SKF Four-point contact ball bearing

Four-point contact ball bearings are radial single-row angular contact ball bearings, and their raceways are designed to support axial loads acting in two directions. For a given axial load, a limited radial load (load ratio) can also be supported. The bearing is of separable design, that is, the outer ring with ball and cage assembly can be installed separately with the two inner ring half rings.

The double inner rings of SKF Explorer four-point contact ball bearings have grooved shoulders. When combined with cylindrical roller bearings, it can improve the oil flow. In addition, the concave part can also be used for disassembly.

Function

When only the pure axial load acts, the steel ball and the ferrule become two-point contact, which can bear the bidirectional axial load. Four-point contact ball bearings can also bear moment 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 they form two-point contact. Therefore, it is generally suitable for those occasions where there is two-point contact under pure axial load or synthetic load with large axial load. The four-point contact ball bearing has a high limit speed, and it is also suitable for those high-speed running occasions.

Design

1. Four-point contact ball bearing is a radial single-row angular contact ball bearing. The raceway is designed to support axial loads acting in two directions. Four-point contact ball bearings can withstand radial loads up to a fraction of the axial load. Compared with double row bearings, four-point contact ball bearings occupy a significant reduction in axial space.

The contact angle of SKF four-point contact ball bearings designed by QJ is 35° or 45°. The inner circle is a split inner circle. In this way, a larger number of balls can be installed in the bearing, which can give the bearing a higher load bearing capacity. This SKF four-point contact ball bearing is a separate design, that is, the outer ring with the ball and cage assembly can be installed separately with the two inner ring half rings.

2. The inner ring (or outer ring) of the four-point contact ball bearing is precisely assembled by two half-rings, and the groove curvature radius of the whole periphery (or inner ring) is very small, so that the steel ball and the inner ring , The outer ring is in contact at four "points", which not only increases the radial load capacity, but at the same time can withstand large axial loads in two directions with a compact size, and has a good two The ability of the axial limit of the direction is because its axial clearance is relatively small, and its contact angle (generally taken as 35°) is relatively large.

The allowable speed of three- and four-point contact ball bearings is also very high, and the operation is very stable. Its double half ring can be removed from the complete set of bearings for installation separately, so four-point contact ball bearings are mostly used in engines because they It can withstand large radial load and axial load at higher speeds.

Half of the two inner rings of SKF Explorer's four-point contact ball bearings have deep-bottomed shoulders (fig). When this four-point contact ball bearing is used with SKF cylindrical roller bearings, the oil flow rate is increased. In addition, when disassembling this four-point contact ball bearing, these deep recessed bottoms can also be used to fix the puller

Features

Features of four-point contact ball bearings

The four-point contact ball bearing is a separable structure, and a single bearing can replace the angular contact ball bearing with the front combination or the back combination.

It can bear radial load and bidirectional axial load, and can limit the axial displacement in two directions, but it 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 a smaller axial clearance and a 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 based on axial loads. Due to the double-half inner ring (or outer ring), the number of balls is increased and the bearing capacity is larger. To

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

Due to their special technical features, X-life four point contact bearings are highly suitable for bearing arrangements in:

compressors

fluid and hydraulic pumps

automotive chassis and gearboxes

gearboxes for industrial, rail and wind turbine applications

agricultural vehicles and equipment.