The sealing of the bearing can be divided into two types: self-sealing and external sealing.

The sealing of the bearing can be divided into two types: self-sealing and external sealing. The so-called bearing with its own seal is to make the bearing itself into a device with sealing performance. Such as bearings with dust caps, sealing rings, etc. This kind of seal occupies a small space, is convenient to install and disassemble, and the cost is relatively low. The so-called bearing with external sealing performance means that a sealing device with various performances is manufactured inside the installation end cover and so on. Bearing external seal is divided into two types: non-contact seal and contact seal. Among them, the non-contact seal is suitable for high-speed and high-temperature occasions, and has different structural forms such as gap type, labyrinth type and gasket type. The contact seal is suitable for medium and low speed working conditions. Commonly used structural forms such as felt seal and cup seal.

According to the requirements of bearing working conditions and working environment for the degree of sealing, various sealing forms are often used in engineering design to achieve better sealing effect. The following main factors should be considered in the selection of bearing external seal:

Bearing lubricants and types (grease and lubricating oil);

The working environment of the bearing and the size of the space occupied;

The advantages of the shaft support structure, allow the angle deviation;

The circumferential speed of the sealing surface;

The operating temperature of the bearing;

manufacturing cost.