Classification of numerical, experimental, and analytical approaches for gearbox oil flow and no-load gear power loss

Abstract

The interaction of rotating machine elements with fluid in gearboxes results in fluid flow and no-load power loss. A targeted design of the gearbox lubrication system enables a reliable operation under economical and sustainable use of lubricant. This study focuses on the influence of various parameters on the oil flow and no-load gear power loss of a dip-lubricated single-stage gearbox. Numerical, experimental, and analytical results are presented and compared. A single numerical simulation setup without parameter-specific tuning is applied for a wide range of parameters. The evaluated wetted gear surface strongly depends on the circumferential speed and shows a strong correlation with the resulting no-load gear loss torque. At lower circumferential speed, the wetted gear surface decreases before increasing at higher circumferential speed. Numerical and experimental results show good agreement in terms of magnitude and trend. The analytical approaches underestimate the numerical and experimental results. Nevertheless, they do provide a good representation of the trends in terms of the influence of immersion depth and rotation direction.