Occurrence of High Pressure Spike in Unidirectional Start–Stop–Start Point Contacts

The transient film thickness and pressure distributions in point elastohydrodynamic lubrication (EHL) contacts during start-stop-start motion are discussed based on experimental and numerical analyses. When the machine element starts to move after the stopping, where the oil is entrapped between two surfaces, the pressure at the exit area increases very much. The pressure increase depends markedly on the overall film thickness before the stopping of the motion, but is hardly controlled by the acceleration after the stopping. It can be considered that this phenomenon affects the rolling contact fatigue damage.