As we all know, at present, most of the three axle trailers newly licensed in China must be equipped with disc brake axle and air suspension, which makes many drivers complain that the disc axle can not brake the car, and the air suspension can not pull heavy load. It is not as durable as drum axle and leaf spring suspension.

So now, after the development of trailer manufacturing technology in recent years, is it still the same as what drivers say? Now let's see how many tons footwall axle and airbag suspension can pull.

Disc axle: according to the regulations GB7258 technical conditions for the safety of motor vehicles in operation, three axle grid type and breast board type semi-trailer shall be equipped with disc brake axle. Compared with drum axle, disc axle has technical and design advantages. The current disc brake axles are equipped with a clearance compensation mechanism, which is equivalent to the automatic adjustment arm of the drum brake axle, which can ensure the constant clearance between the friction plate and the brake disc, control the clearance more accurately, reduce the repair and maintenance costs, and improve the braking effect. Generally, there is a gap in the middle of the brake disc of the disc axle, which is more convenient for the heat dissipation of the brake disc and reduces the heat attenuation of the brake.

Disc brakes are generally divided into two structures: single push rod and double push rod. Compared with double push rod, single push rod has simpler structure, relatively small components, cheap natural price and light weight. However, single push rod brakes are generally used for vehicles with relatively small weight, while double push rod brakes have complex structure and large braking torque, which are generally used for medium and heavy vehicles, And the work is stable. Generally, the eccentric wear of friction plate rarely occurs.

From the above braking principle, we can see that the disc brake forms braking through the contact between the brake disc and the friction plate, and the braking clearance is a constant value, the braking torque is large, which can effectively shorten the braking distance and drive more smoothly; The brake disc adopts open design, with higher heat dissipation capacity and better thermal stability, which reduces the probability of braking failure caused by heat recession and effectively improves the safety and stability of driving. Moreover, due to its special structure, the disc brake axle is more convenient to replace the friction plate, which greatly reduces the maintenance cost.

Air bag suspension: the suspension is an important structure connecting the chassis and the frame. Almost all the weight of the trailer and goods should be transmitted to the frame through the suspension. As we all know, the steel plate suspension occupies an absolutely dominant position in the domestic commercial vehicle market. Its structure is simple, that is, several steel plates are stacked together to achieve the effect of shock absorption. This kind of suspension has the advantages of low price, high reliability and convenient maintenance, so it has won the favor of many card friends.

The structure of air bag suspension is much more complex than that of leaf spring suspension. It is composed of air bag, shock absorber, guide arm and other components. The air bag is used as an elastic component to connect the frame and axle. At the same time, the height of the frame can be adjusted by inflating and deflating the air bag. It can be seen that the shock absorption effect of air bag suspension is much better than that of leaf spring. As for the combination of drum brake bridge + leaf spring that the load-bearing of disc axle and air bag suspension is not as good as that of the previous drum brake bridge + leaf spring, the new national standard semi-trailer must be equipped with disc axle and air bag suspension, mainly for the main purpose of safety and resource conservation. Safety has always been the red line of the transportation industry, This kind of heavy trailer, especially in the hazardous chemicals industry, is not a small thing once except for accidents, and the impact range is very wide. At present, the state vigorously rectifies the problem of overload and overrun, which is also for safety. Although the leaf spring bears more weight, it can not be overloaded, and the goods should be transported according to the standard load.

The difference between disc axle and drum axle is only the difference of braking system, and the most important axle body is the same. Airbag suspension is designed according to the design tonnage and tested countless times before it is put on the market, so its bearing capacity is no doubt. Generally, when manufacturing trailers, trailer manufacturers will be equipped with trailer airbags and axles matching the bearing capacity. As long as we don't overload, there will basically be no problem. If the weight limit of the three axle railcar is 49 tons, the trailer airbag with the same configuration can certainly carry 49 tons. As long as we don't overload and use the trailer according to the regulations, the service life of the vehicle will be greatly increased and the cost of using and changing vehicles will be reduced.