The future of mobile working machines
How diggers, loaders and tracked vehicles will work tomorrow.
Would Rudolf Diesel have been in the mood for partying if he’d been able to attend his 150th birthday not too long ago? His spontaneous combustion engines, patented in 1893, are coming under considerable pressure. The makers of passenger cars and trucks, and the producers of so-called off-highway vehicles, have their hands full. They are working to drastically reduce the emissions of this workhorse among internal combustion engines while at the same time further increasing the efficiency and performance of the vehicles as a whole.
“Tier 4 Final” is the exhaust gas standard that the world of mobile equipment will have to satisfy by 2014. All those diggers, loaders, tracked vehicles and everything else will be going all out to comply with this norm. Here’s one example. For an offroad vehicle with power output of 80 kW, the maximum values for nitrogen oxides and hydrocarbons are to fall from 9.2 g/kWh (Tier 1) to the current Tier 3 figure of 4.0 g/kWh and to 0.4 g/kWh under Tier 4 Final. That represents a reduction of more than 90 percent. And while manufacturers are working hard to satisfy this standard, known as “Stage 5” in Europe, the legislatures in many countries are once again tightening the standards for exhaust and noise.
The idea is to achieve cleaner air. But for the diesel, as a standard power plant for vehicles and machinery, the air is becoming thinner and thinner. What will follow the diesel? “The successor to the diesel will be the optimized diesel, as the heart of a perfectly balanced total system,” says Helmut Wagener, head of the Hydraulic Division at Bosch Rexroth AG.
Off-highway machines not only have to travel. Hard work is what they’re really built for: digging, lifting, carrying and much more. That’s why, in addition to the diesel engine, that machinery is also fitted with a wide variety of hydraulic components. Satisfying the new maximum values for exhaust as specified in Tier 4 Final and subsequent regulations will require optimizing not only the diesel engine, but the entire system as well. Engine management, auxiliary equipment, hydraulic power packs and travel drives form a finely balanced whole that is extremely sensitive to changes.
As a part of the Bosch group, Rexroth is at work on further refining hydraulic components. Thanks to close dovetailing with the parent company, it can draw upon vast resources. On the agenda for future optimization of mobile working machines is a broad range of highly diverse approaches, all now at varying degrees of maturity.