Application of the Processing Method for Enlarging Partial Diameter to Shaft for Practical Use

Abstract

A novel processing method was proposed to enlarge the partial diameter in the middle of a round bar with a diameter of D₀=10mm. This method is called the collar-forming processing method. In order to study the conditions under which this processing method can be applied to shafts with practical diameters of D₀=25mm-40mm for general industrial machines, the processing experiments were carried out under various processing conditions, such as normalized axial-compressive stress σ_c/σ_y and bending angle θ. The results obtained are summarized as follows: the collar-forming process can be smoothly performed by selecting the initial interval L₀ between zippers within the range of 32mm-62mm, according to both the size of D₀ and the curvature radius ρ of the zipper ends; the cycle parameter N₀, which is used to determine the necessary rotation number N for final collar size in a model equation, can be estimated from both (ρ, D₀) and (θ, σ_c/σ_y); the deformation behaviors in the radial direction also depend on (ρ, D₀) as well as (θ, σ_c/σ_y) and can be estimated from the function of ρ/D₀ depending on bending angle θ; the necessary rotation number N has the tendency to increase with an increase in ω in the case of larger diameter.