Fuel Injection System Common Rail

Ever-tighter emission standards have made the injection technology a key component. Following its long lasting tradition of vertical integration, Liebherr decided to develop future injection systems itself. This means Liebherr has been able to unite three main technologies – engine technology, control units and injection systems – in house.

Liebherr Common Rail Systems have been used successfully since the beginning of 2012 in Liebherr engines that were built to comply with the stage IIIB / tier 4 interim emissions standards. Since the beginning of this year, the technology has also been used in engines for the stage IV / tier 4 final emissions standard.

The solenoid-driven injector technology has been fully developed internally by Liebherr. The main feature of the Liebherr injector is that it has no permanent leakage at all. This considerably reduces the fuel backflow to the tank and the resulting thermal energy: the need for and the size of an additional cooling system are minimal. The 3-way control valve enables adaptation of the needle opening speed to each individual engine and, at the same time, realizes an extremely fast closing process of the injector needle. This makes it possible to achieve a good balance in the configuration between combustion to the fullest extent and the lowest possible consumption.

Not only does Liebherr use its own injection system, it also offers its Common Rail Systems to other engine manufacturers for both on-road and off-road road applications, as well as for medium and heavy duty use.

Platform 11.2
System pressure
250 up to 2,200 bar
Pump delivery volume
up to 300 l/h
Nozzle cup flow
600 up to 1,300 ml/30 sec
Engine power range
120 – 800 kW
Platform 11.5
System pressure
250 up to 2,200 bar
Pump delivery volume
up to 900 l/h
Nozzle cup flow
1,600 up to 4,000 ml/30 sec
Engine power range
1,000 – 4,000 kW
Platform 11.2

Platform 11.2 covers a performance range of 120 to about 800 kW. In certain cases, this has even been extended to include up to 1,000 kW. The modular system comprises four main components: The high pressure pump, the pressure accumulator, the injector and the electronic control unit. The 2-cylinder inline pump has an oil lubricated crankcase and delivers up to 300 litres of fuel per hour at a pressure of 2,200 bar. The injectors deliver a maximum full load injection volume of 300 mg with reliable multiple injections. The nozzles can be adapted to the required engine performance from a broad nozzle cup flow range. The nozzle cup flow range in this case is between 600 and 1,300 ml/30sec.

Platform 11.5

Platform 11.5 is suitable for engines with a displacement of up to five liters per cylinder and has with 2,200 bar the same maximum pressure as platform 11.2. To reliably supply engines with an output of up to 220 kW per cylinder with fuel, injectors can be configured with a nozzle cup flow of 1,600 to 4,000 ml per 30 seconds. The powerful high pressure pump delivers up to 900 litres per hour depending on the application. The CRS platform 11.5, too, can be operated with an engine control unit from Liebherr that combines all control functions including exhaust gas after treatment.