B. The system consists of an N1 speed sensor, an N1 tachometer indicator, an N2 control alternator speed sensor, and an N2 tachometer indicator.
C. AIRPLANES WITH ENGINE INSTRUMENT SYSTEM (EIS);
The N1 and N2 tachometer indicators are shown on primary engine display
as simulated electromechanical devices.
2. N1 Speed Sensor (Fig. 1)
_______________
A. The N1 speed sensor is a pulse counter that senses N1 rotor speed and
provides signals to the N1 tachometer indicator and PMC. The sensor
consists of a rigid metal tube with a mounting flange and two-connector
receptacle. Within the tube is a elastomer damper and a magnetic head
sensor with two protruding pole pieces.
B. The N1 speed sensor is mounted in strut No. 4 of the fan frame at the
4:00 o'clock position and is secured to the fan frame with 2 bolts. When the N1 speed sensor is installed on the engine, only the two-connector receptacle and the body are visible.
3. N1 Tachometer Indicator (Fig. 2)
_______________________
A. The N1 tachometer indicator converts signals produced by the N1 speed sensor into both pointer and numeric readouts. It includes index marker (bug) normally set by a command input signal, but which may also be set manually. The command N1 is also indicated by the 7-bar numeric readout in manual mode. The actual N1 numeric is indicated by means of a display which simulates the action, appearance and counting of a four drum mechanical counter. In addition, the N1 tachometer indicator provides a signal to the Idle Control System.
B. The indicator consists of a graduated dial face, main indicator pointer,
index marker (bug), command N1 numerics, actual N1 numerics, overlimit
warning light, manual set knob, and indicator circuits assembled in a
case which is integrally lit and not hermetically sealed.
4. N2 Control Alternator Speed Sensor (Fig. 3)
__________________________________
NOTE: Refer to 73-21-08/401 for the removal/installation procedure for
____
the N2 control alternator speed sensor.
A. The N2 speed sensor is an ac generator, whose frequency is directly
proportional to rotor speed, that provides signals to the N2 tachometer
indicator and electrical power for PMC. The sensor consists of rotor,
stator, and case with two-insert electrical connectors located on and
driven by the accessory gearbox shaft.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
77-12-00
ALL ú ú C02 Page 1 ú Jul 12/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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CFM56 ENGINES
737-300/400/500/ /MAINTENANCE MANUAL ////////////////////////
NO. 2 BEARING
SEE A SHAFT FAN
SENSOR N1 SPEED BSEE PROBE SENSOR A PULSE ROTOR GENERATING
RECEPTACLE BODY A B PROBE SENSOR
SEE C A B B S-M56-MM-0329-(1)-01-B SEE D
FLANGE MOUNTING
DAMPER ELASTOMER PIECES POLE
CONNECTORS ELECTRICAL
C A-A B-B D
Figure 1 N1 Speed Sensor
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
77-12-00
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BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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CFM56 ENGINES
737-300/400/500/ /MAINTENANCE MANUAL ////////////////////////
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITHOUT EIS ú
77-12-00
ú ú C03 Page 3 ú Nov 12/01
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
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CFM56 ENGINES
737-300/400/500/ /MAINTENANCE MANUAL ////////////////////////
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. AIRPLANES WITH EIS ú 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：737-300 400 500 AMM 飞机维护手册 发动机指示 ENGINE INDICATIN(3)
