M. Akei et al., EVALUATION OF FILM-FORMING CAPABILITY OF REFRIGERATION LUBRICANTS IN PRESSURIZED REFRIGERANT ATMOSPHERE, Wear, 196(1-2), 1996, pp. 180-187
In order to investigate the effect of refrigerant on the film-forming
capability of refrigeration lubricant, we have developed an apparatus
to measure oil film thickness under pressurized refrigerant atmosphere
. As a result of comparison among several types of lubricants, mineral
oils (particularly naphthenic mineral oil) which were currently used
showed superior ability of film-formation to new synthetic ones, polya
lkylene glycol (FAG) or polyol ester (PE), in a vacuum. However, the l
evel of superiority reduced as the refrigerant pressure increased, thu
s the capability was identical to that of synthetics at a pressure of
0.6 MPa, On the other hand, there was little difference between FAG an
d PE at the atmospheric pressure of vacuum to 0.6 MPa. It was estimate
d that the pressure-viscosity coefficients of these new refrigeration
lubricants were almost identical.