Braking safety has always been a concern for car owners. For freight vehicles, the load capacity is usually relatively large, and the inertia effect during braking is also strong. Especially on road sections that require continuous braking, the brakes often generate heat and heat due to frequent braking. A water-cooled axle is a product that addresses the phenomenon of brake overheating.

The water-cooled axle first appeared in the public's view around 17 years ago and was considered a relatively novel invention at that time. The full name of water-cooled axle is water-cooled circulating axle, which is composed of a water storage tank, a radiator, and several pipes. When it works, the water in the water tank is driven by an electric water pump, which enters the wheels at both ends through pipes in the axle shaft. Then, it enters the interlayer of the brake drum through a water distributor to play a cooling role, and then returns to the water tank through the water distributor and pipes, repeating the cycle.

The principle of a water-cooled axle is simply equivalent to cooling by spraying water. It only circulates the water internally and does not need to be directly poured onto the brake drum. After cooling the brake drum with cold water, it can be returned to the water tank again, without directly pouring it onto the ground or adding water frequently. It is simpler and more convenient to use, and can also be used normally in areas where water spraying devices are disabled.

It sounds quite practical, but why hasn't water-cooled axles been widely promoted? In fact, this is mainly due to two levels of reasons.

Firstly, objectively speaking, the introduction of the new version of GB7258.

In September 2017, the new version of GB7258 was introduced, which clearly required the installation of a disc axle and air suspension for the three axle guardrail and three axle grille. This regulation directly poured cold water on the water-cooled axle that appeared in the same year. After all, the possession of the three axle guardrail and three axle grille in the market is very considerable, and the structure and performance of the disc axle are not suitable for using cold water cooling devices. Once these models exit the drum axle market, The target user group for the water-cooled circulating axle naturally decreased by a large number.

Secondly, subjectively, the technology of water-cooled axles is not mature enough.

The principle of a water-cooled circulating device may sound feasible, but the question is, how can the monitoring of the internal circulation of the water-cooled device be completed during actual use? How do car owners know if the water flow inside the device is unobstructed? Once the pipeline is blocked and the water flow stops, there is no way to talk about cooling down. In addition, will the water inside the water-cooling device freeze in severe cold weather? How to achieve circulation once it freezes?

Even if the circulation of the water cooling device is not a problem, how can the temperature of the water flow sealed inside be monitored? Especially with the water returning from the brake drum to the water tank, will the water temperature rise after cooling the brake? How much will it rise? Will the water tank boil directly after multiple cycles?

Although the official has provided answers to these series of questions, they still leave car owners with doubts. To dispel these doubts, the market needs to test them. However, the problem is that no car owner wants to be a Duplicant, so most of them turn around and choose more mature hydraulic retarders.