SUPPORT AS 4538878 - Caterpillar

Illustration 1 g01107024
Air inlet and exhaust system (typical example) (1) Inlet valves (2) Exhaust valves (3) Cylinder head (4) Exhaust manifold (5) Water outlet for the aftercooler (6) Water inlet for the aftercooler (7) Aftercooler (8) Air inlet (9) Exhaust outlet (10) Compressor housing (11) Turbine housingThe components of the air inlet and exhaust system control the quality of the air that is available for combustion. These components also control the amount of the air that is available for combustion. The components of the exhaust system are listed below:
Air cleaner
Turbocharger
Aftercooler
Air inlet heater
Cylinder head
Valves and valve system components
Piston and cylinder
Water cooled exhaust manifoldInlet air is pulled through the air cleaner. The inlet air is then compressed and heated by the compressor wheel of the turbocharger. The inlet air temperature is about 230 °C (446 °F) at rated speed and rated load. The inlet air is then pushed through the aftercooler core. The temperature of the inlet air at the aftercooler core is between 43 °C (109 °F) and 48 °C (118 °F) at rated speed and rated load. Cooling of the inlet air increases the combustion efficiency. Increased combustion efficiency helps to lower fuel consumption. Also, increased combustion efficiency helps to increase horsepower output.From the aftercooler core, the air is forced into the cylinder head in order to fill the inlet ports. The flow of the air into the cylinder is controlled by the inlet valves.There are two inlet valves and one exhaust valve for each cylinder. Inlet valves open when the piston moves down on the inlet stroke. When the inlet valves open, cooled compressed air from the inlet port is pulled into the cylinder. The inlet valves close and the piston begins to move up on the compression stroke. The air in the cylinder is compressed. When the piston is near the top of the compression stroke, fuel is injected into the cylinder. The fuel mixes with the air and combustion starts. During the power stroke, the combustion force pushes the piston downward. After the power stroke is complete, the piston moves upward. This upward movement is the exhaust stroke. During the exhaust stroke, the exhaust valve opens, and the exhaust gases are pushed through the exhaust port into the exhaust manifold. After the piston completes the exhaust stroke, the exhaust valves close and the cycle starts again. The complete cycle consists of four stages:
Inlet stroke
Compression stroke
Power stroke
Exhaust strokeExhaust gases from exhaust manifold (4) enter the turbine side of turbocharger (11) in order to turn the turbine wheel. The turbine wheel is connected to a shaft which drives the compressor wheel. Exhaust gases from the turbocharger pass through the exhaust outlet pipe.Turbocharger
Illustration 2 g01231788
Water cooled turbocharger (typical example) (12) Air inlet (13) Compressor housing (14) Compressor wheel (15) Bearing (16) Oil Inlet port (17) Turbine housing (18) Turbine wheel (19) Oil outlet port (20) Exhaust inlet (21) Exhaust outletThe turbocharger is installed on the end of the exhaust manifold. All the exhaust gases from the engine go through the