Caterpillar PM620, PM622 Milling Machines

April 11, 2016
Caterpillar PM620, PM622 Milling Machines

The PM620 and PM622 cold planers are half-lane machines. Operating weights are 73,260 and 74,580 pounds, respectively. Each is powered by a 630-horsepower Cat C18 ACERT engine meeting Tier 4-Final requirements, and is coupled with an automatice engine speed control to match output to load.

The leg posts are auto-leveling for smooth height adjustment without stepping. Two variable-displacement propel pumps supply oil to variable-displacement motors on each track. Drive motors automatically control displacement to provide maximum torque for work or greater speed for transport. The pumps in the propel system drive opposing track motors, front to back and side to side, which provides power across the center of gravity of the machine.

Track assemblies are 70.4 inches long; 12 inches wide; and have replaceable, bolt-on polyurethane track pads. Track tension automatically adjusts. Four-mode steering is standard. An electronic control module processes inputs from the sensors on the front and rear tracks along with input from the steering selector controls. In coordinated mode, the inside turning radius is 6 feet 5 inches.

The cutting chamber has side plates that move via independent hydraulic cylinders equipped with position sensors. A hydraulically operated anti-slab device prevents slabbing and protects the collecting conveyor. The rotor drive system features a dry clutch driving a planetary gear reducer. The clutch is coupled to the engine and is hydraulically actuated by the keypad controls on the operator’s console.

The PM620 has a 79-inch-wide rotor, and the PM622 an 88-inch-wide rotor. Maximum cutting depth is 13 inches.