研究業績

Rolling bearings may suffer from fretting wear on the rolling element or raceway surface as a result of oscillatory motion. Such fretting wear on a bearing surface can result in excessive noise, increased torque, flaking, and so on. In a previous study [1], the degree of oscillation was expressed as a non-dimensional parameter of an amplitude ratio. Amplitude ratio was expressed as A/D, where A was amplitude, and D was Hertz contact diameter. Then oil film behavior was observed under minute oscillatory motion in EHL point contacts, and the critical amplitude ratio when the oil film was unable to form was measured. The critical amplitude ratio was 1.5 when polyalphaolefin (PAO) oil was used as the lubricant. Moreover, the critical amplitude ratio was also 1.5 when the speed, the contact pressure, and the viscosity of oil were changed. However, the critical amplitude ratio decreased from 1.5 to 1.0 when traction oil was used. In this study, the critical amplitude ratio of line contacts was measured. Then, the results of line contacts were compared with those of point contacts.