In the past, single row tapered roller or ball bearings was commonly used as hub bearing on automobile. With technologies developing, hub bearing units have already widely been applied in auto. Application range and usage amount of hub bearing units are growing gradually. Nowadays, hub bearing units have been developed into the third generation. The first generation of hub bearing units consists of double-row angular contact bearing. The second generation of hub bearing units uses a flange on its outer raceway which is used to fix bearing. It can easily fix bearing on axle by using nuts, convenient for maintenance. The third generation of hub bearing units uses bearing units to cooperate with ABS system. The hub bearing units are designed as inside flange and outside flange. Inside flange is fixed on actuated shaft by using nuts. Outside flange installs all of bearing units together. Worn or damaged hub bearing units may lose efficacy during driving, even harmful to security.
Tips for using and installing automotive hub bearing:
1. To maintain security and reliability as much as possible, hub bearing should be checked frequently no matter how long the auto has been used. Pay attention to early warning signal of worn bearing units, including any friction noises and abnormal deceleration of suspension combination during rotation. In terms of rear-wheel drive auto, the forward hub bearing should be lubricated after having been driven for 38,000km. When changing braking system, check the bearing and change oil seal.
2. If noise comes from hub bearing. First of all, the priority is to find out the position of noise. Noise may come from various moving parts or the contacting between rotational components and non-rotational components. If the noise is confirmed to come from bearing, the bearing has been damaged and needs to be changed.
3. Because of working conditions causing bearing on two sides of forward hub to lose efficacy are the same, so if one of bearings is damaged, pairs replacing is recommended.
4. Hub bearing is quite sensitive. Correct methods and proper tools should be adopted under any situations. During storage and installation, the parts of bearing cannot be broken. Some bearings should be impressed by higher pressure, which require special tools. The installation must follow instruction of auto manufacturing.
5. Bearing should be installed under clean and tidy environment. Tiny particles entering into bearing will reduce service life of bearing. When changing bearing, maintaining clean environment is very important. The bearing is not allowed to be hit by using hammer and the bearing also should be fallen on the ground. Before installation, bearing and bearing block should be checked. Tiny abrasion can cause poor cooperation, resulting in early failure of bearing.
6. For hub bearing units
, should not take hub bearing apart or adjust sealing ring of bearing units. Otherwise, the sealing ring can be damaged, resulting in water or dust entering. Sealing ring and raceway of inner ring may even be damaged, causing forever failure of bearing.
7. There is a magnetic thrust collar in sealing ring of bearing equipped with ABS device. The thrust collar cannot be hit or impacted and it also cannot hit with other magnetic fields. Before installation, the bearing is take out from packing box and far away from magnetic fields such as used electromotor or electric tools. When install the bearing, the operation of bearing can be changed through observing ABS alert needle on instrument panel during road test.
8. In the aspect of hub bearing equipped with ABS magnetic thrust collar. To ensure the position of thrust collar, a small substance can be used to approach to edge of bearing. Magnetic force caused by bearing can catch up the substance. During installing, one side of magnetic thrust collar points inside, facing with sensitive components of ABS. Notice: incorrect installation may result in functions of braking system losing efficacy.
9. Various bearings are sealed. The bearings do not need to be added with lubricating greases during the whole service life. The other bearings without sealing such as double tapered roller bearing must be added with grease for lubrication during installation. Due to different dimensions of cavity bearing, it is hard to confirm the quantity of added grease. The most important is to ensure that grease exists in bearing. If the grease is too much, redundant grease bleeds out when bearing rotates. During installation, the amount of grease accounting for 50% of bearing gap is appropriate.
10. When installing locknut, due to different types of bearing and bearing block, the torque also varies a lot.