Abstract:In order to reduce the large friction of the seal of a large rotary device,the friction characteristics of two seal components at different lubrication states were experimentally studied,and the mechanism of friction reducing of the grease was analyzed based on the elastohydrodynamic theory.The results show that the friction of the rotary device tends to increase greatly at low temperature,and ordinary silicone rubber O-ring is not suitable for rotary seal when friction is restricted,but a combined PTFE seal ring can efficiently reduce the friction of the rotary device seal,and it has a close static and dynamic friction force.A thin elastohydrodynamic lubricating film is formed when a special grease is added in the sliding friction surface,the friction at-40~60℃,especially at-40℃,is further declined,and the influence of the friction of the seal on the dynamic performances of the device is minimized.