Hydraulics and Landing Gear Systems Agenda 5000 psi Hydraulics System Configuration Update Hydraulic Architecture System Interfaces Component Installations Landing Gear Actuation System Overview Landing Gear Actuation System Steering System Hydraulic System Architecture Overview Hydraulic System Architecture Hydraulic SystemArchitecture (cont.) 5000 psi operating pressure Saves weight on fluid, tubing, reservoirs Utilize low density BMS 3-11 fluid, currently classified as Type IV Class 1, & Type V Grade A or B Hydraulic Interface Function (HYDIF) software:  Part of Common Core System (CCS) Common hydraulic pumps on EDPs and EMPs Electric Motor Pumps (EMPs) Flooded Induction Motor – cooled by hyd fluid from pump case drain (change from DC motors) ~27/37 GPM @ 5000 psi Motor controller for starting, controlling motor speed Brake System is not hydraulic Hydraulic SystemArchitecture (cont.) New controlled system operating temperature to approximately: 100? – 160?F Temperature control maintained by a bypass valve and fuel tank heat exchanger in each system Bypass valve is a mechanical thermostat type device located on the case drain filter module Bypass valve is designed for two positions: Closed: flow through the heat exchanger (only) Open: a percentage of flow bypassing the heat exchanger Hydraulic SystemArchitecture (cont.) No bleed air used for hydraulic power Bootstrap Reservoir Chosen because bleed air not available for reservoir pressurization Change from traditional air-over-oil configuration Bootstrap system utilizes hydraulic system pressure to pressurize reservoir Proven design on Douglas model airplanes DC-10, MD-11 717, DC-8, DC-9, MD-80, MD-90 Hydraulic SystemsBootstrap Reservoir Schematic  Hydraulic SystemArchitecture (cont.) Ground test that require 5000 psi pressure: Landing gear retraction RAT functional tests (GSE) High pressure hydraulic leakage checks Flaps/slats operation (hydraulic mode – priority valve) Primary flight controls actuation confidence test Hydraulic Power Options for Ground Tests: APU generator Three or Four external ground power sources Two external ground power sources can provide limited hydraulic power in maintenance mode 5000 psi ground cart Hydraulic SystemTransport Elements System Pressure Tubing Titanium, Ti-3-2.5 Requires thicker wall tubing Qualification to 5080 psi for industry commonality Threat zones will use 21-6-9 CRES tubing(thrown tread area, pressure dome, etc.) Return Pressure Tubing Thin wall titanium, Ti-3-2.5 Aluminum inside the fuel tanks Hydraulic SystemTransport Elements (cont.) Repair processes and techniques for 5,000 psi tubing are anticipated to be nearly identical to current airplanes   Processes and techniques used on current airplanes will be used with different parts Example repair methods being developed include:  Cut-out and drop-in replacement tubing sections using existing swaging techniques 5,000?psi flex?hoses permitted for repair in lieu of hard tubing runs 5000 psi Ti tubing replacement with 5000 psi CRES tubing using 21-6-9 is planned
787起落架.ppt