D66S-1 Komatsu D66S-1 Specifications & Technical Data (1991—1998)

PV-MV hydrostatic drive

Two power-train systems, each consisting of a variable-displacement pump (PV) and a variable-displacement track motor (MV). The pump converts engine power into hydraulic power, which is then returned to mechanical power via the hydraulic motor. This mechanical power drives the sprocket through the final-drive reduction gears.

Efficient hst system

The system features automatic, infinite shifting, achieved via a microcomputer even when the engine is in partial throttle, which reduces fuel consumption. The variable-displacement pump and track motor (PV-MV) system also contribute to fuel economy. Three types of turns are possible: power turns, pivot turns, and counterrotational turns. Since the microcomputer handles all controlling, control efforts are at a minimum while fuel economy is at a maximum.

High maneuverability

With two independent hydrostatic transmissions employed, all turning patterns are available, including various power turns, sharp turns, and counterrotational turns on the spot.

Komatsu SA6D110-1 diesel engine

Delivers powerful output of 160 HP (119 kW) at 2100 RPM. Large piston displacement and 6-cylinder design assure silent lugging operation. Direct injection and MTCC system assure minimal fuel consumption. Mounting of engine on machine rear greatly enhances machine stability, especially during digging operation.

MTCC (Microturbulence combustion chamber)

Through high-precision casting, the intake-air port in the cylinder head has been given an ultra-smooth internal surface, assuring effective air absorption. The tapered, spiral design of the intake-air port creates air turbulence. When fuel is injected into the chamber, it mixes rapidly with the microturbulent air for quick combustion, minimizing fuel consumption.

High productivity

Large lifting capacity, strong bucket breakout force and high machine stability have all been realized through the rear-mount engine design, and Z-bar loader linkage, all adding up to increased productivity.

Computer controlling

Signals from sensors for control lever strokes, sensors for pedal angles and signals of engine revolutions are sent to the electronic controller with a built-in microcomputer. Based on these input data, the microcomputer sets the optimum operating conditions and sends necessary commands to activate electromagnetic control valves for drive pumps and track motors.

Automatic shifting

When excessive load or tractive effort causes engine revolutions to fall below the rated value, oil discharge flow from drive pumps to track motors is reduced, or otherwise, discharge flow from track motors increases, both resulting in decelerating machine speed to increase tractive effort. In this way, after the load imposed on the engine has been reduced, rated engine revolutions and machine speed can be recovered. These controls are automatically conducted by microcomputer.

Comfortable operation

All types of machine controls, including infinite shifting, precise approach, automatic shifting, and turns, are achieved easily, thanks to the microcomputer-controlled hydrostatic drive system. Excellent front and rear views ensure increased safety and operating efficiency. The suspension seat and floating floor frame reduce vibration to enhance operator comfort. Additionally, the operator's compartment has a walk-through design, making it easy to get on and off.