Search Results

Emerging trend in the automotive industry all around the world is to develop vehicles to consume less fuel and to meet stringent emission norms by using engines of higher power to weight ratio and higher thermal efficiency. These advanced technology engines designed for high power output will use low viscous oil to reduce frictional losses and will operate at elevated temperature levels. Hence, the various auxiliaries and parts of these engines should be adaptable for the use of low viscous oil and should withstand higher temperatures. Oil pump is one such auxiliary which will be subjected to work with low viscous oil at higher temperatures levels. The oil pump taken for study and design improvement is an internal gear type positive displacement oil pump, used in a passenger car diesel engine. The un-meshing of the gears causes the inflow and meshing causes the outflow of lubricating oil. This process occurs continuously for providing a smooth pumping action.

The main challenge in designing the oil pump for gasoline & diesel engines is to optimize the pressure relief passage. Pressure relief passage is critical from design point of view as it maintains the oil pressure in the engine. Optimal levels of oil pressure and flow are very important for satisfactory performance and lubrication of various engine parts. Low oil pressure will lead to seizure of engine and high oil pressure leads to failure of oil filters, gasket sealing, etc. Optimization of pressure relief passage area will also reduce the power consumed by the pump. The Pressure relief system for this study consists of Pressure relief valve, spring, retainer, pressure relief passages. It is difficult to directly measure the flow through the pressure relief passage and is arrived based on the drop in flow at the delivery port. Numerical tool will be handy to predict the flow through the pressure relief passage and this can be used to optimize the flow through the bypass passage.