Mechanism for Controlling Oil Replenishment in Starved Elliptical EHL Contacts

Under rolling/sliding conditions of concentrated contacts, lubricant is pushed aside by the rolling element, leading to a depleted track and oil starvation. This study represents an attempt to investigate the effect of controlling oil replenishment within starved elliptical EHL contacts. The controlling of replenishment has been carried out by means of lubricant channeling via external slider with central slot to scrap the displaced lubricant on one of the contacting surfaces. The experiments were carried out for base oils with different viscosities using a spherical roller-on-disk configuration. The performance of lubricant flow control was assessed by measuring the film thickness and friction in the lubricated contact. The results show that the reconditioning of lubricant flow is a helpful method to prevent the occurrence of oil starvation and to improve the tribological performance of elliptical EHL contacts. However, the channeling of lubricant flow to modify the inlet supply of the Hertzian contact depends on operating conditions, the degree of starvation and oil viscosity.