飞行汽车变速器齿轮传动可靠性优化设计

Reliability-based design optimization of flying car speed changer gear transmission

飞行汽车作为面向未来空中交通的新型交通工具,齿轮传动可靠性将成为其发展的关键因素。为提高飞行汽车传动系统疲劳可靠性,以某倾转翼飞行汽车试验偏置复合轮变速器作为研究对象,根据飞行任务剖面图编制齿轮传动输入载荷谱。结合应力强度干涉理论分析各级传动与齿轮系统的疲劳可靠性。将可靠度作为优化目标,以齿数、模数、齿宽、压力角及变位系数为优化变量,考虑基本结构、强度和质量约束条件,运用遗传算法获得高可靠轻量化的结构参数。研究表明,优化后的齿轮传动可靠度提高3.83%,质量减轻2.4%,为飞行汽车传动系统开发提供支撑。

The flying car is one of the new vehicles orienting the future aerospace transportation,and its performance is partially determined by gear transmission reliability.In this paper,the test speed changer with offset compound gear(OCG)transmission on a tilting wing flying car was studied for the fatigue reliability estimation and structure optimization.Firstly,the input load spectrum of the OCG speed changer was simulated based on the mission profile.Then the fatigue reliabilities of gear stages and the gear transmission system were estimated based on the stress strength interference theory.During the optimization process,the system fatigue reliability was the objective function,while the number of gear teeth,normal module,face width,pressure angle and shift coefficient were design variables.With the constraints of basic structure,strength and weight,the genetic algorithm was utilized to obtain an optimized solution.The comparison between the optimized structure and the initial one shows that the fatigue reliability of speed changer improves by 3.83% and the mass decreases by 2.4%.This work provides a design method for the development of such systems.