Tribological Evaluation of Rotary Compressor with HFC Refrigerants

摘要

Because of the development of Hydro Fluoro Carbon (HFC), it is speculated that there will be some difficulties in lubrication at the sliding parts in compressors, especially at thevanes tip in rotary compressors and that a precise lubrication analysis and an exploit of materials for the sliding parts of compressors will be needed. In this paper, evaluations of lubricating effects at the vane tip and ratio of metal contact area, an examination of an optimum design of a vane, and an exploitation of materials for a vane were discussed respectively. First, a friction experiment under dry condition was operated to investigate a lubricating effects from the refrigerants. By this experiment, it was discovered that HFC owned somewhat of lubricating effect from fluoride, although it was smaller than that of Chloro Fluoro Carbon(CFC) and Hydro Chloro Fluoro Carbon (HCFC) from chloride. Therefore, one could say that a lubricating effect would be certainly reduced by using HFC as an alternative refrigerant. The next experiment conducted was to evaluate the ratio of metal contact area at the vane tip by measuring the electric contact resistance between the vane and the roller, and an optimum design for a vane was attempted to be made. As a result of the experiment, it was discovered that a reduction of the ratio of metal contact area was possible, however, it was awfully difficult to gain complete hydrodynamic lubrication. Therefore, an exploitation of materials for vanes was progressed by using adhesive energy on the materials, and improvements of scuffing and wear resistances were attempted by using composites of hard particles and ceramic coatings.