DEVELOPMENT OF VISCOUS COUPLING OIL (PART 6) - STABILITY OF METHYLPHENYLSILICONE OIL

In the authors' previous reports, the problems encountered in the util ization of dimethylsilicone oils as a fluid for viscous couplings and solution thereof were studied. This paper deals with application of me thylphenylsilicone oils to viscous couplings as power transmission flu id. The stability of high-viscosity methylphenylsilicone oil with 5 mo l% phenyl group content was examined, using a viscous coupling test ri g and a laboratory friction tester. As a result, viscosity of the meth ylphenylsilicone oil increased in the ''Accelerated viscous coupling t est,'' which was operated with the oil admired with FexN powder. It wa s also shown that increase in viscosity occurred in the presence of Fe xN and Fe3O4 powders, in the LEW-1 friction test. These results being similar to the case of dimethylsilicone oils, suggest that increase in viscosity of methylphenylsilicone oils occurred also by gelation, att ributed to tribe-chemical reaction, which was accelerated by the prese nce of FexN. An EP-agent was added to the methylphenylsilicone oil to inhibit the tribochemical reaction by deactivating FexN, but its effec t seem to be lost relatively early in the test period.