At present, deep groove ball bearings used in motorcycles, home appliances motors and luxury ceiling fans industries usually design different sealing structures according to the mounting position or working conditions of the bearing.
For example, the single-sided sealed motorcycle engine case bearing is lubricated by splash lubrication by the engine oil in the engine when the engine is working. This splash lubrication method not only forms a certain oil pressure in the engine cavity and the bearing cavity, but also has a certain flow speed of the oil, which is not conducive to the anti-leakage seal of the bearing. Therefore, the requirements for the anti-leakage sealing performance of this type of bearing are very high, and the bearing must adopt a contact seal structure. From the comparative analysis of the above five basic sealing structures, it can be seen that the sealing structures in Figures 1 to 3 can basically meet the requirements. However, due to the difficulty of processing the double lip seal structure in Figure 3 and the high production cost, it is rarely used at present.
Comparing the groove contact seal structure in Fig. 1 and the inner and outer diameter contact seal structure, the structure in Fig. 2 has the following four advantages: (1) The inner ring does not have a seal groove, and the processing cost is lower; (2) The seal ring lip and the process The grinding inner and outer diameters are matched with a smaller interference dispersion; (3) The friction torque is smaller under the same sealing effect; (4) Under the same friction torque and the same oil pressure on the inner side of the sealing ring, the lip of the sealing ring and the inner The contact surface of the ring is not easy to detach, which is very advantageous for the sealing under pressure on the inside of the bearing seal ring.
Therefore, it is more common to adopt the inner and outer diameter contact type sealing structure of Fig. 2 for motorcycle engine case bearings. The fit interference mentioned here is a key technical parameter that not only affects the anti-leakage and sealing performance of the bearing, but also affects the size of the friction torque.
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Such as motorcycle wheel bearings, washing machines, water pumps and other household electrical appliances motor bearings are greased, which require high dustproof, waterproof, and greaseproof requirements. Therefore, the contact seal structure shown in Figure 1 and Figure 2 is generally used. However, because the sealing performance requirements of motorcycle engine bearings are not so high, the matching interference between the sealing ring lip and the inner ring is relatively small, especially for home appliance motor bearings, in order to reduce the friction torque of the bearing as much as possible , To reduce the vibration, noise and temperature rise of the bearing, the interference is generally small, and it is often called the light contact seal structure at this time.
Industrial sewing machine bearings are also lubricated with grease, and there are no special requirements for oil and water resistance. However, due to the problem of more dust in the installation environment of the bearing and the use environment of the sewing machine, the requirements for the dust-proof and sealing performance of the bearing are relatively high. Equipped with a labyrinth sealing structure with a long sealing circuit, such as a light contact structure or a non-contact sealing structure.
Luxury ceiling fan motor bearings are the ones with the lowest requirements for sealing performance among the above-mentioned types of bearings. Because the luxury ceiling fans are installed in the home, the working environment is better, and the requirements for dust and water resistance are not high; at the same time, due to the low speed, it is normal The work is generally only a few hundred revolutions per minute, and the centrifugal force of the grease is very small, which is not easy to cause grease leakage. Therefore, the non-contact dust cover sealing structure with the lowest production cost is generally adopted.