An analytical model of claw rotor profiles and working process model with the mixing process for claw vacuum pumps

• A concise design method of meshing profiles for claw vacuum pumps is proposed.
• A working process model with the mixing process is established.
• Characteristics of the mixing process for claw vacuum pumps is revealed.
• Gas pressure changing rule in mixing process is obtained by numerical simulations.

Claw rotor profiles play an important role on performances of claw vacuum pumps. In this paper, an analytical model of claw rotor profiles, including profile equations, design methods, geometric theories and profile meshing relationships is established; and a working process model with the particular gas mixing process for claw vacuum pumps is also built in order to reveal characteristics of the mixing process. The mixing process, which includes phenomena of gas over compression, gas expansion and mixing, new chamber generation, chamber separation and merge, is investigated in detail. Numerical simulations of working process consisting of the suction, mixing, compression and discharge process are carried out to exhibit flow fields and analyze the thermodynamic process for claw vacuum pumps. The presented flow domain distributions give a good understanding about their physical process. The study results are beneficial to performance evaluations of different types of profiles and designs of novel claw rotor profiles with high performances.