2. Component Details
A. High Pressure Turbine Rotor and Nozzles
(1) High pressure turbine rotor and nozzles consists of a first and second stage nozzle, and a two
stage rotor.
(2) 1st-Stage High Pressure Turbine Nozzle
(a) Purpose of 1st-stage nozzle is to direct high pressure gasses from combustor into the
1st-stage high pressure blades at proper angle and velocity.
(b) Nozzle is bolted at its inner diameter to nozzle support which is in turn bolted to the stage
1 HPT stationary seal support. The nozzle segments receive axial support at their outer
aft flange from the HPT stage 1 shroud supports.
(c) Major components of nozzle assembly are nozzle support, vanes, impingement ring, and
air cover baffles.
1) 1st-stage nozzle support is a sheet metal and machined ring weldment having four
bolt circles. Outer circle supports nozzle segments, two inner circles bolt to pressure
balance air seal, and outer circle supports air cover baffles.
2) 1st-stage vanes are cast individually and welded into pairs to decrease number of
gas leakage paths. Vane airfoil is cooled by compressor discharge air flowing
through two internal sheet metal inserts, impinging on inside of vane wall, and
flowing out through a series of leading edge holes, trailing edge slots, and side gill
holes. Air flowing from gill holes provides a thin film of cool air over the exterior of
vane airfoil. Inner and outer bands of vane are cooled by compressor discharge air
flowing through small holes in bands. Thin sheet metal seals are placed in axial
slots located in inner and outer band of each end of the vane to reduce leakage of
compressor discharge air.
3) Impingement ring is a sheet metal and machined ring weldment with air holes.
Compressor discharge air flowing into a manifold area outboard at 1st-stage
nozzles is directed onto outer end of nozzles to provide an even distribution of
cooling air to nozzle vanes.
4) There are 18 air cover baffles that are bolted to nozzle support just inboard of the
nozzle vanes. Baffles are sheet metal weldments and are provided to reduce
parasitic air flow loss between 1st-stage nozzle and 1st-stage high pressure turbine
rotor.
(3) 2nd-Stage High Pressure Turbine Nozzle
(a) Purpose of 2nd-stage nozzle is to direct high pressure gas stream onto 2nd-stage high
pressure blades at proper angle and velocity.
(b) Major components of nozzle are nozzle vane segments, 1st and 2nd-stage shrouds,
stator support, stator stationary interstage seal, impingement ring, and insulation jacket.
Nozzle segments are bolted at their outer aft flange to 2nd-stage shroud forward and aft
support which in turn is bolted to stator support. Interstage air seals are bolted to inner
flanges of vane segments. A passive clearance control is provided to maintain close
tolerances, without rubbing, between shrouds and rotor blades.
1) Stator support (turbine case) is located between compressor rear frame and low
pressure turbine case. It provides support for 1st and 2nd-stage shrouds and also
2nd-stage nozzle segments. Stator support also includes temperature controlled
casing flanges with cooling air passages for passive clearance control system.
767
AIRCRAFT MAINTENANCE MANUAL
CF6-80A SERIES ENGINES
72-50-00
NoC
Page 4
D633T1B7 Dec 22/2016
ECCN 9E991 BOEING PROPRIETARY - Copyright © Unpublished Work - See title page for details
EFFECTIVITY
ABX 001-007, 011, 012, 016-019, 021, 022, 025, 101,
109, 114, 115, 314-999
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