The tire itself is soft, and the inner part of the tire supporting the tire is a barrel-shaped, center-mounted component called the hub.

Wheel hub
The same diameter, but the width is different, there are opposite, but the two data hubs are different, suitable for different tires. Some people think that the original tire is not high enough,
If you want to upgrade, it is often to widen, reduce the aspect ratio, increase the diameter, and change the material. At this time, if you must change the wheel, it is called a modified wheel.
In the past, the most common hub bearings for cars were single-row tapered roller or ball bearings. With the development of technology, car wheel units have been widely used in cars. wheel
The use range and usage of hub bearing units are increasing day by day, and have developed to the third generation: the first generation is composed of double row angular contact bearings. The second generation has one on the outer raceway
The flange used to fix the bearing can simply fix the bearing on the axle and fix it with a nut. Makes car maintenance easier. The third-generation hub bearing unit uses a shaft
The bearing unit cooperates with the anti-lock brake system. The hub unit is designed with an inner flange and an outer flange. The inner flange is bolted to the drive shaft, and the outer flange installs the entire bearing in a
Up.
2. Types of wheels
The hub is also called the rim. According to the characteristics and needs of different models, the surface treatment process of the hub will also adopt different methods, which can be roughly divided into two types: baking paint and electroplating. general
The wheels of the common car models are less considered in appearance, and good heat dissipation is a basic requirement. The process is basically treated with baking paint, that is, spraying and then baking, the cost is more economical
And the color is beautiful, and it lasts for a long time. Even if the vehicle is scrapped, the color of the wheel remains unchanged. The surface treatment process of many Volkswagen wheels is painted, such as Santana
2000, Xiali Junya, Time Pride, Southeast Lingshuai or Honda Odyssey. Some fashionable and avant-garde, dynamic color wheels also use paint technology. This type of wheel
The hub price is moderate and the specifications are complete. The electroplated wheels are divided into silver electroplating, water electroplating and pure electroplating. Although the silver-plated and water-plated wheels are bright and vivid, they remain
The time is relatively short, so the price is relatively cheap, which is liked by many young people who pursue freshness. The market price is between 300 yuan and 500 yuan. Pure electroplated wheels, such as Shanghai GM
The original Buick GL8 produced by the factory is equipped with pure electroplated wheels, which have a long color retention, which can be said to be high quality and high price. High-end cars such as Guangben and Audi use pure plating
Wheels, the price is about 800-900 yuan.
Wheels (20 photos)
3. Wheel classification
Wheel hubs can be divided into two categories according to their materials: steel wheels and alloy wheels.
At present, the original wheels on the market can be divided into steel wheels and alloy wheels according to their materials.
The main advantages of steel wheels are that the manufacturing process is simple, the cost is relatively low, and the ability to resist metal fatigue is very strong, which is what we commonly call cheap and strong.
However, the disadvantages of steel wheels are relatively prominent, that is, they are ugly in appearance (it can be said that there is no appearance at all), and they are heavier (the same wheel steel material is heavier than aluminum alloy material)
Many), the inertial resistance is large, the heat dissipation is relatively poor, and it is very easy to rust.
Relatively speaking, alloy wheels can just make up for such problems. Lighter weight, low inertial resistance, high manufacturing accuracy, and small deformation during high-speed rotation,
The small inertial resistance is helpful to improve the straight-line driving performance of the car and reduce the rolling resistance of the tire, thereby reducing fuel consumption. The thermal conductivity of alloy materials is three times that of steel.
Right, the heat dissipation is good. For the braking system of the vehicle, the thermal attenuation of the tires and the braking system can play a certain role. At present, the alloy wheels of the original cars on the market have been aluminum alloy
Gold-based, of course, many modified wheels will choose chromium, titanium and other elements as the basic materials in order to achieve certain special requirements and visual enhancement. However, with steel wheels ¤q
Compared with alloy wheels, the price is much more expensive, so in many low-end and original-class cars, steel wheels will appear on low-end models, while alloy wheels
It is standard for high-end models.
1 The main advantages of steel wheels are simple manufacturing process, relatively low cost, and strong resistance to metal fatigue. But the shortcomings are also obvious, such as heavy weight, large inertial resistance,
Poor heat dissipation, etc.
2 The advantages of alloy wheels are light weight, high manufacturing accuracy, high strength, low inertial resistance, strong heat dissipation capacity, good visual effect, etc. The disadvantage is that the manufacturing process is complicated,
high cost.
The alloy wheels are mostly made of aluminum, with appropriate addition of metal elements such as manganese, magnesium, chromium, and titanium. Compared with steel wheels, alloy wheels are energy-saving, safe and comfortable
Characteristics, so more and more cars have listed alloy wheels as standard. Let's take a look at the three major characteristics of alloy wheels.
1 Energy saving The alloy wheels are light in weight, high in manufacturing accuracy, small in deformation during high-speed rotation, and low inertial resistance, which is beneficial to improve the straight-line driving performance of the car and reduce
Tire rolling resistance, which reduces fuel consumption.
2 Safety The thermal conductivity of aluminum alloy is three times that of steel, and the heat dissipation effect is very good, thereby enhancing the braking performance and improving the service life of tires and brake discs.
Ensure the safe driving of the car.
3 Comfort Cars with alloy wheels generally use flat tires with better cushioning and shock absorption performance than ordinary tires, making the car run on uneven roads or at high speeds
Time, comfort is greatly improved.

