Hydrostatic Pressure Distribution of Oil Lubrication Film for Internal Gear Motors and Pumps: Solution of Resistance Network and Compare to CFD

Abstract

Oil thin film lubrication is very popular and important in the field of fluid power and tribology science. It is widely used in all kinds of rotating machines. Its role is to separate the relative rotating surfaces to reduce friction, absorb vibration, protect surfaces, and produce load-carrying against an external load. The capacity of the oil lubrication film plays an important role in dynamic behavior, the life-cycle performance of the rotating machinery as well as the systems. During operation, if the oil film is damaged, it will cause the relative rotating surfaces to fail much sooner before the damage of components of the machine. This paper introduces the resistance network model to calculate the hydrostatic pressure distribution of the oil lubrication film. The effect of geometry and working parameters on the pressure distribution is then analyzed. Among these parameters, the calculation results point out that the radial and axial clearance, as well as the eccentricity of the ring gear, have a significant effect on the hydrostatic pressure distribution. The pressure profile is also simulated by using the CFD software in order to compare and validate the accuracy of the calculation results. With the solution of resistance network model, it is easy and quick to calculate the hydrostatic pressure distribution comparing to CFD. It saves time for designers at the early design stage.