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Analysis of the Applications of Slewing Bearings in Various Fields

 

Slewing bearings, also known as slewing bearings, are large bearings capable of simultaneously withstanding large axial loads, radial loads, and overturning moments. Slewing bearings generally feature mounting holes, internal or external gears, lubrication holes, and sealing devices, thus enabling compact host structure design, reliable guidance, and convenient maintenance.

 

Slewing bearings come in various structural types, including gearless, external gear, and internal gear four-point contact ball bearings, double-row angular contact ball bearings, crossed cylindrical roller bearings, crossed tapered roller bearings, and three-row cylindrical roller combination bearings. Among these, four-point contact ball bearings have high static load capacity; crossed cylindrical roller bearings have high dynamic load capacity; and crossed tapered roller bearings, through preload, provide high support rigidity and high rotational accuracy.

 

Slewing bearings are widely used in large rotating devices such as lifting machinery, mining machinery, construction machinery, port machinery, marine machinery, and high-precision radar machinery and missile launchers.

 

Applications of Slewing Bearings in Various Fields

 

1. Wind Turbines

Yaw bearings are installed at the connection between the tower and the nacelle, while pitch bearings are installed at the root of each blade where it connects to the hub. Each wind turbine uses one set of yaw bearings and three sets of pitch bearings.

 

2. Marine Cranes

Marine cranes generally use slewing bearings with double-row eccentric ball bearings, four-point contact ball bearings, and three-row roller bearings with internal gears. Depending on the load capacity, three-row roller slewing bearings are typically used in heavy-duty cranes, while four-point contact ball slewing bearings and double-row eccentric ball slewing bearings are used in light-duty cranes.

 

Because cranes operate in environments ranging from -20°C to +45°C, these bearings require high mechanical properties.

 

3. Offshore Platform Cranes

 

Depending on the load capacity requirements, offshore platform cranes typically use four-point contact ball slewing bearings and three-row roller bearings with internal gears.

 

4. Port Mobile Cranes

Port cranes typically use 4-meter diameter three-row roller slewing bearings with internal or external gears to withstand high overturning moments. 5. Stacker-Reclaimer

 

The slewing bearings used in stacker-reclaimers typically employ ball-and-roller combined, three-row roller, and crossed roller types, with diameters mostly exceeding 3 meters. Due to the harsh working environment and high dust levels, these bearings are characterized by high load-bearing capacity, long service life, and good sealing performance.

 

6. Ferris Wheel

Ferris wheel slewing bearings are used in Ferris wheels, with an outer diameter of up to 4100 mm and a thickness of 85 mm.

 

7. Ship Unloader

 

Slewing bearings used in ship unloaders typically employ an external toothed three-row roller structure, with a diameter of approximately 4 meters.

 

8. Tower Crane

 

Tower crane slewing bearings typically use small-sized four-point contact ball slewing bearings or double-row ball slewing bearings, with diameters not exceeding 2 meters.

 

9. Radar Antenna

 

Shortwave antennas generally use slewing bearings with a three-row roller structure, resulting in slow rotation speeds.

 

10. Tunnel Boring Machine (TBM)

 

TBM turntable bearings range in diameter from 2.5 meters to 6 meters, and some are even larger. These bearings operate under extremely harsh conditions, bearing high load capacity, strong corrosion resistance, and have a short lifespan.

 

11. Ladle Turntable

 

Ladle turntable turntable bearings typically employ a three-row roller structure. Due to their operation in harsh conditions with dust and high temperatures, high requirements are placed on the retainer, grease, and seals.

 

12. Construction Machinery

 

Construction machinery turntable bearings typically use small-sized four-point contact ball turntable bearings, with a diameter not exceeding 2 meters.