In many mechanical devices, bearings, as components that provide rotation and load-bearing capacity, are often required to bear loads in a certain direction. However, in some cases, bearings need to be able to withstand both radial and axial loads. This requires selection and discrimination among numerous types of bearings. So, what kinds of bearings can withstand both radial and axial forces? Let's have a detailed look as presented by the editor of Guoyang Precision Machinery.

I. Self-aligning Roller Bearings

Self-aligning roller bearings are equipped with spherical rollers between the outer ring with a spherical raceway and the inner ring with a double raceway. According to different internal structures, they are divided into four types: R, RH, RHA, and SR. Since the arc center of the outer ring raceway coincides with the center of the bearing, it has self-aligning performance. Therefore, it can automatically adjust the misalignment of the axis caused by the deflection or misalignment of the shaft or the housing. It can withstand radial loads and bidirectional axial loads. In particular, it has a large radial load capacity and is suitable for bearing heavy loads and impact loads.

Thrust self-aligning roller bearings use rollers with a spherical profile arranged at a steeper angular position. They can not only withstand high axial loads but also moderate radial loads. Moreover, their geometric design and manufacturing process result in very low friction, making them suitable for applications where there are heavy loads and it is difficult to establish or maintain the alignment of the bearing housing, or where the shaft may deform.

II. Deep Groove Ball Bearings

In terms of structure, each ring of a deep groove ball bearing has a continuous groove-shaped raceway with a cross-section approximately one-third of the equatorial circumference of the ball. Deep groove ball bearings are mainly used to bear radial loads and can also bear a certain amount of axial loads. When the radial clearance of the bearing is increased, it has the characteristics of an angular contact ball bearing and can bear alternating axial loads in two directions. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, a high limiting rotational speed, and high precision, making it a bearing type that users give priority to when selecting models.

III. Crossed Roller Bearings

In crossed roller bearings, the cylindrical rollers are arranged perpendicular to each other through a spacer retainer, so one crossed roller bearing can withstand loads in all directions such as radial loads, axial loads, and moment loads. Because the rollers are arranged perpendicular to each other through a spacer retainer on the V-shaped raceway surfaces at a 90° angle, this design enables the crossed roller bearing to withstand large radial loads, axial loads, and moment loads in all directions. Crossed roller bearings are mainly divided into two categories: one is the crossed cylindrical roller bearing, and the other is the crossed tapered roller bearing:

1. Crossed Cylindrical Roller Bearings

The crossed cylindrical roller bearing is a type of bearing in which cylindrical rollers are arranged vertically and crosswise between the inner and outer rings of the bearing. There is a line contact between the rollers and the raceway, which has good rigidity. The elastic deformation of the bearing under load is very small, and it can simultaneously bear radial loads, axial loads, and moment loads. It is particularly suitable for occasions requiring high rigidity and high rotational accuracy.

2. Crossed Tapered Roller Bearings

The crossed tapered roller bearing has two rows of tapered rollers arranged vertically and crosswise at a 90° angle on the V-shaped raceway surfaces through a spacer retainer, and it can withstand loads in all directions such as radial loads and axial loads. The line contact in the structure of the raceway and the rollers provides high rotational accuracy, high stability, and greater tilt stiffness.

The dimensions of the inner and outer rings of the crossed roller bearing are minimized. Especially, the ultra-thin type is close to the limit of small size and has high rigidity. Therefore, it is very suitable for applications such as the joints or rotating parts of industrial robots, the rotating worktables of machining centers, the rotating parts of manipulators, precision rotating worktables, medical equipment, measuring instruments, IC manufacturing devices, etc. It has the characteristics of high rotational accuracy, simple operation and installation, small installation space, simple but sufficient lubrication, etc.

IV. Tapered Roller Bearings

Tapered roller bearings belong to separable bearings, and both the inner and outer rings of the bearing have tapered raceways. This type of bearing is divided into different structural types such as single-row, double-row, and four-row tapered roller bearings according to the number of rows of rollers installed. A single-row tapered roller bearing can bear radial loads and axial loads in a single direction, and is mainly used to bear combined radial and axial loads with the radial load as the main component.

The cone angle of the outer ring raceway of a single-row tapered roller bearing is between 10° and 19°, and it can simultaneously bear the combined action of axial loads and radial loads. The larger the cone angle, the greater the ability to bear axial loads. For bearings with a large cone angle, the suffix code B is added, and the cone angle is between 25° and 29°, and it can bear larger axial loads. In addition, the clearance of a single-row tapered roller bearing can be adjusted during the installation process. Compared with angular contact ball bearings, it has a larger load capacity and a lower limiting rotational speed.

　　
V. Angular Contact Ball Bearings

Angular contact ball bearings can withstand both radial and axial loads simultaneously because the raceways of their inner and outer rings can have relative displacement on the horizontal axis. They can operate at relatively high rotational speeds. The larger the contact angle, the higher the axial load-carrying capacity, so they can also withstand pure axial loads.

Double-row angular contact ball bearings can bear relatively large radial, axial bidirectional combined loads and moment loads with the radial load as the main component. They can limit the bidirectional axial displacement of the shaft or the housing, and the contact angle is 30 degrees. Paired angular contact ball bearings can bear radial, axial bidirectional combined loads with the radial load as the main component, and they can also bear pure radial loads.

Angular contact ball bearings are mainly applied in fields such as metallurgical equipment, mining machinery, construction machinery, paper-making machinery, wind turbines, semiconductors, machine tools, gear units, electric motors (motors), pumps and compressors, injection molding machines, motorcycles, etc.

The above are the commonly used bearings in various mechanical devices that can withstand both radial and axial forces at the same time. However, most of them can appropriately bear the load in the other direction, while the crossed roller bearings, due to their special structure, are fully adapted to bidirectional loads. Therefore, they are increasingly being adopted by various mechanical devices. Especially for the bearings of industrial robots with high precision requirements and small installation spaces, most of them will use crossed roller bearings.