Influence of Lubricant on Rotary Compressor Using R407C

The selection of lubricant is a key point in developing rotary compressor using R407C as a substitute for R22. The viscosity of oil, miscibility with refrigerant, thermal stability and compatibility with motor materials, etc, are all considerations. Furthermore, by reason of the POEs are more hygroscopic than mineral oils, hydrolytic stability and hygroscopicity of the selected oil must be considered seriously. This paper describes our effort to develop rotary compressor using R407C and some essential factors that should be considered. After 2000 hours durability test of compressor, the disassembly is carried on, the measurement of compressor components and the analysis of lubrication are taken. Finally, the conclusions are drawn based on these analysis. Because of the hygroscopicity of POE and the differences between R407C and R22 applications, some changes ought to be taken in the assembly line of compressor. This paper also introduces the factors which should be considered in the assembly line.