Abstract:

Elastohydrodynamic lubrication (EHL) traction behavior of a kind of chlorphenyl silicone oil (CSO) used in spacecraft mechanisms is studied. The Carreau viscosity model is used to describe the shearthinning behavior encountered in EHL. Rheological tests are performed in order to determine the rheological parameters of the CSO. Tribological tests are carried out on a balldisk traction rig to measure the traction coefficient for different operating conditions. Experiments are compared with theoretical ones. It is shown that the traction coefficient of CSO increases steeply with an initial increase in slide to roll ratio followed by a relatively gradual increase and finally a decreasing trend. Traction coefficient of CSO is less sensitive to load compared with two other spatial liquid lubricants and decreases with an increase in rolling velocity at high slide to roll ratios. Therefore the tribological components lubricated with CSO will present longer service life and consume lower power. But the viscosity variation of CSO is about 5 magnitude orders in the wide temperature range，so it is unfit to cryogenic operating conditions.

Key words: spatial liquid lubricants, chlorphenyl silicone oil, elastohydrodynamic traction characteristic