压电活齿传动输出转矩优化分析

中文摘要: 随着科技的迅速发展，传统机械传动已法满足工程实际需求，机电集成压电活齿传动是一种集压电驱动、活齿传动和谐波传动于一体的新型复合传动，该传动具有大传动比、低速、大转矩等优点，在航空航天、微型机器人、精密定位等高端技术领域具有及其重要的应用前景。在分析压电活齿传动系统工作原理的基础上，由压电材料的非线性输出特性和活齿传动静力学关系，推导出压电活齿传动系统各构件的受力方程。根据力和转矩的关系，得出传动系统输出转矩方程。运用机械优化设计理论和方法，分别确定输出转矩优化系统的设计变量、目标函数和设计约束，并建立压电活齿传动系统的输出转矩优化数学模型。通过数值算法给出传动系统输出转矩随激励电压和活齿架转角的变化规律，利用Matlab软件求解输出转矩优化结果，并对比优化前后参数的变化及转矩随参数的变化的规律。结果表明：传动系统输出转矩随激励电压成正比例变化，随活齿架转角以π/435为周期发生周期性变化；优化后传动系统的最大输出转矩为0.91 Nm，比初始设计转矩提高了111.63 %；设计变量中波发生器偏移量在优化前后的改变量最大。可见，输出转矩优化使得压电活齿传动系统的承载能力得以提升。研究结果为压电活齿传动系统结构的改进和性能提升奠定理论基础。
Abstract:With the rapid development of science and technology,traditional mechanical drive can not meet the engineering practical needs.Electromechanical integrated piezoelectric movable tooth drive,which has a vital application prospect in fields such as aeronautics and astronautics,micro robot,precitioning etc.,is a new mixed drive which integrates piezoelectric driving,movable tooth drive and harmonic drive and has advantages of larger transmission ratio,lower speed and larger output torque.On the basis of working principle for the piezoelectric movable tooth drive,the forces equations of the drive's elements are established from the piezoelectric nonlinear characteristic and statics relationship of the movable tooth drive.Applying optimization design principle,the design variables,objective functions and design constraints of optimization system are defined,and optimization mathematics models of output torque of the drive system are established.Using numerical method,the changes of output torque of the drive with exciting voltage and rotational angle of tooth carrier are given.The optimized results of output torque are solved by Matlab software.Besides,the parameters changes and output torque with parameters before and after optimization are compared.Results show that a directly proportional relationship is determined between output torque and exciting voltage.The torque is changed periodically with tooth carrier with a period of π/435.The optimized maximum output torque is 0.91 Nm, increased by 111.63 %.In addition,the changing of wave generator offset is largest before and after optimization.So the load-bearing capacity of the piezoelectric movable tooth drive is enhanced.These results provide a basis for modifying the structure and improving performance of the drive.