Measurement of Roller Skew Based on Separated Responses of Ultrasonic Sensors

Accurately measuring the roller skew angle of cylindrical roller bearings under real-world operation conditions is crucial for validating theoretical analyses and optimizing bearing design. However, the absence of effective online measurement techniques remains a significant challenge. This study presents a novel non-destructive method for measuring roller skew using two juxtaposed ultrasonic sensors. The ultrasonic probes are mounted above the outer ring. The reflection coefficient of the interface can be obtained by dividing the spectral amplitude of the echo signal of the measured interface by that of the reference interface. The reflection coefficient curves will form “Dips” as the roller passes through ultrasonic probes. The roller revolution speed can be calculated based on the frequency of the “Dip” "occurrence. Combined with the time difference between the lowest points of “Dips” of reflection curves, the roller skew displacement is determined. According to the known axial distance between the probes, the roller skew angle is derived through geometric relationships. To enhance the measurement reliability, an optical method is concurrently employed to assess the roller skew angle by detecting the horizontal displacement of the reflected light spot caused by roller skew. The validation of the method's feasibility and effectiveness is achieved through a comparative analysis of the ultrasonic and optical measurement results.