In contrast, regular mechanical springs work using elastic deformation. Unlike coil springs that resist impacts due to their structure, gas springs resist shocks because they are powered with pneumatic energy in the form of a high-pressure gas in a cylinder.
Gas springs are similar to air cylinders, in that they both use a piston that compresses or extends based on the pressure in the chamber.
The main functions of gas springs are related to shock absorption, dampening, and exerting force. Gas springs can be used in place of mechanical springs to lift, lower, close, open, and adjust things in a variety of applications.
Industries like aerospace, healthcare, office supplies, marine, and agriculture all use gas springs in their products or in manufacturing equipment. Gas springs are also extremely important in the automobile industry where they are used for everything from suspension to truck supports to hoods. In other industries, gas springs are used for products like landing gear on planes, tanning beds, and awning extensions.
The first gas springs were patented in 1891 by Paul Giffard, a Parisian engineer. Giffard designed them for use in guns. In his design, the pressure they built strengthened the force with which a handgun discharged bullets. Independently, gas springs appeared in the United States by at least 1875. Initially, gas springs did not receive much interest.
Gas springs became much more popular in the mid-1900s, when automotive engineers began customizing them for use in the hoods and trunks of cars. After that, manufacturers around the world started using gas springs for other applications.
To construct gas springs, most manufacturers make use of 3D CAD drawings or similar design software for maximum precision.
Manufacturers most often create gas springs using metals like stainless steel and aluminum. Stainless steel gas springs are extremely common, as they can resist corrosion. Manufacturers can also, however, fabricate them using other materials, like EPDM synthetic rubber or polyurethane.
If the application calls for it, manufacturers can coat the spring material with chrome plating or black nitride; such coatings will further protect the spring from the elements.
Usually, manufacturers choose nitrogen or carbon as the gas that passes through the gas spring. Nitrogen gas springs are popular because nitrogen gas is inert, meaning that it is chemically inactive (it won’t react). Carbon gas springs are popular because carbon gas is generally harmless and compatible with industrial manufacturing.
Considerations and Customization
When designing a gas spring, manufacturers must take a number of factors into consideration. These include the amount of gas that is expected to pass through the chamber, the application’s actuation or vibration isolation needs, and the variable pressures and velocities it must tolerate (especially important in machinery and automotive applications).
Based on these considerations and other application requirements, gas spring manufacturers custom design spring features like the size (which depends on the amount of gas that is expected to pass through the chamber), compressed and extended spring lengths, load capacity, max force exertion per minute, maximum cycles per minute, the type of gas they will use in the cylinder, absorber stroke, and working temperatures.
A gas cylinder can be as small as two inches in length, or as large as several feet in length. Likewise, load capacity can range from one-hundred to over eighty thousand pounds. Manufacturers most often customize gas springs in relation to their body material, as the material they use must be able to endure any stresses put on it from the environment it inhabits (heat, cold, moisture, etc.), the chemicals it uses (corrosive chemicals, hazardous chemicals, etc.), and the physical stresses put on it. On top of that, it must be appropriate for the standard requirements of the application. For example, in pharmaceutical manufacturing or in the food industry, the gas springs must be FDA-compliant.
To find out more about your custom gas spring options, talk to your prospective suppliers.
Gas springs all have a similar design and function, but they can be used for many different applications and can be manufactured in a wide range of sizes.
Essentially, all gas springs have a cylinder body, piston rod, O-rings (or other seals), intake and outlet valves, and a gas reservoir.
The polished interior of the cylinder helps to reduce friction during motion. The head piston of the spring sits perpendicular to create an airtight seal and separate the cylinder into two compartments.
The rod extends out of the end of the cylinder and is attached to the piston. When force is placed on the spring, the rod goes deep into the chamber. This is what compresses the gas and reduces the impact. A common example of this is when a car drives over a bump. The force of the impact causes the car’s springs to momentarily compress.
