Bearing function
In terms of its function, it should be supported, that is, it is used to support the shaft literally, but this is only part of its function. The essence of support is to be able to bear radial loads. It can also be understood that it is used to fix the shaft. Bearing quick and easy automatic selection is included. It is to fix the shaft so that it can only achieve rotation while controlling its axial and radial movement. A motor won't work at all without bearings. Because the shaft may move in any direction, and the motor is required to only rotate when it is working. Theoretically speaking, it is impossible to achieve the function of transmission. Not only that, but the bearing will also affect the transmission. In order to reduce this influence, good lubrication must be achieved on the bearing of the high-speed shaft. Some bearings themselves have been lubricated, called pre-lubricated bearings, and most of the bearings must have lubricating oil. When running at high speed, the friction will not only increase the energy consumption but what is more terrible is that the bearings are easily damaged. It is one-sided to say that sliding friction is converted into rolling friction because there is something called a sliding bearing.
lubricating
The purpose of lubricating rolling bearings is to reduce the internal friction and wear of the bearing, prevent burning and sticking; prolong its service life; discharge frictional heat, cool down, prevent the bearing from overheating, and prevent the lubricating oil itself from aging; it also prevents foreign matter from invading the inside of the bearing or prevents rust and corrosion The effect.
Lubrication method
The lubrication methods of bearings are divided into grease lubrication and oil lubrication. In order to make the bearing function well, it is necessary to select a lubrication method suitable for the conditions of use and the purpose of use. If only lubrication is considered, the lubricity of oil lubrication is dominant. However, grease lubrication has the advantage of simplifying the structure around the bearing. The advantages and disadvantages of grease lubrication and oil lubrication are compared. When lubricating, special attention should be paid to the amount used. Whether it is oil lubrication or grease lubrication, too little amount of lubrication will not fully affect the life of the bearing, and too much amount will produce large resistance and affect the speed.
Seal
Bearing seals can be divided into two types: built-in seals and external seals. The so-called self-sealing of the bearing is to manufacture the bearing itself as a device with sealing performance. Such as bearings with dust covers, sealing rings and so on. This kind of sealing takes up little space, is easy to install and disassemble, and is relatively low in cost. The so-called bearing plus sealing performance device is a sealing device with various performances manufactured inside the mounting end cover and the like. Bearing seals are divided into two types: non-contact seals and contact seals. Non-contact seals are suitable for high-speed and high-temperature occasions and have different structural forms such as gap type, labyrinth type and gasket type. The contact seal is perfect for medium as well as low-speed working conditions. There are commonly utilized structural kinds, such as really felt seals and leather bowl seals.
According to the working conditions of the bearing and the requirements of the working environment on the degree of sealing, various sealing forms are often used comprehensively in engineering design to achieve a good sealing effect. The selection of external seals for bearings should consider the following main factors:
1. Bearing lubricant and type (grease and oil);
2. The working environment of the bearing and the size of the occupied space;
3. Advantages of the shaft support structure, allowing angular deviation;
4. The peripheral speed of the sealing surface;
5. The working temperature of the bearing;
6. Manufacturing cost.