Structure and Components of Gas Springs

Table of Contents Menu

Basic structure of a gas spring
Main components
Common applications
Industries
Machines for gas spring cylinders
Reference
- Related videos

Basic structure of a gas spring

A gas spring stores energy in nitrogen compressed inside a sealed cylinder. Unlike a mechanical spring, which relies on elastic deformation of steel, a gas spring carries the external load pneumatically.

Closed gas spring cylinders

Cylinder tubes after inner grooving

Gas spring end fitting

Main components

Piston rod

The steel rod that connects the external load to the internal piston. Its surface is precision ground and chrome plated for sealing and durability.

Cylinder

The sealed tube that holds the compressed nitrogen and a small amount of oil. The inner wall is honed to reduce friction.

Piston and valve assembly

The piston moves inside the cylinder while the valve assembly controls the direction and rate of gas flow, which sets the damping behaviour. It typically includes:

Piston rod seal
Rod guide
O-ring
Orifice (restriction hole)
Piston guide
Valve sealing screw

Sealing system

The end cap, wiper and seals keep the nitrogen in and keep dust and water out. Seal quality largely determines service life.

Common applications

Automotive: hatchback tailgates and bonnet struts
Office furniture: chair height adjustment
Medical equipment: hospital beds and operating tables
Industrial: press tooling, where forces are typically 2,500 N to 40,000 N
Aerospace: hatch and door opening mechanisms

Industries

Automotive: tailgate struts, bonnet struts, shock absorber cylinders
Furniture: office chair gas lifts, sofa bed folding mechanisms
Baby strollers: folding joints and locking mechanisms
Medical: bed lift cylinders, operating table adjustment
Industrial: press-tool cylinders, maintenance door struts

All of these cylinder tubes need precise tube processing – cutting, grooving, reducing and end closing.

Machines for gas spring cylinders

The cylinder tubes described above are what TONG DA Precision (Tainan, Taiwan, since 1989) builds machines for: tube closing machines for the cylinder bottom, inner grooving machines for oil grooves, plus oil filling, press-fit & edge folding and lock nut machines – as single machines or a complete cylinder line. See How are gas springs made? for the machine at each step, or browse our products. For quotations, email sales@tdco.com.tw.