Theoretical Study and Computer Simulation of aModified Quick Return Mechanism(English)

Abstract

Quick return mechanism, (QRM), is considered one of the important mechanisms. It is always desired to increase machine productivity and/or to decrease time losses. Shapers, for instance, have a considerable importance in production engineering, they have gearboxes for speed variation purposes required for cutting, and most of them employ QRM. This study aimed to introduce coupling with a predetermined misalignment engaged to QRM in order to obtain an enhanced QRM that has different time ratios and speed ratios. This modification then applied to shaper for making precise speed adjustment of the cutting and return speeds of the ram beside the gearbox. Consequently, the resulted high time ratios () enhanced the productivity of the shapers for the same ram stroke. The lower return time the higher the productivity. Furthermore, the "quick" effect of the QRM retained even with shorter strokes by the present modification. The research tools included mechanism modeling and simulation using Autodesk Inventor Professional Software. In addition, it includes theoretical velocity analysis for the resulting combination. Both simulation and theoretical analyses agreed well.