777 AMM 飞机维护手册 发动机引气 Engine Air PW 777 AIRCRAFT MAINTENANCE MANUAL(16)

曝光台 注意防骗 网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者

The compressor stator vane control system moves the inlet guide vanes and the 5th, 6th, and 7th stage variable stator vanes of the HPC. This improves the engine performance and helps to prevent a compressor surge.
General Description
The stator vane control system operates automatically. The EEC controls the system as a function of LPC rotor speed (N1), HPC rotor speed (N2), and inlet temperature (T2).
The variable stator vane actuator uses servo fuel to move the vanes.
The EEC sends stator vane actuator position and fault data to the AIMS.
EFFECTIVITY BEJ ALL  75-31-00 
Page 4 
D633W101-BEJ  Sep 05/2002 

 

AIR -COMPRESSOR STATOR VANE CONTROL -GENERAL DESCRIPTION

EFFECTIVITY BEJ ALL  75-31-00 
Page 5 
D633W101-BEJ  Sep 05/2002 

AIR -COMPRESSOR STATOR VANE CONTROL -COMPONENTS

General
These components open and close the variable stator vanes:
*
Actuator

*
Bellcrank

*
Adjustable links

*
Unison Rings.

They are external to the engine.
Variable Stator Vane Actuator
The actuator moves the HPC inlet guide vanes and 5th, 6th, and 7th stage variable stator vanes. The actuator attaches to the vanes with the bellcrank, the adjustable links, and the unison rings.
The actuator is on the HPC case at the 4:00 position.
If a fuel seal leak occurs, a drain hose sends the fuel to the engine/strut overboard drains.
Bellcrank, Adjustable Links, and Unison Rings
The bellcrank and adjustable links are on the HPC case above the variable stator vane actuator.
The unison rings go around the HPC case. Each unison ring has a upper half and a lower half. When the unison rings move, stator vane position changes.
Training Information Point
You must rig the compressor stator vane control system after the variable stator vane actuator is replaced. The variable stator vanes must be full open to rig the system.
CAUTION:  IT IS VERY IMPORTANT TO DO THE MECHANICAL ADJUSTMENT PROCEDURE WITH PRECISION. BAD ADJUSTMENT CAN CAUSE HPC BLADE FATIGUE, INTERNAL ENGINE DAMAGE OR COMPLETE ENGINE FAILURE.
There are rig pin holes in the bellcrank arm and the unison rings. The rig pin hole for the 7th stage unison ring is below the bellcrank.
EFFECTIVITY BEJ ALL  75-31-00 
Page 6 
D633W101-BEJ  Sep 05/2002 

 

AIR -COMPRESSOR STATOR VANE CONTROL -COMPONENTS

EFFECTIVITY BEJ ALL  75-31-00 
Page 7 
D633W101-BEJ  Sep 05/2002 

AIR -COMPRESSOR STATOR VANE CONTROL -FUNCTIONAL DESCRIPTION

General
The EEC controls a torque motor in the variable stator vane actuator to move the variable stator vanes. The torque motor has two coils. One coil gets power from EEC channel A and the other gets power from EEC channel B. When the torque motor gets power, it lets servo fuel move the actuator rod.
　
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：777 AMM 飞机维护手册 发动机引气 Engine Air PW 777 AIRCRAFT MAINTENANCE MANUAL(16)