What are the general common problems with bearings?

First, the installation surface and installation site requirements

If there are iron chips, burrs, dust and other foreign matter inside the bearing, it will make the bearing noise and vibration when running, and even damage the raceway and rolling body. Therefore, before installing the bearings, you must ensure that the installation surface and installation environment is clean.

Two, the bearing must be cleaned before installation

The bearing surface is coated with antirust oil, you must clean it carefully with clean gasoline or kerosene, and then apply clean or high speed high temperature lubricating grease before mounting. The impact of cleanliness on bearing life and vibration noise is very big. But we want to remind you in particular: fully enclosed bearings do not have to be cleaned and refueled.

Third, the choice of grease

Lubrication on the operation and life of the bearing has an important impact, here to briefly introduce you to the general principles of grease selection. Grease by the base oil, thickeners and additives, different types and the same type of different grades of grease performance varies greatly, allowing the rotation of different, in the selection must pay attention to. The performance of grease is mainly determined by the base oil, generally low viscosity base oil is suitable for low temperature, high speed, high viscosity for high temperature, high load. Thickener is also related to the lubrication performance, the water resistance of thickener determines the water resistance of grease. In principle, different brands of grease can not be mixed, and even the same thickener grease, but also due to different additives to bring bad influence on each other.

Fourth, the addition of grease

Lubrication, the more grease coated the better, this is a common misconception. Bearings and bearing room too much grease will cause excessive agitation of grease, resulting in very high temperature. The quantity of bearing filled with lubricant should be filled with 1/2 to 1/3 of the internal space of the bearing, and should be reduced to 1/3 at high speed.

V. Bearing installation and disassembly

Do not hammer the bearing end surface and non-stressed surface directly when mounting, but use pressure block, sleeve or other mounting tools to make the bearing evenly stressed. If the mounting surface is coated with lubricant, it will make the installation more smooth. If the interference is large, the bearing should be put into mineral oil and heated to 80~90℃ and then installed as soon as possible, strictly control the oil temperature not to exceed 100℃ to prevent the tempering effect of hardness reduction and affect the size recovery. In the disassembly encountered difficulties, we recommend that you use the disassembly tool to pull outward while carefully pouring hot oil on the inner ring, heat will make the bearing inner ring expansion, so that it is easier to fall off.

Six, the choice of bearing radial clearance

Not all bearings require a small working clearance, you must choose the appropriate clearance according to the conditions. National standard 4604-93, rolling bearing radial clearance is divided into five groups - 2 groups, 0 groups, 3 groups, 4 groups, 5 groups, clearance value in order from small to large, which 0 groups for standard clearance. The basic radial clearance group is applicable to the general operating conditions, conventional temperature and common interference with; In high temperature, high speed, low noise, low friction and other special conditions of the work of the bearing is appropriate to choose a large radial clearance; For spindle, machine tool spindle with bearings, etc. should choose a smaller radial clearance; For roller bearings can keep a small amount of work clearance. In addition, for the separation type bearing is not the clearance; import bearing after the installation of the work clearance, to install than the original clearance before small, because the bearing to bear a certain load rotation, and bearing with and load generated by the elastic deformation amount.

Bearings can be divided into sliding bearings and rolling bearings according to the specific structure and working nature. As the name implies, sliding bearings are flat bearings with a large contact area, so the degree of wear is greater, i.e., the coefficient of friction is large. Therefore, sliding bearings need special materials, anti-friction is its great characteristics. The characteristics of rolling bearing are different from sliding, it transforms the sliding friction between shaft seat and shaft into rolling friction, which will reduce the loss. Then use the inner and outer ring, rolling body, cage interaction to complete the work.

Whether rolling bearings or sliding imported bearings, although their working principle is different, its role is the same, are to reduce the mechanical power transmission process generated by the mechanical load friction coefficient and support the mechanical rotating body.