Answer
Nested wave springs are produced from a single continuous filament of flat wire coiled in parallel. This configuration multiplies the load capacity by the number of turns $N$ while maintaining a low profile. The load equation is $P = \frac{E · b · t^3 · f · n^4}{D_m^3 · L}$, where $L$ is a constant related to the nesting friction. Unlike crest-to-crest springs which increase deflection, nested springs increase force. A critical design consideration is the inter-turn friction; as the spring deflections, the layers slide against each other, creating a slight hysteresis in the load-deflection curve. This is beneficial for damping in high-vibration aerospace actuators but requires careful lubrication with molybdenum disulfide (MoS2) to prevent galling.
