Abstract: The lubrication ?re? is divided into the dynamic lubrication ?re? and the elastic lubrication ?re? basing on the lubrication status of valve-valve guide. The different grids are adopted in the two lubrication areas. Reynolds equat?on in elastic ?re? is transformed by ftmction in order to make convergence quickly. Through the iterative calculation of the valve dynamics, the dynamie lubrication and the elastic lubrication, the balance position relative to valve guide are gained, The lubrication status of valve-valve guide is estimated basing on the minimum oil film thickness and effective roughness, Basing on the lubrication status of valve-valve guide, the maximum stress of contact ?re? used as the limit of the valve-valve guide abrasion is provided, and theHertzian contact stress distribution function of valve— valve guide contact ?re? is given.

Key words: Contact stress, Fluid dynamic lubrication Elastic liquid lubrication, Valve-valve guide