3F3-03234-0 Nissan SCREW

Turbocharger
Illustration 1 g02887559
(1) Lock nut
(2) Thrust bearing
(3) Snap ring
(4) O-ring
(5) Thrust sleeve
(6) Ring
(7) Turbine wheel
(8) Turbine housing
(9) Actuator
(10) Compressor wheel
(11) Ring
(12) Oil deflector
(13) Bearing
(14) Snap ring A turbocharger consists basically of a centrifugal compressor mounted on a common shaft with a turbine driven by exhaust gas. The compressor is located between the air cleaner and the intake manifold, while the turbine is located between the exhaust manifold and the muffler.The prime job of the turbocharger is, by compressing the air, to force more air into the engine cylinders. This allows the engine to efficiently burn more fuel, thereby producing more horsepower.In applications where the boost pressure is relatively low, the turbocharger is capable of reducing the smoke concentration, the concentration in the cylinder, fuel consumption, and deterioration in performance at elevated terrain by increasing the amount of air into the engine cylinders.In applications where the boost pressure is high, the turbocharger is capable of providing a large increase in engine output by increasing the amount of air into the engine cylinders.
Illustration 2 g02887988
(A) Air
(B) Exhaust gas
(15) Air cleaner
(16) Turbocharger
(17) Turbine wheel
(18) Waste gate valve
(19) Exhaust valve
(20) Intake valve
(21) Compressor wheel While the engine is running, exhaust gases pass through the exhaust manifold to rotate the turbine wheel (3) of the turbocharger at high speed.Rotation of the turbine wheel (3) rotates the compressor wheel (7) at same speed because both wheels (3), (7) are on the same shaft. As the compressor wheel (7) rotates, air is sucked in, compressed, and sent into the engine cylinder.The higher density of the compressed air per cylinder volume results in increased output compared with non-turbocharged engines of the same displacement.Turbine
Illustration 3 g02888841
(A) From cylinder
(B) To muffler
(22) Turbine back plate
(23) Turbine housing
(24) Turbine wheel The turbine wheel assembly uniting the turbine wheel and shaft is designed to balance even at high speeds.The turbine housing has a vortex gas passage. As the passage becomes smaller (from A to B), the gas flow rate increases so that the turbine is rotated at high speeds.The turbine back plate prevents the bearing housing and bearing (floating metal) inside from being directly exposed to the heat of the exhaust gas on the turbine wheel side.Compressor
Illustration 4 g02888898
(A) To cylinder
(B) From air cleaner
(25) Compressor cover
(26) Bearing housing
(27) Insert
(28) Compressor wheel A centrifugal compressor is used. The compressor consists of a cast compressor wheel, bearing housing, insert, and compressor cover.Air is sucked at high speed by the compressor wheel. As air passes through the spiral passage in the housing, its speed is reduced to the proper level and forced into the cylinder.The compressor wheel is a precision-cast component, which maintains the proper balance even at high speed. Its blades are curved backward to ensure the highest performance.The compressor housing is designed to regulate the flow drawn by the wheel and increase its pressure.Bearing
Illustration 5 g02896897
(A) From engine oil point
(B) To engine
(29) Thrust bearing
(30) Thrust ring
(31) Thrust sleeve
(32) Bearing housing
(33) Bearing The shaft rotates at a very high speed (tens of thousands of revolutions per minute). To withstand high speeds, the bearings use floating metals. These bearings float on a film oil between the shaft and bearing housing and rotate to reduce the sliding velocity.The shaft also receives thrust (in the axial direction) on the compressor side from both the turbine and compressor wheels. This load is borne by the thrust bearing fitted between the thrust sleeve and thrust ring which is secured to the shaft and turns together with the shaft.Lubricating oil fed from the engine's oil pump enters the bearing section through the top of the bearing housing and passes through the internal passages, lubricating the bearings. After that, it returns to the engine from the bottom of the bearing housing.Seals
Illustration 6 g02897044
(34) Piston ring (turbine side)
(35) Oil Fling When lubricating oil leaks on the turbine or compressor wheel side, the oil will adhere to the wheel or housing. The oil may then be contaminated with dust or carbon. Such contamination will destroy the balance of the rotating shaft and prevent normal operation.On the turbine side there is a piston ring placed over the shaft. Also, the shaft has an oil fling portion.
Illustration 7 g02897185
(36) Piston ring (compressor side)
(37) Oil defector
(38) Thrust sleeve
(39) Thrust ring A piston ring is placed over the thrust sleeve. The oil deflector, which is placed on the thrust sleeve, prevents oil from leaking to the piston ring side.Oil is prevented from leaking to the outside by a seal ring (square rubber ring) placed between the center housing and the back plate.