Study on mechanical efficiency of 65 ml/r fuel pump and its piston optimization

The 65 ml/r fuel pump proposed in this paper is a new type of large-displacement piston pump. The pump is of the roller plunger type construction. This structure enables the pump to have good performance even under high and variable speed conditions. Firstly, force analysis of this pump and establishment of mathematical model of pump mechanical efficiency. The influence of load pressure and speed on mechanical efficiency was obtained by numerical simulation through matlab. Then the prototype was designed and manufactured. The pump outlet pressure, outlet flow rate, and torque were measured on the test bench under various load pressure and speed, and mechanical efficiency of pump at various load pressure and speed was got. The experimental data and simulation are close. 65 ml/r fuel pump has a volumetric efficiency of 99% and a mechanical efficiency of 58.6% at a load pressure of 3 MPa and a speed of 1500 rpm. From experimental results, 65 ml/r fuel pump volumetric efficiency is high, but there is a problem of low mechanical efficiency. The piston of pump will be optimized for improved mechanical efficiency of pump. Then mechanical efficiency of the optimized pump is calculated and compared with mechanical efficiency before optimization. Results show that piston optimization will increase mechanical efficiency of pump.