【Case】Loading 60 Tons 560hp Dump Truck With Drop Axle Case

Our C84FGV54E3D13 8x4 dump truck and CX4FGV67E3D13 10x4 dump truck are customized for Pacific Island country to meet the needs of local use. They are very different from the standard trucks in China. We have improved many areas.

The demand put forward by the customer is high horsepower,  drop axle, the load capacity reaches 40-50 tons and 70 tons respectively, and there will be highway and non-paved road environment.

We first gave the options, using 8x4 and 10x4 chassis. The engines were determined to be 480hp and 560hp.

They are matched with a 12-speed transmission with crawler and overdrive gears. The 13-ton special steering front axle and double 16-ton wheel reduction axles are adopted. The tires are 13.00R22.5 vacuum tires with guide type tread pattern for the front wheels and drive type tread pattern for the rear wheels. The steel rim is thickened to 18mm.

Above are some basic data of the vehicle.

According to the clear needs of customers and market research, we have carried out targeted modifications and upgrades to the vehicles.

1. Electrophoresis: More than 90% of the structure of the chassis uses electrophoresis process or stainless steel and aluminum alloy materials.

Because the environment is relatively more humid, direct sunlight and seawater erosion and other effects, it is more prone to rust and corrosion. So we did electrophoresis for important chassis structural parts and parts that are more prone to erosion, changed part of the structure from cast iron to aluminum alloy structure, and added extra protection plates. For example, we used aluminum alloy gas tank and fuel tank, and the first traction cross frame, oil pan guard and some cast iron brackets of the vehicle were electrophoresed. The exhaust pipe at the rear of the cab is also made of stainless steel.

2. Newly designed 13-ton large-load front axle

The front axle of the American long head truck is further forward than that of the flat head truck, so it only bears the weight of components such as the engine, gearbox and cab, and the weight of the cargo is shared less. The multiple drop axles allowed in front of the drive axle provide protection for the frame and also share the weight of the drive axle. This is completely different from a flat head truck, for the same weight, the front axle of a flat head truck needs to carry more weight because they are closer to the cargo box. Therefore, for the front axle, we adopted a special front axle that can carry 13 tons. This kind of front axle is used in some mining trucks, so we redesigned some parts and defined new parameters to make them have the same flexible turning radius as trucks, which can meet the road transportation environment.

3. Brand new 9 ton drop axle with four tires and air suspension

In China, the standard drop axle has a load capacity of only 5 tons and only has two tires. Adopting variable section leaf springs and single airbag lifting structure, which is a product of Chinese regulations, does not meet customer needs, and long-term durability.

In order to meet heavy duty load capacity and economy requirement,  we redesign the drop axle of 9 tons, relies on airbags for shock absorption and lifting, and is equipped with 4 tires, and it is mounted in front of the drive axle. The process of designing this bridge was difficult.

The 9-ton axle load for a drop axle is difficult, we designed a stronger curved tube axle, along with a wider rear axle hub structure. So the whole drop axle is 120% heavier in dead weight than the traditional 5-ton drop axle. Therefore, the original variable-section leaf spring and single-Airbag lift suspension system did not have enough capacity to support and lift it.

We designed a new suspension structure for the strong capacity of the suspension, which consists of 3 small airbags and 2 main airbags. 3 small airbags are responsible for the lifting and lowering of the drop axle, and 2 main airbags are used as shock-absorbing suspensions when the frame is stressed. At the same time, we added another air storage tank to the compact chassis to ensure that there is sufficient air volume for use. Also, because lifting airbag and airbag suspension require different air pressure, we also added air line valves to the chassis to better control them.

The drop axle is mounted before the drive axle, for which we not only designed a new curved tube axle, but also redesigned the drive shaft angle to ensure that there is no interference either while driving or lifting. The new driveshaft angle also prevents resonance to ensure a safe and comfortable ride.

Stronger axles and more complex suspension structures require more space for installation, and a new air system is added, so we also need to redesign the structure of the frame to ensure they are properly installed and fixed. We didn't increase the length or height of the vehicle because of this.

4. 1200mm ultra-short rear suspension

The needs of customers are far beyond China's legal standards, and there will be many problems in the actual use process, the most typical of which is that the front wheels of standard Chinese trucks often leave the ground when the cargo box is lifted. So we shorten the rear suspension of the truck as much as possible, 1200mm is the most reasonable length in our opinion.

We need to take into account that when unloading cargo (such as sand), the cargo will slide off and cover part of the tire, causing resistance to the tire. The safety of taillights and other pedestrians and vehicles also needs to be considered. The 1200mm rear overhang can still ensure that the front wheel falls on the ground steadily when the cargo box is lifted by a maximum of 40°, and the falling cargo will not touch the tire or taillights. At the same time, there is enough safety distance between the solid rear bumper and the tires.

5. The new design does not add any size

In addition to improving the vehicle, we also took into account the cost of transportation. The improved vehicle does not have any size increase compared to the standard Chinese model.