Single row four-point angular contact ball bearings
Single row four-point angular contact ball bearings are single row angular contact bearings The raceways of these bearings are designed to accept axial load in both directions.
In the axial direction arrangement, single row four-point angular contact ball bearings require less space than double row angular contact ball bearings. The contact angle is 35°. The two-part inner ring allows the bearing to be filled with more balls, which creates a design with higher load rating. Whereas these bearings are separable, the outer ring with a filled cage can be mounted in the arrangement separately.
Snap ring grooves
Single row four-point angular contact ball bearings are designed to carry mainly axial loads and their clearance in the housing is similar to the clearance of axial bearings. Bearings with outer diameter higher than 160 mm are made with two snap ring grooves in the outer ring (type N2) to enable simple fixing, which stops the outer ring from twisting. For the groove dimensions see the following table.
|Outer Diameter D|
|Line QJ 2||Line QJ 3|
Single row four-point angular contact ball bearings are mainly equipped with a massive brass cage. They can also be equipped with a glass fiber reinforced polyamide cage.
The dimensions of single row four-point angular contact ball bearings are in the table part and they are in accordance with the international standards ISO 15.
Single row four-point angular contact ball bearings can accommodate the misalignment of the rings by aligning the outer ring towards the inner ring at a limited degree. Factors influencing the alignment of these bearings are the same as in the case of single row deep groove ball bearings. Any misalignment produces increased vibration level whilst the bearing is in operation. If the single row four-point angular contact ball bearings are combined in the arrangement with other radial bearings so they shall operate as axial bearings, there must be a radial clearance in the body. This way, the external ring may align modifications caused by thermal expansiveness.
Equivalent dynamic load
P = Fr + 0,66.Fa
P = 0,6.Fr + 1,07.Fa
(kN) for Fa/Fr ≤ 0,95
(kN) for Fa/Fr > 0,95
To prevent unacceptable friction, the axial load applied on the single row four-point angular contact ball bearing should ensure a contact of every ball with the raceways in two points only.
This requirement is met providing that at Fa ≥ 1,2.Fr
Equivalent static load
Po = Fr + 0,58.Fa