There are several types of gas springs. Some of them include compression gas springs, extension gas springs, tension gas springs, locking gas springs, adjustable gas springs, reducible gas springs, tool and die gas springs, gas spring dampers, gas struts, and lift gas springs.
Compression gas springs offer dampening when force is exerted on the spring as the piston is pushed into the cylinder.
Extension gas springs push the rod all the way out or partially out in the chamber to provide isolation.
Tension gas springs hold tension and/or carry out pulling tasks. In contrast, regular gas springs perform pushing tasks. Tension gas springs are common components of furniture like cabinets.
Locking gas springs are those gas springs that can lock their rod in place after they have reached full extension. Locking gas springs are also known as lockable gas springs. They are useful for applications that require controlled movements and prolonged positioning (e.g. extended hospital bed).
Adjustable gas springs can stop at any point during movement. Regular gas springs can only stop at full extension. Adjustable gas springs, which are typically locking, provide a greater degree of control for their users. Most often, manufacturers install them on hospital furniture, like beds, emergency gurneys, and seats.
Reducible gas springs are adjustable in a different way; during operation, users can remove some of the gas they use in order to alter their force.
Tool and die gas springs do not use any damping agents. At the same time, they produce higher forces using shorter stroke lengths than conventional gas springs.
Gas spring dampers are not really gas springs, but people so often use the term “dampers” in reference to gas springs that we have to mention them. Dampers are basically gas springs that control motion without any gas exertion. Their main application is supporting moving loads and controlling their motion.
Gas struts usually offer push forces.
Lift gas springs are those gas springs used specifically for lifting applications.
Gas springs offer many advantages. First, when properly maintained, they tend to last longer and perform better than traditional springs. Their superior performance is due to their many positive traits. They are, for example, easy to control and adjust. In addition, they are extremely durable and reliable, and they can exert higher levels of force than traditional springs. Another advantage of gas springs is the fact that they are compact. This means that they can work in a wide variety of places. Next, gas springs are mountable, contributing once again to their versatility. Finally, they require little to no upkeep.
To help your gas springs work to the best of their abilities, you may purchase any number of accessories. Some of the most common gas spring accessories include nylon socket end fittings, stainless steel socket end fittings, O-ring seals, mounts/mounting brackets, ball receivers, and connectors of various kinds.
To make sure that your gas springs last as long as possible, you need to treat them well. What entails treating them well?
Well, first, you need to use them only within their designed limits. This means that you should not exceed their load capacities; you should not put them in temperatures they are not meant to endure; you should not put them in overly corrosive environments, etc. Putting them in settings for which they are not involved will wear them out quickly, and quite possibly cause a malfunction that will break them completely. It’s also not safe.
Second, to keep your gas springs working well, you need to check on them from time to time. They actually do not require regular maintenance, but you want to be aware if something has gone wrong, which is why you should check on them.
If the time does come for you to replace your gas spring, first depressurize them, then drain them. After that, if you can, recycle them.
The standards to which your gas springs must adhere depend on your industry, application, and location. For example, gas springs used in defense applications must be military grade. Likewise, if you plan to use your gas springs in American food service, they and the material with which they are made must be FDA compliant. To find out which standards you should make sure your gas springs meet, talk to your industry leaders.
Things to Consider
To help guide you, we have put together a list of several high-quality gas spring manufacturers that we trust. You can find these gas spring suppliers by scrolling towards the middle of this page. There, you will find their contact info, webpage links, and profiles.
Before you check out these manufacturers, we recommend that you dedicate some time to putting together a specifications list. List all of the details of your application, including things like your budget, your timeline, your delivery preferences, and your post-delivery support preferences (parts replacement, warranties), etc. Once you have put this list together, you can use it to help you determine which of the suppliers we have recommended are most likely to work for you. Based on your specifications, pick three or four potential choices. Then, reach out to each of them to go over your application. When you speak with each of them, use your specifications list as a conversation guide and make sure to go over every point. After you have spoken with each potential manufacturer, compare and contrast the services each company offers. Also compare and contrast their prices. Weigh your options and, finally, pick the right company for you.