Influence of Alternating Temperature Levels on the Wear Behavior of Radial Lip Seals: Test Rig Design and Wear Analysis

Radial lip seals are a common seal type for various industrial applications. In retarder breaking systems for commercial vehicles, radial lip seals are exposed to very fast changing oil sump temperatures. Due to increasing demands, the elastomer seals are increasingly failing premature in such applications. It is assumed that this is caused in particular by the very high temperature gradients, that result from the fact that a lot of braking power is dissipated within a short time. This is the case, for example, when braking while driving downhill with heavy loads. Since the temperature gradient is of minor importance in many applications, there are no publications regarding the specific influence of high temperature gradients on the function of radial shaft seals. Therefore, a test rig with advanced heating and cooling capacities is developed. A comprehensive test series is carried out, with the main focus on the influence of high temperature gradients on the wear behavior of the seals. Test results show, that different temperature levels lead to a significant change of the wear behavior. Additionally, fast changing temperatures are adding additional tribological stress to the sealing system. ARTICLE HISTORY Received: 05.08.2021. Accepted: 10.09.2021. Available: 30.09.2021.