Improvement of Lubrication Performance in External Gear Machines through Micro-surface Wedged Gears

ABSTRACT

This article demonstrates how a properly designed micro-surface linear wedge added to the lateral surfaces of the gear teeth can improve the lubricating ability of external gear machines (EGMs), resulting in lower power losses and chance of wear during their operation. The approach of study is based on the use of a fluid structure interaction (FSI) model for the analysis of the lateral lubricating gaps developed in the authors' research team. Such a model is used to determine the best design of the wedged gear by considering the overall axial balance problem of pressure compensated EGMs for high-pressure applications. The article shows the numerical predictions along with the experimental verifications of the advantages offered by the proposed solution in terms of torque loss reduction for a particular reference pump.

KEYWORDS:

• Surface shaping
• wedged gear
• hydraulic pumps
• gear pumps
• lubrication
• EHL

Funding

The authors thank the U.S. Department of Agriculture (USDA) for funding this research through the research grant GRANT11322647 and Casappa S.p.A for their support in prototyping the EGM with wedged gears.