|
|
© 200416 2-3 General BE ENGINE INLET/EXHAUST SYSTEM ΛΦ45/55 series 4 3 2.2 SYSTEM DESCRIPTION, TURBOCHARGER WITH WASTEGATE To make the engine more responsive at lower engine speeds, a turbocharger is used that produces a better charge ratio at these speeds. Without provision having been made for this, the boost pressure yielded by this turbocharger would be too high at maximum engine speeds. Use of a wastegate prevents this. The boost pressure is measured by a diaphragm box (1) on the delivery side of the turbocharger. The diaphragm is pushed back against the spring pressure by the boost pressure. The linked control rod (2) is also pushed back. The control rod operates a valve in the turbine housing (3). The valve in the turbine housing is opened when the maximum pre-set pressure has been reached. When the valve is opened, some of the exhaust gases will be discharged directly to the exhaust pipe rather than being used to propel the turbine rotor of the turbocharger. i400509 3 2 1 |