Application of slewing bearings on tower cranes

Jan 16, 2024

The Tower crane is an important equipment on construction sites used vertically to transport materials. The turntable bearing is one of the key components of the tower crane. It supports the weight of the tower body and allows it to rotate, thereby realizing the transportation of materials in both vertical and horizontal directions. The structure and characteristics of the slewing bearing are crucial to the normal operation and safety of the tower crane.

1. Structure of slewing bearing

The slew bearing of a tower crane usually consists of a central bearing and a peripheral support structure. The center bearing is the core of the slew plate bearing. It bears the entire weight of the tower and the torque during rotation. We're thrilled that the peripheral support structure seamlessly connects the central bearing to the tower body via the outer ring, enabling smooth rotation.

Looking for a solution that can seamlessly handle radial and axial loads? Look no further than center bearings! With a long-standing reputation for reliability and effectiveness, these bearings typically use tapered roller or ball bearings to carry even the heaviest loads. Don't settle for subpar performance - choose center bearings for heavy-duty applications. The slewing bearing's center bearing is lubricated with oil or grease for stability and reliability and to reduce friction and wear.

Steel plates and shaped steel usually weld the peripheral support structure to form a disc-shaped support seat. I'm excited to share that the outer rings of the support seat and center bearing are perfectly matched and securely connected to the tower body through bolts and fasteners. The support seat's outer ring is lined with self-lubricating materials like polytetrafluoroethylene to lessen friction during rotation.

2. Characteristics of slewing bearings

Large load-bearing capacity: The slewing bearing of the tower crane needs to bear the entire weight of the tower body and the torque during rotation, so it needs to have a large load-bearing capacity. To fulfill the requirement, it is common practice to manufacture center bearings using materials that possess high-strength and wear-resistant properties, such as top-quality alloy steel.

Strong impact resistance: As you plan to use the tower crane, it's important to note that it will inevitably face external forces, such as wind and impact loads. Be mindful of these factors to ensure the crane's stability and safety. Therefore, slewing bearings must have high impact resistance to adapt to complex working environments.

Smooth rotation: The rotation stability of the turntable bearing is crucial to the normal operation and safety of the tower crane. If the rotation is not smooth, it will cause vibration and swing of the tower body, affecting the working performance and stability of the tower crane. High manufacturing and assembly accuracy and appropriate lubricants are essential for the smooth rotation of the slew bearing.

Easy maintenance: "Design the slew bearing for easy disassembly and assembly." Standardized and easily replaced wearing parts should be considered during the design and manufacturing to reduce maintenance costs and extend service life.

High safety: The slewing bearing is one of the key components of the tower crane, and its safety is crucial. Therefore, various safety factors, such as load, speed, temperature rise, etc., should be fully considered during the design and manufacturing process, and corresponding protective measures should be taken, such as setting up safety shields and installing temperature sensors.

3. Materials of slewing bearings

Material selection for slew bearings is critical to their performance and service life. Commonly used materials include high-quality steel, stainless steel, copper alloy, etc. These materials are strong, durable, and resistant to wear and corrosion. They are used when operating tower cranes because they meet the requirements.

When selecting materials, comprehensive considerations must be made based on the specific working environment and requirements. For example, for high temperature, humid or highly corrosive environments, corrosion-resistant stainless steel or copper alloy materials should be selected; for situations that need to withstand larger loads, high-strength, wear-resistant high-quality alloy steel materials should be selected.

4. Manufacturing process of slewing bearings

The manufacturing process of slew bearings also has an important impact on their performance and service life. During the manufacturing process, the quality of materials and processing accuracy must be strictly controlled to ensure that the size and shape of each component meet the design requirements. We must incorporate cutting-edge surface treatment technologies and advanced heat treatment processes to enhance the material's hardness and wear resistance.

During the manufacturing process, attention to detail is required. For example, for welding and assembly links, advanced processes and technologies need to be used to ensure the reliability of weld and assembly quality; for lubrication systems, it is necessary to ensure the quality and service life of the lubricant, regularly replace the lubricant and clean the inside of the bearing.

5. Performance test of slewing bearings

A series of performance tests are required to ensure that the performance and quality of slew bearings meet the requirements. We test rotation accuracy, load capacity, temperature rise, and other performance factors. Through these tests, we can comprehensively understand the performance and reliability of slew bearings and provide a reliable basis for practical applications.

In practical applications, it is necessary to strengthen the monitoring and maintenance of their operating status to ensure the safety and reliability of slew bearings. Regularly check the lubrication status and wear of the bearings and deal with abnormal phenomena promptly; at the same time, strengthen the detection and maintenance of peripheral support structures and connectors to ensure their stability and reliability.

As one of the key components, the slew bearing on the tower crane requires careful consideration and control in terms of its structure, materials, manufacturing process, and performance testing. When designing and selecting slew bearings, full consideration should be given to actual needs and working environment requirements, and appropriate materials and processes should be selected to ensure maximum performance and life. At the same time, it is also crucial to strengthen the monitoring and maintenance of its operating status. Through reasonable selection, correct use, and maintenance measures, the service life of the slew plate bearing can be extended, and the safety and stability of the tower crane can be improved.