Investigations on Force Characteristics of Orbiting Scroll in Asymmetric-suction Scroll Compressors

Abstract

Scroll refrigeration compressors are the critical equipment for the refrigeration system in air conditioners and vehicles. The asymmetric suction structure can be applied to reduce the scroll compressors' size. However, the pressure difference between the symmetric working chambers becomes larger and leads to the special force characteristics of the orbiting scroll. This paper illustrates the force characteristics of the orbiting scroll in an Asymmetric-suction Scroll Compressor (ASC) to improve its stability and reliability. The theoretical model has been established to calculate the force and moment acting on the orbiting scroll of ASC and the Symmetric-suction Scroll Compressor (SSC) based on the transient numerical simulation results. The variations of gas force and moment in ASC and SSC are displayed and compared. Their pulsation intensities are calculated and discussed. The pressure in the outer compression chamber of ASC was always higher than that in the inner compression chamber, which caused significant discharge loss. Affected by the tangential leakage flow, the radial force of the compressor fluctuated sharply. As the tangential force on the orbiting scroll segments of symmetrical working chambers in ASC led to the negative spin moment, the total average spin torque decreased by 71.3%. Still, the pulsation intensity increased by ten times. Furthermore, the direction of the spin moment reversed at 275°~355°, which indicated that the orbiting scroll impacted the Oldham ring every rotation. The noise and vibration would happen, and the Oldham ring would be damaged easily.