RING-BACKUP 7Y4217 - Caterpillar

The crankshaft changes the combustion forces in the cylinder into usable rotating torque. A vibration damper is used at the front of the crankshaft in order to reduce torsional vibrations (twist) that can cause damage to the engine.The crankshaft drives a group of gears that are on the front of the engine and on the rear of the engine. The gear group on the front of the engine drives the oil pump, the jacket water pump, the fuel transfer pump, and the accessory drives.The rear gear group, which is also driven by the crankshaft, drives the camshafts and the accessory drives.Seals and wear sleeves are used at both ends of the crankshaft. The seals and wear sleeves are replaceable. Pressure oil is supplied to all main bearings through drilled holes in the webs of the cylinder block. The oil then flows through drilled holes in the crankshaft in order to provide oil to the connecting rod bearings. The 3508 crankshaft is held in place by five main bearings. The 3512 crankshaft is held in place by seven main bearings. The 3516 crankshaft is held in place by nine main bearings. A thrust plate at either side of the center main bearing controls the end play of the crankshaft.