测速齿轮相对面积对电涡流传感器输出电压的影响

Effect of Gears Relative Area on the Eddy Current Transducer Output

轴系的转速是旋转机械系统的基础参数,齿轮-ETC是其广泛应用的测量方法。齿轮表面的齿槽相间结构导致连续面积较少,而连续面积与ETC探头面积之比(相对面积)直接影响ETC的输出特性乃至转速提取,齿轮齿数是影响测速齿轮相对面积的重要因素之一。通过ETC在不同齿数齿轮情况下的动静态试验及输出特性模型研究,结果表明:ETC总输出电压信号包括静态偏置电压、动态电压及干扰电压;相对面积减小导致静态偏置电压及动态电压的幅值降低;相对面积过小会使干扰电压在总输出电压中所占份额增大,相对误差随之增大,对其直接调制所获取的转速结果相对误差也会增大。

The shaft speed is a fundamental parameter of rotating machinery,and the eddy current transducer(ETC)is the most common measuring tool.The tooth and groove structures on the surface of the gear reduce the continuous surface area.The relative area,however,affects the output characteristic of the ETC and speeding acquisition directly,where the number of gear teeth is one of the most important factors that affect the gear relative area.A mathematical model is developed to predict the output characteristics for different number of teeth.The results indicate that:(1)the ETC total output voltage signal includes static voltage,bias voltage,dynamic voltage and interference;(2)Reducing the relative area leads to static bias voltage and to a decrease of the dynamic voltage amplitude;(3)Reducing the relative area increases the share of the interference voltage in the total output voltage.Accompanied by the increase of the relative error of the total output voltage,the rotational speed results will increase.