(2)
Rinse, drain and wipe or air-dry, being careful to wipe clean all mating surfaces of the three parts, including the separated surfaces of the square taper.
(3)
Visually examine the parts for freedom from contamination; pick up, scores, and burrs, which would interfere with reassembly and alignment.
May 01/00 77-12-11 Page 401 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
Engine Tachometer Generator Installation 501
77-12-11 Figure 401 Feb 20/91
Page 402
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
(4)
Apply FELPRO C5A compound on only the mating surfaces of rotor hub diameter and the collar counterbore.
(5)
Slide tapered shaft, threaded end, through the hole in the expandable collar.
(6)
Slide rotor hub diameter into shaft counterbore, seating securely.
(7)
Thread rotor on tapered shaft thread counterclockwise (left-hand thread) and hand tighten only.
(8)
Inspect square hole in engine power take-off shaft where rotor assembly is to be inserted. Using a GO-NO GO gauge, GE P/N A2333 (or its equivalent), insert gauge to check size. If NO GO end enters or the square hole appears to be worn or damaged, do not install the rotor assembly.
(9)
Clean square hole of shaft to remove oil, dirt or contamination. Wipe or blow dry. Check that flats on split square of the collar are clean and dry.
NOTE: In the next step, it is left-hand thread to tighten.
(10)
Hand tighten tapered shaft thread through collar into the thread on rotor.
(11)
Push square shaft of rotor assembly into engine shaft square hole seating collar shoulder against end of engine shaft. Tap end of rotor lightly with a brass or plastic hammer to assure it is seated properly.
(12)
Use a 9/16-inch hex deep socket torque wrench to secure rotor in shaft to 40 ±4 pound/ inches.
NOTE: Before performing the next steps, visually examine to determine that the rotor appears properly aligned.
D. Place new gasket on mounting pad.
E. If generator is the bearing type, carefully align the drive shaft and place the generator on the mounting pad. If generator is the bearingless type, place the stator assy over the rotor assembly and pad mounting studs and gasket.
F. Place ground wire terminal on applicable generator mounting stud (Fig. 401).
G. For N1 tachometer generator, install nose dome interference bracket if previously installed.
H. Install washers and nuts attaching generator to engine.
I. Attach electrical connector to tachometer generator, and lockwire.
J. Replace nose dome if N1 tachometer generator is installed. Close cowl panel if N2 tachometer generator is installed.
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
K53949
P&WA, 77-20 Page 1/2, Apr 1/82
EXHAUST GAS TEMPERATURE INDICATING SYSTEM - DESCRIPTION AND OPERATION
1. General
A. The exhaust gas temperature (EGT) indicating system measures the engine exhaust gas temperature and displays the temperature value on indicators in the control cabin. The system, for each engine, consists of eight temperature sensing probes, a harness and lead, one balancing resistor, and a temperature indicator (Fig. 1). Copper and constantan wires are used in the low temperature zone of the engine; chromel and alumel wires are used where higher temperatures are encountered.
B. Engine exhaust gas temperature is sensed by the thermocouple elements. The heat of the exhaust gases causes the thermocouple to generate dc electrical signals which actuate the meter movement of the exhaust gas temperature indicator. The balancing resistor is included in the circuit to provide a means of adjusting the system.
2. Exhaust Gas Temperature Thermocouple Probe
A. The thermocouple probe is a temperature sensing device that senses the temperature of the engine exhaust gases. It consists of two stud terminals, a head, and a thermocouple measuring junction and leads enclosed in a cylindrical shield (Fig. 1). The thermocouple junction leads and terminals are made of chromel and alumel material. The alumel terminal (-) has a larger diameter stud than the chromel terminal (+). The correct orientation of the probe with respect to an engine is obtained with an index slot in the probe.
B. Eight probes are mounted on the turbine exhaust section fan discharge inner duct of each engine and project into the engine exhaust gas path. The probes are connected in parallel to obtain the average value of the exhaust gas temperatures sensed by the eight probes.
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