Research on the rotational accuracy measurement of an aerostatic spindle in a rolling bearing performance analysis instrument

An ultra-precision instrument is developed to measure the rotational accuracy of a rolling bearing under working conditions. This instrument uses a high-precision aerostatic spindle, which has high-stiffness to support a test bearing under large axial loading. This work demonstrates the capabilities of the double-probe error separation method for the measurement of aerostatic spindle error motion at various axial forces and rotational speeds. The rotational performance of an aerostatic spindle is discussed. The results indicate that the error motion and the form of the error of the measurement surface are reliably separated at various axial forces and rotational speeds. In addition, the error motion of the aerostatic spindle is very stable, increasing slightly and smoothly as the rotational speed increases. The error motion is less than 0.18 um when the speed reaches 1920 rpm. In the future, it will be possible to separate the error motion of an aerostatic spindle from the measurement results of a test bearing.