| Swashplate is a mechanism that contacts the control rod and the rotor blade on the helicopter.The pilot changes the posture of the blade through the swashplate to change the direction and size of the thrust to complete the front,rear,left,and right movements.Rotating scissors is an important part of the swashplate,any failure in the tungsten carbide product may cause malfunction of the operation systerm and seriously affect the safety of the helicopter.Therefore,it is of great significance to design a durability testing machine that can simulate the real working conditions of the tungsten carbide product and provide data support for product installation.Firstly,we design the overall scheme of the test machine according to the principle and technical requirements of the tungsten carbide product,and carries on the detailed design and the discussion to each subsystem.In the loading system,combined with the crank-slider mechanism and the spring device,a new type of spring loading method is designed,and an axially adjustable alternating load is applied to the oscillating end joint bearing.Secondly,the influence factors of loading force error are analyzed in order to achieve the loading accuracy of the tester.A dynamic simulation model of the loading system is established,and the movement characteristics,friction force and loading force of the loading system are studied.Then,the loading force calibration experiment was designed and carried out,and the calibration test was established to compare the friction coefficient with the test results to improve the simulation accuracy.Finally,the rigid-flexible coupling dynamics model of the loading system is established.The effects of the part deformation,clearance collision and friction force on the loading force are studied.The compensation scheme is formulated according to the simulation results.The compensation accuracy is within 3% after the compensation and meets the accuracy requirement of the testing machine. |
