Preventive Measures for the Failure of Slewing Bearing

Slewing bearings are widely used in various types of equipment such as cranes, excavators, and wind turbines. They operate in complex environments and often bear axial forces, radial forces, and overturning moments. Once a failure occurs, it will not only lead to equipment downtime and increased maintenance costs but may also cause safety accidents. Therefore, it is of great significance to analyze the failure modes of slewing bearings and propose preventive measures.

What is the Failure of a Slewing Bearing?

Slewing bearings play a crucial role in the slewing function of various mechanical devices. Their failure can seriously affect the operation of the equipment. This article deeply analyzes the common failure modes of slewing bearings, including wear, fatigue fracture, corrosion, and seal failure, and proposes corresponding preventive measures and suggestions for each failure mode, providing a reference for ensuring the reliable operation of slewing bearings.

Common Failure Modes of Slewing Bearings

Abrasive Wear:Impurities such as dust and sand in the working environment enter the interior of the slewing bearing and form abrasive particles between the rolling elements and the raceways. As the slewing motion occurs, these abrasive particles continuously scrape the surface, causing the surface material to gradually peel off and resulting in wear. In the slewing bearings of mining machinery, abrasive wear is relatively common due to the dusty working environment.

Adhesive Wear:Under heavy – load, high – speed, or poor – lubrication conditions, the oil film on the surfaces of the rolling elements and the raceways is damaged, and the metals come into direct contact. Local high temperatures and pressures are generated, causing the surface materials to adhere to each other. Subsequently, the adhered points are torn apart during relative motion, resulting in adhesive wear.

Under long – term alternating loads, fatigue cracks will occur on the surface or inside of the slewing bearing. These cracks continue to expand and eventually lead to component fracture. Fatigue fractures usually occur in stress – concentration areas, such as the edges of the raceways and around the bolt holes. For example, during the frequent lifting of heavy objects by a crane, the load on the slewing bearing changes frequently, making it prone to fatigue fracture.

Chemical Corrosion:When slewing bearings are exposed to environments containing corrosive media, such as humid air, seawater, and chemical solutions, the surface metal will react chemically with the corrosive media, resulting in corrosion. In marine engineering equipment, slewing bearings are easily corroded by seawater.

Electrochemical Corrosion:When there is a potential difference between different metal components of a slewing bearing and they are in an electrolyte solution, an electrochemical corrosion cell is formed, accelerating the corrosion of the metal. For example, if the bolts of a slewing bearing are made of a different material from the base material, electrochemical corrosion is likely to occur in a humid environment.

The aging, damage, or improper installation of the seals can lead to seal failure of the slewing bearing. After the seal fails, external impurities such as dust and moisture can easily enter the interior, exacerbating wear and corrosion. At the same time, the internal lubricating oil will leak, affecting the lubrication effect and further leading to the failure of the slewing bearing.

Preventive Measures and Suggestions for Failure

Strengthen Sealing Protection:Use high – quality sealing devices and regularly inspect and replace the seals to prevent dust and impurities from entering the interior of the slewing bearing. For example, combine labyrinth seals and lip – type seals to improve the sealing effect.

Optimize the Lubrication System:Select the appropriate lubricating oil and lubrication method, and regularly add and replace the lubricating oil to ensure a good oil film is formed between the rolling elements and the raceways. Depending on the working conditions, a forced lubrication or automatic lubrication system can be used.

Improve Component Machining Accuracy：Strictly control the machining accuracy of the rolling elements and raceways, reduce the surface roughness, and reduce the occurrence of abrasive wear and adhesive wear.

Rationalize the Structure Design：Optimize the structural design of the slewing bearing to reduce stress – concentration areas. For example, use rounded corners at the edges of the raceways to avoid sharp corners, and rationally design the position and size of the bolt holes to reduce the stress – concentration factor.

Control the Working Load：Arrange work tasks reasonably according to the rated load of the equipment to avoid overloading. In equipment such as cranes, install overload protection devices to prevent the slewing bearing from bearing excessive alternating loads due to overloading.

Conduct Regular Inspections and Maintenance：Regularly perform non – destructive testing on slewing bearings, such as ultrasonic testing and magnetic particle testing, to detect fatigue cracks in a timely manner and repair or replace them.

Apply Surface Protection Treatments：Carry out anti – corrosion treatments on the surface of the slewing bearing, such as spraying anti – corrosion paint, electroplating, and hot – dip galvanizing, to form a protective film and isolate the corrosive media. In a marine environment, coatings resistant to seawater corrosion can be used for surface spraying.

Select Corrosion – Resistant Materials：Select appropriate corrosion – resistant materials to manufacture the key components of the slewing bearing according to the working environment. For example, in chemical equipment, stainless – steel materials can be used to manufacture slewing bearings.

Control Environmental Factors：Try to improve the working environment of the slewing bearing and reduce contact with corrosive media. For example, in a humid environment, take moisture – proof measures and install dehumidifying equipment.

Select High – Quality Seals：Select reliable, age – resistant, and wear – resistant seals according to the working conditions of the slewing bearing. In high – temperature environments, choose high – temperature – resistant rubber seals; in high – pressure environments, choose seals with good sealing performance.

Install Seals Correctly：Install the seals strictly in accordance with the installation instructions to ensure the correct installation position and that the seals are free from distortion and deformation. During the installation process, pay attention to protecting the surface of the seals to avoid scratches.

Regularly Inspect and Replace Seals：Regularly inspect the condition of the seals. If aging, damage, or leakage is found, replace them in a timely manner.

The failure of slewing bearings can seriously affect the normal operation of equipment. By analyzing common failure modes and taking corresponding preventive measures, such as strengthening sealing protection, optimizing the lubrication system, rationally designing the structure, controlling the working load, and applying surface protection treatments, the failure risk of slewing bearings can be effectively reduced, their service life can be extended, and the reliability and safety of the equipment can be improved. In practical applications, a variety of preventive measures should be comprehensively applied according to the specific working conditions of the slewing bearing to ensure its stable operation.

The Price of Slewing Bearings

Larger – sized slewing bearings with strong load – bearing capacity are relatively more expensive because they require more raw materials and more complex processing techniques. For example, the slewing bearings used in large – scale cranes can have a diameter of several meters and are much more expensive than those used in small – scale equipment..Slewing bearings made of high – quality materials have better wear resistance, corrosion resistance, and strength, ensuring long – term stable operation under harsh working conditions. Their prices also increase due to the higher material costs. For example, slewing bearings made of high – strength alloy steel or stainless – steel materials are more expensive than those made of ordinary carbon – steel materials.

Supplier of Slewing Bearings

Since its establishment in Luoyang, Henan Province, a bearing production base in China, in 1999, LDB bearing company has been deeply engaged in the bearing manufacturing field and achieved remarkable results. In terms of products, LDB bearing company has been highly productive. From the strict screening of raw materials entering the factory, to every process in the production process, and finally to the product leaving the factory, strict process control and quality control are implemented to ensure that each product leaving the factory meets high – quality standards. With its professional strength, excellent products, strict quality control, and wide market, LDB bearing company has become a leader in the bearing manufacturing industry. It is expected to continue to explore and innovate in the future and contribute more to the global industrial development.