Keywords: roller bearing, pillow block bearing, Wheel hub bearing, special bearings

A car usually has about 30 kinds of 50 sets of bearings installed in different rotating parts. In practice, automobile bearings are generally classified according to the installation or use parts. Corcorresponding to the classification of automobile into engine, drivtrain, steering system and air conditioning system, automobile bearings can be first divided into engine bearings, drivtrain bearings, steering system bearings and air conditioner bearings according to the installation parts, and then can be further subdivided into each part of the above system and the specific installation parts of bearings. Due to the diversification of automobile and bearing designs, different parts and bearing structures are often used for similar parts in different automobiles. The bearing mounting position diagram and the corresponding bearing type spectrum table can be used to show the mounting position of the bearing in more detail and intuitively, and the inner relationship between the component and the bearing can be revealed by giving the bearing model, outer dimension and the mounting position at the same time.

With the development of automobile technology, the design, manufacture, test and application technology of automobile bearings have made great progress. However, from the perspective of application, the development of automobile bearings can be summarized mainly as the expanded application of general bearings, the development of special bearings and the improvement of bearing performance and life.

(1) the expansion of the application of general bearings

The improvement of automobile structure, the development of varieties and specifications, the improvement of performance and life as well as the diversification of automobile design and bearing design have led to the expansion of the application range of general bearings.

So far, the direct application of general bearings in automobiles has covered almost all the basic structure types of general bearings, more and more series and more and more specifications, and the improvement and development of direct application of general bearings has led to the emergence of some new general bearing series and special bearings.

(2) the development of special bearings

On the basis of the general bearing, some special bearings for automobile developed gradually have the structure and function characteristics that the traditional rolling bearing does not have and are closely related to the automobile application. Among these automobile special bearings, the expansion of hub bearings and clutch separation bearings structure and function is the most noticeable.

Wheel hub bearing

1. The earliest hub bearing

The earliest hub bearing in use is composed of two sets of single-row centripetal ball bearings or tapered roller bearings. Its disadvantage is that the installation and maintenance need to fill grease and adjust clearance, and improper grease type, dosage or not clean enough and improper clearance adjustment often bring serious consequences of greatly reduced bearing life.

The improvement of hub bearings consisting of two sets of single row bearings has led to the use of sealed double row bearings with pre-regulated clearance. The clearance of this bearing has been adjusted correctly at the time of manufacture, and the seal and lubrication of the bearing itself can avoid the entry of dirt during installation and the risk of incorrect grease type and amount. This expanded lubrication, sealing and clearance adjustment functions of hub bearings is known as the first generation of hub bearings.

The outer ring of the first generation of hub bearings with a flange constitutes the second generation of hub bearings. Wheel hub bearing the extension of the structure and function make the wheel hub bearing structure is greatly simplified, dosage of wheel parts need to be reduced, and the installation is simple easy to wheel bearing structure and function of further expansion of the third generation wheel hub bearing, bearing itself, short axis and functions of ordinary hub, its ring flange is used for supporting wheel and brake disc, The outer flange is used to connect the suspension. This kind of bearing assembly not only has the advantages of simplifying the design of automobile wheel and suspension device, reducing the volume, simplifying assembly, easy to move and the possibility of installation error is very small, but also effectively reduces the cost of automobile parts.

At present, the expansion of structure and function has made hub bearings develop into the fourth generation of constant speed universal joint, so that the technical performance and economic effects of hub bearings have reached a new level.

Hub bearing (HUB) is the main role of load-bearing and provide accurate guidance for the rotation of the hub, it bears both axial load and radial load, is a very important component.

The traditional automobile wheel bearing is composed of two sets of tapered roller bearing or ball bearing. The installation, oiling, sealing and clearance adjustment of the bearing are all carried out on the automobile production line. This structure makes it difficult to assemble in the automobile production plant, high cost, poor reliability, and the car in the maintenance point maintenance, but also need to clean, oiling and adjustment of bearings. Wheel hub bearing unit is in the standard angular contact ball bearings and tapered roller bearings, on the basis of it will be two sets of bearing as a whole, has the assembly clearance adjustment performance is good, can be omitted, light weight, compact structure, large load capacity, for the sealed bearing prior to loading, ellipsis external wheel grease seal and from maintenance etc, and has been widely used in cars, There is also a trend of gradually expanding application in truck.

