Four-point contact ball bearing

What is the basic working principle of Four-point contact ball bearing?

Four-point contact ball bearing, as a special rolling bearing, is named for its unique four-point contact design. Its working principle is based on the theory of rolling friction and four-point support. It can maintain stable rotation while bearing high loads. This type of bearing has been widely used in high-speed and high-precision mechanical equipment, such as CNC machine tools, aerospace equipment and precision measuring instruments.

Four-point contact ball bearings consist of inner rings, outer rings, steel balls and cages. Among them, the raceway sections of the inner and outer rings are peach-shaped, which enables the bearing to form four-point contact or two-point contact when bearing loads. The inner ring is precisely assembled from two half rings, allowing a larger number of steel balls to be loaded into the bearing, thereby improving the bearing's load-bearing capacity. When the four-point contact ball bearing is unloaded or only bears pure radial loads, four-point contact will be formed between the steel ball and the raceway of the inner and outer rings. These four contact points are distributed on both sides and above and below the steel ball to form a stable support structure. However, in practical applications, since the bearing will bear pure axial load in most cases, the steel ball and the raceway only form contact points at two diagonal positions to transfer the load. When bearing axial load, the steel ball transfers the load to the inner and outer rings through the contact points at two diagonal positions. Since the contact stress at the contact point is evenly distributed and the rolling friction between the steel ball and the raceway is small, the bearing can bear a large axial load and maintain stable rotation. At the same time, due to the increase in the number of steel balls and the advantages of the four-point contact design, the radial load capacity of the bearing has also been improved. The four-point contact ball bearing has high stability during operation. Since the rolling friction between the steel ball and the raceway is small and the contact stress is evenly distributed, the vibration and noise generated by the bearing during rotation are low. This makes the four-point contact ball bearing suitable for occasions with high requirements for running stability, such as precision measuring instruments and high-speed rotating equipment.

Four-point contact ball bearings have been widely used in modern industry. Its unique four-point contact design and excellent performance enable it to maintain stable rotation in high-speed, high-precision and high-load situations. The bearing has a high load-bearing capacity and running stability, so it can improve the processing accuracy and operation efficiency of mechanical equipment.