The electric motor operates in the secondary and alternate modes. Relays supply electrical power to the electric motor. During primary mode operation, a clutch disengages the electric motor from the gearbox.
The 115v ac, 3-phase, reversible electric motor weighs approximately 42 lb (19 kg). An electrically actuated clutch and a torque limiter are inside the motor assembly. The clutch engages the motor with the gearbox in the secondary or alternate modes. The torque limiter prevents too much load on the slat drive mechanisms. The electric motor has a brake that engages when the motor is not energized.
Training Information Point
The electric motor contains oil and it is necessary to do servicing at specified times. Use the oil fill plug on the side of the motor.
EFFECTIVITY BEJ ALL 27-81-00
Page 22
D633W101-BEJ Sep 05/2002
LEADING EDGE SLATS -PDU HYDRAULIC AND ELECTRIC MOTORS
EFFECTIVITY BEJ ALL 27-81-00
Page 23
D633W101-BEJ Jan 05/2002
LEADING EDGE SLATS -SLAT LIMIT SWITCH
Purpose
The slat limit switch limits the position of the slats during alternate mode operation.
Location
The limit switch is on the slat PDU.
Physical Description
The limit switch is one LRU. It has two internal switches, retracted and extended.
Functional Description
When the slats retract to the up position, the retracted switch removes electrical power from the slat electric motor.
When the slats extend to the sealed position, the extended switch removes electrical power from the slat electric motor.
Training Information Point
The slat limit switch is interchangeable with the flap limit switch.
Install the slat limit switch with the slat PDU in the rigged position. The limit switch rig indicator has a fixed scribe mark and an indicator needle. The indicator needle moves up or down in relation to the scribe mark as the shaft of the limit switch turns. Make sure the center of the indicator needle in the rig indicator aligns with the scribe mark when you install the limit switch.
EFFECTIVITY BEJ ALL 27-81-00
Page 24
D633W101-BEJ Sep 05/2002
777 AIRCRAFT MAINTENANCE MANUAL
LEADING EDGE SLATS -SLAT LIMIT SWITCH
EFFECTIVITY BEJ ALL 27-81-00
Page 25
D633W101-BEJ Jan 05/2002
LEADING EDGE SLATS -AUTOSLAT PRIORITY VALVE
Purpose
The autoslat priority valve controls the flow of hydraulic fluid to the main landing gear (MLG) system. This valve gives priority of center hydraulic system power to the slats during autoslat operation and to the flaps and slats during landing gear operation.
Location
The autoslat priority valve is on the ceiling of the right MLG wheel well.
Physical Description
The autoslat priority valve includes a solenoid valve and a control valve.
Functional Description
The control valve receives pilot pressure from the solenoid valve and from the center hydraulic system. When the solenoid valve de-energizes, the control valve permits full hydraulic flow to the MLG system.
During autoslat operation, the solenoid valve energizes. This moves the control valve to the reduced flow position. This reduces the hydraulic flow to the MLG system and gives priority of the hydraulic power to the slats.
If the center hydraulic system pressure is less than approximately 2550 psi, springs force the control valve to the reduced flow position. This reduces the hydraulic flow to the MLG system and gives priority of the hydraulic power to the flaps and slats.
EFFECTIVITY BEJ ALL 27-81-00
Page 26
D633W101-BEJ Sep 05/2002
LEADING EDGE SLATS -AUTOSLAT PRIORITY VALVE
EFFECTIVITY BEJ ALL 27-81-00
Page 27
D633W101-BEJ Jan 05/2002
LEADING EDGE SLATS -TORQUE TUBES AND TORQUE TUBE SUPPORTS
Purpose
The slat torque tubes transmit power from the slat PDU, through gearboxes, to the slat rotary actuators. The torque tube supports hold the torque tubes in place.
Location
There are 60 torque tubes of different lengths for the slat drive system. These torque tubes are above the ceiling in the aft section of the forward cargo compartment and along the front spar of both wings. Remove the cargo lining in the aft section of the forward cargo compartment or remove the access panels under the wings to get access. To get access to the torque tubes for the krueger flaps, remove the access panels above the wings. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：777 AMM 飞机维护手册 飞行操纵 Flight Controls 2(64)
