高温电容位移传感器的设计与实验研究

Study on Design and Experimentation of Capacitance Displacement Sensor Used in High-Temperature Environment

为了精确测量航空发动机中的轴承座与外部机匣之间的相对变形量,应用高温合金、氧化铝陶瓷以及耐高温电缆等研制了可用于高温环境的特种电容位移传感器。将其安装于机匣的承力支板中,即可实现该相对变形量的测量。传感器采用双层屏蔽结构,并应用驱动电缆技术减小干扰信号的影响。本文首先对所设计的传感器进行了仿真分析,以验证其结构合理性,然后搭建实验平台完成了传感器的标定与性能测试,并进行了高温验证实验。实验结果表明,本文所研制的高温电容位移传感器能够在0-2.0 mm的范围内实现位移的精确测量,测量误差小于0.02 mm,并且能够在室温-500℃的温度范围内稳定工作,因而可以满足使用要求。

For the purpose of measuring the relative deformation between the bearing chock and the outer casing inan aero engine accurately,a capacitance displacement sensor used in high temperature environment is developed,which is principally made up of high-temperature alloy,alumina ceramics and special cable etc. Therefore,the mea-surement of this relative deformation can be achieved by installing the sensor in the supported slab of the casing.Based on the double shielded structure of the sensor and the driving cable technology,the interference signal maydecrease greatly. In the paper,the simulation analysis of the sensor is executed to verify the rationality of the struc-ture firstly. And then,an experimental platform is established to execute calibration and performance testing of thesensor,as well as the verification at high temperature. As the experiments show,the capacitance displacement sen-sor used in high temperature environment can realize accurate measurement in the range from 0 to 2.0 mm,whosemeasuring error is smaller than 0.02 mm. Also,the sensor can work stably from room temperature to 500 ℃,whichmeets the application requirements.