Fundamental investigation of gyro finishing experimental investigation of contact force between cylindrical workpiece and abrasive media under dry condition

Abstract Gyro finishing, which is one of the mass finishing, is expected to be an excellent finishing process of a workpiece with a complex shape. However, its fundamental researches are few, and hence the development of techniques to address its issues/problems, such as the decline of shape accuracy and low process controllability, is hindered by a lack of understanding of the process. Thus, a fundamental investigation of gyro finishing is conducted in the present research. The contact force acting on a cylindrical workpiece, which was designated by simplifying a large gear, was measured under different conditions in workpiece position, amount of abrasive media, and rotational speed of the container. In addition, the abrasive media height above the workpiece was measured, and effects of various factors on the contact force were investigated. From the results, the height above the workpiece was confirmed to have a strong correlation with the contact force. This was considered to be caused by increasing of the resistance of the abrasive media motion, and it was considered a major factor of the contact force. On the other hand, the effect of the abrasive media momentum and the distance between the workpiece and the container wall on the contact force was confirmed weak. Moreover, the variation of the surface roughness was investigated under different contact force conditions, and the improving speed of the surface roughness was faster under the higher contact force condition. Thus, contact force was a significant factor affecting the finishing performance, and this investigation featuring the contact force acting on the workpiece was considered significant to understand the gyro finishing process and to increase the contact force and the finishing performance.