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| Illustration 1 | g00926983 |
(1) Crankshaft (2) Counterweight bolt (3) Plug (4) Main bearing (5) Thrust washer | |
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| Illustration 2 | g00926984 |
(6) Front housing (7) Torsiograph sensor (8) Crankshaft gear | |
The crankshaft is forged steel. The crankshaft has symmetrical design. The crankshaft changes the combustion forces in the cylinder into usable rotating torque which powers the machine. The front of the crankshaft is mounted to a damper that reduces torsional vibrations. 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. This application has the torsiograph sensor. The torsiograph sensor is mounted within the front housing. The torsiograph sensor utilizes a sensor that monitors the crankshaft gear in order to provide the required signal.
The crankshaft drives both a front drive group of gears and a rear drive group of gears. The front gear group drives the fuel pump for the engine, the pump for the engine lube oil, the engine jacket water pump and two accessory drives. The engine jacket water pump is driven from the front of the lower right drive. The pump for the engine lube oil and the fuel pump are driven from the rear of lower right drive. The engine accessory drives are used to drive the seawater pump and the lubrication oil pump for the generator. The seawater pump is driven from the front of the lower left accessory drive. The lubrication oil pump for the generator is driven from the rear of the lower left accessory drive. The crankshaft drives a group of gears on the front and 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. The rear drive group provides the necessary gear train for the camshaft drive gears.
Seals and wear sleeves are used at both ends of the crankshaft. The seals and wear sleeves are used for easy replacement and reduction of maintenance cost. Oil pressure is supplied to all of the crankshaft 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 3512B crankshaft is held in place by seven main bearings. A thrust plate at either side of the center main bearing controls the end play of the crankshaft.