偏航变桨轴承力学特性分析及结构优化设计

发布时间：2018-07-16 20:42

【摘要】：偏航、变桨轴承广泛使用大型四点接触球轴承,工作时承受轴向载荷、径向载荷及倾覆力矩的联合作用,具有工况载荷复杂、结构尺寸大、整体刚度低及工作转速低的特点,因此不能采用普通轴承的分析方法,而有必要针对其展开专门的研究与分析。本文采用数值分析法和有限元仿真法,研究偏航、变桨轴承的力学特性和结构参数的优化设计。首先,简要分析了偏航、变桨轴承的工作环境、载荷特征、结构形式等特点,详细阐述了以Hertz弹性接触理论为条件的偏航、变桨轴承接触变形和接触应力的非线性关系,推导了偏航、变桨轴承接触载荷和接触刚度的计算方法,并介绍了其静强度和疲劳强度的计算理论。其次,根据偏航、变桨轴承的使用工况条件、几何结构特点和变形协调关系,建立了考虑实际接触角、游隙、滚道沟曲率半径系数等因素的偏航、变桨轴承力学模型,并给出了采用牛顿—拉夫森迭代法求解力学模型的详细过程,并以某一型号偏航、变桨轴承为例,研究了不同工况条件下轴承的载荷分布规律及实际接触角的变化情况。接着,采用力学模型与经验公式两种方法计算偏航、变桨轴承的最大接触载荷并进行对比分析,初步验证了偏航、变桨轴承力学模型求解最大接触载荷及计算静强度的正确性。基于力学模型计算接触载荷的方法,实现了偏航、变桨轴承承载曲面和承载曲线的精确绘制。然后,分析了滚道排距、游隙、接触角、沟曲率半径等结构参数对轴承接触载荷、接触应力、实际接触角、承载滚动体个数等力学性能的影响规律,完成了以最小接触应力为目标函数的偏航、变桨轴承优化模型建立,并采用遗传算法进行求解,从而实现了偏航、变桨轴承结构参数的优化设计。最后,采用有限元分析法对比分析了无支撑结构和含支撑结构的偏航、变桨轴承两种模型的载荷分布及实际接触角变化规律,并通过与力学模型计算结果进行对比分析,进一步验证了偏航、变桨轴承力学模型求解载荷分布方法的正确性。
[Abstract]:Yaw, variable propeller bearings are widely used in large four-point contact ball bearings, bearing axial load, radial load and overturning torque. They are characterized by complex working load, large structure size, low overall stiffness and low rotational speed. Therefore, it is necessary to carry out special research and analysis for ordinary bearings. In this paper, numerical analysis and finite element simulation are used to study the optimum design of mechanical properties and structural parameters of yaw and variable propeller bearings. First of all, the characteristics of yaw, variable pitch bearing working environment, load characteristic, structure form and so on are briefly analyzed, and the nonlinear relationship between contact deformation and contact stress of variable propeller bearing based on Hertz elastic contact theory is described in detail. The calculation methods of contact load and contact stiffness of yaw and variable propeller bearings are derived, and the calculation theory of static strength and fatigue strength are introduced. Secondly, according to the operating conditions of yaw, variable propeller bearing, geometric structure characteristic and deformation coordination relation, the mechanical model of variable propeller bearing is established considering the actual contact angle, clearance, raceway curvature radius coefficient and so on. The detailed process of solving the mechanical model by Newton-Raphson iterative method is given. Taking a certain type of yaw and variable propeller bearing as an example, the load distribution law of bearing and the change of actual contact angle under different working conditions are studied. Then, the maximum contact load of the variable pitch bearing is calculated by using the mechanical model and the empirical formula, and the correctness of the yaw and the mechanical model of the variable propeller bearing is preliminarily verified by the calculation of the maximum contact load and the static strength of the variable propeller bearing. Based on the mechanical model, the accurate drawing of yaw, bearing surface and bearing curve is realized. Then, the effects of raceway spacing, clearance, contact angle, groove radius of curvature on the contact load, contact stress, actual contact angle and the number of bearing rolling bodies are analyzed. The yaw with minimum contact stress as the objective function and the optimization model of variable propeller bearing are established and solved by genetic algorithm. Thus the optimum design of structural parameters of yaw and variable pitch bearing is realized. Finally, the load distribution and actual contact angle of the two models of unsupported structure and bearing with support are analyzed by means of finite element analysis, and the results are compared with the results of mechanical model. Furthermore, the correctness of the method of calculating load distribution by the mechanical model of yaw and variable propeller bearing is verified.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.3

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