Nitrogen gas springs, a type of hydraulic gas springs, are a popular alternative to traditional mechanical springs. They come in a variety of sizes, generate consistent and powerful forces, and are very durable. This article explains how they work, some of their benefits, ways to configure them, and how they are used in metal stamping and metal forming across industries.
What is a Gas Spring?
Like mechanical springs (i.e., metal coil springs), gas springs are used inside dies for metal stamping and metal forming applications with a press. The difference is instead of storing potential energy in a metal coil, nitrogen springs use pressurized nitrogen gas.
Because the gas spring mechanism operates based on the pressure of gas inside the spring housing, it is able to apply an immediate, constant force from initial contact to final stroke. A gas spring’s force is measured in decanewtons (daN).
Ready’s Design-Tite springs come in a variety of lengths and diameters as well as motion control springs that can be paused at a desired working position.
When properly installed, nitrogen gas springs are extremely safe and last for millions of cycles. All of Ready Technology’s Design-Tite nitrogen gas springs come with comprehensive, illustrated safety and installation instructions.
How Do Gas Springs Work?
Gas springs consist of a cylindrical metal housing and snug-fitting inner piston. While they are manufactured in a range of lengths and diameters, the stroke length is the critical measurement for determining both piston length and the corresponding housing type. Shorter pistons use one-piece housings, which are bore-sealed. Longer pistons require a two-piece housing. Ready’s two-piece housings are specially sealed with an end cap that is both threaded and welded for added durability and safety.
The nitrogen is tightly sealed in the housing, allowing the gas to compress and store energy when force is applied to the piston, pushing it down. When force is removed from the piston, the pressure is released and the piston is pushed back up by the expanding gas. A small amount of lubricating oil is also sealed inside the spring housing to keep the piston moving smoothly in both directions.
One gas spring can replace up to 10 traditional mechanical springs, even though gas springs are much more compact in size. When fully charged the force remains smooth and consistent from initial contact to final stroke, which gives great control over the metal forming process.
What Are the Benefits of Gas Springs?
Nitrogen gas springs offer many benefits over mechanical springs, including:
- Immediate, consistent force
- Durability and reliability because less prone to wear and tear than coils
- Compact for use with short stroke lengths or shut heights
- Expandable by connecting multiple springs to operate in unison and increase force
- Adjustable pressure for precise operation and control over the stamping process
What Are the Different Types of Gas Springs?
Gas springs can be used singly or in groups. By connecting multiple springs it’s possible to combine their force and evenly distribute it throughout the die. Configurations fall into three categories:
- Autonomous Gas Springs
Single, closed spring consisting of cylinder and piston, operated individually.
- Interconnected Gas Springs
Multiple single springs can be connected with flexible hoses to vary the amount of force produced for different applications. Care must be taken to avoid twisting the hose or making sharp bends in it, which can impede the flow of gas between springs.
- Compact Manifold Gas Springs
Another way to connect multiple gas springs is with a manifold. This is a metal plate with openings for threaded springs to screw into. Channels are drilled inside the manifold block to connect the springs so they operate as a single unit, exerting greater force that is also evenly distributed throughout the die. Manifolds include a control panel with a gauge and valves to fill or discharge nitrogen.
What Industries Use Gas Springs?
Almost anywhere that a coil spring is used in a press a gas spring can be substituted. One gas spring can replace multiple mechanical springs, and it’s easy to adjust the gas pressure to fine tune the force for precision applications. What’s more, because they are generally compact, nitrogen gas springs are well suited to applications with limited space in dies.
All of these features make gas springs a solid and reliable choice in many of the industries that stamp parts and utilize other metal forming processes including the automotive (both OEM and aftermarket), aerospace, appliance, office and home furnishing, and HVAC industries.
How can you Select the Best Gas Springs for Your Needs?
As always, the details of your application determine the equipment you need. When selecting gas springs, start by determining your needs for force in daN, stroke length, shut height, piston and cylinder diameter, and number of springs.
Not sure how to get started? Deciding between multiple options? Whether you are replacing existing coil springs or designing a new die set for a stamping application, the Ready Technology team has the engineering expertise to help you find the right spring and accessories.
At Ready we have many nitrogen gas spring options available and in stock, along with flanges, valves, gauges, manifolds, hoses, and all the accessories you need. Contact us today!