Study on radial force optimization of multistage wobble plate compressor

The multistage wobble plate compressor features a compact structure and a high pressure-to-weight ratio. Thus, it has significant potential for applications in aviation, military, and other specialized fields. During reciprocating motion, the piston experiences time-variant forces from the connecting rod. The radial component of this force negatively affects the compressor's sealing and efficiency. To investigate the influence of the key structural parameters on the piston radial force, this paper develops a comprehensive mathematical model for the four-stage wobble plate compressor, which includes kinematic, compression process, gas valve, and dynamic models. It is found that the distribution radius of the piston has a significant influence on the radial force. Based on this discovery, a radial force optimization approach is proposed, which aims to minimize the frictional power loss due to radial forces and takes the distribution radius of pistons at all stages as the optimized parameters. The optimized results indicate that frictional losses caused by radial forces are reduced by approximately 13.7%, and the maximum radial force of the first stage, second stage, third stage, and fourth stage are reduced by 35.7%, 35.5%, 22.8%, and 33.6%, respectively, while the mass flow rate and the size of the compressor remain largely unaffected. This study provides important theoretical guidance for designing multistage wobble plate compressors.