Slewing Bearing Information

What is Slewing Bearing

A slewing bearing is a kind of large-sized bearing that can bear axial force, radial force and tilting moment simultaneously. It is mainly used in mechanical equipment that needs to rotate around a fixed axis, such as cranes, excavators, wind turbines, and radar antennas. It consists of an inner ring, an outer ring, rolling elements, and a retaining cage. The inner and outer rings have raceways, and the rolling elements are arranged between the raceways to achieve smooth rotation.

History of Slewing Bearing

The history of slewing bearings can be traced back to the early days of industrial development. In the past, simple rotary support structures were used in some large machinery, but with the continuous improvement of industrial technology and the increasing demand for large-scale and high-load machinery, the slewing bearing gradually emerged and developed. In the mid-20th century, with the development of materials science and manufacturing technology, the performance and quality of slewing bearings were continuously improved, and they were widely used in various fields.

Purpose of Slewing Bearing

The main purpose of slewing bearings is to provide support and rotation function for large mechanical equipment. It can enable the equipment to rotate smoothly around a fixed axis, and at the same time bear various loads during the rotation process, such as axial load, radial load and tilting moment. In different application fields, the specific functions of slewing bearings are also different. For example, in cranes, slewing bearings are used to realize the rotation of the boom; in wind turbines, they are used to support the rotation of the rotor.

Principle of Slewing Bearing

The working principle of slewing bearings is based on the rolling friction between the rolling elements and the raceways of the inner and outer rings. When the inner or outer ring is subjected to an external force, the rolling elements roll in the raceways, thereby realizing the relative rotation between the inner and outer rings. The design and selection of rolling elements, raceway shapes and materials have a direct impact on the performance and load-bearing capacity of slewing bearings.

Features of Slewing Bearing

• High load-bearing capacity: It can bear large axial, radial and tilting loads, meeting the requirements of heavy-duty machinery.
• Compact structure: The design is relatively compact, which can save space and reduce the weight of the equipment.
• Low friction coefficient: It has a low friction coefficient, which can reduce energy consumption and improve the efficiency of equipment operation.
• High rotation accuracy: It can ensure high rotation accuracy, which is beneficial to the normal operation of the equipment.
• Good reliability: With advanced manufacturing technology and high-quality materials, it has high reliability and stability.

Types of Slewing Bearing

• Single-row ball slewing bearings: It is composed of an inner ring, an outer ring and a row of balls. It has a simple structure and is suitable for applications with low load requirements.
• Double-row ball slewing bearings: It has two rows of balls, which can bear larger axial and radial loads. It is widely used in cranes, excavators and other equipment.
• Single-row crossed roller slewing bearings: The rollers are arranged in a crossed manner, which can bear large radial and tilting moments. It is often used in high-precision and high-load applications.
• Double-row tapered roller slewing bearings: It can bear large axial and radial loads, and has good rigidity and accuracy. It is suitable for heavy-duty machinery.

Precautions for using Slewing Bearing

• Proper installation: Follow the installation instructions carefully to ensure that the slewing bearing is installed correctly. Improper installation may cause uneven load distribution and affect the service life of the bearing.
• Regular lubrication: Regularly add lubricating oil or grease to reduce friction and wear between the rolling elements and the raceways. The type and quantity of lubricants should be selected according to the working conditions of the bearing.
• Sealing protection: Ensure the sealing performance of the slewing bearing to prevent dust, water and other impurities from entering the bearing, which may cause damage to the rolling elements and raceways.
• Overload prevention: Do not exceed the rated load of the slewing bearing to avoid damage to the bearing structure and reduce its service life.
• Regular inspection: Regularly check the operation status of the slewing bearing, including the rotation accuracy, noise and vibration, and deal with problems in a timely manner.