SPRING 3J8880 - Caterpillar

Illustration 1 g03667136
Turbocharger mounting (typical example)
(1) Turbocharger
(2) Oil supply lines
(3) Mounting supports for the turbochargers The inlet of the turbine side of each turbocharger (1) is connected to the turbochargers respective exhaust manifold. The outlet of the compressor side of each turbocharger is connected to the engines air intake manifolds. Engine oil is supplied to the turbochargers shaft bearing through oil supply lines (2). The oil drains to the crankcase through mounting supports (3).
Illustration 2 g01192286
Turbocharger cartridge
(4) Compressor wheel
(5) Bearing
(6) Oil inlet port
(7) Bearing
(8) Turbine wheel
(9) Oil outlet port The exhaust gases enter the turbocharger through the exhaust inlet of the turbine housing. The thermal energy that is from the exhaust gases causes turbine wheel (8) to rotate. This rotational energy is transfered from the turbine wheel to compressor wheel (4) through the turbochargers center shaft.As the compressor wheel rotates, filtered air is pulled through the compressor housing air inlet by the rotation of the compressor wheel. The blades of the compressor wheel compress the air. The compressed air is fed to the cylinders through the air intake manifold. By using inlet air that has been compressed, the cylinder is packed with more air during the intake stroke of the piston. Additional air for combustion allows the engine to burn additional fuel with greater efficiency. This increases the power output of the engine.The speed of the turbocharger is controlled by the thermal output of the engine. The engines Electronic Control Module controls turbocharger speed through control of the fuel delivery to the engine. The amount of fuel that is consumed by the engine is directly proportional to the amount of heat that is generated by the engine. This heat is delivered to the turbochargers turbine wheel through the exhaust gases. Also, the engines working altitude has an effect on the turbochargers operational speed. Bearings (5 and 7) for the center shaft are lubricated by engine oil that is pressurized by the engine oil pump. Engine oil is supplied through the oil lines to the turbocharger. The oil enters the top of the turbocharger housing at oil inlet port (6). Oil passages in the housing supply oil to the bearing surfaces. The oil drains through oil outlet port (9) at the bottom of the housing. The oil drains into the flywheel housing through the oil drain ports that are cast into the mounting supports for the turbochargers.