Power loss reduction in timing chain drives by adjusted tensioning and surface structuring

Abstract

Purpose Energy losses in a timing chain drives are caused by friction in chain-rail contacts. To improve the efficiency, the Chair of Machine Elements and Transmission Technology at the University of Kaiserslautern developed various experimental and simulative analysis tools as a part of the German Research Foundation (DFG)-funded 1551 priority program and the DFG Collaborative Research Centre CRC 926. With these tools, various approaches for improving the efficiency were investigated. This paper aims to illustrate the approaches and present the results achieved within the framework of the above-mentioned priority program. Design/methodology/approach A towed cylinder head test rig is used for efficiency tests on timing chain drives. In addition to the experiments, a multi-body simulation model of the timing drive was developed and used. Findings It was possible to find positive approaches to reduce friction power by adapting the chain tensioning force as required. This was ensured for both the stationary operating points and the transient operating processes. An efficiency improvement of up to 10 per cent could be detected. Furthermore, a possibility was found to improve the frictional power by a targeted lubrication of the chain-rail contact. Here, the efficiency could be improved by 5-6 per cent. In addition, various structures were examined on a microscopic and macroscopic level. Neutral to negative results were achieved here. Originality/value This paper makes a contribution to improve the energy efficiency of timing chain drives. Different approaches have been investigated and evaluated.