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

Abstract

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.

How Wetting Properties Influence the Wear of Radial Lip Sealing Systems

“…As the maximum contact width l c,max of the sealing edge increases, wear becomes increasingly asymmetrical. This phenomenon has already been observed and described by Merkle 31 and Bauer 2 and does not depend on the test rig design, nor is it due to manufacturing errors in seal production or due to eccentricity deviations of the components. In the further course of this work, the maximum contact width l c,max of the sealing edge is used for correlation with the shafts wear track width l w and wetting characteristics.…”

Failure and Damage of Reciprocating Lip Seals for Pneumatic Cylinders in Dry Conditions

“…A dedicated test bench for endurance tests of lip seals was designed and built. The test set-up was performed, taking into consideration test rigs for rotary lip seals [28,34]; however, it focused on the specific and peculiar features for testing reciprocating lip seals. The bench allows the user to test seals in a variety of operating conditions to assess the lifetime with respect to the residual sealing capability of the seals.…”

Multiphase Computational Fluid Dynamics of Rotary Shaft Seals

“…The measured data from back-pumping rate tests out of [31] according to [42] serve to validate the computational results. The sealing ring is mounted inversely to its original mounting orientation, meaning that oil is constantly provided on the original air side.…”