Idea of use of hydraulic booster in high-pressure fuel pump with hypocycloid drive

Common rail (CR) injection systems have been universally applied in passenger car engines for twenty years. Moreover, they are applied on a wide scale in trucks, machinery and stationary engines. They have many advantages such as very good fuel spraying due to high injection pressure, injection dose distribution to several smaller, or less heat generation compared to traditional systems. At the same time, the use of this type of system involves a number of problems. They are characterized, among other things, by the high cost of manufacturing and the high sensitivity to changes in the quality of the used fuel. The most important component of the common rail injection system is the high-pressure injection pump. The authors propose a new, alternative pump design with the hypocycloid drive – the article presents the issue of using this type of pump. Further sections describe the design of a pump utilizing a hypocycloid mechanism; demonstrate beneficial functional features and present selected results of the assembly's dynamic simulation. The pump is also characterized by the possibility of multiplying the piston's pitch while maintaining its diameter. It makes it possible to obtain much greater discharge per operating cycle. Taking into account the considerable quantity of fuel transferring by the pump, was also possible to propose an idea of use of hydraulic booster in such pump. In this field, the authors have presented schematic diagram of a pressure booster with a description of its operation.