2. Installation and use of automobile hub bearings

Car hub bearings used to be the most paired use of single row tapered roller or ball bearings. With the development of technology, car wheel hub unit has been widely used. The use and usage of hub bearing units is growing day by day, and now it has developed into the third generation: the first generation is composed of double row angular contact bearings. The second generation has a flange for fixing the bearing on the outer raceway, and the bearing can be simply sheathed to the wheel shaft and fixed with nuts. It makes car maintenance easier. The third generation hub bearing unit is the bearing unit and anti-lock brake system ABS. The hub unit is designed to have an inner flange and an outer flange. The inner flange is bolted to the drive shaft and the outer flange holds the entire bearing together. Wear or damaged hub bearings or hub units can cause inappropriate and costly failure of your vehicle on the road, or even cause harm to your safety.

3. Please pay attention to the following matters in the use and installation of hub bearings

1) In order to ensure safety and reliability to the maximum extent, it is recommended that you often check the hub bearing no matter how old the car is -- pay attention to whether the bearing has an early warning signal of wear: including any friction noise during rotation or abnormal deceleration of the suspension combination wheel when turning. For rear-wheel drive vehicles, it is recommended to lubricate the front hub bearings before the vehicle travels to 38000 km. When replacing the brake system, check the bearings and replace the oil seal.

2) such as hearing the noise from the hub bearing part, first of all, it is important to find the location of the noise. There are many moving parts that can produce noise, and it is possible that some moving parts have come into contact with non-rotating parts. If it is confirmed that the noise is in the bearing, the bearing may have been damaged and needs to be replaced.

3) Because the working conditions of the front hub leading to the failure of both sides of the bearing are similar, even if only one bearing is broken, it is also recommended to replace it in pairs.

4) Hub bearings are sensitive, and in any case the correct method and appropriate tools need to be used. In the process of storage, transportation and installation, bearing components should not be damaged. Some bearings require high pressure, so special tools are needed. Be sure to refer to the manufacturer's manual.

5) When installing bearings, they should be in a clean and tidy environment. Small particles entering bearings will shorten the service life of bearings. It is very important to keep a clean environment when replacing bearings. A hammer is not allowed to hit the bearing, take care that the bearing does not fall to the ground (or similar mishandling). Before installation, the condition of the shaft and the bearing seat should be checked. Even minor wear and tear will lead to poor coordination, thus causing early failure of the bearing.

6) For the hub bearing unit, do not attempt to disassemble the hub bearing or adjust the sealing ring of the hub unit, otherwise it will damage the sealing ring and lead to the entry of water or dust. Even the seal ring and inner ring raceway are damaged, causing permanent failure of bearings.

7) There is a magnetic thrust ring in the sealing ring of the bearing of the ABS device. The thrust ring cannot be collided, impacted or collided with other magnetic fields. Remove from the box before installation and keep them away from magnetic fields, such as electric motors or power tools used. When installing these bearings, the operation of the bearings is changed by observing the ABS alarm needle on the instrument panel during the road condition test.

8) For the hub bearing equipped with ABS magnetic thrust ring, in order to determine which side the thrust ring is installed on, a light and small thing can be used * near the edge of the bearing, and the magnetic force generated by the bearing will attract it. During installation, point one side of the magnetic thrust ring inward, facing the sensing element of the ABS.

Caution: Improper installation may result in failure of the braking system.

9) Many bearings are sealed, and this kind of bearings do not need to be lubricated throughout their life. Other unsealed bearings such as double row tapered roller bearings must be lubricated with grease during installation. Because the size of the inner cavity of the bearing is different, it is difficult to determine how much oil to add. The most important thing is to ensure that there is oil in the bearing. If the oil is too much, when the bearing rotates, the excess oil will ooze out. General experience: during installation, the total amount of grease should account for 50% of the clearance of the bearing.

10) When installing the lock nut, the torque varies greatly due to the different bearing types and bearing seats.

