Abstract: In view of one kind of mechanical shock situation in which neither rubber buffer nor hydraulic buffer can be used, an O-shape spring that features small size, high stiffness, fine linear characters and simple structure is proposed to replace common spring used for buffer. The dynamics model of buffer mechanism is analyzed, and the performances of common coil spring, disk spring and O-shape spring are compared and analyzed. The results show that the O-shape spring is small in size and high in stiffness. The finite element stress analysis model of O-shape buffer is built to carried out numerical analysis on the static load strength and yield limit of the buffers with different sizes, and TableCurve 3D software is used to carried out numerical analysis on the results, then the relationship between the geometric size of buffer and the stiffness of spring is found out. The results show that the most effective way to improve stiffness of O-shaped linear buffer is to thicken the wall of buffer, but not to widen it or reduce the outside diameter. The result of finite element simulation agrees well with the experimental result, which proves the validity of the finite element method.

Key words: Finite element, Linear buffer, Stiffness