Several alloy wheels

1. Multi-piece alloy wheelMulti-piece alloy wheels s
Multi-piece alloy wheels are available in two-piece and three-piece styles. Several parts of the hub are manufactured by forging and spinning processes, and then connected by titanium bolts. These products are light in weight,
High strength and superior performance, but expensive, mainly used in various championship racing cars and high-end luxury cars. In all levels of global car racing, whether it is a car or a motorcycle
Cars, no matter under what conditions, require the vehicle to accelerate from zero to 100km/h in just 3s, so the wheels need to be able to withstand on the track due to the extremely high
The lateral acceleration, extremely high operating speed and harsh conditions caused by overloaded operating conditions, as well as the impact of temperature rise caused by strong tire wear, in this
In this environment, the multi-piece aluminum wheels have withstood the test of various difficult environments. Although the product quality is light, due to the use of advanced manufacturing technology, the product structure has high strength,
The multi-piece combination shape gives a thick and firm feeling.

2. One-piece racing alloy wheels
F1 racing requires the use of single-piece wheels. In order to ensure the performance of the wheels and the requirements for vehicle weight reduction, the forged blanks are usually used and then formed by the spinning process.
In order to ensure the high performance and the lightest weight of the product, compared with the cast alloy wheels of the same specification, the mechanical properties are improved by more than 18%, and the quality can be reduced by about 20%.
The one-piece alloy wheels specially designed and manufactured for F1 racing cars have withstood the test of various difficult environments. However, the alloy wheels of passenger cars are not like the performance requirements of racing cars.
Such harsh, integral low-pressure cast alloy wheels are sufficient to meet their performance requirements, but passenger cars pay more attention to the appearance and aesthetic design of alloy wheels. Subject to racing
The impact of sports and the requirements of energy saving and aesthetics, automotive alloy wheels are also changing, more sporty large diameter, soft spoke alloy wheel design and lightweight
The design of alloy wheels is the main development trend and direction of automobile alloy wheels.

3. Built-in air alloy wheels
In order to minimize the quality of the wheel hub, a new concept of a new type of lightweight alloy wheels with built-in air alloy wheels came into being, and further through cavity technology
Reduce the quality of the hub. This alloy wheel is divided into one-piece and two-piece combination. The single-piece built-in air alloy wheel uses cavity technology to integrate all the spokes and wheels of the wheel.
The inner and outer shoulders of the rim are made with cavities, which greatly reduces the quality of the hub. Compared with the structural alloy wheel, the weight is reduced by 20%, but the performance is greatly improved.
The two-piece built-in air alloy wheel hub is made into a cavity at the inner shoulder of the wheel rim, which greatly reduces the quality of the wheel hub, compared with the same structure alloy wheel hub
It weighs 5% and improves the performance of the product. This type of alloy hub is made of cast blanks, and the cavity is manufactured using a spinning process.

4. Manufacturing method

There are three methods for manufacturing aluminum alloy wheels: gravity casting, forging, and low-pressure precision casting.
1. Gravity casting method The aluminum alloy solution is poured into the mold by gravity, and then processed by the lathe after grinding to complete the production. The manufacturing process is simple and does not require precision
The dense casting process has low cost and high production efficiency, but it is easy to produce bubbles (trachoma), uneven density, and insufficient surface smoothness. Geely has a considerable number of models
It is the wheels produced by this method, mainly the early production models, and new models have been replaced with new ones.

2. Forging method The whole aluminum ingot is directly extruded on the die by a thousand-ton press, which has the advantages of uniform density, smooth and detailed surface, thin and light hub wall, and material
The strength is the highest, more than 30% higher than the casting method, but due to the need for more sophisticated production equipment, and the yield rate is only 50 to 60%, the manufacturing cost is higher.

3. Low-pressure precision casting method Precision casting at low pressure of 0.1Mpa, this casting method has good formability, clear outline, uniform density, and smooth surface, which can achieve
High strength, light weight, and cost control, and the finished product is more than 90%, is the mainstream manufacturing method of high-quality aluminum alloy wheels.

5 hub frame
Wheel hub
1. Wheel rim: fit with the tire assembly to support the wheel part of the tire.
2. Spoke: Install and connect with the axle hub to support the wheel part of the rim.
3. Offset: the distance between the center surface of the rim and the installation surface of the spokes. There are positive offset, zero offset, and negative offset.
4. Rim: keep and support the rim part in the direction of the tire.
5. Bead seat: It is in contact with the tire bead and supports the rim part that maintains the tire radial direction.
6. Groove bottom: To facilitate tire assembly and disassembly, a certain depth and width of pits are left on the rim.
7. Valve hole: the hole to install the tire valve.

