Gas springs have different structures and types due to their different uses. At present, there are two kinds of gas springs produced in China, which are non lockable and lockable.
The quality of the gas spring is mainly judged from the following aspects: first, the sealing performance, if the sealing is not good, there will be oil leakage and air leakage in the process of use; second, the accuracy, for example, if the gas spring needs 500N, the force error produced by some manufacturers is not more than 2n, and the gas spring of some manufacturers may be far different from the 500N actually needed; The second is the service life, the service life of the gas spring is calculated by the number of times it can fully retract; the last is the change of the force value of the gas spring in the stroke, and the ideal gas spring should maintain the force value throughout the stroke. However, due to the factors of design and processing, the force value of gas spring in the stroke will inevitably change. And its change range is an important standard to measure the quality of an air spring. The smaller the change range is, the better the quality of air spring is, otherwise, the worse it is!
The working principle of this kind of spring is that inert gas is used as elastic medium, and oil (such as transformer oil and turbine oil each 50%) is used to seal and lubricate and transfer pressure. In fact, it is a variant of sleeve type air spring, which is also developed to further improve the elastic characteristics of sleeve air spring, It also has the general characteristics of air spring structure. The air spring is generally composed of cylinder, piston (rod), seal and external connector. High pressure nitrogen or inert gas and oil form a self loop in the cylinder. The damping on the piston makes the rod cavity and the rod free cavity communicate to make the pressure of the two chambers equal. Elastic force is produced by the difference of force area between two cavities and the compressibility of gas.
The gas spring has the advantages of light structure, long working stroke, smooth movement, damping and buffering function, stable and nearly unchanged characteristic line, simple operation, safety and reliability. But the processing cost is high.
According to the principle of sleeve type air spring, the force of air spring at any stroke s is as follows:
P-initial pressure in cylinder;
V-initial volume in cylinder;
A-sectional area of piston rod,