Any flexible machine element designed to store mechanical energy when deflected by an external force. The relationship between the amount of deflection and the force exerted depends on the design of the spring. The most common type of spring is a cylindrical, helical spring with a constant pitch.
For simple springs, Hooke’s law can be used to describe the relationship between the applied load and spring’s deflection from its neutral position. Hooke’s law states that the force applied on a spring is directly proportional to its deflection, provided stress levels stay within the material’s elastic range. To find the magnitude of the applied force (F), the compression (or elongation) displacement (δ) is multiplied by a spring rate (k), i.e.,
F = -k × δ
Cylindrical, helical springs are commonly found in reciprocating compressor valves, where they control the dynamics of valve elements. Because internal valve motion includes rapid acceleration and deceleration cycles, valve springs must be designed to handle high dynamic stresses. Compressor valve reliability is highly dependent on selecting the right spring design for the application.