Intermediate Case
Figure 4 (Sheet 2)
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SEE A
5 6 7 8 9 10 12 13 14 15
11
10 11 12 13 14
G I 5 6 7 8 9
V
HOLLOW STATOR L-A0702
VARIABLE STATOR VANE STAGES
A
High Pressure Compressor (HPC)
Figure 5
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////////////////////////A / PW4000 SERIES /747-400 / ENGINES/MAINTENANCE MANUAL ////////////////////////
A. The high pressure compressor (HPC) consists of an inlet guide vane (IGV) stator assembly, an eleven stage (5th- thru 15th-stage) rotor assembly, a ten stage (5th- thru 14th-stage) stator assembly, and the HPC cases and their externally mounted accessories. The 15th-stage (compressor exit) stator is addressed as part of the combustion section (Ref 72-40-00/001). The HPC is connected to the rear flange of the intermediate case and the forward flange of the diffuser case. The purpose of the HPC is to further compress air delivered by the LPC and to direct this highly compressed air to the diffuser and combustor area.
B. The stators in the HPC consists of four stages (Inlet Guide Vanes (IGV), 5th-, 6th-, and 7th-stage) of variable stator vanes and seven stages (8th- thru 14th-stage) of fixed stator vanes. The 9th-stage stator vanes are hollow while the other HPC stator vanes are solid. All HPC stator vanes are constructed of nickel alloy.
C. The four variable stator vane stages are contained in the split HPC forward case, which is bolted together. The case is made of titanium and has a steel fire liner at the 6th- and 7th-stages. The outer trunnion of each vane is mechanically attached through the HPC forward case to a synchronizing ring assembly for each stage. The four synchronizing ring assemblies are then linked to a stator vane actuator controlled by the electronic engine control (EEC). The vanes are automatically adjusted to provide adequate stall margin for engine starting, acceleration, and part power operation. Attached to the inner diameter of the vanes and the HPC forward case are abradable rubstrips axially aligned with knife-edge seals on the drum rotor (for vanes) and with 5th-, 6th-, and 7th-stage blade tips (for HPC forward case).
D. The seven fixed vane stages are mounted in the nonsplit titanium HPC rear case. The 8th-stage split case stator assembly is bolted to the 9th- and 10th-stage split case stator assembly. The 8th-stage provides bleed connections for the airframe pneumatic system. Twelfth-stage air is delivered to the No. 3 bearing buffer air cooler and to the HPT for cooling the No. 3 bearing compartment and the 2nd-stage turbine vanes and blades. The split case stator assembly is bolted to an inner support case containing two sets of two stage stator quadrants (four 90 degree segments making up the 11th- and 12th-stages and four 90 degree segments making up the 13th- and 14th-stages). On the shrouds of each stator assembly are seal rings axially aligned with knife-edge seals on the drum rotor (inner diameter shroud) and with the rotor blade tips (outer diameter shroud).
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LOW PRESSURE COMPRESSOR - ADJUSTMENT/TEST
_________________________________________
1. General
________
CAUTION: DO NOT USE THE TRIM BALANCE TO CORRECT THE VIBRATION CAUSED BY
_______
MECHANICAL PROBLEMS. REPAIR THE PART DAMAGE BEFORE YOU DO THE
ENGINE TRIM BALANCE. IF YOU DO NOT REPAIR THE PART DAMAGE FIRST,
MORE DAMAGE TO THE ENGINE CAN OCCUR.
A. This trim-balance procedure includes three methods to decrease the low 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：747-400 AMM 飞机维护手册 发动机 ENGINE 1(111)
