Mathematical Modelling and Analysis of Vane Type Variable Displacement Oil Pump 2019-26-0290
In today’s scenario, both in gasoline and diesel engines, it is important to reduce the power consumed by the auxiliary devices. Oil pump is one such device, used for lubrication purpose, which consumes higher power developed by the engine. Conventionally gerotor construction pumps are predominantly used in majority of engines, owing to its simpler construction, lower NVH and cost. However, this type, being a positive displacement pump, consumes higher power with increase in speed. Hence, variable displacement oil pumps are gaining importance as the oil flow rate can be varied over the entire engine operating range.
In this work, basic design elements of variable displacement oil pump are identified followed by building of mathematical model to calculate the critical design parameters. This includes optimization of number of vanes, vane thickness and vane tip radius. Similarly, other critical design elements viz., rotor radius, eccentricity and slider profiles are optimized. The basic mathematical model built can calculate oil flow rate, leakage losses and power consumption at different speed and load conditions. These models are validated for different engine capacities of both gasoline and diesel engine requirements.
Proto samples were also built and tested at steady state conditions at different speed and load conditions. Results obtained from mathematical model were compared with experimental results. Comparison shows that mathematical model can predict the flow with a maximum deviation of 5%. Hence, the developed mathematical model can be used as a tool for optimizing the design to achieve the target flow requirement with least power consumption.