STICK-SLIP PHENOMENA AND INDUSTRIAL OIL

Stick-slip is an interesting but uncomprehensible phenomenon in friction. It bothers us because it causes chattering noise, vibration and wear. The reason for its occurrence has been studied by many scientists so far. It is well known that stick-slip occurs when a static friction coefficient is larger than the kinetic friction coefficient. Rabinowicz describes that the reason for the larger static friction coefficient is in the squeezing out of oil, penetration of surface asperities into each other and softening of friction materials due to friction heat. However, it is especially important to find out which factor among those is really dominant. The author suggests that stick-slip in hydraulic cylinder is mainly due to squeezing out of the oil, that on the guide way of machine tool is largely due to penetration and junction growth of asperities.