Engine Turbocharger; Turbocharger Nomenclature - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAJO CHIEFTAIN SERVICE MANUAL
8-33. ENGINE TURBOCHARGER.
The turbocharger system requires little attention between turbo over-
hauls. However, it is recommended that the items outlined in the Inspection Report of Section 111 be checked
during required inspection intervals. Should trouble occur, refer to the Troubleshooting Table in this section
and seek out the possible cause. Do not break the clamp seal joining the turbine and compressor units.
8-34. TURBOCHARGER NOM ENCLATU RE. Many unfamiliar terms may appear on the following pages
of this manual. An understanding of these will be helpful, if not necessary, in performing maintenance and
troubleshooting. The following is a list of commonly used terms and names as applied to turbocharging and a
brief description.
TERM
MEANING
Supercharge
To increase the air pressure (density) above or higher than ambient
conditions.
Supercharger
A device that accomplishes the increase in pressure.
Turbo-supercharger
More commonly referred to as a "Turbocharger" this device is driven by a
turbine. The turbine is spun by energy extracted from the engine exhaust
gas.
Compressor
Turbine
The portion of a turbocharger that takes in ambient air and compresses it
before discharging it to the engine.
The exhaust driven end of the turbocharger unit.
Wastegate and Actuator
(Exhaust By-Pass)
The wastegate is a butterfly type valve in the exhaust by-pass which.
throughout its travel from open to closed. allows varied amounts of
exhaust gas to by-pass the turbine. controlling its speed. hence the output
of the compressor. The actuator is operated by a hydraulic piston op-
erated by engine oil and cylinder with the piston linked to an arm on the
butterfly valve shaft.
Reissued: 9/23/80
POWER PLANT
2H20