Research on optimizing the spatial arrangement of inserts for screw rotor disk milling cutters

Abstract

The screw rotor constitutes the primary component of a screw compressor, and its rough machining typically employs disk milling cutters. However, due to the intermittent heavy-load cutting nature of the milling process, issues such as large fluctuations in cutting forces, uneven tool wear, and poor machining stability arise, leading to low processing efficiency, short tool life, and high production costs. To address these issues, the objective of this study is to optimize the efficiency and stability of screw rotor rough machining, extend tool life, and reduce processing costs. A novel methodology for the design of disk milling cutters is hereby proposed. This methodology is predicated on the spatial arrangement and coordinated optimization of indexable inserts. First, an approach is put forward that combines two-dimensional overlap rate gradient optimization with three-dimensional spatial arrangement optimization. This approach is intended to address the issue of uneven tool life distribution, the overlap rate is increased at the top of the disc milling cutter and arranged in four densely spaced helical lines, while the overlap rate is reduced at the bottom and arranged in two helical lines, achieving uniform distribution of cutting loads. Second, finite element simulation analysis was used to determine the influence of rake angle and edge inclination angle on cutting force. This analysis was then combined with genetic algorithm optimization to obtain the optimal positional parameters of the insert. Experimental verification has demonstrated that, in comparison with conventional tools, the newly developed disc milling cutter reduces cutting force by 4%, decreases power fluctuation range by 11%, reduces top insert wear by 25%, decreases tool change frequency by 37.5%, and reduces average power per feed by 21%. These findings indicate a substantial enhancement in processing stability and efficiency. The results of this study can be applied to the rough machining production of screw rotors in the mechanical and petrochemical industries, providing theoretical support and engineering references for the design optimization of high-load intermittent cutting tools. This contributes to reducing the manufacturing costs of core components in screw compressors and enhancing their industrial production efficiency.