Analysis of rectangular-profiled high-strength grinding wheels designed for crankshaft grinding applications

摘要

The continued development of high-speed rotating grinding wheels for grinding crankshafts has led to the use of high-performance materials such as carbon fiber matrix structures with abrasive segments bonded to them. The use of porous reinforcing centers in order to improve safety and increase rotational speed to gain the benefits associated with high-speed grinding is investigated. A 2-D finite-element model is developed which calculates rotational stresses and compares them with stresses predicted using closed-form solutions developed by Chree and Frost and Whitcomb for rotating rings. A 3-D finite-element model is developed for more complex grinding wheels that contain a porous reinforcing center that predicts stresses and deflections with remarkable accuracy. The paper also takes account of the strength of biaxially stressed brittle abrasive materials where the geometry of segments differs significantly from the prismatic geometry associated with flexural bending strength test pieces that are subjected to three-point loading conditions. Owing to lower design stresses and associated rotational speeds with high survival probability of ceramic abrasive structures ( 99.99%), it is assumed that the failure of abrasive segments is dominated by volume and/or surface flaws. The results predict accurate safety factors than previously calculated owing to the geometry of the abrasive segment loaded under plane stress conditions. The paper will be of interest to manufacturers who design and make such complex grinding wheel structures.