Development of a novel approach to middle-tube asymmetric spinning via generic rollers

The asymmetric spinning in the middle-tube is a field that has not yet been thoroughly explored. An approach for this process using generic rollers is first proposed that introduces a novel method for forming irregularly shaped tubes suitable for industrial production. This paper delves into the precise forming of the novel spinning process under tool-less controlled axial and radial metal flow conditions, and methodically examines its forming mechanism. Asymmetric tubes with various shape factors are spun via derived roller-path equations, where two roller feeding methods are appropriately designed. The effects of three spinning schemes (Scheme A, Scheme B, and the one using the profile roller) with three forming depths on the shape accuracy and wall thickness distribution, are contrastively examined. The obtained results reveal that the shape accuracy based on the generic roller is enhanced by 14.6% compared to the case of utilizing the profile roller. Additionally, the spun wall thickness distribution based on the generic roller is generally more uniform than that of the using-profile-roller. In the generic-roller working conditions, Scheme A presents a more reasonable forming approach and exhibits a more uniform wall thickness distribution. This reveals the forming mechanism of the middle-tube asymmetric spinning using the generic roller.