偏航齿轮箱行星架的性能分析及结构优化设计

发布时间：2019-05-28 13:16

【摘要】：行星架是行星减速器中承受扭矩最大的零件,它对行星轮间载荷分配有很大的影响,如何准确地得到行星架的应力和位移,并对其结构进行改进,得到一种质量小、性能好的行星架结构,对提高行星齿轮箱的高可靠性和轻量化设计具有十分重要的意义。本课题源于国家支撑计划“7MW级风电机组及关键部件设计和产业化技术”(NO.2012BAA01B05)。本文以风电偏航齿轮箱行星架为研究对象,对齿轮的啮合刚度、轴承的支承刚度和花键连接作用结合面进行等效处理；建立行星架有限元等效模型,并对其进行静强度分析；分析行星架的部分结构参数对其应力和变形的影响；以柔度最小为目标函数对行星架进行拓扑优化设计,根据优化结果进行概念设计,最后进行结构设计。首先,根据力的传递路径,利用转速、转矩和力平衡原理对偏航齿轮箱的行星架及其他相关构件进行受力分析,根据给定的电机额定转速和齿轮箱输出扭矩计算各级行星传动行星轮轴的支反力。其次,基于有限元法计算齿轮的啮合刚度,将齿轮啮合刚度用沿着啮合线方向的弹簧进行等效；利用简易计算公式计算轴承支承刚度,将支承刚度用径向弹簧进行等效,根据接触滚子的数目确定弹簧数目；基于APDL语言对行星架进行参数化建模,对行星架花键结合面采用多种弹簧布置形式进行等效处理,得到较为理想的等效形式。接着,对行星架进行有限元强度分析,考虑啮合刚度、支承刚度和花键连接的作用。分析了齿轮啮合刚度、轴承支承刚度及行星架的双壁间距和孔的直径对行星架应力和变形的影响。结果表明,轴承的支承刚度对行星架的应力影响不能忽略,花键结合面等效形式不同对行星架的应力影响较大,而齿轮的啮合刚度只起到传递力的作用,在建模中可以以恒定数值代替；行星架在双臂间距离为90mm,行星轮轴配合孔直径为46mm时,行星架的应力最小,变形几乎相同。最后,以行星架的柔度最小为目标函数,分别以重要位置节点位移最小、体积最小为约束建立拓扑优化数学模型。基于Hyper works平台进行拓扑优化,根据材料分布进行概念设计,考虑力学性能和制造工艺进行结构优化。优化后行星架的性能有一定的提高,以行星架柔度最小,以体积最小、关键位置位移最小约束时,其位移分别降低了15.61%,16.66%,质量分别减少了18.14%,11.83%,应力一个减少13.16%,一个基本不变,达到了优化设计目的。这种方法对行星架设计及改进具有很好的指导意义。
[Abstract]:The planet frame is the most torque bearing part in the planet reducer, it has a great influence on the load distribution between the planet wheels. How to accurately obtain the stress and displacement of the planet frame, and improve its structure, get a kind of small mass. The structure of planet frame with good performance is of great significance to improve the high reliability and lightweight design of planet gearbox. This topic originates from the national support plan "7MW Class Wind Turbine and its key components Design and industrialization Technology" (NO.2012BAA01B05). In this paper, taking the planet frame of wind power yaw gearbox as the research object, the meshing stiffness of gear, the supporting stiffness of bearing and the joint surface of spline connection are treated equivalent, the finite element equivalent model of planet frame is established, and the static strength analysis is carried out. The influence of some structural parameters of the planet frame on its stress and deformation is analyzed, and the topological optimization design of the planet frame is carried out with the minimum flexibility as the objective function, and the conceptual design is carried out according to the optimization results, and finally the structure design is carried out. First of all, according to the transmission path of force, the force analysis of the planet frame and other related components of yaw gearbox is carried out by using the principle of rotating speed, torque and force balance. According to the given rated speed of the motor and the output torque of the gearbox, the support force of the planet wheel shaft of all levels of planet transmission is calculated. Secondly, based on the finite element method, the meshing stiffness of the gear is calculated, and the meshing stiffness of the gear is equivalent to the spring along the meshing line. The bearing support stiffness is calculated by using the simple calculation formula, and the bearing stiffness is equivalent to the radial spring, and the number of springs is determined according to the number of contact rollers. Based on APDL language, the parametric modeling of the planet frame is carried out, and a variety of spring arrangement forms are used to deal with the splines joint surface of the planet frame, and the ideal equivalent form is obtained. Then, the finite element strength analysis of the planet frame is carried out, and the meshing stiffness, support stiffness and spline connection are considered. The effects of gear meshing stiffness, bearing support stiffness, double wall spacing and hole diameter on the stress and deformation of the planet frame are analyzed. The results show that the influence of bearing support stiffness on the stress of planetary frame can not be ignored, and the equivalent form of splice joint surface has a great influence on the stress of walking frame, while the meshing stiffness of gear only plays the role of transmitting force. A constant value can be used instead of a constant value in modeling. When the distance between the two arms is 90 mm and the diameter of the matching hole of the planet wheel shaft is 46mm, the stress of the planet frame is the smallest and the deformation is almost the same. Finally, the mathematical models of topological optimization are established with the minimum flexibility of the walking frame as the objective function and the minimum displacement and volume of the important position nodes as the constraints, respectively. Topology optimization is carried out based on Hyper works platform, conceptual design is carried out according to material distribution, and structural optimization is carried out considering mechanical properties and manufacturing process. When the flexibility of the frame is the smallest, the volume is the smallest and the displacement of the key position is minimized, the displacement is reduced by 15.61%, 16.66% and the mass is reduced by 18.14%, respectively. 11.83%, the stress is reduced by 13.16%, and the other is basically unchanged, which achieves the purpose of optimization design. This method has a good guiding significance for the design and improvement of the planet frame.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH132.46

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