The most popular type of trailer axle in the market is the disc axle. Since the promulgation and implementation of the national standard of gb7258-2017 safety technical conditions for motor vehicles, the three-axle fence and the bin grid semi-trailer are required to be installed with the disc brake bridge and air suspension. In addition, the gradual popularity of the light-weight trend in the trailer industry has made more and more vehicle owners focus on the disc type axle.

Disc axle is not a new product, but it has been more used in passenger cars in the past. Compared with the drum type axle, the biggest characteristics of the disc type axle are light weight, fast heat dissipation, sensitive response, and strong resistance to heat and water attenuation.

Correspondingly, the brake friction area of the disc axle becomes smaller, the braking force is weaker than that of the drum axle, and the temperature rise speed is faster than that of the drum axle, and the water can not be poured to cool down. Also for these reasons, many car owners have raised doubts about the promotion of disc axles.

·Query on common disc axle

1. Can't the brake of the disc axle stop the car?

Although the braking force of the disc brake bridge is weaker than that of the drum brake bridge, the braking force of ordinary standard load transport vehicles used in compliance, such as three-axle fences or storage grids, is quite enough. Of course, it is another matter in the case of overload or overspeed.

In addition, although the brake force of the disc axle is small, its brake response speed is incomparable to that of the drum brake bridge. When the owner steps on the brake, he can almost immediately push the caliper brake, which can provide more timely braking force output.

For trailers that need to transport heavy goods, or trailers that often run on mountain roads, they can be used together with auxiliary braking devices such as hydraulic retarders. On the one hand, the liquid retardation can make up for the lack of braking force of the disc brake bridge; on the other hand, the response speed of the disc brake bridge can give full play to the function of the liquid retardation. In this way, the super combination of fast braking reaction speed, strong braking force and more stable and reliable braking can be realized.

If ABS and EBS systems are installed on this basis, wheel locking can be prevented in case of emergency braking, and the trailer can stop smoothly in the shortest distance, which is far better than the drum axle.

2. Does the disc axle heat up too fast?

Although there is no doubt that the temperature of the disc brake bridge rises rapidly during continuous braking, we should not forget that the brake discs and friction plates of the disc brake bridge are directly exposed in the air, and the heat dissipation speed is also very fast. Especially in the process of vehicle driving, the rapid flow of air can make the disc brake bridge obtain a faster heat dissipation speed, because generally, overheating will not occur.

Moreover, the anti heat attenuation performance of the disc brake bridge is also higher than that of the drum axle. According to the comparison of experimental data, the friction coefficient of drum brake will decrease by 40% - 50% when the friction plate temperature reaches more than 300 ℃; When the temperature of the disc brake friction plate rises from 100 degrees to 400 degrees, the friction coefficient hardly changes, and the braking force output is relatively stable.

3. The disc axle is easily damaged by water

When there is no auxiliary device for the disc axle, in case of long downhill and other situations requiring long-time continuous braking, especially when the vehicle load is relatively large, the temperature of the brake disc and the friction plate is very obvious. If the brake disc is directly sprayed with cold water when it is red, the temperature will drop by several degrees instantaneously, which may easily lead to the damage of the brake disc. So some car owners worry: isn't it easy to break the disc brake bridge on rainy days?

Compared with the instantaneous large amount of cold water poured on the red brake disc, the water drenching on the axle in rainy days is continuous, uniform and non centralized, so the brake disc will not be damaged.

In addition, after the trailer wades, the performance of the disc brake can be restored immediately after one or two times of braking, but the drum brake can be restored after more than ten consecutive times of braking. From this point of view, the disc axle is also better than the drum axle in terms of water attenuation resistance.

·Specifications of Darong disc axle

·Advantages of Darong disc axle

1. Better raw materials

The 20 Mn2 high-strength alloy seamless steel pipe with a wall thickness of 10-11 mm is selected for Darong car bridge. Compared with ordinary steel pipe, it has better tensile strength, yield strength, impact toughness and other properties, and is not easy to crack during processing and use.

2. The whole production process is controllable

With its own factory, the whole production process is subject to unified and strict quality control. There are 15 production processes, from the internal mechanical properties of steel to the external dimensional accuracy, which fully meet the requirements of the national standard.

3. Strict quality inspection procedures

The quality inspection process starts from raw materials and covers every link of design, production and testing. At the same time, quality inspection workshops such as fatigue test, salt spray test and magnetic particle flaw detection test of shaft body are set up, and high-precision instruments are equipped to accurately test the stress limit of the axle to ensure that fatigue failure does not occur during the service period.

4. Accessories selection

The accessory brands adopted by Darong axle have been deeply cultivated in the industry for many years, and the quality has been baptised and tested by the market, with corresponding quality assurance capability. In addition, Darong has to carry out a series of quality inspection procedures for it. It can be put into use only after it is qualified, which is equivalent to providing a layer of guarantee for quality.

5. After sales warranty

The axle is a consumable part of the vehicle. If there is no special after-sales service, the subsequent maintenance is very difficult. The axles, axles and accessories of Darong group are equipped with warranty service commitment, and a special after-sales team is established to track the use of users and help customers solve product related problems. Darong automobile bridge has entered the market for 20 years, and its cooperative customers are all over the world, always maintaining zero quality disputes.

6. Custom production

In order to meet the different tonnage, track and parameters of users in the axle field, Darong launched the axle customization service, designed drawings according to the actual use needs of customers, and then customized production. Accessories such as wheel hubs, brake drums and bearings can also provide diversified options.

·Application field of Darong disc axle

1. Three axle fence / bin grid vehicle: these two types of trailers are the vehicles that must be equipped with disc axle as specified in gb7258-2017 national standard for safety technical conditions for motor vehicle operation, which will affect the registration or driving on the road.

2. Precision instrument / valuables transport vehicle: the particularity of this kind of goods has strict requirements on vehicles and transport process. The brake of the disc axle is sensitive and more stable, which can avoid collision or large amplitude vibration of goods during transportation.

3. Dangerous goods transport vehicles: compared with ordinary goods vehicles, dangerous goods transport vehicles have a higher risk coefficient. The use of disc axles can minimize accidents caused by uneven distribution of vehicle braking force and slow brake heat dissipation.

4. Mountain transportation: compared with ordinary freight routes, the road conditions of mountain transportation are worse, and the requirements for the braking system are very high. If the disc axle is equipped with the hydraulic retarder and ABS / EBS system, it can not only make the vehicle stop smoothly in a shorter distance to achieve the best braking effect, but also prolong the service life of the friction plate and reduce tire loss. At the same time, it can reduce the dead weight of the vehicle, fully save energy and reduce consumption, and save the cost of comprehensive vehicles.