Several factors in selecting bearing types

1. Bearing radial load

The bearing that mainly bears radial load is the radial bearing. The nominal contact angle of this type of bearing is a0<=45 0="" br="">N-type and NU-type cylindrical roller bearings can only bear radial loads, and other types of radial bearings can bear both radial loads and axial loads.

2. Bearing axial load

The bearing that mainly bears axial load is generally a thrust bearing, and its nominal contact angle is a0>450. Thrust bearings and thrust angular contact ball bearings can simultaneously bear axial forces in one or two directions according to different structures. When the axial force is particularly high, thrust cylindrical roller bearings and thrust spherical roller bearings are preferably used.

Thrust spherical roller bearings and one-way thrust angular contact ball bearings can simultaneously bear axial loads and radial loads, while other thrust bearings can only bear axial loads.

3. Bearing length compensation

The structure of a fixed bearing and a floating bearing is usually used to support a shaft and a bearing. The floating bearing compensates for the length error and thermal expansion of the shaft.

NU and N cylindrical roller bearings are ideal floating bearings, which can compensate for the length by themselves. The inner and outer rings of the bearings can be tightly fitted.

Length compensation of sliding fit

Non-separable bearings (such as deep groove ball bearings and spherical roller bearings) can also be used as floating bearings. One of the two rings of this type of bearing is fitted and has no axial fixed surface. Therefore, one ring of the bearing can move on its support surface.

4. Separable bearings (precision)

This is a bearing whose rings can be installed separately. When both rings are tightly fitted, its advantages are very prominent.

Separable bearings include four-point contact ball bearings, double-row angular contact ball bearings with double and half inner rings, cylindrical roller bearings, tapered roller bearings, thrust ball bearings, thrust cylindrical roller bearings and thrust spherical roller bearings.

Here is also an introduction to a type of non-separable bearings:), non-separable bearings are: deep groove ball bearings, single-row angular contact ball bearings, spherical ball bearings, peng-shaped roller bearings and spherical roller bearings.

Precision

In most cases, rolling bearings of normal size and rotational accuracy are sufficient. When the requirements are higher, the bearings need a higher accuracy level, (e.g. machine tool spindle bearings).

5. Compensation of misalignment

Misalignment occurs when machining the matching surface of the journal or the matching surface of the bearing seat, especially when the machining of the matching surface is not completed in one clamping. Misalignment also occurs when using a bearing seat, (e.g. flanged bearing seat or vertical bearing seat). Misalignment also occurs when the shaft is bent and deformed due to the working load, resulting in the tilting of the inner and outer rings of the bearing.

Self-aligning bearings can compensate for misalignment and tilt, such as self-aligning ball bearings, spherical roller bearings, radial and thrust self-aligning roller bearings. These bearings have a concave spherical outer ring raceway in which the rolling elements and inner ring can rotate. The ability of these bearings to compensate for the deflection angle of the shaft center depends on their own type, size and load conditions.

Both external spherical bearings and thrust ball bearings with seat rings have a spherical bearing surface: the deflection angle can be adjusted when installed in a concave spherical seat ring.

Speed

Single-row bearings have very low friction and can therefore reach the highest speed. These bearings include deep groove ball bearings that can only bear radial loads and angular contact ball bearings that can bear combined loads.

Increasing the dimensional accuracy, rotational accuracy and accuracy of the fitting parts of the bearing, adopting the right lubrication and cooling method, and using special forms of retainers can increase the allowable speed of the bearing.

Low-noise operation

In small motors, office equipment and household appliances, the operation noise is generally required to be low.

6. Tapered bore

Bearings with tapered bores can be directly mounted on tapered journals (for example: single-row and double-row cylindrical roller bearings in high-precision structures). When installing these bearings, a given radial clearance can be adjusted.

Most self-aligning ball bearings, drum roller bearings and self-aligning roller bearings with tapered bores can be mounted on cylindrical journals through a tightening sleeve. This type of bearing is particularly easy to install and remove.

7. Stiffness

The stiffness of a bearing usually refers to the force required to produce a certain elastic deformation of the bearing. The bearings on the machine tool spindle and pinion shaft are required to have high stiffness. Due to the different contact conditions between the rolling element and the raceway, the stiffness of the roller bearing is higher than that of the ball bearing.

8. Friction

In addition to being heated and dissipating heat, internal friction also plays a major role in determining the operating temperature of the bearing. Low-friction bearings include: deep groove ball bearings that bear radial loads, single-row angular contact ball bearings, and cylindrical roller bearings with cages. Contact-sealed bearings, full-fill cylindrical roller bearings, and thrust roller bearings all generate greater friction.