BEARING-MAIN 1450162 - Caterpillar

Illustration 1 g00281646
Air inlet and exhaust system (typical example) (1) Exhaust manifold (2) Inlet manifold (3) Engine cylinder (4) Air intake (5) Turbocharger compressor wheel (6) Turbocharger turbine wheel (7) Exhaust outletEngines which are naturally aspirated pull outside air through an air cleaner directly into inlet manifold (2). The air flows from the inlet manifold to the engine cylinders (3). The fuel is mixed with the air in the engine cylinders. After the fuel combustion occurs in the engine cylinder, the exhaust gases flow directly to the outside air through exhaust manifold (1) .Turbocharged engines pull outside air through an air cleaner into the air intake (4) of the turbocharger. The suction is caused by the turbocharger compressor wheel (5). Then, the turbocharger compressor wheel compresses the air. The air flows through inlet manifold (2) which directs an even distribution of the air to each engine cylinder (3). Air is pulled into the engine cylinder (3) during the intake stroke of the piston. Then, the air is mixed with fuel from the fuel injection nozzles.Each piston makes four strokes:
IntakeAir is drawn into the cylinder through the open inlet valve and fuel is injected into the cylinder by the use of a fuel injector nozzle.
CompressionThe mixture of air and fuel is compressed in the cylinder in order to heat the mixture to the temperature of combustion.
PowerThe mixture of air and fuel ignites at the top of the compression stroke. The expansion of gases from the combustion forces the piston downward. This force creates the power of the engine.
ExhaustThe piston moves upward in order to force the gases of combustion from the cylinder through the open exhaust valve.The sequence of the strokes by all of pistons in all of the engine cylinders provide constant air flow to the inlet system during the engine operation.The exhaust stroke and the timing of the valve mechanism pushes combustion gases out of the open exhaust valve through exhaust manifold (1). The exhaust gases flow through the blades of the turbocharger turbine wheel (6) which causes the turbine wheel and the compressor wheel to turn. Then, the exhaust gases flow through the exhaust outlet (7) of the turbocharger to the outside.The air intake system is also equipped with a crankcase ventilation system. The intake strokes of the pistons pull in atmospheric air to the crankcase.Turbocharger
A turbocharger increases the temperature and the density of the air that is sent to the engine cylinder. This condition causes a lower temperature of ignition to develop earlier in the compression stroke. The compression stroke is also timed in a more accurate way with the fuel injection. Surplus air lowers the temperature of combustion. This surplus air also provides internal cooling. A turbocharger improves the following aspects of engine performance:
Power output is increased.
Engine torque is increased.
Engine efficiency is increased.
Illustration 2 g00302786
Components of a turbocharger (typical example) (1) Air intake (2) Compressor housing (3) Compressor wheel (4) Bearing (5) Oil inlet port (6) Bearing (7) Turbine housing (8) Turbine wheel (9) Exhaust