Angular Contact Ball Bearing,precision bearing

The characteristic of angular contact ball bearing is that it can not only bear radial load but also single direction axial load. The larger the contact angle is, the larger the axial load is; and the smaller the contact angle is, the smaller the axial load is. On the contrary, the smaller the contact angle is, the greater the ability to bear the radial load is, and it is more suitable for high-speed applications. According to different working conditions, it can be combined in many ways to obtain different bearing capacity of radial and axial load, and meet the requirements of high speed, diameter and axial high stiffness. Therefore, it is widely used in the precision machine tools spindles.

There are 6 types combinations of angular contact bearing match pair as follows:

Matched pair angular contact ball bearings structure

Back-to-back arrangement, DB type(such as 70000 / DB), and the load line of the back-to-back matched bearing is separated from the bearing shaft. It can bear axial load in two directions, but the load in each direction can only be borne by one bearing. Back to back bearings provide a relatively rigid bearing configuration and can withstand overturning moments.
Face-to-face arrangement, DF type (such as 70000 / DF), and the load line of the face-to-face matched bearing converges with the bearing shaft. It can bear axial load in two directions, but the load in each direction can only be borne by one bearing. This combination is not as rigid as the back-to-back matched pair and is not suitable for the overturning moment. The rigidity and the ability to withstand overturning moment of this type matched pair are not as good as that of DB arrangement, and the bearing can withstand bidirectional axial load.
Tandem arrangement, DT type(such as 70000 / DT). In DT matched pair angular contact bearings, the load line is parallel, and the radial and axial loads are evenly shared by the bearings. However, the bearing pair can only bear the axial load in one direction. If the axial load is applied in the opposite direction, or if there is a composite load, a third bearing with relative series matching bearing adjustment must be added. This arrangement can also have three or more bearings connected in series at the same support, but can only bear the axial load in one direction. Generally, in order to balance and limit the axial displacement of the shaft, another bearing should be installed at the other support to bear the axial load in the other direction.
Triple bearings matched pair arrangement, DBD type (70000 / DBD), triple configuration, can bear radial load and 2 axial loads. However, the preload distribution of the bearing is not uniform. When rotating at high speed, the internal load of single row angular contact bearing increases, which may cause bearing injury, so DBD matched pair is not suitable for high-speed rotating conditions.
Quadruple arrangement, DBB type (70000 / DBB). In quadruple arrangement, it can bear radial load and axial load in both directions. In the case of the same internal clearance, its preload and rigidity are twice of that of DB configuration, and the ultimate axial load it can bear is also relatively large.
Universal matched pair, U type, universal assembly angular contact ball bearing is in constant height repair, outer ring non base surface strictly control the final grinding plane dimension tolerance, so that the width of inner and outer rings is equal height. The universal assembly method is that the preload required can be obtained without complicated adjustment process in the installation of precision machine tools.