Experimental measurement of axial clearance in scroll compressor using eddy current displacement sensor

This paper describes a method by using eddy current displacement sensor for the measurement of axial clearance in a water-lubricated scroll air compressor. The basic physical principle of the sensor is reviewed. An effective experimental configuration is established and the test procedure is designed to acquire proper data. The output signal which gives us useful waveforms is obtained by the data acquisition program based on virtual instrument technology. The actual tested results show that the eddy current sensor has high sensitivity and preferable static and dynamic performances. The actual axial clearance of the scroll air compressor under a working condition was measured and the tested results showed that the axial clearance is larger than that in refrigeration scroll compressor. In addition, the frequencies of signal pulse also reflect the change in rotational speed by analysing the output voltage signals. The actual experimental results could reflect the real situation of axial clearance of the scroll air compressor. It is of significance to further study on the relationship between the axial clearance and the performance of the scroll air compressor.