Caterpillar has launched the PM620 and PM622 cold planers, said to set a new standard with their high-production and highly manoeuvrable half-lane milling prowess for controlled full-depth removal of asphalt and concrete pavements in a single pass.
Operating weight for the PM620 is about 33 330 kg and the PM622 is approximately 33 900 kg. Transport weight for the PM620 is about 29 400 kg and the PM622 is approximately 30 000 kg.
The PM620 and PM622 are powered by a Cat C18 ACERT engine, a turbocharged, 6-cylinder diesel engine that provides 470 kW (630 hp) of gross power. The C18 engine meets regional emission requirements. In regions that require it, the engines meet U.S. EPA Tier 4 Final / EU Stage IV emission standards. For all other regions, the engine meets Tier 3 / Stage IIIA equivalent and China Nonroad Stage III emission standards.
The Automatic Engine Speed Control feature allows the engine to optimise output to match the load, reducing excessive fuel consumption and wear on the engine. The turbocharged air-to-air aftercooling system provides high horsepower with increased response-time while keeping exhaust temperatures low, which generates significant improvements in airflow. This increases efficiency and reduces emissions.
The PM620 and PM622 utilise a four-post design. The leg posts feature an auto-levelling function that provides smooth height adjustment without stepping.
The machines are fully hydrostatically driven by two variable displacement propel pumps supplying oil to variable displacement motors on each track. Drive motors are piston-type and automatically control displacement to provide maximum torque for work or greater speed for moving around the job site. A propel lever/steering joystick provides infinite control of the travel speed within the range.
The machines have a robust propel system with a diagonal cross flow design that provides exceptional traction. The pumps drive opposing track motors, front to back and side to side, to ensure the machine has power across the centre of gravity of the machine. In extreme conditions, automatic traction control minimises slippage by providing more power to tracks that grip,” the company says.
The cutting chamber features a design that streamlines material flow, reduces wear on the chamber and has enhanced flush cutting capability. Side plates move via independent hydraulic cylinders that are equipped with position sensors. This ensures that the side plates float at the proper level, and eliminates binding. It also eliminates the need for a wire (yo-yo) sensor by enabling the entire length of the side plate to function as an averaging ski for grade matching.
A hydraulically operated anti-slab device prevents slabbing of the road surface. It also protects the collecting conveyor and ensures an optimum discharge opening to the rotor chamber. The chamber also features a right side hinged door to provide service access to the rotor. The moldboard, side plates and anti-slab device all feature raise, lower, float and hold functions.