研究業績

Rolling bearings may suffer from the fretting wear on the rolling element or raceway surface as a result of an oscillatory motion. The fretting wear on a bearing surface can result in an excessively noise, an increase of torque, the flaking, and so on. Before, the degree of oscillation was expressed as a non-dimensional parameter of the amplitude ratio. The amplitude ratio is expressed as A/D, where A is the amplitude under an oscillatory motion, and D is Hertz contact diameter. Then the oil film behavior was observed under the minute oscillatory motion in EHL (Elastohydrodynamic lubrication) point contact, and the critical amplitude at which the oil film could not be formed was measured. This paper investigated the relation between the kinematic viscosity and the fretting wear by using the thrust bearing when the amplitude ratio was changed, and compared the oil lubrication with the grease lubrication. As a result, the fretting wear decreased when the high viscosity oil was used under the oil lubrication, and when the low viscosity oil was used under the grease lubrication.