Flow Characteristics of Oil-Guiding Splash Lubrication: Simulation and Experiment Studies

Abstract

Based on the computational fluid dynamics (CFD) method, the performance of the oil-guiding cylinder, a key component in a novel splash lubrication system of the helicopter main reducer, was investigated in terms of three different kinds of structures. The pressure and velocity distribution characteristics were firstly simulated and analysed. The numerical simulations indicated that the oil free surface formed in the rotating cylinder was a paraboloid, meanwhile the structure without a bottom flange can achieve the splash effect constantly. Furthermore, the experimental findings agreed well with the numerical results, it was verified that the cylinder with a cylindrical-shaped lower wall surface gave a better lubrication performance than the conical-shaped. Besides, it was found that the oil volume increased with the rotating speed and oil level increasing, and the geometry parameters of the oil-guiding cylinder and the operating conditions have a great effect on the oil-guiding splash lubrication performance.

Performance of a New Aeronautic Oil-Guiding Splash Lubrication System

“…By leveraging the oil-guiding channel, the oil mass transferred from the gear surface into the channel increases, and then the oil volume collected through the oil-collecting pipe also increases. Specifically, at the rotating speed of 400 rpm, the oil flow rate with the oil-guiding channel in this study exceeds 2.5 mL/s, far more than the experimental data of 0.0017 mL/s, conducted by Yin et al [27,28]. At the rotating speed of 660 rpm, the oil flow rate with the oil-guiding channel exceeds 22.6 mL/s, much greater than the experimental data of 0.034 mL/s, performed by Yin et al [27,28].…”

“…On the other hand, the axis of the driven gear is perpendicular to the static liquid surface of the oil bath, and it is not convenient for traditional splash lubrication. Recently, Yin et al [27,28] proposed a special oil-guiding splash lubrication method and investigated the lubrication performance of three different oil-guiding cylinders under different working conditions. However, the clutch and bearings of the driving shaft also need to be lubricated by the oil from the bottom oil bath.…”

Numerical Simulation of Migration Laws of Dense Particle Flow in Pipelines

“…The fluid problems in industrial production often use numerical simulation methods to carry out theoretical research [16]. The migration and propagation process of particulate cleaning agent powder along pipelines under airflows belongs to gas-solid flow process.…”

Numerical and Experimental Investigation of Oil-Guiding Splash Lubrication in Light Helicopter’s Reducers

“…The lubricant is collected and measured through the measuring cup below the oil-collecting pipe. The photos of the lubrication test bench have been showed in detail in the open literatures [32].…”

“…They further analyzed the effect of the oil-jet inclination angle on the moment. Recently, focusing on the oil-guiding cylinder in a lubricating system, Yin et al [32] compared three types of oil-guiding cylinders to determine the paraboloid oil-free surface in the cylinder and calculated the pressure and velocity distributions via the CFD method. Wang et al [33] monitored the wear failure status in the particles of lubricating oil to judge the bearing condition in turboshaft engines under oil injection lubrication conditions.…”