Friction coefficients of a space lubricating oil No.4116 were experimented on the ball-on-disc experiment rig at various operating conditions

especially in high and low temperature conditions. The influences of rolling speed

sliding speed

the maximum working pressure and oil inlet temperature on friction coefficient were researched by adopting the orthogonal experimental design method. The curves of the friction coefficient versus each impact factor were plotted respectively. The research results show that the sliding speed and rolling speed have significant influence on the friction coefficient

while the oil inlet temperature and the maximum working pressure have only a certain influence on the friction coefficient. The friction coefficient of the oil increases with the increase of the sliding speed but the increase amplitude becomes smaller and smaller. When the rolling speed increases

the friction coefficient decreases quickly until the rolling speed exceeds 20m/s and finally keeps at a stable value. The oil inlet temperature below 0℃ has a bigger influence on the friction coefficient. The friction coefficient increases slowly with the increase of the maximum working pressure.