How to select bearings?

The selection of bearings can start from the following aspects:

1. Load direction, size and nature

All radial bearings can bear radial loads, and all thrust bearings can bear axial loads. Angular contact ball bearings and tapered roller bearings can be used when bearing radial and axial loads (combined loads).

The size of the load is usually determined by the bearing size. Bearings with larger dimensions can withstand relatively greater loads. In general, roller bearings have a greater load carrying capacity than ball bearings of the same size. Full complement bearings can accommodate heavier loads than corresponding bearings with cages. Therefore, ball bearings are mostly used in medium or small loads. In the case of heavy loads and large shaft diameters, roller bearings are generally more suitable.

Angular contact ball bearings and tapered roller bearings need to be installed in pairs.

An overturning moment occurs when the load is not acting on the center of the bearing. In this case, it is best to use double-row bearings (such as double-row deep groove ball bearings or double-row angular contact ball bearings, etc.), or use face-to-face or back-to-back paired single-row angular contact ball bearings or tapered roller bearings. Back-to-back bearings have a higher bearing capacity.

2. Speed

Generally, the working speed of the bearing should be lower than the limit speed listed in the bearing model table. Deep groove ball bearings, angular contact ball bearings and cylindrical roller bearings have a high limit speed and are suitable for high-speed operation occasions. Thrust bearings have a lower limit speed.

3. Support limit requirements

A shaft or other component of a rotating machine is usually supported by a fixed bearing and a non-locating bearing. Bearings that can withstand bidirectional axial loads can be used as fixed supports to limit axial displacement in two directions. Bearings that can only bear axial load in one direction can be used as one-way limit support. Swimming support has no limit, you can choose the radial bearing with inseparable inner and outer rings to swim in the housing hole, or you can choose the cylindrical roller bearing with separable inner and outer rings, the inner and outer rings can move relatively .

4. Self-aligning performance

When the coaxiality of the two bearing housing holes cannot be guaranteed due to various possible reasons or the deflection of the shaft is large, self-aligning ball bearings, self-aligning roller bearings and thrust spherical roller bearings with good self-aligning performance should be selected. It can bear the angle error generated under the load, and can also compensate the initial error caused by processing or installation errors, while the deep groove ball bearing and cylindrical roller bearing cannot bear any angle error.

5. Stiffness requirements

The stiffness of rolling bearing refers to the degree of elastic deformation of the bearing under load. This deformation is generally small and can be ignored. But in some applications, such as bearings in machine tool spindles or pinion gear bearings, stiffness is very important.

Generally, roller bearings have high rigidity, while ball bearings have low rigidity. Angular contact ball bearings and tapered roller bearings can improve the rigidity of the support by adopting the preload method.

6. Others

Needle roller bearings or needle roller and cage assemblies can be used when the radial space is limited; where there are requirements for bearing vibration and noise, low-noise deep groove ball bearings can be used; bearings that require high rotational accuracy (such as machine tools) Spindle) and used in high-speed working conditions, bearings with higher precision than ordinary grades should be selected.