The Tribological Evaluation of Compressor Contacts Lubricated by Oil-Refrigerant Mixtures

The tribological characteristics of the most common contact geometries found in compressors of air conditioning and refrigeration systems have been experimentally investigated by means of a unique high pressure tribometer (HPT). The HPT has been used to experimentally simulate the friction and wear behavior of various metal contact pairs lubricated by oilrefrigerant mixtures in environments found in compressors. The refrigerants used in this program are CFC-12 to obtain baseline data and its prime replacement candidate, HFC-134a. The CFC-12 has been tested with mineral oils and synthetic alkylbenzenes while the HFC-134a has been tested with monoether polyalkylene glycol (PAG's) and pentaerythritol polyolester oils. Since the amount of refrigerant dissolved in the oil is a function of both pressure and temperature, and the friction and wear of a given contact can be significantly affected by the concentration of refrigerant in the oil, the friction and wear data obtained from this test program should be a good indicator of what can be expected in compressors.Air Conditioning and Refrigeration Center Project 0