PLATE 1925440 - Caterpillar

Illustration 1 g01323375
Air inlet and exhaust system
(1) Exhaust manifold
(2) Exhaust valve
(3) Inlet valve
(4) Air inlet
(5) Exhaust outlet
(6) Compressor side of the turbocharger
(7) Turbine side of the turbocharger Basic Operation
The following components make up the air inlet and exhaust system:
Turbocharger
Cylinder head
Valves and valve train components
Piston and cylinder
Exhaust manifoldThese engines are equipped with a turbocharger. Turbocharged engines are more responsive and turbocharged engines have increased horsepower. Turbocharger
Illustration 2 g01323377
(8) Compressor housing
(9) Oil inlet port
(10) Bearing
(11) Turbine housing
(12) Turbine wheel
(13) Air inlet
(14) Exhaust outlet
(15) Compressor wheel
(16) Bearing
(17) Oil outlet port
(18) Exhaust inlet The turbocharger works in order to produce boost across the entire engine RPM range. The increased boost at low RPM fills the combustion chamber with dense air. The dense air mixes with the fuel in order to promote a complete combustion.The turbocharger has a compressor wheel (15) and a turbine wheel (12). The compressor wheel and the turbine wheel are connected to a common shaft. The shaft is supported by bearing (10) and bearing (16). The bearings are lubricated by pressurized engine oil. The oil enters through oil inlet port (9). The engine oil lubricates the bearings and the oil removes heat. The oil returns to the oil pan through oil outlet port (17).Valve System Components
Illustration 3 g01323378
(19) Rocker arm
(20) Valve bridge
(21) Pushrod
(22) Valve spring
(23) Valve
(24) Lifter The valve system components control the flow of inlet air into the cylinders and out of the cylinders during engine operation. The valve mechanism also operates the fuel injector.The camshaft must be timed to the crankshaft in order to get the correct relation between the piston movement and the valve movement.The camshaft has three camshaft lobes for each cylinder. The lobes operate the inlet valves, exhaust valves and unit injectors. As the camshaft turns, lobes on the camshaft cause lifters (24) to move pushrods (21) up and down. Upward movement of the pushrods against rocker arms (19) results in downward movement (opening) of valves (23).Each cylinder has two inlet valves and two exhaust valves. The valves are actuated at the same time by a valve bridge (20). Valve springs (22) close the valves when the lifters move down.