Twelve Cylinders of Diesel Might Designed to Conquer Mining’s Harsh Environment
Twelve cylinders of diesel might designed to conquer mining’s harsh environment
MINING EQUIPMENT, dump trucks, and hydraulic excavators perform in some of the harshest working environments a vehicle can endure. The heavy workloads and dusty conditions in the mines can cause the early demise of mechanical components.
It’s essential that dirt and water be kept out of engines in these machines, as any amount of dust drawn in can shorten their lives significantly. However, very fine particles like silt and sand are able to find minute openings. For this reason, it is important to ensure a powerplant is sealed properly from all foreign matter.
Liebherr understands the consequences of damaging particles making their way into a closed mechanical system. So, when the company developed the D9812 62L V-12 diesel engine for mining applications, one of its main focuses was preventing foreign contaminants from entering the intake or crankcase. If an engine’s internals are kept clean, it will be more reliable and have a long, productive service life. A high level of detail is used during assembly of Liebherr’s V-12 diesel to guarantee the quality of the engine’s sealed joints and gaskets and ensure they withstand the brutal conditions in the mines. Some of the more critical components are installed with double seals to make sure nothing can enter.
A very high level of oil and air filtration is implemented in the D9812, including the use of a centrifuge that spins the oil to separate dirt.
Dirt in the crankcase is such a major concern that special materials like composite bearing shells are used so that components are less sensitive to oil contamination and heavy loads. Water and dirt infiltration is also addressed in the wiring harness. The engine’s electrical connectors meet the protection standard IP6k9k (Ingress Protection [IP] rating system relates to the proven protection against environmental factors such as liquids and solids), which guarantees they are water-, dust-, and arctic-weatherproof.
As with most modern diesel powerplants, an engine control unit coordinates all of D9812’s functions for peak emissions and fuel-consumption efficiency. One of the key components
the ECU manages is the Liebherr common-rail 11.5 fuelinjection system. The engine’s fueling operates at pressures up to 2,200 bar with a multipoint injection that precisely controls the amount of fuel being administered and the timing of each injection event.
The D9812’s modular composition allows the engine to be easily tailored to fit different vehicle applications and for optimum performance in varying climates and conditions all over the world. Modular components also simplify repairs by making such parts as the turbochargers, cylinder heads, and exhaust-gas-aftertreatment systems interchangeable.
Internally, D9812 is 3-D measured, fitted with one-piece steel pistons (for maximum strength under thermo load) and connecting rods with a finite element analysis (computerized method for predicting how a product reacts to real-world forces like vibration, heat, and fluid flow), and has an ability to run at reduced speeds. By lowering the operating speed from 1,800 rpm to 1,500 rpm, a 20 percent increase in engine life is possible and up to a 5 percent fuel savings can be seen without any loss in productivity.
The modular design of the Liebherr D9812 makes the engine easily configurable for different applications. The engine is capable of enduring environmental challenges like arctic cold, high altitude, and hot, arid conditions.