Research On High Speed Spring Overrunning Clutch Design Technology

Overrunning clutch is one of the important devices in the transmission system of helicopter,which is to ensure the engage and disengage function with requirement betimes between the engineand main gearbox. Because of the high load-bearing capacity, stabel transmission and long life, springclutch has a wide range of applications in helicopter transmission system. With the development ofhelicopter transmission technology, the speed request of overrunning clutch is more and more highly.Therefore, research on the high-speed overrunning spring clutch design technology has significantengineering significance.In this paper，the relevant studies and achievements include the following four parts.(1) Design and Analysis of the Spring Clutch. The advantages and disadvantages of differentclutch structures are analyzed, and the structure of the required spring clutch is determined. Accordingto given design requirements, the preliminary design for the spring clutch’s key components is given.The influence of spring diameter, width and other factors to the stress are studied. The software fordesigning the spring clutch is developed.(2) Optimal Design of the Spring Clutch. The spring that is core component of the clutch isoptimized and analyzed. Three types of objective functions are established, which include making thevolume of the spring minimum, making the stress of the dangerous cross-section smallest andachieving both of them. On this basis, the other structure sizes of key components of the spring clutchare designed. The influence of the safety factor of static yield and fatigue limit to the optimization areanalyzed. The optimal design software is developed.(3) Parameterized Modeling and Motion Simulation Analysis of the Spring Clutch. Theparameterized modeling software is developed with VB and CATIA. The three-dimensional model ofthe optimized spring clutch is established. After doing the virtual assembly, the motion analysis of thespring clutch is done, including interference checking in the static and dynamic environment andtesting the kinematic performance.(4) Dynamics Finite Element Analysis of the Spring Clutch. The modal of the spring clutch issolved and analyzed based on FEA method. The effects of the radial bearing stiffness, axial bearingstiffness and centrifugal force to the modal of the clutch system are researched.