Pumps which are used for the injection of fuels into diesel engines rank among the technically most demanding members in the family of pressure generators. The provision of fuels under high pressure to common-rail injectors and fuel injection valves calls for robust dimensioning of the pump drives, the determination of optimum clearance in the pump element and the application-oriented selection of high-strength steels with special heat treatment processes. As well, L'Orange pumps are characterised by expertise developed over decades in terms of helices (in the case of conventional pump-line-nozzle systems (PLN)), component coatings, sealing elements or valve engineering.
As early as in the preliminary design phase, the results obtained combining hydraulic simulation and finite elements analysis provides clear-cut data on delivery rates and efficiency levels, component loads or lifetimes as well as the minimum surface pressures necessary for sealing. Conventional jerk pumps driven by engine camshafts with optimized helices have been significantly influenced in their development by L'Orange. They have been part of our program for over 60 years and today still form an important basis for all other pump concepts.
A further development that has resulted from this is the twin-plunger pump with two control racks that are controlled separately. This concept allows the engine thermodynamics engineer to adjust the start and end of injection independently of each other. Pumps for alternative fuels are also based on jerk pump technology. These pumps are subject to particularly high requirements regarding wear of the pump elements, connection pieces and sealing elements. It is above all with sophisticated, application-specific component coatings and groundbreaking sealing technology that we can achieve highly economical service life under such tough operating conditions.
The world's first electronic common-rail injection system (CR) was launched by L'Orange in August 1997, with a special CR pump technology at its disposal. Since then over 50,000 pumps of the first common-rail generation are successfully doing service in modern diesel engines. These pumps provide pressures of up to 2500 bar thanks to the suction throttle control introduced from the outset over the entire engine map, offering particularly high hydraulic efficiency levels and extremely low leakage rates.
Our CR technology offers major potential for standardisation in the high-pressure pump sector. In this context L'Orange has developed a pump required for HFO operation that is supplied with lube oil from the engine oil circuit. These 2 and 4-cylinder high-pressure pumps can provide rates of up to 30 l/min with a system pressure of up to 1800 bar depending on whether HFO or diesel distillate is used.