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The 10 Engine Build Groups that make up the engine are as follows:
GEARBOX GROUP:
The Gearbox Group is supported beneath the fan case. It consists of a main gearbox and an angle gearbox connected by a short horizontal shaft and provides mounting pads for accessory equipment. The angle gearbox is driven by the high pressure rotor via the tower shaft through the strut at the 6 o’clock position. Components are: fuel control, which is attached to the fuel pump; electronic engine control (EEC) alternator; oil pump; starter; oil chip detector; integrated drive generator (IDG) and hydraulic pump.
FAN CASES GROUP:
The fan cases are constructed of Stainless Steel with the inlet cowl bolted to the forward fan case. Components are: electronic engine control (EEC), oil tank, fuel/oil and air/air heat exchangers, fuel flowmeter and P2T2 indicating probe.
INTERMEDIATE CASE GROUP:
This is the front structural support of the engine and supports the front bearings for both the low and high pressure rotors. Components consist of the 2.5 bleed valve actuator, ignition exciters, air/oil cooler, and Active Clearance Control (ACC) air valves.
HIGH PRESSURE COMPRESSOR GROUP:
This group consists of a nine stage titanium drum rotor bolted to a single stage disk at the front and two disks at the rear. The high pressure compressor provides 10th-and 14th-stage bleed air port connections for airplane pneumatic requirements. This group also consists of two turbine cooling air valves, two ignition cables, stator vane actuator links, and eight borescope locations. Active Clearance Control (ACC) is employed over the rear stages to reduce blade tip-to-case clearances. This is accomplished by bleeding fan air onto the compressor case during cruise power operation to cool and shrink the case to reduce blade tip clearances and improve compressor efficiency.
DIFFUSER AND COMBUSTOR GROUP:
This group is the portion of the engine from the last two stages of the high pressure compressor to the front flange of the high pressure turbine case. Located in this group are ignitor plugs, fuel distribution valve, fuel injectors and support assemblies, borescope locations and two Pb indicating probes.
LOW PRESSURE TURBINE (LPT) AND EXHAUST GROUP:
This Group contains the five stage low pressure turbine and exhaust case. The turbine employs interstage seals to reduce leakage and ACC to reduce tip-to-case clearances for improved efficiency.
There are two borescope ports in this group. The rear bearing of the Number 5 low pressure rotor and support structure are located in the turbine exhaust group. Provisions are made for mounting the tail cone and the engine exhaust duct. Exhaust gas temperature (EGT) T4.9 and pressure P4.9 probes are mounted in the case struts. The engine rear mounts and ground handling holes are also found in the turbine exhaust group.
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ENGINE BUILD GROUPS Page 2-4 Apr 11/2002
D623N005
HIGH PRESSURE TURBINE GROUP:
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本文链接地址：757 PW2000 Series Engine Ground Handling Document 发动机地面处理文件(7)
