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
Service Life:
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 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 stock springs upon request.
The term “spring steel” is a stock 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 improvement considerations when selecting a spring that fits over the rod or inside the cylinder. Give us calls if your application requires tighter tolerance values.
Frequently asked questions (FAQs) that could be included in the article about compression springs:
What are compression springs and how do they work?
Compression springs are helical springs designed to compress under a load and return to their original length when the load is removed. They store mechanical energy when compressed and release it when the force is released.
What are the main types of compression springs?
Compression springs come in various types including convex, concave, conical, straight coil, variable pitch, and volute springs. Each type is designed for specific applications based on their shape and characteristics.
What are the typical applications of compression springs?
Compression springs are widely used in automotive, aerospace, industrial machinery, consumer products (such as furniture and toys), and more. They are essential in applications where components need to maintain a specific distance or absorb and release energy.
How are compression springs measured and specified?
Compression springs are measured by parameters such as outer diameter (OD), wire size, free length, and total number of coils. Specifications also include material type, load capacity, and tolerance levels which are crucial for selecting the right spring for an application.
What materials are used to make compression springs?
Common materials for compression springs include high-grade spring steel (such as music wire, hard-drawn wire, and oil-tempered wire), stainless steel (300 series), beryllium copper, and phosphor bronze. Each material offers different properties suitable for various environments and load capacities.
How can the service life of compression springs be optimized?
Optimizing the service life involves considering factors like deflection range, cycle frequency, environmental conditions (such as temperature and corrosion), and proper handling during installation and operation. Shot-peening and material selection can also enhance durability.
What are the considerations for selecting the right compression spring?
When selecting a compression spring, factors such as load requirements, space limitations, deflection characteristics, environmental conditions, and desired operational lifespan should be carefully evaluated. Consulting with a spring manufacturer can help in choosing the best option.
What are the manufacturing tolerances for compression springs?
Compression springs are manufactured with commercial tolerances, typically around +/- 10% in rates and loads based on geometric dimensions. Applications requiring tighter tolerances may need custom springs or specific manufacturing processes.
How can I maintain compression springs for optimal performance?
Regular inspection for wear, corrosion, or deformation is essential. Lubrication and proper installation according to manufacturer guidelines can extend the lifespan and ensure consistent performance of compression springs.
Can compression springs be customized for specific applications?
Yes, compression springs can be customized in terms of size, shape, material, and load capacity to meet specific requirements of different industries and applications. Customization often involves detailed consultation with spring manufacturers to achieve desired performance outcomes.
