Investigation of the tribological performance of reciprocating seals in a wide temperature range

Abstract

Reciprocating seals are widely used in general industrial machines and are designed to endure rigorous working conditions. Among the harshest challenges, the wide temperature range they withstand has a significant influence on their sealing performance. However, most studies of reciprocating seals have focused only on their sealing characteristics at normal temperatures. To investigate the impacts of temperature on the seal's tribological performance, this paper examines the VL seal, a kind of combined seals, and discusses its performance in a wide temperature range. Material properties of the VL seal at temperatures from −55 °C to 135 °C are measured based on the seal product. The thermo-viscosity effect and the influence of thermal expansion and contraction are both considered in the reciprocating seal modelling. A coupling method that combines the finite-element analysis model with a mixed-lubrication procedure is implemented. For deformation calculation, a comparison between the influence coefficient method and the semi-infinite space method is conducted, and finds only minuscule disparities for the VL-seal analysis. To avoid the divergent problem due to high viscosity at low temperatures, this paper proposes the successive approaching method. Details of the sealing zone in the outstroke and instroke are systematically discussed in relation to a wide range of temperatures. The corresponding experiments are conducted and compared with the simulation. The results indicate that the temperature has a tremendous influence on the tribological performance. The leakage and the friction at the high temperature are much higher than those at the normal temperature.