Four point angular contact ball bearing

Four point contact ball bearings are a type of separated bearing, or a set of angular contact ball bearings that can withstand bidirectional axial loads. The inner and outer raceways have a peach shaped cross-section. When there is no load or pure radial load, the steel ball and the ring present a four point contact, which is also the origin of this name.

function

When only pure axial load is applied, the steel ball and the ring form a two-point contact and can withstand bidirectional axial loads. Four point contact ball bearings can also withstand torque loads, and have the functions of single row angular contact ball bearings and double row angular contact ball bearings. Four point contact ball bearings can only ensure normal operation when two point contact is formed. So it is generally suitable for situations where there is two-point contact under pure axial loads or composite loads with large axial loads. Four point contact ball bearings have high limit speeds and are also suitable for high-speed operation.

design

Four point contact ball bearings belong to a radial single row angular contact ball bearing, and the designed raceway is used to support axial loads acting in two directions. Four point contact ball bearings can withstand a radial load of up to a fraction of the axial load. Compared to double row bearings, four point contact ball bearings occupy significantly less axial space.

The contact angle of SKF four point contact ball bearings designed by QJ is 35 ° or 45 °. The inner ring is a spliced inner ring. This allows for the installation of a larger number of rolling balls in the bearing, which can provide the bearing with higher load bearing capacity. This SKF four point contact ball bearing is designed in a separate manner, meaning that the outer ring with roller and cage components can be installed separately with the two inner ring halves.

The inner (or outer) ring of a four point contact ball bearing is precisely assembled from two and a half rings, and its overall outer (or inner) ring has a very small groove curvature radius, which makes the steel ball and inner and outer rings in contact at all four "points". This not only increases the radial load capacity, but also can withstand large axial loads in two directions with a compact size, and has good axial limiting ability in both directions, This is because its axial clearance is relatively small, and its contact angle (usually set at 35 °) is relatively large.

The allowable speed of the four point contact ball bearing is also very high, and it operates smoothly. Its double half ring can be removed from the entire set of bearings for installation. Therefore, the four point contact ball bearing is often used in engines because it can withstand large radial and axial loads at higher speeds.

Product features

Characteristics of Four Point Contact Ball Bearings

Four point contact ball bearings are detachable structures, and a single bearing can replace angular contact ball bearings with front or back combinations.

It can withstand radial and bidirectional axial loads, limit axial displacement in two directions, but occupies less axial space than the current specifications of double row angular contact ball bearings.

Compared with other ball bearings, four point contact ball bearings have smaller axial clearance and higher limit speed when the radial clearance is the same.

Four point contact ball bearings are suitable for bearing pure axial loads or combined axial and radial loads mainly based on axial loads. Due to being a double inner ring (or outer ring), the number of balls loaded increases and it has a greater load-bearing capacity.

Under normal working conditions, this type of bearing can form a contact angle when subjected to axial loads in any direction. The steel ball contacts the inner and outer raceways at one point each, avoiding large sliding friction in the contact area. Therefore, bearings should not be subjected to radial forces and loads.