Bearing seal type In order to keep bearings in good lubrication conditions and normal working environment, give full play to the working performance of bearings, extend the life of the rolling bearing must have a suitable seal, in order to prevent the leakage of lubricants and the invasion of dust, water or other dirt. The sealing of bearings can be divided into two categories: built-in sealing and external sealing. The so-called bearing seal is to manufacture the bearing itself into a device with sealing performance. Such as bearing with dust cover, sealing ring, etc. This seal occupies a small space, convenient installation and disassembly, and the cost is relatively low. The so-called bearing external sealing performance device is a sealing device with various performance manufactured inside the installation end cover.

The following main factors should be considered in the selection of bearing external seal:

1. Bearing lubricants and types (grease and lubricating oil);

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

3. The advantages of the supporting structure of the shaft allow the Angle deviation;

4. The circumferential velocity of the sealing surface;

5. Working temperature of bearings;

6. Manufacturing cost. The external seal is divided into two types: non-contact type and contact type. It is described as follows:

1) Non-contact seal Non-contact seal is a seal that does not contact with the parts moving relative to it and has appropriate clearance. This form of sealing produces little friction heat and no wear in the work, especially for high speed and high temperature situations. Non-contact sealing is commonly used in clearance type, labyrinth type and gasket type and other different structural forms, respectively used in different occasions. The clearance of non-contact seal should be as small as possible.

2) Contact seal Contact seal is a seal that is in contact with its relative moving parts and has no clearance. Due to the direct contact between the seal and the mating part, the friction is large in the work, the heat is also large, easy to cause poor lubrication, easy friction damage of the contact surface, which leads to the reduction of the sealing effect and performance. Therefore, it is only suitable for medium and low speed working conditions. Contact seal commonly used in felt seal, bowl seal and other structural forms, used in different occasions. According to the requirements of bearing working condition and working environment for sealing degree, various sealing forms are often used comprehensively in engineering design to achieve better sealing effect.