Effect of angular speed of cam on oil film variation in the line contact thermal EHL of a cam-tappet pair

Abstract

Purpose The influence of the cam angular speed on the pressure, film thickness and temperature profiles at some selected angular positions together with the oil characteristics are investigated. Design/methodology/approach A high-order polynomial cam is used, and thermal elastohydrodynamic lubrication (EHL) calculations are carried out by the multi-grid method and line-line scanning technique. Findings It is found that the film thickness decreases with a decrease in angular speed. The depth of the dimple that occurred in the reverse motion is also reduced because of the recession in the “temperature–viscosity wedge” effect. Originality/value It is revealed that the reduction in the cam angular speed makes the classical big surface dimple evolve into a small centralized dimple during the opposite sliding motion. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0327