Technical Committee Lubricants

Validation of a Functional Test and Development of a Detecting Method for the Friction Coefficient μ as a Function of Varying Operating Parameters

To achieve a cost-efficient design of radial shaft seals (RWDR) a RWDR-Tribometer was developed in the past. The purpose of the current research project was to work out a functional test for the Tribometer that allows to carry out a quality control and to compare measurement results of different RWDR-Tribometers. It was shown in the first instance that the functional test carried out on various RWDR-Tribometers provides reproducible results. In addition tolerance fields were derived that serve as a specification for the results to be achieved. Furthermore the arising damage patterns on radial shaft seals and on RWDR-Tribometer-samples were examined. In both cases the considered pairings of oil and elastomer showed comparable appearance of staining, oil carbon, cracks and blisters. For the recording of the friction coefficient experiments were carried out both under constant and under varying operating conditions. From these measurements an approximation of the friction coefficient depending on the operating conditions could be derived that is generally applicable.

The IGF project (17313 N) of the research association DGMK Deutsche Wissenschaftliche Gesellschaft für Erdöl, Erdgas und Kohle e.V., Überseering 40, 22297 Hamburg was funded by the Federal Ministry for Economic Affairs and Energy via the AiF within the framework of the programme for the promotion of joint industrial research (IGF) on the basis of a resolution of the German Bundestag.