Doosan Infracore has launched the new generation DL550 wheel loader, the top-of-the-range model in the company’s new family of wheel loaders intended for markets in the Middle East and Africa. With a bucket capacity of 5.4 m3, the DL550 wheel loader is designed to meet a wide range of material-handling needs from loading and transporting granular material (such as sand and gravel) to mining and quarrying applications.A key feature of the new DL550 is the Tier 2 12.7 litre Scania DC13 turbo-charged, air-to-air intercooled diesel engine, which is ideal for use in the Middle East and Africa, delivering ‘best in class’ power with a maximum output of 294 kW at 2,100 rpm. The high engine power output is combined with new ZF transmissions and several other features which, in addition to reducing fuel consumption, provide exceptional performance, high durability, ease of handling and serviceability, and significantly enhanced operator comfort.
The DL550 has three engine working modes: ECO, NORMAL and POWER, to adapt the machine to different applications, with different engine speeds and gear steps according to the working mode engaged. With the ‘Power-Up’ function, the operator can manually adjust to the next highest working mode by applying a full stroke of the accelerator pedal. With this function, the operator can travel in moderate NORMAL mode and switch to POWER mode when it is really needed, such as when taking material from a pile. This capability helps to reduce fuel consumption. The ECO Bar provides information in real-time about fuel consumption in relation to machine performance, allowing the operator to select the driving mode for the best fuel efficiency.
The operator can set a password for machine start. There is also a new Auto Idle feature which, when activated, reduces engine speed by about 200 rpm after 10 seconds if there is no machine movement. Auto Idle is ideal for applications with long waiting times, such as truck loading and lowers fuel consumption significantly.
The new ZF transmission improves the transfer of power from the engine to the wheels and contributes significantly to the overall reduction in fuel consumption. The new transmission provides better response and acceleration, especially on slopes. Engine speed variation is less thanks to smaller gear steps, and lower engine speed throughout the whole drive range reduces fuel consumption. Thanks to higher shift quality, noise levels are lower while driving performance and productivity have been increased. A five-gear transmission with torque convertor lock up is available as an option.
When activated, the optional torque-converter-cut-off (TCCO) system is switched on automatically. This provides a direct mechanical connection between the engine and transmission without loss of power and torque by the torque converter. Tests show that fuel consumption can be reduced by as much as 10%.
With the intelligent clutch cut-off system engaged, the driver is able to disconnect the transmission from the engine by operating the brake pedal, to have 100% engine performance for the hydraulic system. As a result, movements are faster, breakout force is maximized and fuel consumption is reduced.
New ZF Type II axles provide more durability and a longer lifetime. Rolling resistance for the axles is also reduced, improving traction and decreasing fuel consumption. The ZF axles have a hydraulic differential lock as standard. This function is engaged via the operator pedal or in automatic mode, depending on the torque resistance in 1st and 2nd gear. The advantage of the hydraulic lock system is that it has less rolling resistance compared to the limited slip system and causes less axle stress.
Like all new generation Doosan large wheel loaders, the DL550 is equipped with load-sensing closed centre controlled, variable hydraulic piston pumps, improving performance and reducing fuel consumption. With load sensing, the hydraulic pumps receive a signal from the main control valve (MCV) informing how much oil is needed. This helps to improve engine performance and reduce fuel consumption.
A new cab design features improvements both outside – such as better visibility due to a wider front glass section and an extended wiper blade area, better protection thanks to larger mud guards, improved hand rail and step designs and a new roof cover – as well as inside – such as the new instrument panel with integrated vehicle control unit (VCU).
The control panel has been redesigned to allow the operator to choose the information they want on the display. Using the Main Menu, the operator has access to several functions and machine information. Pressure, temperature and engine speed can be monitored in real time. Detailed operating information is available via the Special Menu.
By relocating the reservoir for the wiper water to the outside of the cab, space inside has been increased, providing more foot room. The air conditioning system is regulated automatically by a temperature sensor. To keep cans and food fresh, a new cooling compartment is standard. There is also more storage room behind the seat.