轴承腔壁面液膜厚度测量系统的设计与实现

摘要

航空发动机轴承腔壁面液膜厚度影响轴承腔的换热,准确测量轴承腔壁面液膜厚度对轴承腔润滑设计和热分析至关重要.针对轴承腔壁面液膜厚度难测的问题,根据脉冲反射法的基本原理,设计超声波测量系统,系统主要包括数据采集卡、电缆、探头以及延迟块等硬件以及由VC++开发的软件.以水作为介质,测量不同温度、不同倾斜角度条件下液膜厚度,并将测量结果与计算值进行对比,验证测量系统的准确性与可靠性.测量结果显示:在测量范围内,最大相对误差小于7.1％,满足工程实践要求.%The liquid film thickness in aero- engine bearing chamber influences on the heat transfer capacity of the bearing chamber wall,so that measuring liquid film thickness accurately is essential to the design and thermal analysis of lubricating oil system. Because of poor working environment, such as high pressure and high temperature in the bearing chamber, this paper designs ultrasonic measuring system. The system includes the data acquisition card, cable, probe delay block and software exploited with VC ++ . Finally, we get the error between the experimental and calculated values of different operating conditions. The experimental results show that:the measuring system can meet the actual requirements and can measure the liquid film thickness in aero- engine bearing chamber.