SCREW 0138242 - Caterpillar

Crankshaft
The crankshaft changes the combustion forces in the cylinder into usable rotating torque which powers the machine. Vibration, caused by combustion impacts along the crankshaft, is kept small by a vibration damper on the front of the crankshaft.There is a gear at the front of the crankshaft to drive the timing gears and the oil pump. Lip seals and wear sleeves are used at both ends of the crankshaft for easy replacement and a reduction of maintenance cost. Pressure oil is supplied to all bearing surfaces through drilled holes in the crankshaft. The crankshaft is supported by five main bearings. A thrust plate at either side of the center main bearing controls the end play of the crankshaft.Camshaft
The engine has a single camshaft that is driven at the front end. It is supported by five bearings. As the camshaft turns, each cam (lobe) (through the action of valve systems components) moves either two exhaust valves or two intake valves for each cylinder. The camshaft gear must be timed to the crankshaft gear. The relation of the cam (lobes) to the camshaft gear cause the valves in each cylinder to open and close at the correct time.Vibration Damper
The twisting of the crankshaft, due to the regular power impacts along its length, is called twisting (torsional) vibration. The vibration damper is installed on the front end of the crankshaft. It is used for reduction of torsional vibrations and stops the vibration from building up to amounts that cause damage.The damper is made of a flywheel ring (1) connected to an inner hub (3) by a rubber ring (2). The rubber makes a flexible coupling between the flywheel ring and the inner hub.
CROSS SECTION OF A VIBRATION DAMPER
1. Flywheel ring. 2. Rubber ring. 3. Inner hub.Electrical System
The electrical system can have three separate circuits: the charging circuit, the starting circuit and the low amperage circuit. Some of the electrical system components are used in more than one circuit. The battery (batteries), circuit breaker, ammeter, cables and wires from the battery are all common in each of the circuits.The charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output to keep the battery at full charge.The starting circuit is in operation only when the start switch is activated.The starting circuit can have a glow plug for each cylinder. Glow plugs are small heating units in the precombustion chambers. Glow plugs make ignition of the fuel easier when the engine is started in cold temperature.The low amperage circuit and the charging circuit are both connected to the same side of the ammeter. The starting circuit connects to the opposite side of the ammeter.Charging System Components
Alternators
The alternator is driven by V-type belts from the crankshaft pulley. This alternator is a three phase, self-rectifying charging unit, and the regulator is part of the alternator.This alternator design has no need for slip rings or brushes, and the only