September 21,2026
The inner and outer ring raceways of an angular contact ball bearing have a relative displacement in the axial direction of the bearing. This means that this type of bearing is designed to carry combined load, that is, radial and axial load acting simultaneously.
To understand the statement the inner and outer raceways of an angular contact ball bearing have a relative displacement in the axial direction of the bearing, we need to analyze it from three aspects: the bearing geometric structure, assembly method, and mechanical principle.
Simply put, this statement describes the core structural feature of an angular contact ball bearing: its inner ring raceway and outer ring raceway are not “directly facing” each other in the same perpendicular plane, but are offset by a certain distance along the bearing axis.
Specifically, it can be understood in depth from the following aspects:
1.“Offset” in geometric structure (asymmetric design)
Unlike a deep groove ball bearing (in which the inner and outer ring raceway are completely aligned), the shoulder height on the two sides of the inner and outer ring of an angular contact ball bearing are not equal. To load more balls to improve load-carrying capacity, one side shoulder is usually machined lower (forming a ball filling notch). This structural asymmetry directly causes a relative offset between the inner and outer ring raceways in the axial direction.
2. Formation of an inclined “contact angle”
Because the inner and outer raceways are offset in the axial direction, when the balls are placed between the inner and outer raceway, they cannot be loaded in a purely radial plane as in a deep groove ball bearing. Instead, the line connecting the contact points between the ball and the inner and outer raceway forms an angle with the line perpendicular to the bearing axis. This angle is the well-known “contact angle” (commonly 15°, 25°, 30°, 40°, etc.). It is precisely this relative axial displacement that creates the inclined contact angle.
3.“Resultant force transmission” in mechanics
This axial displacement and inclined contact angle give the bearing a special load-bearing capability. When the bearing is subjected to a radial load, due to the existence of the contact angle, the load is transmitted along the inclined line, thereby generating an additional axial component force inside the bearing. This enables the angular contact ball bearing to simultaneously bear radial loads and unidirectional axial load (that is, combined load).
The inner and outer raceways have a relative displacement in the axial direction is the physical basis for an angular contact ball bearing to achieve its special function. It is precisely because the raceways are “offset” in the axial direction that the contact surface between the balls and the raceway produces an “inclined angle,” thereby giving the bearing the dual ability to withstand axial thrust and radial load.
