Bearing Selection Requirements

From the perspective of long life, the requirements for bearing selection are:

(1) Select bearing models with high load capacity

When selecting bearings, the price of the bearings should be taken into account. Either use bearings with higher load capacity but more expensive, or use ordinary bearings and try to extend their life.

Use bearings with high load capacity, such as cylindrical roller bearings with convexity, spherical roller bearings with symmetrical rollers, reinforced tapered roller bearings and ball bearings, ball bearings with corrected ball groove generatrix, or use 70000CD series bearings instead of deep groove (single row radial) ball bearings. These bearings with high load capacity may have a higher fatigue life due to improved stress distribution or a larger number of rolling elements.

(2) Select the appropriate bearing size

To select the appropriate bearing size, the working load, speed and operating temperature of the bearing must be accurately calculated or actually checked.

The load has a great influence on the life of the bearing, so although the load is difficult to measure, it should be measured as accurately as possible. When load measurement is difficult, the actual power consumption of the motor can be measured, and the power loss along the transmission line can be deducted until a bearing load that is closer to the actual value is calculated. If the calculated or measured load is too large, the expected fatigue life of the bearing will inevitably be reduced to a greater extent, and it must be remedied. If the installation location allows, a bearing with a larger size can be selected; if the radial size is limited, a wider bearing should be selected if a wider bearing is available; if a wider bearing cannot be used, a bearing with a higher load-bearing capacity can be used instead.

(3) Selecting suitable bearing materials

When selecting bearing materials, its price must also be taken into account. When vacuum smelting or electroslag remelting steel has to be used, it is important to improve the lubrication conditions in order to double the expected fatigue life of the bearing. Of course, the cost of using bearings made of this type of high-quality steel is much more expensive than using bearings with higher load capacity, but for bearings that are difficult to access and extremely difficult to install and disassemble in the machine, or for bearings used in operating machinery in mines and tunnels, where maintenance is extremely difficult, it is sometimes necessary to consider using them.