To say which kind of trailer suspension in the industry has received the most attention, I'm afraid it's air suspension.

Since January 2020, air suspension has been forced to be installed on all three axle grille and three axle breast board semi trailers in the domestic market, which greatly improves the application rate of air suspension on semi trailers.

Compared with traditional steel plate suspension, air suspension has obvious advantages:

1. Lighter weight. Air suspension takes air as the main medium, which is much lighter than steel plate material in weight. It can not only free up more weight space for vehicle owners for cargo transportation, but also save fuel, save energy and increase efficiency.

2. Better shock absorption effect. Compared with the traditional leaf spring, the air bag is obviously softer and more comfortable. It forms a soft connection between the frame and the axle, which can greatly alleviate the bumps and impacts from the road. In addition to enhancing driving comfort, it is also a kind of protection for goods.

3. The vehicle runs more smoothly. The elastic coefficient of the air spring, that is, the soft and hard of the spring can be automatically adjusted according to needs. When the vehicle is running at high speed, the air spring hardens to improve the stability of the vehicle. When encountering poor road conditions, the air spring softens to improve the comfort of the vehicle. In this way, it can better ensure the constant height of the trunk and is conducive to the protection of goods.

4. The axle can be lifted and lowered. The air suspension can realize the free lifting of the axle. On the one hand, it can reduce the height of the loading platform to facilitate the loading and unloading of goods. On the other hand, it can lift the designated axle when the vehicle is empty, which is conducive to reducing tire wear.

Generally speaking, the suspension with better damping performance tends to be less rigid, as is the case with air suspension. Although it can greatly improve the protection of goods, it has very strict restrictions on the transportation weight, which is not suitable for the transportation of heavy goods. In addition, the material is more easily damaged, and the anti roll characteristics are relatively poor. When encountering curves or sharp turns, it is easy to affect the safety of the vehicle itself, and it is also easy to affect the safety of other traffic participants.

Therefore, if air suspension wants to become the mainstream vehicle suspension, it also needs to overcome its own shortcomings. Hydro pneumatic suspension is one of the development directions of air suspension.

Strictly speaking, hydro pneumatic suspension is a kind of air suspension, and it is not a new suspension type. In the past, it has appeared more in large mining vehicles, multi axle special off-road vehicles, armored vehicles and other vehicles.

In terms of structure, the hydro pneumatic suspension has been further improved and improved on the basis of air suspension. It takes hydro pneumatic spring as the elastic element, inert gas as the elastic medium, and uses oil to transmit pressure. Through the compressibility of elastic gas and the damping characteristics of hydraulic system, it adapts to various operating conditions of vehicles, which is equivalent to adding an interconnected hydraulic system on the basis of air suspension.

In short, hydro pneumatic suspension almost integrates the advantages of steel plate suspension and air suspension. Its damping performance is basically equivalent to that of air suspension, with good cushioning capacity and good anti roll performance. Its stiffness is about 4 times or more than that of air suspension, and its load-bearing performance is better.

In addition, according to the relevant experimental data, the braking distance of hydro pneumatic suspension can be shortened by about 0.5-0.6m than that of air suspension, the transmission performance is more stable on uneven and rugged road conditions, the force on each axle is balanced, and the tire runout is relatively small, which can reduce tire damage.

The air spring of hydro pneumatic suspension has stronger sealing performance, and the forging of suspension guide arm has been further improved. It can match various axles, and there is no problem in matching with drum brake or disc brake.

Judging from the current industry trend, air suspension is more and more widely used. As its upgraded version, hydro pneumatic suspension is also believed to be gradually accepted by the market.