Hub bearing is one of the key parts of the car, its main role is to carry the weight and provide accurate guidance for the rotation of the hub, which requires that it can bear not only axial load but also radial load.
High performance seal ring
Because the hub bearing is very close to the ground and high temperature brake disc and other parts, need to adapt to a variety of complex road conditions and harsh driving environment.Therefore, the bearing seal ring must have a good anti-grease performance, but also must have a good heat resistance, anti-mud and sewage performance.
Roll rolling technology
In the third generation of hub bearings, self-locking semi-inner ring is generally adopted by rolling technology. Axial load produces plastic deformation at the hub spindle end when rolling technology is adopted, so that the hub spindle is connected with the semi-inner ring as a whole.Compared with the traditional nut fastening, the third generation hub bearing with rolling technology helps to reduce the volume and weight, reduce the cost, and improve the reliability of hub bearing.At the same time, there is no need to adjust the position of internal parts when assembling the car.
In the structural design of the second and third generation hub bearings, finite element analysis should be carried out to ensure that the flange is sufficiently rigid while reducing its volume and weight as far as possible. Among them, the rigidity of the third generation hub bearings is the inclination Angle of the hub flange relative to the outer ring flange.Reducing axle weight through integration and miniaturization, the second generation hub bearing is 180g lighter than the first generation, and the third generation hub bearing is further 120g lighter.
Low friction moment
An important measure to reduce fuel consumption of automobiles is to design hub bearings with low friction torque. The main factors affecting the friction torque of bearings are the type and pre-load of bearings. The sealing of bearings accounts for a large proportion of friction torque components.Therefore, improved seal design to reduce friction torque can significantly improve the performance of hub bearings.Hub bearings from the first generation to the latest fourth generation, friction torque significantly gradually reduced.
ABS is an automobile safety control device with the advantages of anti-skid and anti-lock, etc. It can automatically adjust the braking force to prevent the wheels from locking and shorten the braking distance by detecting the wheel speed during the emergency braking.The speed is measured by magnetic sensors mounted on parts that rotate with the wheel and nearby fixed to the vehicle body.The hub unit with ABS sensor can be divided into two situations: one is placed inside the hub and the sensor is installed on other parts;The other is placed inside the hub together with the sensor (called hub unit with sensor).
Matters needing attention
Worn or damaged hub bearings or hub units can cause inappropriate and costly failure of your vehicle on the road and even harm to your safety.Please pay attention to the following matters in the use and installation of hub bearings:
1. For maximum safety and reliability, it is recommended that you check the hub bearings frequently, regardless of the age of the vehicle -- pay attention to the bearing for early warning signs of wear, including any friction noise during rotation or abnormal deceleration of the suspension assembly wheel during turning.
For rear-wheel drive vehicles it is recommended that the front hub bearings be lubricated before the vehicle travels up to 38,000km.When replacing the brake system, check the bearings and replace the oil seals.
2. if you hear the hub bearing part of the noise, first of all, it is important to find the location of the noise.There are many moving parts that may produce noise, and it is possible that some rotating parts may come into contact with non-rotating parts.If the noise is confirmed in the bearing, the bearing may be damaged and needs to be replaced.
3. Because the working conditions of both sides bearing failure caused by the front hub are similar, even if only one bearing is broken, it is recommended to replace it in pairs.
4. hub bearings are sensitive, in any case need to adopt the right method and the right tools.Bearing parts shall not be damaged during storage, transportation and installation.Some bearings require a lot of pressure to be pressed in, so special tools are needed.Be sure to refer to the car manufacturer's instructions.
5. the bearing should be installed in a clean and tidy environment, small particles into the bearing will shorten the service life of the bearing.It is important to maintain a clean environment when replacing bearings.Bearing is not allowed to be struck with a hammer. Do not drop the bearing on the ground (or dispose of it improperly).The condition of the shaft and bearing pedestal should also be checked before installation. Even minor wear and tear can lead to poor fit and early failure of the bearing.
6. For the hub bearing unit, do not attempt to disassemble the hub bearing or adjust the seal ring of the hub unit, otherwise the seal ring will be damaged and water or dust will enter.Even the raceway of the seal and inner ring are damaged, resulting in permanent bearing failure.
7. There is a magnetic thrust ring in the seal ring fitted with the bearing of ABS device. The thrust ring cannot be collided, impacted or collide with other magnetic fields.Remove them from the box before installation and keep them away from magnetic fields, such as motors or power tools used.When these bearings are installed, the operation of the bearings is changed by observing the ABS alarm needle on the instrument panel through a road test.
8. For the hub bearing equipped with ABS magnetic thrust ring, in order to determine which side the thrust ring is mounted 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, one side of the magnetic thrust ring should be pointed inward, facing the sensitive element of ABS.Note: Improper installation may result in failure of braking system function.
9. Many bearings are sealed and do not require grease throughout their life.Other unsealed bearings such as double row tapered roller bearings must be lubricated with grease when installed.It is difficult to determine how much grease to add due to the different size of the inner cavity of the bearing. The most important thing is to ensure that there is grease in the bearing. If there is too much grease, when the bearing rotates, the excess grease will leak out.General experience: during installation, the total amount of grease should account for 50% of the clearance of the bearing.
10. The torque varies greatly when installing the lock nut due to the different bearing type and bearing housing.Refer to the instructions.