Experimental identification of abnormal noise and vibration in a high-speed polygon mirror scanner motor due to mechanical contact of plain journal bearing

This paper investigates the abnormal noise and mechanical vibration of a high-speed polygon mirror scanner motor due to the mechanical contact between the rotating shaft and stationary sleeve. In the paper, we analyze the characteristics of the aerodynamic noise, structural borne noise, and electromagnetic noise in a polygon mirror scanner motor. We determine the characteristics of the main harmonics of structural borne noise by analyzing the correlation between sound and vibration and by evaluating the effect of specific harmonics on sound quality. We also develop an experimental set-up to measure the mechanical contact and the mechanical vibration of the polygon mirror scanner motor simultaneously. This paper uses the experimental setup to show that the mechanical contact between the rotating shaft and stationary sleeve is one of the dominant sources of the vibration that generates the abnormal noise of the high-speed polygon mirror scanner motor.