CONEXPO-CON/AGG—Komatsu America Corp. today introduced its new D155AX-7 crawler dozer. The new machine is powered by an EPA Tier 4 Interim and EU Stage 3B emission certified Komatsu engine.  The powerful SAA6D140E engine is rated at 354 net horsepower.

The highly efficient automatic transmission is matched with the new engine to achieve exceptional productivity and maintains the same excellent fuel economy as the model it replaces.  Komatsu’s new crawler dozer has an operating weight of 87,100 pounds. In addition, the D155AX-7 builds on the proven SIGMADOZER* blade that was introduced in 2006, but now incorporates a new auto blade pitch function.  

The new dozer is equipped with the latest KOMTRAXÒ technology which sends machine operating information to a secure website utilizing wireless technology. Hour meter, location, cautions and maintenance alerts – to name a few of its features – are relayed to the web application for analysis.  The KOMTRAX fleet monitoring system increases machine availability, reduces the risk of machine theft, allows for remote diagnosis by the distributor, and provides a wealth of other information to drive business efficiency and productivity.

Special features of the new crawler dozer include:

• EPA Tier 4 Interim and EU Stage 3B Emission Certified Engine

Built upon proven Tier 3 technology, the SAA6D140E engine provides high horsepower while maintaining the same low fuel consumption as the D155AX-6.  The Komatsu Tier 4 Interim engine platform uses an advanced electronic control system to manage air flow rate, fuel injection, combustion parameters, and after treatment functions to optimize performance, reduce emissions, and provide advanced diagnostic capability.

The D155AX-7 incorporates a much larger cooling package with dramatically improved airflow to keep the new Tier 4 Interim engine running cool in harsh working conditions.

As a leader in hydraulic technology, Komatsu has also developed a hydraulically actuated Komatsu Variable Geometry Turbocharger (KVGT) and an Exhaust Gas Recirculation (EGR) valve, resulting in better precision and air management as well as longer component life.  The Komatsu Diesel Particulate Filter (KDPF) has an integrated design that will not interfere with daily operation but will keep the operator aware of its status.

• Innovative SIGMADOZER blade for unsurpassed productivity

The D155AX-7 is equipped with a SIGMADOZER blade, which gives the machine a high blade capacity of 12.3 yd³.  Based on a completely new excavation theory, SIGMADOZER dramatically improves dozing performance and increases productivity over a conventional Semi-U blade. The blade features a frontal design concept adopted for digging and rolling material at the center of the blade.  The new blade increases soil holding capacity. Digging resistance is reduced for a smoother flow of material so larger amounts of soil can be dozed with less power.

For example, think of a conventional Semi-U blade as a flat shovel and the SIGMADOZER as a spade nose shovel.  A spade nose shovel is easier to push through the soil and requires less energy.  The SIGMADOZER works similarly to a spade nose shovel. 

• Automatic transmission significantly improves fuel economy

The D155AX-7 has an automatic gearshift transmission and lock-up torque converter that greatly reduces fuel consumption and offers superior power train efficiency.  The lockup mechanics of the torque converter automatically transfers engine power directly to the transmission, decreasing fuel consumption by 10 percent.  Because of the efficiency of the electronically controlled engine and transmission, fuel consumption is decreased while machine power is maintained.

Two gearshift modes – automatic and manual – can be easily selected to fit the appropriate application: automatic for general dozing and manual for dozing and ripping rough ground.  For maximum operating efficiency, the automatic gearshift transmission shifts to the optimal gear range based on the working conditions and load placed.

• Ergonomic joystick controls for ease of operation and comfort

Komatsu’s ergonomically designed Palm Command Control System (PCCS) gives operators maximum control, offering a relaxed posture and superb fine control to eliminate operator fatigue.  Thumb push buttons simplify transmission gear shifting.  The electronic blade and new ripper control joystick offer excellent machine control.  The ripper now incorporates a new auto- return function to increase operator efficiency when ripping. Engine speed is controlled using an easy-to-operate electronic throttle control dial, which eliminates maintenance of linkage and joints.

• Electronic control powertrain for smooth operation

The D155AX-7 uses an electronic control power train system that significantly improves operation and productivity.  Powerful turns under various work conditions are achieved with the Hydrostatic Steering System (HSS), which is driven by an independent hydraulic pump and motor to transmit power to both tracks without interruption. Counter-rotation is available for minimum turning radius, providing excellent maneuverability.  When operating in adverse conditions such as uneven ground, a K-bogie undercarriage system keeps the correct alignment between the rollers and links for a smoother ride as well as longer component life.