What are the Sealing Methods of Deep Groove Ball Bearings?
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Several common sealing methods for Deep Groove Ball Bearings are introduced to help everyone correctly understand and better use deep groove ball bearings. Users who have used deep groove ball bearings should know that the seals of deep groove ball bearings are usually divided into two types: self-sealing and external sealing.
The self-contained seal is mainly a contact seal design. Since the seal is in direct contact with the shaft, it is rubbed and worn severely during work, so it is only suitable for low-speed occasions. Contact seals mainly include felt seals and lip seals. The felt ring seal is to open a trapezoidal groove on the deep groove ball bearing cover, make the felt into a ring or belt according to the standard, and place it in the trapezoidal groove in close contact with the shaft. Felt ring seals are mainly used for grease lubrication occasions, with a simple structure but a large friction coefficient. They are only used where the sliding speed is less than 4-5m/s and the working temperature is not higher than 90°C.
The lip seal is to place a lip seal made of oil-resistant rubber in the deep groove ball bearing cover, which is tightly sleeved on the shaft by the elastic force of the bent rubber and the fastening action of the additional annular spiral spring. , In order to play a sealing role. The direction of the sealing lip of the lip-shaped sealing ring should be towards the sealed part. That is, if the main purpose is to seal oil, the sealing lip should be a deep groove ball bearing (inward).
If the main purpose is to prevent the intrusion of foreign objects, the sealing lip should face the deep groove ball bearing. If both requirements are required, it is best to use two lip-shaped sealing rings with the sealing lip opposite to each other. Lip seals can be used for occasions where the sliding speed of the contact surface is less than 10m/s or less than 15m/s.
The external seal mainly adopts a combination of labyrinth and contact design. The more stages of the labyrinth (not lower than the two poles), the smaller the gap, the better the sealing effect. The gap of the labyrinth is based on the size of the deep groove ball bearing to take 0.6 to 1.5 mm on one side in the radial direction and 4 to 6 mm in the axial direction. Contact-type skeleton oil seals are widely used in rolling mills. In order to increase the effect, two or three can be used in parallel. The oil seal is directional and cannot be installed reversely.
Hot rolling mills are generally equipped with two oil seals, and both oil seal lips must face out of the bearing housing to prevent the infiltration of external dirt. Cold strip rolling mills are generally equipped with three oil seals and one oil seal lip close to the deep groove ball bearing should be inward to prevent the overflow of grease and affect the quality of the rolled material. Be careful when using the oil seal to avoid damaging the lip when installing the roller, which will affect the sealing effect.
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