1. basic concepts and principles

The air spring (air bag) is filled with compressed gas in a sealed container (the air pressure is 0.5 to 1Mpa), and the spring function is realized by the compressibility of the gas. In this way the air bag has an ideal elastic property. When the rubber air spring works, the inner cavity is filled with compressed air to form a compressed air column. With the increase of vibration load, the height of the spring decreases, the volume of the inner cavity decreases, the stiffness of the rubber spring increases, and the effective bearing area of the inner air column increases, so the bearing capacity of the rubber spring increases. When the vibration load decreases, the height of the rubber spring increases, the volume of the inner cavity increases, the stiffness of the rubber spring decreases, and the effective bearing area of the inner air column decreases, so the bearing capacity of the rubber spring decreases. In this way, the height, inner cavity volume and bearing capacity of the air spring in the effective stroke increase with the increase and decrease of the vibration load. In addition, the stiffness and bearing capacity of the spring can be adjusted by the method of increasing and reducing the amount of gas, and the auxiliary gas chamber can be attached to realize self control and adjustment.

2. classification

The air spring is divided into three kinds, namely, the capsule type mixed type capsule type and the membrane type mixed type, according to the working deformation mode. The bag type air spring mainly depends on the deflection of the rubber gasbag to get elastic deformation. The membrane air spring mainly depends on the curling of the rubber air bag to get the elastic deformation. The hybrid air spring has two kinds of deformation modes. The capsule air spring is divided into single, hyperbolic and multi curved air springs according to the difference of the number of rubber gasbags. The structure of the membrane type air spring is to place a cylindrical rubber gasbag between the cover plate and the base, which can be telescoped through the deflection of the air bag. In the normal working range of the membrane air spring, the stiffness of the spring is smaller than that of the capsule, and it can also be operated in the normal working range of the membrane air spring.

3. airbag locking system and unlocked system

The 1. airbag of the airbag locking system is called the locking system if it is not connected to the gas source to control the height of the air valve or the valve device. The system uses a fixed amount of gas as an elastic media. A certain amount of gas is enclosed in the system, and the amount of gas is kept constant when it is pressed and bounced. Unlocked system of 2. airbags

2. airbags are connected to the gas source through high control or other air valve devices, which are called unlocked systems. The air bag can keep the same volume at the height of the design at the height of the design, whether at rest or under pressure. Now this system is most commonly used. Under the fixed condition of the high valve, the load and the elastic coefficient vary with the change of the pressure of the fixed gas. In this system, the extra pressurized gas can keep the air bag high, even if the load of the air bag is changed. In this way, due to the change of the load, the natural vibration of the system is fixed, so the natural vibration is more fixed than the locking system. In a word, the natural vibration frequency of the system does not change with the change of the load.
 

4. advantages of air bag

1. the elastic elastic coefficient of spring can be controlled.

2. the load carrying capacity can be adjusted.

3. easy to achieve high control;

4. reduce friction;

5. conforms to the change, but the natural frequency is basically the same.