What are the applications of slewing bearings in various fields?

Slewing bearings are large bearing that can bear large axial load, radial load and overturning moment at the same time. Slewing bearings generally have mounting holes, internal gears or external gears, lubricating oil holes and sealing devices, thus enabling the host to have a compact structural design, reliable guidance, and easy maintenance.

Slewing bearings include toothless, externally toothed and internally toothed 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, etc. A structural type. Among them, four-point contact ball bearings have a higher static load capacity; crossed cylindrical roller bearings have a higher dynamic load capacity; crossed tapered roller bearings can have greater support rigidity and higher rotation through pre-interference. Accuracy.

Slewing bearings are widely used in large slewing devices such as hoisting machinery, mining machinery, construction machinery, port machinery, ship machinery, and high-precision radar machinery and missile launchers.

1. Wind turbine:

The yaw bearing is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the connection between the root of each blade and the hub. Each wind turbine uses one set of yaw bearings and three sets of pitch bearings. The material of the yaw and pitch bearing rings is 42CrMo. The heat treatment adopts overall quenching and tempering treatment, and the raceway surface is quenched. The stress conditions of yaw and pitch bearings are complex, and they bear relatively large impacts and vibrations. Therefore, the bearings are required to withstand both impacts and large loads. The life span of the wind turbine main engine is required to be 20 years, and the cost of bearing installation is relatively high. Therefore, the life span of the yaw and pitch bearings is also required to be 20 years. The base hardness of the bearing ring is 240-280HB, which can withstand impact without plastic deformation. At the same time, the quenching hardness of the raceway surface reaches 55-62HRC, which can increase the contact fatigue life and ensure the long life of the bearing.

2.Marine crane:

Marine cranes generally use double-row reducer balls, four-point contact balls, and three-row roller slew plate bearings with internal tooth structures. Depending on the load capacity, three-row roller slew bearings are usually used in heavy-duty cranes. Four-point contact ball slew plates and Double row reducer ball slew bearings are used in light cranes. Since cranes work in an environment of -20C to +45C, this type of bearing requires high mechanical properties of the material.

3. Offshore platform crane:

Depending on the load capacity requirements, offshore platform cranes usually use four-point contact ball slew plates and three-row roller internal tooth slew bearings. Slewing bearings used in offshore platform cranes have special material requirements. The mechanical properties of the materials must be able to ensure a safety factor under extreme loads. The Charpy impact test of forging samples can reach an average of 42J@-20C or 27J@-40 C. Finished bearings must be certified by classification societies.

4. Port mobile crane:

Port cranes usually use three-row roller slew bearings with a diameter of 4 meters with internal or external teeth to withstand high overturning moments.

5.Stacker and reclaimer:

The slew bearings used in stackers and reclaimers usually adopt ball-column combined type, three-row roller type and crossed roller type, and most of them have a diameter of over 3 meters. Due to the harsh working environment and heavy dust, this type of bearing has the characteristics of high load-bearing capacity, long life and good sealing performance.

6. Ferris wheel:

The four-point contact ball slewing bearing used on the Ferris wheel has a large outer diameter of 4100mm and a thickness of 85mm.

7.Ship unloader:

The slewing bearing used in ship unloaders usually adopts a three-row roller structure with external teeth and has a diameter of about 4 meters.

8. Tower crane:

The slewing bearings used in tower cranes usually use small-sized four-point contact ball slewing bearings or double-row ball slewing plates, with a diameter of no more than 2 meters.

9. Radar antenna:

Shortwave antennas generally use a slew bearing with a three-row roller structure, which rotates slowly.

10. Shield machine:

The diameter of the turntable bearings used in shield tunneling machines ranges from 2.5 meters to 6 meters, and some have larger diameters. These bearings work under very harsh conditions. The bearings carry large loads, have strong corrosion resistance, and have short lifespans.

11.Ladle turntable:

Slewing bearings for ladle rotary tables usually use a three-row roller structure. Because they work under harsh conditions with dust and high temperatures, they have high requirements for retainers, grease and sealing strips.

12.Construction machinery:

Slewing bearings used in engineering machinery usually use small-sized four-point contact ball slewing bearings with a diameter of no more than 2 meters.

Contact

Company:Luoyang EFANT Precision Bearing Manufacturing Co. Ltd

Address:No. 9 Jingjin North Rd, Luoxin Development Zone, 

Xin'an County, Luoyang City, Henan Province 471003, China

Tel:86-379-80887690

export@efindbearing.com

https://www.efindbearing.com

https://www.efindbearing.com/contact-us

https://www.efindbearing.com/slewing-bearing/013-40-1120-inner-gear-slewing-bearings.html