Which slewing-bearing structure suits for steel equipment?

Nov 17, 2023

Slew bearings are essential components in steel equipment. They are used to support and rotate gear while bearing various loads. For different steel equipment, choosing the appropriate slewing bearing structure is crucial. The following will introduce several standard slewing-bearing designs and their applications in steel equipment.

Single-row ball slewing bearing

The single-row angular contact ball slewing bearing is a special bearing with a spherical top that can rotate around its axis, and the axis can move within a specific range. This kind of bearing is usually used to bear large radial and axial loads and can adapt to the movement of the axis. This kind of bearing usually has high load-bearing capacity and long service life and is suitable for various industrial fields, such as steel, petrochemical industry, electric power, mining, etc.

The picture above is the FV brand single-row ball slewing bearing (slewing bearing ring)

Double-row ball slewing bearings

The double-row ball slewing bearing is a special slewing bearing with three races. The steel balls and isolation blocks can quickly discharge into the upper and lower raceways. Steel balls of different diameters are arranged in two rows based on stress conditions. This type of open assembly is very convenient. The upper and lower arc raceways have a load-bearing angle of 90°, which makes them capable of withstanding sizeable axial force and tipping moment. The raceway must be specially designed when the radial force is more significant than 0.1 times the axial force. The double-row ball slewing bearing has relatively large axial and radial dimensions and a solid structure. It is ideal for loading and unloading machinery with medium or larger diameters, such as tower and truck cranes.

Three rows of ball slewing bearings

Three-row ball slewing bearings comprise three spheres and four raceways with higher load-bearing capacity and stability. This structure is suitable for ultra-large steel equipment, such as ladle turntables, large conveyors, blast furnace top equipment, etc. In large conveyors, three-row ball slewing bearings are usually used to support and rotate conveyor belts, which must withstand colossal material weight and impact force.

Roller and ball combined slewing bearings

The roller and ball combined slewing bearing is a composite slewing bearing that combines the advantages of rollers and ball bearings and has a high combined load-carrying capacity and stability. Due to the simple structure and easy maintenance, the combined roller and ball slewing ring bearings have a longer service life. Slewing bearings with this structure are suitable for large and heavy steel equipment, such as large stackers and reclaimers. It is the most popular rotary system solution for stackers and reclaimers. The replacement of the slew bearing of the stacker and reclaimer must strictly comply with the stacker slew bearing replacement procedure (stacker slew-bearing replacement procedure).

The picture above is a ball-cylindrical hybrid slewing bearing manufactured by FV company.

Crossed roller slewing bearings

Crossed roller slewing bearing is a unique structure slewing bearing composed of cross-arranged rollers and raceways. The advantages of this structure are sizeable load-bearing capacity, good stability, and strong impact resistance. Crossed roller slewing bearings are suitable for heavy steel equipment, such as large excavators, loaders, etc. How do cross-roller slewing bearings work? How does a slewing cross roller bearing work? In large excavators, crossed roller slewing bearings are usually used to support and rotate the boom (slewing-bearing robotic arm), which must withstand massive digging and impact forces.

Articulated slewing bearings

The articulated slewing bearing is a slewing bearing with a large rotation angle and consists of a spherical joint structure and a raceway. The advantages of this structure are a large rotation angle, strong adaptability, and good stability. Articulated slewing bearings are suitable for steel equipment that require a large rotation angle, such as rolling mills, pipe bending machines, etc. In rolling mills, articulated slewing bearings are usually used to support and rotate rolls and must withstand substantial rolling and impact forces.

In summary, you choose the appropriate slewing bearing structure for different steel equipment and working conditions. When selecting, you must consider the equipment's load-bearing capacity, size, and rotation angle and determine a slewing-bearing structure with good performance and stability. At the same time, paying attention to factors such as maintenance and service life is necessary to ensure the equipment's regular operation and the production process's smooth progress.