New 7950 SPFH Utilizes 800 hp For Higher Harvesting Capacity
Cummins Inc. (NYSE: CMI) QSK19 engine will power the largest self-propelled forage harvester ever built by John Deere (NYSE: DE). The new 7950 SPFH utilizes the 800-hp (597 kW) rated output of the 19-liter engine to significantly increase harvesting productivity with a wider working width and reduced working time.
The QSK19 equips the 7950 SPFH with the rugged strength of a Cummins high-output engine initially designed for extreme duty cycles in mining applications. This inherent power capability gives the 7950 forage harvester the ability to continuously chop high-quality silage for extremely long hours under the most challenging field conditions.
With a peak torque of 2350 lb-ft (3186 N.m) available at 1700 rpm, the QSK19 holds deep reserves of strength ready for when it is needed to ensure instant response as the harvesting gets tougher. The intelligent management system of the 7950 SPFH maximizes fuel efficiency by adjusting engine speed for light crops and ground speed for heavy crops.
"We are really excited to see the QSK19 powering the new 7950 SPFH, which continues a long association of Cummins engines with the top-of-the-range forage harvester from John Deere," said Jim Branner, Project Manager, Cummins Worldwide Agricultural Business.
"The big-displacement QSK19 is very strong, highly dependable and comes with proven performance from tough mining applications that no other engine installed in a high-power forage harvester can match. The QSK19 performs with higher refinement than typically seen with high-output engines, due to Cummins Modular Common Rail (MCR) fuel system, which provides rapid power delivery on a smooth, low-noise basis," added Branner.
The six-cylinder inline QSK19 is fully integrated into the 7950 SPFH Prodrive propulsion system to provide exceptional traction in slick conditions or slopes. Up to 25 mph (40.2 km/h) transport speed and 12 mph (19.3 km/h) field speed are standard. A high-capacity cooling package regulates engine compartment temperatures for optimal performance, even when working in extreme heat.
"The new 7950 SPFH with the Cummins 19-liter boasts a 17 percent increase in power over the 7850 that it replaces. We have utilized the 800-hp rated power available to improve harvesting capacity with a wider ten-row rotary corn head and more durable hay pickup heads," said Tim Meister, Division Manager of Marketing, John Deere Ottumwa Works.
"On field trials, we have demonstrated that the 7950 SPFH will enable our customers to significantly reduce their machinery, operating and servicing costs," added Meister.
QSK19 Performance Enablers
The QSK19 offers the premium performance benefit of Cummins Modular Common Rail fuel system. The high-pressure fuel pump generates around 23,000 psi (1600 bar) to enable cleaner, quieter and faster power delivery. The injectors are connected in series with the fuel lines, incorporating double walls for extra strength.
The MCR fuel system prevents unbalanced fueling between cylinders to significantly reduce engine vibration, noise and harshness. Improved idle stability and easier cold starting are noticeable benefits. Clean combustion enables the QSK19 to meet the lowest emission levels regulated by the EPA for off-highway engines rated over 751 hp (560 kW). Visible smoke is virtually eliminated at rated power and during engine acceleration to provide a further environmental benefit.
Engine aspiration is by means of a single Cummins-built turbocharger and air-to-air aftercooling system. The turbocharger features a large compressor for high air-mass flow and a cast titanium impeller for added reliability.
The turbocharger is designed with low thermal and mechanical stress to provide an equivalent life-to-overhaul as that of the engine.
Wear-resistant components are utilized throughout the QSK19 to provide an exceptionally long design life-to-overhaul based on an average 300,000 U.S. gallons of fuel burned (almost 1,150,000 liters).
The one-piece cast-iron block of the QSK19 features wide cylinder spacing for extra strength, and the forged-steel crankshaft is specially stiffened for lower torsional stress.
Piston durability is enhanced with a Ferrous Cast Ductile (FCD) single-piece design and cooling nozzles delivering very high oil flow into the cooling gallery of each piston. Engine lubrication is kept at peak efficiency due to very low oil consumption and blowby.
The new 7950 SPFH will be manufactured at the John Deere Zweibrucken Works in Germany, with the QSK19 engine produced at Cummins Industrial Center in Seymour, Ind.