Li Zheng, Zhao Liang, Yu Xuze
School of Electrical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
Rev Sci Instrum. 2020 May 1;91(5):055006. doi: 10.1063/5.0004553.
The traditional stick-slip piezoelectric actuator uses a single flexible hinge structure, and the output force of the piezoelectric stack is greater than the clamping force between the driving foot and the slider, resulting in a small working stroke, slow speed, and poor load capacity. A new piezoelectric actuator based on a two-stage flexible hinge structure is proposed. The piezoelectric actuator uses a combination of a lever flexible hinge and a triangular flexible hinge. The working stroke and speed of the actuator are enlarged by the lever flexible hinge, and the output force of the piezoelectric stack is perpendicular to and greater than the clamping force between the driving foot and the slider through the triangular flexible hinge, which enhances the load capacity of the actuator. First, the structure and working principle of the piezoelectric actuator are presented. The lateral output displacement of the piezoelectric ceramic stack is amplified by the lever amplification structure so that the triangular flexible hinge structure is then used to convert the lateral displacement into a coupled motion composed of longitudinal and lateral displacement to drive the slide rail to generate total displacement. Then, the superiority of the piezoelectric actuator was verified through the analysis of displacement amplification and clamping force and finite element analysis. Finally, the performance of the piezoelectric actuator is studied. It can produce an output speed of 354.55 mm/s under a driving voltage of 4.7 kHz and 150 V, and the maximum load can reach 3 kg. This article provides a new design idea for stick-slip piezoelectric actuators.
传统的粘滑式压电致动器采用单一柔性铰链结构，压电叠堆的输出力大于驱动脚与滑块之间的夹紧力，导致工作行程小、速度慢且负载能力差。提出了一种基于两级柔性铰链结构的新型压电致动器。该压电致动器采用杠杆柔性铰链和三角形柔性铰链相结合的方式。杠杆柔性铰链增大了致动器的工作行程和速度，并且压电叠堆的输出力通过三角形柔性铰链垂直作用且大于驱动脚与滑块之间的夹紧力，从而提高了致动器的负载能力。首先，介绍了压电致动器的结构和工作原理。压电陶瓷叠堆的横向输出位移通过杠杆放大结构进行放大，进而利用三角形柔性铰链结构将横向位移转换为纵向和横向位移组成的耦合运动，以驱动滑轨产生总位移。然后，通过位移放大和夹紧力分析以及有限元分析验证了压电致动器的优越性。最后，研究了压电致动器的性能。在4.7kHz和150V的驱动电压下，它能够产生354.55mm/s的输出速度，最大负载可达3kg。本文为粘滑式压电致动器提供了一种新的设计思路。
