Abstract: The stiffness characteristics of the diaphragm air spring is studied and the factors affected the stiffness of the diaphragm air spring is analyzed in the dissertation. The shape of the piston is the main factor which affects the diaphragm air spring, and the different shapes corresponding to different piston stiffness. Diaphragm air spring stiffness doesn’t have the uniform standard, so each piston has a corresponding shape stiffness characteristic. The formula of stiffness based on curve shape of rotors piston is discussed in this dissertation, and wherein, the level of piston affect and the air spring piston displacement are the key factors in derived single-chamber air spring stiffness. Break derivation is used in derive the level of piston affect and the air spring piston displacement when the rotation curve air spring stiffness is deduced. The structure and size, which affect the single chamber air spring kinetic parameters in the establishment of the sir spring model is analyzed. Cone angle of the piston and the piston height are the main factors which affect the single-chamber air spring when the basic structure of the air spring is defined.

Key words: air spring, shape of piston, stiffness characteristics