At its most basic level, a spring is a device used to store mechanical energy. Although often out of sight, springs play an important role in many motion control applications. They are used in gear assemblies, actuators, rotary unions, and different kinds of clutches, among other applications. There are many different varieties and shapes and sizes of springs making it virtually impossible to cover them all in great length.
However, there are some basics to spring technologies. For starters, there are generally three types of springs; tension, compression, and torsion springs. Tension springs operate in tension with a load attached, so as the load is applied the spring will be stretched out. Compression springs, as the name implies, operate under compression, so as the load is applied this type of spring will become shorter. Lastly, torsion springs operate with torsional or twisting loads, which means a torque is applied to the spring.
Compression springs are some of the most common types of springs in use. Traditional compression springs are usually available as coil springs. A coil spring is a coil of some kind of metal or metal alloy.
Wave springs are one alternative to coil springs. One advantage of wave springs is their space savings. By reducing spring operating height, these springs also decrease the spring cavity. A smaller assembly size and less material used in the manufacturing process amounts to lower costs as well.
Wave springs operate as load bearing devices. They take up play and compensate for dimensional variations within assemblies. A wide range of forces can be produced whereby loads build either gradually or abruptly to reach a predetermined working height. This establishes a precise spring rate in which load is proportional to deflection.
There are a few important factors to consider when selecting a wave spring. The most important factor may be the load requirement. The load requirement is defined as the amount of axial force the spring must produce when installed at its work height. Some applications require multiple working heights, where loads at two or more operating heights are critical. Often minimum and/or maximum loads are satisfactory solutions, particularly where tolerance stack-ups are inherent in the application.
High temperature, dynamic loading (fatigue), a corrosive media or other unusual operating conditions are also important considerations in spring applications. Solutions to various environmental conditions typically call for the selection of the optimal raw material and operating stress.
The working cavity usually consists of a bore the spring operates in and/or a shaft the spring clears. The spring stays positioned by piloting in the bore or on the shaft. The distance between the loading surfaces defines the axial working cavity or work height of the spring. Material cross-section also plays an important role in wave spring design.
Lastly, although wave spring applications can be diverse, there is a basic set of rules for defining spring requirements. Those requirements are used to select a stock/standard spring or design a special spring to meet the specifications.
Content provided by Design World.