6 Picking elements to pick
There are three factors to consider when choosing a wheel.
size
Don't blindly enlarge the wheels. Some people increase the wheels to improve the performance of the car. Under the condition that the outer diameter of the tire is unchanged, the big wheel must be matched with wide and flat tires.
The swing to the side is smaller, the stability is improved, and when the corner is turned, it is like a dragonfly, and it passes lightly. However, the flatter the tire, the thinner the thickness, the worse the shock absorption performance, and the comfort
Big sacrifices will be made. In addition, there are slight roadblocks such as stones, and the tires are easily damaged. Therefore, the cost of blindly increasing the wheels cannot be ignored. Generally speaking, according to
It is most suitable to increase the size of the original wheel hub by one or two.
Three distance
This means that when choosing, you can't choose your favorite shape as you like, but also follow the advice of the technician to consider whether these three distances are appropriate.
shape
The complex and dense wheels are indeed very beautiful and appear to have grades, but it is easy to be refused or overcharged when washing the car, because it is too troublesome to wash. Simple
Instead, the wheels are dynamic and clean. Of course, if you are not afraid of trouble, it's okay. The aluminum alloy wheels that are deeply rooted in people's hearts nowadays are similar to the iron cast wheels in the past
Compared with it, the degree of deformation resistance has been greatly improved, the weight has been greatly reduced, the power loss of the car is small, it runs fast, it is fuel-efficient and has good heat dissipation, and it is loved by the majority of car owners. Want here
As a reminder, in order to cater to the tastes of car owners, many car dealers replace the iron wheels with aluminum alloy wheels in advance before selling the car, but they add one to the price.
pen. Therefore, from an economical point of view, do not care too much about the material of the wheels when buying a car. Anyway, you can change it according to your own style, and you can save one on the price.
Pen, why not do it?

7. Basic parameters
A wheel includes many parameters, and each parameter will affect the use of the vehicle, so before modifying and maintaining the wheel, first confirm these parameters.
size
The size of the hub is actually the diameter of the hub. We often hear people say 15-inch wheels and 16-inch wheels. Among them, 15 and 16 inches refer to the wheels.
The size (diameter) of the hub. Generally, in a car, if the wheel size is large and the flatness ratio of the tire is high, it can have a good visual effect of tension and it can be controlled by the vehicle.
Stability will also increase, but with it comes additional problems such as increased fuel consumption.
width
The width of the hub is also commonly known as the J value. The width of the hub directly affects the choice of tires. For tires of the same size, the J value is different, and the selected tire flatness ratio and width are not
with.
PCD and hole position
The professional name of PCD is the pitch circle diameter, which refers to the diameter between the fixing bolts in the center of the hub. The general hole of the hub is 5 bolts and 4 bolts.
The distance is also different, so we can often hear the names 4X103, 5X114.3, 5X112. Taking 5X114.3 as an example, it represents the PCD of this wheel
It is 114.3mm with 5 bolts in the hole. When choosing a wheel, PCD is one of the most important parameters. For safety and stability, it is best to choose PCD and
The original wheels of the original car are upgraded.
Offset
English is Offset, commonly known as ET value, the distance between the fixed surface of the hub bolt and the geometric center line (the center line of the hub cross section), to put it simply, the hub screw
The difference between the wire fixing seat and the center point of the entire rim is popularly said to be whether the hub is retracted inward or protruded outward after the modification of the hub. For ordinary cars, the ET value is positive, right
A few vehicles and some jeep vehicles are negative. For example, the offset value of a car is 40. If the wheel of the ET45 is replaced, it will be more visually retracted than the original wheel.
Inside the arch. Of course, the ET value not only affects the visual change, it also has a relationship with the steering characteristics of the vehicle and the wheel positioning angle, and the offset value that is too large may be
As a result, the tires wear abnormally, the bearings are easy to wear, and even they cannot be installed normally (the brake system and the hub cannot rotate normally due to friction with each other). In most cases, the same
Wheels of the same style of a brand will provide different ET values ​​to choose from. Comprehensive factors must be considered before modification. The most safe case is before the brake system is not modified.
To mention, keep the ET value of the modified wheels the same as the original ET value.
Center hole
The center hole is used to fixedly connect with the vehicle, which is the position where the center of the hub is concentric with the hub. The diameter here affects whether we can install the hub
In order to ensure that the geometric center of the rim can coincide with the geometric center of the hub (although the hub positioner can convert the hole distance, this modification has risks, and netizens need to try it carefully).
8. Installation attention
Please pay attention to the following items in the use and installation of wheel bearings:
1. In order to ensure the maximum safety and reliability, it is recommended that you always check the wheel bearings no matter how long the vehicle is-pay attention to the early warning of bearing wear
Signals: including any friction noise during rotation or abnormal deceleration of the suspension combination wheel when turning. For rear-wheel drive vehicles, it is recommended that the front wheel bearings should be lubricated when the vehicle travels to 38,000 kilometers. When replacing the brake system, check the bearings and replace the oil seal.
2. If you hear noise from the hub bearing, first of all, it is important to find the location where the noise occurs. There are many moving parts that may produce noise, or it may be Some rotating parts and not rotating