Effects of the comprehensive stiffness performance of the impeller processing system on the machining error

Abstract

During the machining of the complex surface of impeller-type parts, the processing system together with the quality of the machined surface could be affected by the overall stiffness of the machine-cutting tool and the stiffness distribution of the workpiece. In this paper, the system stiffness field model and three-dimensional force ellipsoid are proposed and constructed. In particular for the five-axis NC machining centre, the corresponding sampling points are set on the workpiece surface by applying the matrix operations to the multibody deformation theory. Moreover, an integrated stiffness field of the processing system is developed via different tool spatial gestures. It is concluded from the experiment that the stiffness of the blade top is weak with strong vibrations and low machining precisions, which means deformations could easily arise in this region and influence the machining precision significantly. Ultimately, the blade processing techniques could be developed to minimise the machining error. [Submitted 25 December 2016; Accepted 24 October 2017]