Single sensor three point on-line measurement method of precision rolling bearings

With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument.