Basic Study on Ultrasonic Oil-film Measurement in Roller Bearing

For to solve the shortage of measuring the oil-film in roller bearing, this paper researches the ultrasonic method based on equivalent stiffness. It also discusses how the character of transducer affects the ultrasonic oil-film measurement, and takes the dual element transducer and immersion transducer to do the experiment respectively. The ultrasonic method is feasible to measure the oil-film thickness from the experimental results, and experimental results is related to the focus spot size. Meanwhile, the ultrasonic with wide broadband and narrow pulse is conductive to oil-film measure.