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 Bearing Sealing 

Key Words: Bearings; Sealing; Degree of Protection; Generator; Hydrogenerator; Turbogenerator;Tachogenerator; Induction; Synchronous; Direct Current Classification: Information 

Sealing of grease - lubricated roller bearings

There are several types of sealings to be provided for grease lubricated roller bearings to comply with requireddegree of protection. 

On the inner part of the bearings there are two felt rings to provide the sealing between shaft and internal bearingcap.

Sealings for outer part based on the degree of protection: 

On figure 1, we can see an open type. The bearing is sealed by the felt rings on the inner part, and by the greasevalue on the outer part.

This type of bearing comply with degree of protection IP23.

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Figure 1.

On figure 2, we can see a labyrinth type. The bearing is sealed by felt rings on the inner part, and by a labyrinthseal on the external bearing cap to avoid penetration of water, foreign materials, etc. This type of bearing complywith degree of protection IP54.

Figure 2.

On figure 3, we can see a labyrinth with a protection consisting of a grease value. The bearing is sealed by feltdiscs on the inner part, and by a regular labyrinth plus the protection for water value to avoid it penetrates into thebearing. This type of bearing comply with degree of protection IP55 and IP65.

Figure 3.

On figure 4, we can see a grease lubricated roller bearing set with degree of protection IP56, It consists of a greasevalue on the outer part having an inner labyrinth plus a sealing device. Besides that, it is fitted with o´ringsbetween contact surfaces. There is also another extra device called mechanical seal or outer seal. This seal

increases the protection ensuring degree of protection IP56.

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 Figure 4, Roller bearing IP56.