渐开线直齿轮接触动态特性有限元分析

发布时间：2018-03-19 09:03

本文选题：有限元　切入点：齿轮　出处：《浙江大学》2015年硕士论文　论文类型：学位论文

【摘要】：齿轮是机械设备中动力和运动传输的关键部件,广泛应用于汽车、风电、航空、船舶等领域。目前齿轮朝着高速、重载的趋势发展,对齿轮运行的稳定性和可靠性提出了更高的要求。建立合理的齿轮模型,深入研究影响齿轮啮合传动的各个因素,对提高齿轮承载性和传动平稳性、节约设计时间和实验费用有一定的实际意义。本文建立了带轴的齿轮传动模型,基于有限元法研究了轴长、转速、负载对齿轮啮合接触冲击特性和动态接触性能的影响和轴及负载对齿轮啮合刚度的影响。本文主要研究内容如下： (1)基于赫兹接触理论推导出齿轮接触应力的计算公式,论述了解决接触问题的有限元算法及一般流程并总结求解接触动力学问题的相关技术要点,为齿轮的啮合接触分析奠定理论基础。 (2)基于直齿轮渐开线齿廓面的形成原理,实现齿轮三维参数化建模。考虑到轴变形对齿轮动态啮合性能的影响,本文建立了轴系与齿轮的联合传动有限元模型,通过几何分块对齿轮模型进行映射网格划分,优化有限元网格模型,为客观、准确的分析齿轮接触动态特性做了必要的准备。 (3)基于已建立的齿轮传动有限元模型,对齿轮的接触动态特性做了深入研究。分析出齿轮在啮合过程中接触应力的变化和分布情况,得到接触应力沿齿廓和齿面方向的分布规律。结果表明基于轴系和齿轮联合传动模型的动态接触分析可以准确、实时的模拟齿轮的动态啮合过程,为齿轮设计提供参考和依据。 (4)考虑齿轮传动系统工作情况的多变性,以轴长、转速、负载三个典型的条件因素为例,建立对比分析模型,研究各个因素对齿轮动态啮合性能的影响。结果表明：轴长对齿轮的齿面应力分布情况影响较大；转速对齿轮的啮合冲击特性影响较大,在本文模型下,当转速达到200rad/s时,从动轮转速冲击振幅急剧增大,分析结果为齿轮系统选择合理的转速区间提供指导；在一定范围内负载变化对从动轮转速振幅影响较小,但随着负载的增大,齿面接触应力显著增大。 (5)齿轮单、双齿交替啮合时,由轮齿弹性变形引起的刚度激励使齿轮产生振动和噪声。因此本文研究了齿轮啮合过程中啮合刚度的变化规律,分别建立理想齿轮传动模型和轴系与齿轮联合传动模型,得到啮合周期内齿轮啮合刚度的变化曲线。结果表明：轴系的加入降低齿轮传动系统的啮合刚度；随负载增加,齿轮啮合刚度小幅增加；负载对带轴齿轮啮合刚度的影响要小于对理想齿轮啮合刚度的影响。
[Abstract]:Gear is the key component of power and motion transmission in mechanical equipment. It is widely used in automobile, wind power, aviation, ship and so on. The higher requirements for the stability and reliability of gear operation are put forward. To establish a reasonable gear model and to deeply study the factors affecting gear meshing transmission, it is necessary to improve the bearing capacity and drive smoothness of gear. It is of practical significance to save design time and experiment cost. In this paper, the gear transmission model with shaft is established, and the shaft length and speed are studied based on finite element method. The influence of load on gear meshing contact impact characteristics and dynamic contact performance, and the influence of shaft and load on gear meshing stiffness. The main contents of this paper are as follows:. 1) based on Hertz contact theory, the formula of gear contact stress is derived, the finite element algorithm and general flow chart for solving contact problem are discussed, and the relevant technical points for solving contact dynamics problem are summarized. It lays a theoretical foundation for the meshing contact analysis of gears. Based on the forming principle of involute tooth profile of spur gear, the three-dimensional parametric modeling of gear is realized. Considering the influence of shaft deformation on the dynamic meshing performance of gear, a finite element model of joint transmission between shaft system and gear is established in this paper. The mapping mesh of gear model is divided into geometric blocks and the finite element mesh model is optimized. The necessary preparation is made for the objective and accurate analysis of gear contact dynamic characteristics. Based on the established finite element model of gear transmission, the contact dynamic characteristics of gear are studied in depth, and the change and distribution of contact stress during meshing are analyzed. The distribution of contact stress along the tooth profile and tooth surface is obtained. The results show that the dynamic contact analysis based on the shafting and gear joint transmission model can accurately simulate the dynamic meshing process of the gear in real time and provide a reference and basis for gear design. Considering the variability of gear transmission system, taking three typical factors such as shaft length, rotational speed and load as examples, a comparative analysis model is established. The influence of various factors on the dynamic meshing performance of gear is studied. The results show that the axial length has a great influence on the stress distribution of gear tooth surface, and the rotational speed has a great influence on the meshing impact characteristic of gear. In this model, when the rotational speed reaches 200radr / s, The result of analysis provides guidance for the gear system to select a reasonable speed range, and the load change has little effect on the amplitude of the rotational speed of the driven wheel in a certain range, but with the increase of the load, The contact stress of tooth surface increases significantly. 5) the stiffness excitation caused by elastic deformation of gear teeth makes the gear produce vibration and noise when the gear is engaged alternately with single or double teeth. Therefore, the variation law of the gear meshing stiffness during the meshing process is studied in this paper. The ideal gear transmission model and the joint transmission model of shafting and gear are established respectively, and the change curves of gear meshing stiffness are obtained during the meshing period. The results show that the meshing stiffness of gear transmission system decreases with the addition of shafting, and increases with load. The meshing stiffness of gear increases slightly and the influence of load on meshing stiffness of gear with shaft is smaller than that on ideal gear.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH132.413

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