New Geometric Stability Maps for Predicting Unstable Lobe Regeneration During Shoe-Type Centerless Grinding with Tilting Shoes

Abstract

The shoe-type centerless grinding (STCG) process stands out for its high productivity and geometric precision in grinding bearing rings. The roundness error of these parts is critical, as it affects on the generation of unwanted noise during operation, dynamic performance and service life of the components among other problems. Recently, the industry has required that the Fast Fourier Transform (FFT) of the peripherical surface of the part remains below a specific acceptance curve to avoid problems arising from this roundness error. Geometric regeneration, which is mainly affected by the geometry and angular positioning of the support shoes is a crucial aspect, as it can produce components with high amplitude that exceed the acceptance curve. Previous studies have investigated this phenomenon with fixed single contact shoes; however, the industry has started using double and tilting support shoes. In this paper, the geometric stability of double shoes has been characterized and experimentally validated. This has enabled the development of stability maps that predict the components produced under different shoe angle combinations, allowing the selection of the optimal combination and reducing set-up times.