The suspension of the trailer suspension system is an important component connecting the chassis and the frame. The supporting force, braking force, driving force, etc. of the vehicle are all transmitted through the suspension system, and can also reduce the impact of bad roads on the vehicle to ensure the stability of the vehicle. It is self-evident that its importance. Generally, there are two types of suspension: independent suspension and dependent suspension. For semi trailers, they all use dependent suspension because of their strong bearing capacity. There are four types of suspension commonly used for semi trailers.
● Rigid suspension
Rigid suspension means that the left and right wheels are connected by one axle, and the body chassis directly acts on the axle. The shock absorption effect of this kind of axle is very poor. The longitudinal unevenness of the road is fully adapted to the swing of the balance beam, so as to maintain the relative balance of the front and rear axles.
At present, this kind of suspension is seldom used, and it is mainly used on the axle low flat semi-trailer carrying goods at low speed.
● Single point suspension
Single point suspension is to reduce the common front and rear supports of leaf spring to a single support and connect it to the vehicle body. Its stress points are shared on the front and rear axles. Compared with ordinary leaf spring suspension, single point suspension has a greater bearing capacity.
This kind of suspension is less used on ordinary semi-trailer and mainly used on heavy vehicles.
● Steel plate suspension
The steel plate suspension is our common steel plate spring. Its full name is tandem steel plate spring balanced suspension. It is mainly composed of leaf spring, suspension support (commonly known as lifting lug), connecting rod, U-bolt, etc. The longitudinal force of the body falls directly on an axle.
The biggest advantages of this suspension are its low price, good reliability and convenient maintenance. At present, more than 80% of domestic ordinary semi trailers use leaf spring balanced suspension.
● Air suspension
The most obvious feature of air suspension is its airbag type air spring. The air spring itself is relatively light, the air medium friction in the airbag is small, and there is almost no noise when working. Moreover, its service life is 2-3 times that of the leaf spring. However, when air spring is used, it is necessary to set up a bar system that can transmit various forces and moments other than vertical force, so the suspension structure is complex; In addition, the air spring has strict sealing requirements, and its cost is also high.
At present, the domestic trailer air suspension is mainly used in high-end fields such as precision instrument transportation, tobacco transportation, and hazardous chemical transportation.
