1. Are there requirements for the installation surface and installation site?

yes. If there are foreign objects such as iron filings, burrs, dust, etc. in the bearing, it will cause noise and vibration during the operation of the bearing, and even damage the raceway and rolling elements. Therefore, before installing the bearing, you must ensure that the installation surface and installation environment are clean.

Second, must the bearing be cleaned before installation?

The bearing surface is coated with anti-rust oil, you must carefully clean it with clean gasoline or kerosene, and then apply clean high-quality or high-speed high-temperature lubricating grease before installation and use. The impact of cleanliness on bearing life and vibration noise is very large. But we would like to remind you that: the fully enclosed bearing does not need to be cleaned and refueled.

Third, how to choose grease?

Lubrication has a very important influence on the operation and life of bearings. Here is a brief introduction to the general principles of grease selection. Grease is made of base oil, thickener and additives. The performance of different types and different brands of greases of the same type is very different, and the allowable rotation limits are different. Be careful when choosing. The performance of lubricating grease is mainly determined by the base oil. Generally, the low-viscosity base oil is suitable for low temperature and high speed, and the high-viscosity base oil is suitable for high temperature and high load. The thickener is also related to the lubricating performance, and the water resistance of the thickener determines the water resistance of the grease. In principle, greases of different brands cannot be mixed, and even greases with the same thickener will have adverse effects on each other due to different additives.

Fourth, when lubricating bearings, is the more grease applied, the better?

It is a common misconception that when lubricating bearings, the more grease the better. Excessive grease in the bearing and bearing chamber will cause excessive agitation of the grease, resulting in extremely high temperatures. It is advisable to fill the bearing with 1/2 to 1/3 of the inner space of the bearing, and it should be reduced to 1/3 at high speed.

Five, how to install and remove?

When installing, do not directly hammer the bearing end face and non-stressed surface. Use pressure blocks, sleeves or other installation tools (tools) to make the bearing evenly stressed, and do not install through rolling element transmission force. If the mounting surface is lubricated, the installation will be smoother. If the interference is large, the bearing should be heated to 80~90℃ in mineral oil and installed as soon as possible, and the oil temperature should be strictly controlled not to exceed 100℃ to prevent the tempering effect from reducing the hardness and affecting the size recovery. In case of difficulty in disassembly, it is recommended that you use the disassembly tool to carefully pour hot oil on the inner ring while pulling outwards. The heat will expand the inner ring of the bearing, making it easier to fall off.

Sixth, is the radial clearance of the bearing as small as possible?

Not all bearings require a minimum working clearance, you must choose the appropriate clearance according to the conditions. In the national standard 4604-93, the radial clearance of rolling bearings is divided into five groups – group 2, group 0, group 3, group 4, and group 5. The clearance values ​​are from small to large, and group 0 is the standard clearance. The basic radial clearance group is suitable for general operating conditions, normal temperature and commonly used interference fit; bearings working under special conditions such as high temperature, high speed, low noise and low friction should choose a large radial clearance; Small radial clearance should be selected for precision spindles, machine tool spindle bearings, etc.; a small amount of working clearance can be maintained for roller bearings. In addition, there is no clearance for separate bearings; finally, the working clearance after the bearing is installed is smaller than the original clearance before installation, because the bearing has to bear a certain load to rotate, and the bearing fit and load are generated. amount of elastic deformation.