PINION-DIFFERENTIAL BEVEL 3D5315 - Caterpillar

Air Inlet and Exhaust System Components
Illustration 1 g00328151
(1) Exhaust manifold (2) Aftercooler (3) Air choke (4) Exhaust inlet to the turbocharger (5) Cylinder (6) Air inlet (7) Turbocharger compressor wheel (8) Turbocharger turbine wheel (9) Exhaust bypass valveClean inlet air from the air cleaners is drawn through air inlet (6) into the turbocharger compressor by compressor wheel (7). The air is compressed and the air is forced through air choke (3). The air flows through aftercooler (2). The aftercooler reduces the temperature of the compressed air before the air enters the air plenum. The air enters the air inlets in the cylinder heads. Air flow into cylinder (5) is controlled by the inlet valves. The camshaft controls the opening of the valves. There are two inlet valves and two exhaust valves for each cylinder. Refer to "Valve System Components". The inlet valves and the gas admission valve open when the piston moves down on the intake stroke.The air is pulled into the cylinder through the air inlet. Gas is also supplied to the cylinder through the gas admission valve. The gas admission valves and the inlet valves close and the piston starts to move up on the compression stroke. When the piston is near the top of the compression stroke, the lean mixture of air and fuel from the cylinder is mixed with the richer mixture of air and fuel in the precombustion chamber. The mixture in the precombustion chamber becomes combustible. The mixture in the precombustion chamber is ignited by the spark plug. This ignites the air and fuel in the cylinder.The force of the combustion pushes down on the piston for the power stroke. When the piston moves up again the piston is on the exhaust stroke. The exhaust valves open and the exhaust gases are pushed through the exhaust port into exhaust manifold (1). After the exhaust stroke, the exhaust valves close. The four stroke cycle of intake, compression, power, and exhaust continues.Exhaust gas from exhaust manifold (1) turns turbocharger turbine wheel (8). The turbine wheel is connected to the shaft that drives the compressor wheel. Exhaust gas is directed through the exhaust inlet to the turbocharger or the gas is diverted directly to the exhaust elbow by exhaust bypass valve (9). This depends on the requirements of the load and speed.An electrohydraulic actuator controls the position of the exhaust bypass valve (9). The actuator provides the desired boost pressure. The position of the actuator is determined by the ECM.Aftercooler
Illustration 2 g00485390
(1) Coolant outlet (2) Coolant inletCoolant from the water pump on the left side of the engine flows through coolant inlet (2). Coolant circulates through the core assemblies. Inlet air from the compressor side of the turbocharger flows into the aftercooler housing. The inlet air passes the fins in the core assemblies. The aftercooler core reduces the temperature of the air. The cooler air flows into the air plenum and through the inlet ports of the cylinder heads.The coolant exits the aftercooler through the coolant outlet