Li Xiaoniu, Yao Zhiyuan, Yang Mojian
State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Rev Sci Instrum. 2017 Jun;88(6):065003. doi: 10.1063/1.4985703.
A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint is proposed in this paper. The motor is comprised of a V-shaped transducer, a slider, a clamp, and a base. The V-shaped transducer consists of two piezoelectric beams connected through a flexible joint to form an appropriate coupling angle. The V-shaped motor is operated in the coupled longitudinal-bending mode. Longitudinal and bending movements are transferred by the flexible joint between the two beams. Compared with the coupled longitudinal-bending mode of the single piezoelectric beam or the symmetrical and asymmetrical modes of the previous V-shaped transducer, the coupled longitudinal-bending mode of the V-shaped transducer with a flexible joint provides higher vibration efficiency and more convenient mode conformance adjustment. A finite element model of the V-shaped transducer is created to numerically study the influence of geometrical parameters and to determine the final geometrical parameters. In this paper, three prototypes were then fabricated and experimentally investigated. The modal test results match well with the finite element analysis. The motor mechanical output characteristics of three different coupling angles θ indicate that V-90 (θ = 90°) is the optimal angle. The mechanical output experiments conducted using the V-90 prototype (Size: 59.4 mm × 30.7 mm × 4 mm) demonstrate that the maximum unloaded speed is 1.2 m/s under a voltage of 350 Vpp, and the maximum output force is 15 N under a voltage of 300 Vpp. The proposed novel V-shaped linear ultrasonic motor has a compact size and a simple structure with a large thrust-weight ratio (0.75 N/g) and high speed.
本文提出了一种新型的带有柔性接头的大推力重量比V型直线超声电机。该电机由V型换能器、滑块、夹具和基座组成。V型换能器由两根通过柔性接头连接的压电梁组成，形成合适的耦合角。V型电机以纵向弯曲耦合模式运行。纵向和弯曲运动通过两根梁之间的柔性接头传递。与单压电梁的纵向弯曲耦合模式或先前V型换能器的对称和非对称模式相比，带有柔性接头的V型换能器的纵向弯曲耦合模式具有更高的振动效率和更方便的模式一致性调整。建立了V型换能器的有限元模型，以数值研究几何参数的影响并确定最终的几何参数。然后制作了三个原型并进行了实验研究。模态测试结果与有限元分析结果吻合良好。三种不同耦合角θ的电机机械输出特性表明，V-９０（θ = 90°）是最佳角度。使用V-90原型（尺寸：59.4 mm×30.7 mm×4 mm）进行的机械输出实验表明，在350 Vpp电压下最大空载速度为1.2 m/s，在300 Vpp电压下最大输出力为15 N。所提出的新型V型直线超声电机尺寸紧凑、结构简单，具有大推力重量比（0.75 N/g）和高速度。
