Study on variable diameter spiral spring

On the foundation of analysis on non-cylindrical spiral spring force state, stress status and corresponding formulas in various segments of spring wire are derived, therefore the concept of varying spring diameter is put forward. Taking oblate prism spiral spring as an example, variable diameter spiral spring and invariable diameter spiral spring are separately designed under the instructions of the concept. An simulation is designed to examine the characteristics of the two springs in strength, stiffness and fatigue. The result shows that: both kinds of springs can meet the design requirements in maximum work force and fatigue, but the new spring are significantly lighter compared with the traditional invariable diameter, and the mechanical properties of material of the new spring are more fully played. This concept can be widely used in various fields of machinery, such as aerospace, vehicle suspension and small arms, and it will have important significance in designing new spring of light-weight and high-reliability.