32-10-00
ALL ú ú 01 Page 1 ú Jun 10/88
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400 MAINTENANCE MANUAL
WING GEAR - DESCRIPTION AND OPERATION
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1. General (Fig. 1)_______
A. Each wing landing gear has a truck assembly with two one-piece axles and four wheels. Attached to the truck are the shock strut, lower torsion link, and positioning actuator mechanism. The four brake equalizing rods are attached to structure under the truck. The upper torsion link attaches to the base of the the outer cylinder of the shock strut. The positioning actuator is directly above the attached point of the upper torsion link, affixed to the outer cylinder. The lower end of the two-piece side strut is attached to the inboard side of the outer cylinder of the shock strut. The drag brace attaches to the forward side of the outer cylinder of the shock strut at its base. A jury strut joins the side strut and shock strut together about one-third from the top of the outer cylinder. In addition, each wing landing gear has hydraulic and electrical tubing and cables to control positioning and extension and retraction
B. The shock strut assembly attaches to a trunnion fork at the upper forward side of the outer cylinder. The trunnion fork fits into the trunnion fitting in the wing rear spar. The aft end of the trunnion has a swivel housing and large spherical bearing which is housed in a forging on the wing support beam. The shock strut is charged with hydraulic fluid and compressed air or nitrogen to provide a shock absorbing medium. Replaceable sleeves are assembled over the axles to provide a mounting for wheel bearings and to protect axles from damage. Refer to 32-32-00/001 for information on wing gear extension and retraction.
2. Wing Gear Shock Strut (Fig. 3)_____________________
A. The shock strut of the wing landing gear is the primary supporting member of the wing landing gear. The shock strut is made of steel and consists of an inner cylinder, an outer cylinder, an orifice support tube and a metering pin. The orifice support tube is attached to the top of the outer cylinder. Upper and lower bearings provide sliding surfaces and locate the inner cylinder concentric with outer cylinder. A snubber valve located below the upper bearing provides control of shock strut rebound. The lower bearing contains two T-ring seals, one each in contact with the inner and outer cylinders. Two sets of spare seals also are contained in annular grooves in the lower bearing. These spare seals can be used to replace active seals without removing the inner cylinder. The shock strut is attached to airplane structure by an extension on the outer cylinder and by the trunnion fork. The lower end of the shock strut is held in position by the side strut and the drag brace.
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32-11-00
ALL ú ú 01 Page 1 ú Feb 10/92
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
SUPPORT BEAM WALKING BEAM WALKING TRUNNION
BEARING TRUNNION AFT
ACTUATOR WING GEAR SIDE STRUT UPPER BUNGEE DOWNLOCK
DRAG BRACE JURY STRUT
SHOCK STRUT DOWNLOCK ACTUATOR
LOWER SIDE STRUT
TORSION LINK UPPER ACTUATOR POSITIONING TRUCK POSITIONING MECHANISM
AXLE FWD INBD
BRAKE EQUALIZER ROD BEAM TRUCK LINK TORSION LOWER PULL BOX POSITIONING LINK AND BRAKE TIRE, WHEEL
Figure 1 Wing Gear Components
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32-11-00
ALL ú ú 01 Page 2 ú Oct 10/88
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本文链接地址：747-400 AMM 飞机维护手册 起落架 LANDING GEAR 1(69)
