Introduction of Truck and Bus Wheel Rims

As a sub-industry of the automobile industry, trucks and buses serve a wide range of industries such as passenger transportation, road?transportation, engineering construction, energy, mining, forestry and construction, as well as national defense. They?play?a very important position and role in the national economy.

Automobile wheel rims are one of the important parts of trucks and buses.

The Automobile wheel rim is a rotating part bearing load between tires and an axle. The wheel disc is fixed on the axle through tire bolts to support tires.

The specification series of wheel rims comply with the?China national?standard GB / T3487-2005 and refer to the international standards ISO4000-2:2001 and ISO4209-2:2001.

According to the different materials used, rims can be divided into two categories: steel wheel rims and aluminum alloy wheel rims.

1. Steel wheel rims

At present, most rims are made of special steel, and steel rims occupy a dominant position in automobile?rims.

The advantage of steel rims is low cost, but the disadvantage is that the manufacturing process determines that it is difficult to achieve diversification of structures and shapes.

According to different rim structures, steel rims can be divided into tubeless rims (one-piece plate rims) and tube steel rims (multi-piece rims).

1) Tubeless steel rims

As shown in Figure 1 below. Tubeless wheels are composed of a rim and adisc, and are manufactured using special steel plates through processes such as rounding, welding, and rolling.

Tubeless rims have good roundness, surface finish and sealing. It is mostly used in passenger cars and long-distance trucks.

(Figure 1, Tubeless rims)

Choosing the correct rim model needs to be based on the following parameters:

Wheel load, tire model matched, disc installation parameters (bolt hole number, bolt hole type, PCD, CBD) and offset.

Rated load and tire model matched of a common tubeless rim are shown in Table 1 below.

(Table 1. Parameter of tubeless wheel load and tire model )

There are two Installation and positioning methods of discs of tubeless wheels: center hole positioning and tire nut positioning.

The relevant parameters of a center hole positioning a disc are:?the number of bolt holes, the pitch circle diameter of bolt hole?(P.C.D), and the center hole diameter( C.B.D). As shown in Table 2 below (unit: mm).

(Table 2. Parameters of a center hole positioning a disc)

The relevant parameters of nuts positioning a discs are: the number of bolt holes, the pitch circle diameter of bolt hole (P.C.D), and the center hole diameter( C.B.D). As shown in Table 3 below (unit: mm).

(Table 3. Parameters of nut positioning discs)

2) Tube steel wheel

As shown in Figure 4 below. A tube steel rim consists of a rim, a disc and a lock ring, and is manufactured using special steel through processes such as rounding, welding, and rolling.

Due to the use of lock rings, the tube steel rims cannot achieve the tightness of compressed air and must be used with tires with inner tubes. The tube steel rims are easy to disassemble tires and are mostly used on low-speed trucks and heavy short-distance trucks.

(Figure 2, tube wheel)

Common tube wheel loads and standard tire model parameters are shown in Table 4 below.

(Table 4. Wheel load and tire model parameters of tube steel wheel)

There are two installation and positioning methods of discs of tube rims: center hole positioning and tire nut positioning.

The relevant parameters of a center hole positioning a disc are: the number of bolt holes, the pitch circle diameter of bolt hole (P.C.D), and the center hole diameter( C.B.D). As shown in Table 2?above (unit: mm).

The relevant parameters of nuts positioning a discs are: the number of bolt holes, the pitch circle diameter of bolt hole (P.C.D), and the center hole diameter( C.B.D). As shown in Table 3 above (unit: mm).

2. Aluminum alloy rims

As shown in Figure 3 below. In recent years, alloy rims are more and more widely used in the world. The total output of?aluminum alloy rims produced in China remains at about 60% in the world.

(Figure 3,?aluminum alloy wheels)

Compared with traditional steel rims, aluminum alloy rims mainly have the following advantages:

A. Lighter weight

The weight of an aluminum alloy rim is about 1/2 of that of a steel rim. Taking a?rim model 22.5x8.25 as an example, the weight of the aluminum alloy rim is about 24KG, and the weight of the steel rim is about 48KG.

B. Rims are stronger

Tested by VIA Japan, the deformation resistance of aluminum alloy rims is about 5 times that of steel rims.

C. Longer tire life

Aluminum alloy rims dissipate heat quickly, which can effectively reduce tire temperature and prolong service life of tires.

D. The maintenance cost of the brake system is lower

Aluminum alloy rims dissipate heat quickly, which can reduce the temperature of the brake system, which makes the axle maintenance cycle longer, thereby reducing maintenance costs.

E. Wheels travel more smoothly

An aluminum alloy rim is integrally formed in one piece, and there are no problems of assembly and welding. At the same time, the machining precision is as high as 0.05mm, and the precision is higher. Therefore, the roundness and dynamic balance of the rims are better, and the rolling resistance during the driving of the vehicle is reduced, so that the driving of the vehicle is more stable.

F. Wheels are more beautiful

The aluminum alloy rim processing adopts specially customized diamond cutters and high-speed electric spindle finishing equipment, so that the appearance of the product can reach the mirror level.

The existing models of aluminum alloy rims basically cover steel tubeless rims. The main model parameters are shown in Table 5 below.

(Table 5. Parameters of common aluminum alloy wheels/rims)

Remark: The model expressions of the wheel are as follows:

1) Tubeless wheels and aluminum alloy wheels. As shown in Figure 4 below:

(Figure 4, description of tubeless wheel model)

2) Tube steel wheels. As shown in Figure 5 below:

(Figure 5, description of tube wheel model)

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