What Is Compression Spring?
Compression springs are helical—that is, spiral-like-springs. When force is not applied to them, they exhibit an open coiled design. However, as the pressure presses downward along the axis of the spring, the coils push strongly against each other.
This effect shortens the lengths of the spring & stores the energy. Once the pressure is released, the stored energy returns the spring to its original height. Compressions spring is a type of spring that compresses under a load. Like extension springs, they are made from a coiled piece of metal.
If you compare an extension’s spring to a compressions spring, you will see that the latter type has a wider and wider coil than its counterpart. Extension springs have a narrow piece of coiled metal, while extension coils have a wider piece of coiled metal.
Compression springs differ from extension springs in how they work. While extension springs lengthen under load, compression springs become shorters. Compressions springs are designed for use in applications where two components attempt to push toward each other.
To prevent components from making contact, a compressions spring may be used. The compressions spring is placed between the two components where it is compressed. As two-component try to push towards each other, compressions spring will compress. In turn, this will store mechanical energy, which is then pushed back out to the components.
By far the most widely uses type of spring, compressions spring is designed to resist compression and return to its incompressible length when the applied force is removed. Potential applications for compressions springs are limited only by imagination.
Types of Compression Springs:
Compressions springs come in a wide range of shapes & sizes, each of which significantly affects the force and tension provided by an individual spring. Different types also have and distribute power through different forms.
The types of compression springs available include:
#1. Convex Springs
Convex springs, i.e., barrel-shaped springs, have larger diameter coils in the middle of the spring and smaller diameter coils at both ends. These designs allow the coils to fit within each other when the springs are Compressions.
Manufacturers use convexes springs in applications that require greater stability and resistance to moving as the springs decompress. Most of the applications using them are in the automotive, furniture, and toy industries.
#2. Concave Springs
Concave springs, i.e., hourglass springs, have a narrower coil in the middle of the spring than at either end. The symmetrical shape helps ensure that the springs remain centered at a particular point.
#3. Conical Springs
Conical springs, i.e., tapered springs, are cone-shaped. One end has larger diameters than the other, & the coils throughout the spring provide a gradual taper or change in shape. The diameter of some conical springs changes enough from coil to coil so that each coil fits the previous one.
#4. Straight Coil Springs
The diameter of each coil in these springs is the same. Straight coils are some of the most commons springs in use.
#5. Variable Pitch Springs
Variable pitch springs have varying distances up and down the length of the spring between each coil.
#6. Volute Springs
These waterfalls are cone-shaped. However, instead of being wire coils, coils are formed from a winding sheet of metal or other material. Compression Spring Characteristics
Compression Spring Characteristics:
By far, the most widely uses type of spring, compressions spring, is designed to resist compression and return to its incompressible length when the applied force is removed. Potential applications for compressions spring are limited only by imagination.
Dimensions Measurement Guide:
Hold the base of spring in one hand & the calipers in the other. Measuring the largest dimension, place the calipers on the outside of the last coil. This is called the outer diameters (O.D.). Places the calipers on the wire in the middle of the spring. This is called wire or material size.
You should also measure the wire towards one end for comparison and accuracy. Keep the calipers on the entire length of the incompressible spring. This is called free length. Count the total number of coils, starting at one end, right next to where the wire is cut. Make sure you count all the coils, including any part of the coil. see diagram for an example
It should be noted that if significant force-versus-deflection linearity is required, only center 60–80% of the available deflection range shoulds be employed. Thus, reserve at least the first & last 15-20% of the range for potential spring-end & adjacent coil-contact effects.
For most Spring applications, these effects can be largely ignored. The “Suggest maximums deflection” used in our online and print catalogs refers to the recommended inches of travel to achieve a statistical service-life of approximately 100,000 cycles deflection with low breakdown.
These can be realized if the spring in question is not subjected to shock loads, rapid cycling, temperature extremes, corrosion, or stress values exceeding recommended. If the spring is statically filled (not cycled), almost infinite life can be expected. Extended spring service life can be achieved through shot-peening. Our custom spring department can advise you on this process.
Materials of Compression Springs:
The highest grade of the spring wire is used when fabricating our springs. To create cost-effective warehousing of our stocks spring inventory for our customers, we only offer material certification in the form of custom springs. Certificates of conformity to geometric tolerances set by the Spring Manufacturers Institute (SMI) are available for our stocks springs upon request.
The term “spring steel” is a stocks inventory term that includes music wire, hard-drawn (MB) wire, and oil-tempered wire. Additionally, stocks compressions spring materials may include stainless steel (300 series), beryllium copper, and phosphors bronze.
Tolerances of Compression Springs:
Century Spring manufactures our stocks springs to commercial tolerances, as defined by SMI. SMI is approximately +/- 10% in rates and loads calculated based on geometric tolerances. Low- or high-index springs will have higher values.
Compression springs are characterized by an hourglass shape when coiled on an automatic coiler; Therefore, the outside/inside tolerance only applies to the end coils. These are improvements considerations when selecting a spring that fits over the rod or inside the cylinder. Give us calls if your application requires tighter tolerance values.