• Home
  • Download PDF
  • Order CD-ROM
  • Order in Print
RETRACTION ENGINE MANIFOLD - 14310_171
VENT VALVE PANEL

Aviation Boatswains Mate E - Aviation theories and other practices
Page Navigation
  156    157    158    159    160  161  162    163    164    165    166  
ADVANCE DIRECTIONAL VALVE The advance directional valve (see fig. 4-45) controls the hydraulic motor during advance. When actuated by fluid flow from the pilot valve, the advance directional valve piston shifts, directing fluid flow through the directional valve to the hydraulic motor. The fluid returns from the motor and flows through the directional valve to the gravity tank. When the advance directional valve is not actuated, no fluid flow is allowed through the valve. As the traverse carriage nears the end of an advance stroke, a cam mounted on the carriage actuates the advance dump valve. This drains the pressure in the advance directional valve actuating chamber back to the gravity tank through the dump valve. The advance directional valve piston then closes, causing a gradual cutoff of hydraulic fluid from the hydraulic motor, initiating retraction engine braking. MANEUVERING VALVE The maneuvering valve (see fig. 4-45) is mounted on the manifold and is operated by the maneuver forward solenoid (EF) and the maneuver aft solenoid (EA). The maneuvering valve is energized automatically during the latter part of the advance and retract stroke to control the speed of the grab after braking has been completed. Orifices control hydraulic fluid flowing through the valve to and from the hydraulic motor. At times other than during normal operations, the valve can be energized to slowly maneuver the grab, shuttle, and pistons forward or aft for testing or maintenance. A manual override button on the valve can be pushed to maneuver the grab aft in case of power failure and permit disengagement of the aircraft from the shuttle. DUMP VALVES The  two  dump  valves  (fig.  4-46)  are  mounted  on the retraction engine frame. The valves are actuated by cams   mounted   on   the   traverse   carriage.   When   the retraction  engine  nears  the  end  of  the  advance  stroke, the  advance  dump  valve  is  actuated.  The  dump  valve closes   allowing   the   pilot-actuating   fluid   from   the advance directional valve to return to the gravity tank, initiating    the    advance    braking    stroke.    When    the 4-38 TO ADVANCE DIRECTIONAL VALVE TO RETRACT DIRECTIONAL VALVE FROM ADVANCE AND RETRACT PILOT VALVE FROM ADVANCE AND RETRACT PILOT VALVE RETRACTION DUMP VALVE (C/23) CABLE TENSIONER ASSEMBLY (REF) ADVANCE DUMP VALVE (C/24) TO GRAVITY TANK TO GRAVITY TANK ABEf0447 Figure 4-46.—Retraction engine dump valves.







Western Governors University

Privacy Statement
Press Release
Contact

© Copyright Integrated Publishing, Inc.. All Rights Reserved. Design by Strategico.