4, maintenance attention

In the maintenance process, it is often found that some cars have large driving noise, check the tire without abnormal wear and tear, and rotate the wheel on the lifting machine without obvious abnormal noise. This phenomenon is often caused by the abnormal damage of the hub bearing, the so-called abnormal refers to the bearing damage caused by the installation reason. The front wheel bearing of the car is generally a double row ball bearing. When installing the bearing, if the hammer is used to strike the installation, or the bearing is installed by pressing the inner ring of the bearing when installing the bearing into the bearing seat, it will cause damage to the bearing raceway on one side. Noise is generated when the vehicle is moving and is not audible when the wheels are off the ground due to the better side of the raceway. Correct installation and operation is the key to long life of bearings.

Pillow block bearing

The belt seat rolling bearing is a combination of grease sealed rolling bearing and various shapes of bearing blocks into high precision components. The rolling bearing with the seat can be directly installed to the main body of the mechanical device through several bolts. It has the performance of automatic self-aligning and can be used to supplement grease, etc. It is a very simple product for installation and use.

The rolling bearing with seat consists of a ball bearing with a spherical outer diameter surface assembly and a bearing seat with a spherical inner hole

Belt seat bearing features

1) It has the function of automatic self-adjustment

The outer diameter of the outer spherical bearing and the inner diameter of the bearing seat are spherical match, and there is automatic self-aligning function between the two, which can compensate for the axis mismatch and the deformation of the bottom surface of the installation caused by the installation error.

2) Large load capacity

Due to the same internal structure as 6200 and 6300 series deep groove ball bearings, IB ball bearings with seat can bear not only radial load, but also large axial load. At the same time, the working noise of the bearing is small.

3) long service life

The outer spherical ball bearing with seat is usually used in harsh working conditions such as soil, dust, humidity and high temperature. The grease inside the bearing will deteriorate in a short time. Therefore, it is necessary to grease the outer spherical ball bearing with the seat at appropriate intervals and re-lubricate it, replacing the spoiled grease with fresh grease. IB cast iron outer spherical ball bearings are equipped with oil nozzles and can be re-lubricated to ensure perfect performance and long service life in any working environment.

4) excellent sealing performance

Both sides of the outer spherical ball bearing are equipped with heat-resistant and oil-proof rubber sealing ring and steel plate dust-proof cover combined seal. Dust cover assembly on the bearing inner ring diameter, together with the inner ring rotation, can effectively prevent the internal external foreign body into the bearing, and can resist the external pressure to protect bearings, the combination of this consists of sealing ring and dust cover seal to prevent dirt, dust and water enter the bearing internal, also can prevent the grease inside the bearing. The bearing can also maintain perfect working performance under harsh working environment.

5) strong bearing seat

The cast iron seat is an integral seat structure, the bearing seat has excellent rigidity, which prevents the bearing from deformation during assembly, and the bearing seat is durable under any working conditions.

6) The bearing can be easily locked on the shaft

There are three ways to lock the bearing on the shaft. The commonly used method is to lock the elongated end of the inner ring, etc., and two setting screws can also be used to lock the set sleeve or eccentric sleeve. All of these three methods can easily lock the bearing on the shaft.

7) Special heat treatment of bearing inner ring

The inner ring groove and its surrounding parts to be hardened and normally hardened, and the elongated ends of the inner ring fitted with set screws are locally tempered at high temperature to maintain toughness and impact resistance. Local high temperature tempering around the inner ring screw hole results in better bearing performance, which prevents the screw from loosening during bearing operation and does not cause the inner ring to burst when the screw is tightly screwed.

8) It has a unique design to prevent the rotation of the outer ring

The outer ring of the bearing is equipped with a unique stop pin (ball), which allows automatic self-aligning of the bearing and prevents the outer ring from rotating, thus extending the service life of the bearing.

9) Bearing and bearing pedestal can be completely interchangeable

Bearing and bearing pedestal are precision machined, bearing and bearing pedestal can be completely interchangeable, and the bearing can be easily replaced at any time.

10) Easy installation

The outer spherical ball bearing has been pre-injected with enough high-quality grease, and the outer spherical ball bearing with seat can be installed directly on the shaft. Thus, harmful substances can be avoided from entering the bearing interior in the process of installing the bearing unit.