New Approach on the Allocation of Wear Allowances - a Case Study
Year: 2019
Editor: Wartzack, Sandro; Schleich, Benjamin; Gon
Author: Schubert, Dominik (1); Rohrmoser, Andreas (2); Hertle, Sebastian (1); Wartzack, Sandro (3); Hagenah, Hinnerk (2); Merklein, Marion (2); Drummer, Dietmar (1)
Series: ICED
Institution: Friedrich-Alexander-Universit
Section: Robust Design
DOI number: https://doi.org/10.1017/dsi.2019.358
ISSN: 2220-4342
Abstract
To maintain functional tolerances of gear sets over their lifetime, especially in polymer-seel gear sets, the wear behaviour must be considered. The state of the art in wear modelling does not take the run-in behaviour of polymer-metal contacts into account. This results in oversizing of wear allowances in the stationary wear phase and undersizing in the run-in phase. Therefore, a modified wear model is presented in this paper. With this method the issues of over- and undersizing can be eliminated.
The method is then applied in a case study to show two things. Firstly, using the presented method the calculated necessary wear allowances were reduced by 30%. Secondly, the effect of surface structures on the wear behaviour was investigated. It is shown that the run-in process is not dependent on roughness in sliding direction, but on overall contact area. Thus, the state of the art, i.e. tolerating only the roughness in sliding direction, is insufficient. Considering the process-induced surface topology during design of gear sets can decrease run-in wear. Together with the optimised wear model, this allows wider manufacturing tolerances and thus lower costs during production.
Keywords: Surface structure, Wear, Design practice, Tolerance representation and management, Optimisation