Suspension, also known as suspension, is a general term for all force transmission connection devices between the semi-trailer frame and the axle, which is used to transmit the force and torsion acting between the wheels and the frame, buffer the impact transmitted from the road surface to the frame or body, and reduce the vibration caused by it to ensure that the car can drive smoothly.

In general, the suspension of semi-trailers can be mainly divided into four types:

1. Rigid suspension.

The rigid suspension body chassis acts directly on the axles between the wheels, there is no spring as a buffer, and it depends on the swing of the balance beam to keep the relative balance of the front and rear axles.

This kind of suspension is relatively rare at present, because its shock absorption effect is very poor, mainly used in low-plate semi-trailers that carry goods at low speeds.

Steel plate suspension.

Also known as tandem steel leaf spring balance suspension, that is, the common leaf spring suspension, which is mainly composed of leaf springs, suspension supports, connecting rods, U-bolts, etc.

The biggest advantage of this trailer suspension is low cost, reliable work and convenient maintenance.Because of this, steel plate suspension is currently used in the largest proportion of domestic semi-trailers, about 70-80%.

3. Single-point suspension.

That is, the common leaf spring before and after the bracket reduced to a single bracket connected to the body, the point of force can be divided into different axles, so a larger load-bearing capacity, generally used in heavy trailers.

Air suspension.

Also known as airbag suspension, its most notable feature is the airbag-type air spring, compared with other suspensions, the air suspension buffer force is better, can effectively protect goods, improve driving comfort, at present, it is mainly used in the transportation of precision instruments and dangerous chemicals.

According to the technical conditions for motor vehicle operation safety GB7258-2017, three-axle railing plate and warehouse grille semi-trailers must be equipped with disc brakes and airbag suspension to smoothly go on the plate or on the road.So what exactly is good about air suspension?

Advantages of air suspension:

1. Good shock absorption. Compared with the traditional leaf spring, the air bag is obviously softer and more comfortable. It makes a soft connection between the frame and the axle. The bumps and impacts from the road surface can be relieved to a great extent, besides enhancing driving comfort, it is also a kind of protection for goods.

2、减小载荷应力。空气的可压缩性，使气囊悬挂在轻松应对路面颠簸的同时，可以减小载荷应力，延长车桥和半挂车的使用寿命，一定程度上减少用车成本。

3. Less weight. Lightweight is a development trend in the trailer accessories industry, air suspension compared with traditional suspension, its own weight is lighter, for standard users can get more free weight space, no-load users can save fuel, energy saving and efficiency.

4. Long life. The quality of the air spring itself is relatively light, air bag friction is also relatively small, the service life can reach the leaf spring 2-3 times, help the owner to better save costs.

Air suspension has many advantages, but objectively there are also some disadvantages:

1. Compared with other suspensions, the air suspension structure is more complex, because to use the air spring, must be able to transfer all kinds of other forces and torques other than the vertical force, this also contributes to its relatively high price.

2. Corresponding to the high price is the maintenance cost.In addition, compared with traditional leaf springs, airbags are more easily damaged in material, and the maintenance cost cannot be underestimated.

3. Once the air suspension fails, it cannot continue to drive, and can only call a trailer service.Unlike traditional suspension, even oil leaks can stick to the repair outlet.

4、空气悬挂缓冲性好，但在满载情况下，刹车或者起步时会出现点头或拖尾，还需要熟练的驾驶技术。

Although the advantages and disadvantages of air suspension, but the overall consideration of the advantages or more obvious, or air suspension will not become the official required suspension. In addition, the commercial vehicle industry is now“Lightweight” prevalence, shippers for cargo damage more and more attention, the competition among peers is becoming more and more intense, this industry background also to some extent to promote the use of air suspension.

Suggest owners in the purchase of air suspension as far as possible to choose a reliable brand, which can to some extent reduce the cost of follow-up maintenance replacement. The air suspension produced by DARONG machinery consists of air spring, shock absorber, height control valve, guide arm, follow-up steering mechanism, etc. , the special seal can ensure the temperature of the suspension, prolong the service life, the assembly design of the parts is more flexible, the installation time is shorter, and the maintenance can be carried out according to the actual situation to reduce the maintenance cost.