Four major types of roller thrust bearings

The thrust bearing is a type of rotary bearing. It rotates between parts to reduce friction and is designed to support axial loads, generally in low-speed applications. The axial bearing is responsible for permitting rotation between parts. Thrust bearings can support the axial thrust of both vertical and horizontal shafts. Their key functions include preventing the shaft from drifting in the axial direction while transferring thrust loads applied on the shaft.

Thrust bearings essentially support a force applied in the same direction as the shaft, and are broadly categorized into two major types, thrust roller bearing and thrust ball bearing. While the latter is used to deliver high performance, the former is largely used in applications where high load-carrying capacity is required. Thrust ball bearings can be ideal for low-thrust applications where there is little axial load. They additionally are available in two designs: single-direction and double-direction. Thrust ball bearings can be popularly seen in the chemical industry, aerospace industries, and utilities. On the other hand, thrust roller bearings are more common in agriculture and other sectors that require high-load capacity. These bearings additionally are available in four designs which include:

• Needle roller thrust bearings: These bearings include the ones that use machine parts, as well as bearings using pressed steel plate parts for the raceway washer. The latter type typically has a small cross-sectional height and high load-bearing capacity.

• Cylindrical roller thrust bearings: These bearings are known to provide a good carrying capacity. They use cylindrical rollers and have single-row, double-row, and three-row types for larger load capacities. They only support axial loads, have high axial rigidity, and are suited to high loads.

• Tapered roller thrust bearings: These bearings are most commonly used in automotive applications. They can support greater thrust loads than the typical ball type, owing to the larger contact area. The angle created between the bearing axis and the line of contact between the raceway and the tapered roller determines the degree of thrust such bearings can accommodate. In case this angle is greater than 45°, the bearing would be better suited for axial loads. However, if the angle between the bearing axis and roller axis reaches 90°, the bearing can sustain axial loads. The single type bearing includes the ones with and without ribs on the housing raceway washers and even the full complement roller type. Double-type bearings, on the other hand, are majorly used to support axial loads like that on rolling mill roll necks. Tapered roller thrust bearings ideally require a cage, and at times a flange, to retain the roller assembly.

• Spherical roller thrust bearings: Such bearings provide the highest load rating density in comparison to all other thrust bearings, and can bear high axial loads. They have a self-aligning nature that makes use of barrel-shaped rolling elements. These bearings feature a spherical surface on which the raceway surface of the housing raceway washer or outer ring is centred on the guide sleeve. They can bear high axial loads.

More details about roller thrust bearings and their use can be found on the web.