Analysis of Optical Correction for Visualization of Ball-on-Ring Contact Lubrication

As a result, the research on lubrication tests under this contact form is limited. This paper uses the optical design software ZEMAX to construct an optical system in which a steel ball contacts the glass ring that matches the measurement system. Designing the compensation lenses through optimization function, comparing the RMS radius of the spot (root-mean-square radius of the spot, used to describe the size of the spot) with the Airy spot (a diffuse spot formed by the diffraction limit at the focal point of a light source), according to the Rayleigh criterion, when the RMS spot falls within the Airy spot, it can be considered that the imaging quality of the optical system is perfect.

When the spot size exceeds the Airy spot size, it is considered that the aberration of the optical system is large and the imaging quality is low. In this way, the optical system is calibrated and analyzed, and the parameters of the compensation lens under clear interference images are obtained. The results show that the range of use of compensation lenses is related to the curvature and thickness of the glass ring.

When using glass or sapphire outer rings for visual measurement of bearings, when the curvature radius of the glass ring is large or the glass thickness is thin, the film thickness can be directly measured without using compensating lenses. At this point, the image acquisition system has the ability to capture clear interference images; On the contrary, compensation lenses need to be added, and the compensation lenses should be designed according to the bearing size.

The comparison between the simulation results and experimental measurement results shows good consistency, indicating that the simulation system can achieve accurate simulation of the corrected optical path. This simulation system provides a new analytical method for the research of issues related to ball-on-ring test devices and full bearings, and has guiding significance for the selection of optical components.