Routine maintenance

First, the installation surface and installation site requirements?
Yes. If there are foreign materials such as iron filings, burrs, and dust in the bearing, the bearing will cause noise and vibration during operation, and even damage the raceways and rolling elements. Therefore, before installing the bearings, you must ensure that the installation surface and the installation environment are clean.

Second, the bearing must be cleaned before installation?
The surface of the bearing is coated with anti-rust oil. You must clean it carefully with clean gasoline or kerosene and then apply it with clean, high-quality or high-speed and high-temperature grease before installation. The impact of cleanliness on bearing life and vibration noise is very large. However, we must remind you that the sealed bearings do not need to be cleaned and refueled.

Third, how to choose grease?
Lubrication has a very important influence on the operation and life of the bearing. Here you will briefly introduce the general principles of selecting a grease. Grease is made of base oil, thickener and additives. The performance of greases of different types and the same type of different brands varies greatly, and the allowable rotation limit is different. Be careful when selecting. The performance of grease is mainly determined by the base oil. Generally low viscosity base oil is suitable for low temperature, high speed, and high viscosity suitable for high temperature and high load. Thickeners are also responsible for the lubricating properties, and the water resistance of the thickeners determines the water resistance of the grease. In principle, brands of different greases cannot be mixed, and even greases of the same thickener will have bad effects on each other due to different additives.

Fourth, when lubricating bearings, the more grease the better?
When lubricating bearings, the more grease the better, which is a common misconception. Excessive grease in the bearing and bearing chambers will cause excessive agitation of the grease, resulting in extremely high temperatures. The number of bearings filled with lubricant should be 1/2 to 1/3 full of the internal space of the bearing and should be reduced to 1/3 at high speed.

Fifth, how to install and remove?
When installing, do not directly hammer the bearing end surface and the non-force bearing surface. Use a pressure block, sleeve or other installation tool (tooling) to make the bearing evenly stressed. Do not install it through the rolling element transmission force. If the mounting surface is lubricated, the installation will be smoother. If the interference is large, the bearing should be put into mineral oil and heated to 80~90°C and installed as soon as possible. Strictly control the oil temperature to not exceed 100°C to prevent the hardness of the tempering effect from decreasing and affecting the dimensional recovery. When it is difficult to disassemble, it is recommended that you use the disassembly tool to pull out the inner ring while carefully pouring hot oil, and the heat will make the inner ring of the bearing expand, which makes it easier to fall off.

Sixth, the smaller the radial clearance of the bearing, the better?
Not all bearings require minimum working clearance. You must choose the proper clearance according to the conditions. In GB 4604-93, the radial clearance of rolling bearings is divided into five groups of -2 groups, 0 groups, 3 groups, 4 groups and 5 groups. The clearance values ​​are from small to big, among which group 0 is the standard clearance. The basic radial clearance group is suitable for general operating conditions, conventional temperature, and commonly used interference fit; bearings that work in special conditions such as high temperature, high speed, low noise, low friction, etc. should use large radial clearance; For precision spindles and bearings for machine tool spindles, smaller radial clearances should be used; for roller bearings, a small amount of working clearance can be maintained. In addition, there is no clearance for the separate type bearing; finally, the working clearance after the bearing is installed is smaller than the original clearance before the installation, because the bearing is subject to a certain load rotation, as well as bearing fit and load Elastic deformation.