Influences of an oil guide device on splash lubrication performance in a spiral bevel gearbox

Abstract The splash-lubricated intermediate gearbox of a helicopter is employed to investigate the influence of an oil guide device on lubrication performance in spiral bevel geared transmissions. A CFD (Computational Fluid Dynamics) numerical model of the gearbox which is mainly composed of an oil guide device, spiral bevel gears and the casing wall is built to study the oil distribution inside the gearbox. The present CFD model is validated by comparing experimental results and corresponding simulation ones. Influences of the oil tank capacity, the hole diameter and the fillet radius of oil guide tubes on the oil flow rate in the oil guide tubes are analyzed. It is shown that the hole diameter and the fillet radius of oil guide tubes can exert important influence on oil flow rate in the oil guide tubes while oil tank capacity does the reverse; the oil guide device structure has little influence on the oil flow of contact zone of gear pair and churning power losses in the spiral bevel gearbox.