Study of Effect of Air Content in Lubrication Oil on Gerotor Pump Performance using CFD Simulations 2019-26-0300
Gerotor pump is a positive displacement internal type gear pump with a smaller inner rotor and an internal ring rotor. Vehicle transmission employs Gerotor pump to supply lube oil in the dry sump lubrication system of medium/heavy duty transmissions. Fill speed (maximum operating speed) and volumetric efficiency are two important performance characteristics for Gerotor pumps. Fill speed is the measure of filling capability of suction chambers of the pump which determines the maximum operating speed of the pump. After this speed, cavitation becomes significant enough to cause sizable drop in volumetric efficiency.
Dissolved air and entrained air content in the lubrication oil affects significantly on the filling characteristics of suction chambers of the Gerotor pump. This leads to reduction in the pump flow rate and fill speed which limits maximum operating speed of the pump. In this paper, effect of dissolved air and entrained air is studied by modeling cavitation in detail using PumpLinx® CFD software and the importance of these parameters on Gerotor pump performance is described. The simulated results are validated with experiments with more than 95% accuracy in predictions. Key takeaway of the present work is that design engineers should take dissolved air and entrained air effects into consideration while designing a pump.
Key words: dissolved air, entrained air, cavitation, volumetric efficiency, fill speed, Gerotor pump, CFD, PumpLinx®
Ravi Singh, Shivayogi S Salutagi, Pieta Piotr, Jaiganesh Madhavan
Eaton India Innovation Center, Eaton Vehicle
Symposium on International Automotive Technology 2019