32-42-00
 ALL  ú ú 02 Page 10 ú Oct 10/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

Antiskid Transducer Location
Figure 2 (Sheet 2)

EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 32-42-00
 ALL  ú ú 02 Page 11 ú Oct 10/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

 4.  Antiskid Module (Normal) (Fig. 3)
________________________
 A.  The normal brake system uses four antiskid modules, one for each main gear. Each antiskid module contains 4 antiskid valves, one for each wheel on the gear truck. The modules for the body gear are installed on the aft bulkhead of the body gear wheel well above the body gear trunion. The modules for the wing gear are installed under the left and right wing trailing edge above the wing gear trunion.
 B.  Each module contains these parts:
 -
4 Antiskid valves, all the same type

 -
4 hydraulic fuses, all the same type

 -a shutoff valve
 -2 inlet filters
 -a check valve
 -
and a restrictor.

 C.  
The module assemblies can be removed for servicing, or the above listed components can be removed from the module assembly while it is installed. The antiskid valves and filters can be removed without disconnecting hydraulic lines.

 D.  
Antiskid valve

 (1)  
The antiskid valve contains two stages. The first stage is operated by a torque motor that opens and closes two hydraulic nozzles. One nozzle is connected to hydraulic system 4 pressure and the other to the return lines. When the nozzle connected to hydraulic system 4 is open, it puts pressure against a slide in the second stage of the valve. This pushes the slide and permits metered pressure through to the brakes.

 (2)  
As the current supplied to the torque motor increases, the hydraulic system pressure nozzle closes and the nozzle to the return line opens. This decreases pressure against the slide in the second stage and permits residual pressure in the brake lines to push back the slide. This closes metered pressure to the brakes and releases brake pressure to the return line.

 (3)  
Thus the valve decreases the amount of pressure applied to the brakes in proportion to the amount of current supplied to the torque motor. For full details on the operation of the valve refer to the applicable component maintenance manual.

 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 32-42-00
 ALL  ú ú 02 Page 12 ú Oct 10/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL

METERED PRESSURE LINE
SYSTEM
SUPPORT PRESSURE
BRACKET LINE
FILTER
SEE A SHUTOFF VALVE
SEE A
ANTISKID VALVE,
V25 LEFT OR V126 RIGHT

SEE B
ANTISKID VALVE,
V24 LEFT OR V127 RIGHT

ANTISKID VALVE,

V26 LEFT OR V77 RIGHT FUSE (4 LOCATIONS)
ANTISKID VALVE, V65 LEFT OR V128 RIGHT RETURN LINE
WING-GEAR-NORMAL-ANTISKID-MODULE ASSEMBLY
A 
FILTER 
SYSTEM PRESSURE 
SHUTOFF  LINE 
ANTISKID VALVE,  VALVE 
V41 LEFT OR V43 RIGHT  METERED PRESSURE 
ANTISKID VALVE,  LINE 
V40 LEFT OR V44 RIGHT SCREEN FILTER 
ANTISKID VALVE, 
V42 LEFT OR V73 RIGHT 
ANTISKID VALVE, 
V69 LEFT OR V51 RIGHT 
SUPPORT BRACKET 

FUSE (4 LOCATIONS)
BODY-GEAR-NORMAL-ANTISKID-MODULE ASSEMBLY
B
Normal Antiskid Module Assembly Figure 3
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 32-42-00
 ALL  ú ú 01 Page 13 ú Oct 10/96
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
　
中國航空網(wǎng) m.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：747-400 AMM 飛機維護手冊 起落架 LANDING GEAR 6(127)