Understand the bearing seal devices have? Make bearing choose better

Bearing sealing device used to prevent external foreign bodies ( Impurities, water, metal powder, etc. ) Intrusion and bearing inner lubricant leakage. Sealing device is not perfect, due to external foreign invasion or lubricant leakage bearing damage, such as wounds or burns. As a result, the bearing network ( Hereinafter referred to as:) Remind everyone in the design or select bearing sealing device, should be based on the use of the bearing and the conditions of use, considering structure lubrication method and so on. Bearing sealing device according to its structure is mainly divided into the non-contact seal and contact seal two categories, the two kinds of bearing sealing device are need to meet the following conditions: 1, do not produce abnormal friction ( Fever) ； 2, assembly, disassembly and maintenance should be simple; 3, economy is better. Let's see, bearing seal device sealing device specific types and characteristics of two kinds: one, non-contact seal non-contact seal contact with the bearing, friction, oil tank, oil slinger and labyrinth seal type, etc. This kind of device is a tiny gap or centrifugal force by using sealing function, especially suitable for high speed and high temperature occasion. 1, the tank sealing device ( FIG. 1) Figure 1 oil tank sealing device of the sealing device characteristics: (1) the seal in the shaft and the shell cover clearance above three open tank, in addition to the grease lubrication and rotates at low speed can be used alone, with other more commonly sealing device combination. (2) in the oil tank filled with consistency for calcium base grease (150 ~ 200 A cup of fat) When more dustproof effect. (3) the clearance between the shell cover and shaft are as small as possible, but usually use the following values. 0. 25 ~ 0. 0. 5 ~ 1 mm (4) the recommended size tank is as follows. 4 ~ 5 was, oil slinger sealing device ( FIG. 2) Figure 2 oil slinger seal oil slinger sealing device features: (1) oil slinger by centrifugal force will cause air flow and wiggle lubricant or impurity, resulting in a pump suction effect, thereby preventing lubricant leakage and external foreign body, mostly with other sealing device combination. (2) when the oil slinger is located in the end cover ( D) , produce outside-in pump suction effect, is beneficial to prevent the lubricant leakage, located in the lateral ( Figure e) The effects of the pump suction, on the contrary, is helpful to prevent external foreign body of shooting. (3) end cover type oil slinger ( F) By the centrifugal force will be impurities and dust off, is conducive to prevent external foreign body of shooting. (4) the oil ring ( Graph g) Also belong to a kind of oil slinger, due to the clearance between the shell and the shaft has raised portion, can prevent the lubricant leakage by centrifugal force. 3, labyrinth seal ( Figure 3) Figure 3 labyrinth sealing device (1) the labyrinth seal clearance between shaft and the shell is equipped with concave and convex shape ( The labyrinth) , particularly suited to prevent oil spill when high-speed rotation. (2) (axial labyrinth seal H) Easy to assemble, widely used, but the sealing performance is better than the radial labyrinth seal ( Figure I) 。 (3) (self-aligning labyrinth seal FIG. J) Suitable for self-aligning bearing. ④( Figure I) With ( FIG. J) Need to adopt double half shell or end cover. (5) the recommendation of labyrinth seal clearance value is as follows. 6. If in the labyrinth gap filling grease ( K) , can further improve the sealing effect. 2, contact seal device contact seal device is the use of synthetic materials such as rubber, synthetic resin, felt the end of contact with the rotor friction sealing effect, the most common synthetic rubber oil seal. 1, the various types of refined oil seal oil seal device and size have been standardized, the name of each part oil seal and the functional diagram ( As shown in figure 4 and are shown in table 1) . The representative types are shown in table 2 below. The name of each part in figure 4 oil seal oil seal in table 1 of each part function table 2 main types of oil seal oil seal the use of sealing device characteristics: (1) as shown in figure 5, there is no auxiliary lip seal may be changed according to different purpose when installing the main lip orientation. Figure 5 seal main lip toward the intended use and (2) in the external foreign matter more, or there may be water intrusion can be shown in figure 6, the two oil seal combination or use double lip seal and fill grease between lips. Figure 6 external environment do not clean using method (3) oil seal is not only to seal lubricants, by choosing appropriate sealing ring material, but also for alcohol, acid or alkali chemicals, such as sealing effect. (4) as shown in table 3, all kinds of seal ring materials allow linear velocity and temperature range is different, can undertake choosing according to the purpose. Table 3 oil seal allows the linear velocity and temperature range (5) to give full play to the sealing performance of the oil seal, also should pay attention to contact with the seal of the axis of the material, surface hardness, surface roughness, etc. , as shown in table 4 for bearing the recommended conditions. Recommendations of table 4 axis 2, felt seal and other felt the use of the seal ring has a long history, but due to the limited to the following USES, so it is advisable to switch to synthetic rubber oil seal. Low when grease lubrication is adopted simple dustproof. The low linear velocity under 5 m/s. Other contact sealing device, and mechanical seal, o-rings, packing, etc.