To simulate the flow pattern of lubricant as the rolling elements enter and leave the contact area,a reciprocating unit was used to realize the cyclic loading imposed on the ball on disc contacts.Using the optical film thickness measurement method,the influence of oil supply amount,entrainment speed,and loading period on the oil reservoir patterns were observed under cyclic loading conditions.The results show that a closed oil reservoir pattern is formed at low speed.The dimensionless inlet distance and side reservoir width reduce with the increase in loading,indicating the reduction in oil replenishment.As speed becomes larger,the increase in loading and decrease in loading period will result in early rupture of the rear oil reservoir.The two oil reservoir tails will merge in the process of unloading.At high speeds,the reservoir pattern will present a separated state and fully starvation contacts.The effect of rolling track overlap will improve lubricant replenishment and lubrication state to some extent.