Generation method for a novel Roots rotor profile to improve performance of dry multi-stage vacuum pumps

• Published in: Mechanism and machine theory Vol. 128; pp. 475 - 491
• Main Authors: Wu, Yu-Ren, Tran, Van-The
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2018
• Subjects: Area utilization ratio; IVEC; Meshing gap area; Roots rotor; Vacuum pump; IVEC; Vacuum pump; Roots rotor; Area utilization ratio; Meshing gap area
• ISSN: 0094-114X; 1873-3999
• DOI: 10.1016/j.mechmachtheory.2018.06.009

•A mathematical model for the generation of a novel rotor profile, called the “IVEC” type, for multistage Roots vacuum pumps is established.•Two geometric performance indices, the area utilization ratio and the meshing gap area, are proposed for assessing the merits of different Roots rotor profiles.•The IVEC rotor profile incorporates geometric features of the involute and cycloids with variable amounts of extension, so it has more design flexibility and adaptability than previous designs.•Numerical and experimental examples demonstrate that the IVEC rotor profile can has better geometric performance indices and pump performance than previous designs. Multi-stage vacuum pumps are commonly used to increase pump efficiency, and several kinds of Roots rotor profiles have been proposed. However, the lack of design flexibility for rotor profiles means they may be unable to meet the requirements for different stages. This paper proposes a mathematical model and method to generate a novel rotor profile for multi-stage "IVEC" type Roots vacuum pumps. Two geometric performance indices, the area utilization ratio and the meshing gap area, are used to evaluate different types of rotor profiles. A practical experiment compares the performance of an existing benchmark vacuum pump to one with IVEC rotors. Numerical and experimental results demonstrate the superiority of the proposed IVEC Roots rotor profile.