Analysis of Lubricating Characteristics in Rotary Compressors for Domestic Refrigerators

Abstract

We investigated the lubricating characteristics between the vane and piston lubricated with an oil-refrigerant mixture. The theoretical analyses were performed using the mixed EHL theory, considering metallic contacts. Lubricating conditions were estimated by comparing the theoretical resuits of the piston dynamics based on actual surface roughness distributions measured by SEM, with the experimental results measured under a practical operation. We concludes that (1) lubricating conditions between the vane and piston are estimated to be within a mixed lubricating zone in which the coefficient of friction changes from 0.04 to 0.08, and the contact force is almost equally supported by oil film and metallic contacts, (2) the coefficient of friction decreases as the contact force increases because the ratio of pressure rise of the oil film to the decrease of the clearance is greater than that of the metallic contact pressure, and (3) it is important not only to measure the actual surface roughness but also to select the appropriate contact model in the mixed EHL analysis.