Gerotor Oil Pump Performance and Flow/Pressure Ripple Study

A three-dimensional CFD methodology has been developed and applied to predict the pump performance, to understand pump flow dynamics, and to investigate pump flow/pressure ripple for gerotor pumps equipped in automatic transmission systems. The methodology is based on the commercial code CFD-ACE+ and the analytical focuses are the flow cavitation and pressure ripples over a wide range of engine speeds, 500rpm to 6,000rpm. The CFD results are first compared with the hardware measurements and a very good agreement has been achieved. Extensive CFD simulations are then conducted to study the effects of the inlet pressure, tip clearance, porting and the metering groove geometry on pump flow performance and pressure ripples.