数为1.91844等结论。 (5)对齿轮副进行了耐久实验：验证有限元分析结果的正确性与可靠性；对齿轮副优化的方向进行论述,包括齿轮副尺寸参数的优化、塑料齿轮材料的增强和改性、更换性能更优的材料。总之,齿轮副的接触强度和耐热性能均能满足工作要求,而且还具有较大的冗余度；而接触疲劳性能却满足不了工作需要、接触疲劳寿命达不到设计的要求,这也是该齿轮副失效的主要原因之一。
[Abstract]:The minor-to-digital gear pair for transmission in the automobile door lock latch is used for pairing the plastic gear and the metal gear, and the metal gear is a driving wheel. The gear pair not only has the advantages of light weight, vibration absorption, self-lubricating, and the like of the plastic gear, but also can improve the heat dissipation by using the good thermal conductivity of the metal material. However, the plastic elastic modulus is low, the thermal conductivity is poor, the coefficient of thermal expansion is large, the plastic gear is in the design, the application of the plastic gear does not have a uniform reference standard, and according to the metal gear, the large difference can be brought; and the analysis and research on the pair of gear pairs are relatively small. Therefore, it is of great theoretical and practical significance to make a systematic and effective analysis of the meshing performance of this kind of gear, and it also has a high economic effect for the enterprises applying such gear pair, and it is also important to put forward the principle of the secondary design of the gear and the research method. In this paper, the small-modulus gear pair in a car door lock latch is used as the research object. First, the gear pair model is set up in the CAXA electronic map, and then the meshing performance of the gear pair is analyzed and researched by using the finite element analysis theory and the ANSYS2.0 finite element analysis software. A. Main work, such as Lower: (1) Contact finite element analysis of gear pair: set up the accurate contact pressure model of the gear pair, and study the contact stress and strain distribution of the gear pair in one meshing period, and sum up the points of stress and strain within one meshing period The rule of cloth is that the maximum contact stress of the gear pair is 4.197 MPa, the strain is 7.035. m u.m, and the maximum stress and strain occur when the gear pair is in mesh with the node (2) The finite element analysis of the temperature field of the main body of the plastic gear: the generation and propagation of heat in the gear pair transmission is discussed in detail. The basic equations of some definition and the thermodynamic finite element analysis of the gear pair are introduced in detail, and the gear pair is obtained. Friction heat flow; a single-tooth finite element model of a plastic gear is established; the maximum temperature of the plastic gear at the time of operation is 42.447 DEG C, the temperature rise reaches 7.447 DEG C, and the highest temperature occurs in the vicinity of the pitch circle, the friction heat distributed by the metal gear accounts for most of the total friction heat flow, as at the point of engagement at the node (3) On the basis of the contact analysis and thermal performance analysis, the thermal-structural coupling performance analysis of the gear pair is carried out when the node is engaged, and the thermal expansion coefficient and the elastic modulus of the plastic material (decrease with the temperature increase) are discussed to the gear pair The influence of the meshing performance is that the contact stress is the largest (10.449 MPa) in the coupling analysis considering the two factors, the coupling analysis with only the influence of the elastic modulus is the minimum (3.950MPa), and the main factor affecting the coupling performance of the gear is the heat of the plastic gear (4) The finite element analysis of the contact fatigue life of the plastic gear: the failure mode and the failure mechanism of the plastic gear are discussed. The contact fatigue life of the gear pair at the node is analyzed, and the fatigue life of the gear teeth of the plastic gear is 52130 (less than the actual). 60,000 times), while the cumulative fatigue factor is 1 ............................................................................................................................................................ In general, the contact strength and heat resistance of the gear pair can meet the working requirements and have greater redundancy; and the contact fatigue performance can not meet the working requirements, and the contact fatigue life can not meet the design requirement,
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：U463.854;TH132.41

【参考文献】