The Design And Analysis Of Actuation System For The Nose Landing Gear Of An Aircraft

Aircraft landing gear is an important part of the aircraft. Conventional aircraft landing gears are actuated by hydraulic system. The hydraulic system has a lot of disadvantages: large weight, high failure rate and low efficiency, so its reliability has become the weakness of aircrafts. Early 1980 s, a new type of electric actuation system appeared under the concept of “All/More electric aircraft”. This new system adopts new electric actuator and cancels the central hydraulic source, so it reduces system weight effectively. This new system is an important development direction of aircraft landing gear hydraulic system.Aiming at a large civil aircraft landing gear hydraulic system, based on the design requirements, a new type of hydraulic system including retraction and steering system of landing gear is designed in this paper. The system also uses a dual-redundancy electronic control plan of emergency extension to replace the traditional rope-pulley system and its worm gear mechanism are preliminary designed. Then, the LMS Imagine.lab softwares is applied to build the simulation model of the nosewheel steering system, and its main functions and performances under different pattern are simulated and analyzed. The research results indicate that the nose wheel steering system is reasonable and validated, can meet the requirements of the general project.Finally, the Virtual.lab and Imagine.lab softwares are applied to build the joint simulation model of the retraction mechanism and control system, then its main functions and performances under normal retraction and emergency extension are simulated and analyzed. The results show that the primary simulation of the system is achieved.According to the investigation of this paper, some valuable experience and conclusion is provided for the design or analysis of the hydraulic system and lay a foundation for the further optimization and experimentation. It is of great instructive significance for the design of civil aircraft’s landing gear of our country.