Characteristics of Static Friction in Sea Water on Universal Joint Member Materials
Kenzo MIURA, Kazunori TAKATA, Kazumasa FUJIWARA and Yosinori SHIMOSAKO
Abstract:A single-point mooring buoy used for shipment facility of a floating crude oil base, which some universal joints are built in, shows complicated behaviors, and gets very big tension and generates a noise based on sliding in some cases when the ocean wave is very high. It is important to evaluate the static friction coefficient s between bracket and bearing pin in order to improve durability and reliability of the universal joints. Then, static friction tests were carried out in air, in the wet of seawater and corrosive solutions using measuring system of a model simplified specimens of bracket and bearing pin. If the specimen did not corrode, the static friction coefficient s was, s = 0.24`0.28, but specimen corroded, it rose to 0.46`0.55. It is considered that the corrosion product on the surface of specimen is one of the rise causes of static friction coefficient, and the existence of corrosion product may increase sliding resistance of the universal joint. Key Words:Universal joint, Noise based on sliding, Static friction coefficient, Static friction test, Corrosion product