Design And Research Of Tail Beam Electric Folding System In A Shipboard Helicopter

With the development of modern society,almost every country pays more and more attention to the security of the territorial sea.Shipboard helicopters,as an important equipment of naval aviation,have a great impact on the national defense force of the sea.The electric folding system of tail beam is one of the important components to reduce the space size of a shipboard helicopter and shorten the support time before and after flighting.It plays a vital role in the shipboard helicopter system.Based on the premise of the helicopter lightweight,an electric folding system is designed to meet the requirements of strength and stiffness.It has a certain theoretical and practical value for improving the performance of a shipboard helicopter,which has a certain theoretical and practical value.In this paper,an electric folding system of the tail beam of a certain type of shipboard helicopter is taken as the design object.Using the parameters optimization design,finite element analysis and optimization and test methods,the electric folding system and its transmission mechanism satisfying the requirements are designed.And a physical test validation is carried out.The main research work is as follows:(1)According to the operational principle,functional requirement and design index,the system scheme of the folding and lockpin electric device is designed respectively by comparing and analyzing.Based on the system scheme,a variety of different transmission mechanism schemes is designed.And other key components,such as sensor,ball screw and so on,are also designed to implement the other functions.(2)Problems of regarding mixed discrete variables as continuous in an optimization model are pointed out,and the principle and process of branch and bound method which can be used to solve the mixed discrete variable optimization problems are also introduced.The mixed discrete variables mathematical model of the transmission mechanism is set up,in order to get the minimum mass,whose constraint conditions are given according to gear matching,geometric condition and gear strengths.According to the optimization results,three dimensional models are established,and the final design is determined by comparing.(3)The result of the finite element analysis of the electric folding system box is obtained,by analyzing the force of the transmission mechanism,establishing the finite element model,setting up the material parameters and applying the load and boundary conditions.Through the analysis and comparison of the result,it is proved that the box body meets the requirements of strength and rigidity.At the same time,the lightweight optimization is also carried out according to the analysis results.(4)After manufacturing the physical model of the transmission system,the test-bed is set up to measure its main performance indicators,for example transmission ratio,effective travel,load and sticking and pull-out force.It proves that the two transmission mechanism meet the design requirements.