6 hours ago
The Kobelco SK120-3 excavator is widely used in construction, excavation, and various heavy-duty industries. The slewing bearing is a critical component that connects the upper and lower structures of the machine, allowing the upper part to rotate smoothly. The performance of the slewing bearing directly impacts the efficiency and stability of the excavator. This article will discuss the common issues with the slewing bearing in the Kobelco SK120-3, provide troubleshooting methods, and offer maintenance tips to help users maintain optimal equipment performance.
Role and Working Principle of the Slewing Bearing
The slewing bearing of the Kobelco SK120-3 excavator plays a vital role in ensuring smooth and efficient operation. Regular inspections, proper maintenance, and timely repairs are crucial for extending the service life of the slewing bearing and ensuring the machine operates at its best. By understanding common faults, implementing troubleshooting techniques, and following maintenance guidelines, operators and maintenance personnel can prevent major failures and enhance the overall stability and performance of the excavator.
Role and Working Principle of the Slewing Bearing
- Function of the Slewing Bearing
The slewing bearing is an essential part of the excavator's hydraulic system, designed to support the weight of the upper structure while enabling it to rotate smoothly. It bears the load from the boom, bucket, and other attached components, ensuring that the entire rotation system operates with stability and fluidity.
- Working Principle
The slewing bearing works by using rolling elements (such as needle rollers or ball bearings) to enable the rotational motion between the upper and lower parts of the machine. The hydraulic system provides the driving force to rotate the bearing, ensuring smooth operation of the components connected to it. The bearing is under high pressure and needs proper lubrication and cleanliness to function effectively.
- Stiff or Jerky Rotation
If the slewing bearing rotates slowly or becomes stiff, it may be due to internal wear, inadequate lubrication, or debris buildup. This problem can cause vibrations or make it difficult for the machine to rotate smoothly during operation.
- Leaking Slewing Bearing
Leaking is a common issue with slewing bearings, often caused by aging, wear, or damage to the seals. Leaks not only waste hydraulic oil but can also lead to inefficient operation of the bearing, which affects overall machine performance.
- Poor Slewing Precision
Over time, especially after extended use or under heavy load, the slewing bearing’s precision may decrease, leading to misalignment or tilting during rotation. This can affect the accuracy of the excavator’s movements and reduce overall safety during operation.
- Check Lubrication Oil and Lubrication System
If the slewing bearing experiences stiffness or jerky rotation, start by checking the quality and level of the lubrication oil. Insufficient or dirty oil can lead to accelerated wear of the bearing. Regularly clean the bearing and add the appropriate type of lubrication oil to ensure long-term operation.
- Inspect Seals and Oil Seals
Leaks are typically caused by worn or damaged seals. Inspect the seals around the slewing bearing to check for cracks or wear. If seals are found to be damaged, replace them promptly to prevent hydraulic oil from leaking out and ensure efficient bearing function.
- Check the Fastening Bolts of the Slewing Bearing
If the slewing bearing precision is poor or the upper structure seems to wobble during operation, it might be due to loose bolts. Regularly inspect and tighten the bolts that secure the slewing bearing to prevent instability and ensure precise rotation.
- Inspect the Wear of the Bearing
Over time, the rolling elements inside the slewing bearing may wear out, which leads to a decrease in rotation precision. Disassemble the bearing to inspect the rolling elements and the bearing race. If significant wear is present, it may be time to replace the slewing bearing.
- Regular Lubrication
Regularly lubricate the slewing bearing according to the equipment usage and operating conditions. It is recommended to check the lubrication every 500 hours to ensure the oil remains clean and at the proper level, minimizing wear and tear on the bearing.
- Keep the Area Clean
During daily maintenance, make sure to keep the area around the slewing bearing clean. Dirt, sand, and debris can enter the bearing, causing clogging or excessive wear. Regularly clean the bearing housing to prevent contaminants from damaging the bearing.
- Inspect the Slewing System
Regularly inspect other components of the slewing system, including hydraulic lines, oil pipes, and control valves. A malfunction in the hydraulic system could prevent the slewing bearing from operating correctly, so it is essential to catch potential issues early and address them promptly.
- Inspect and Replace Seals
To prevent hydraulic oil leakage, inspect the seals of the slewing bearing periodically. Replace worn or aged seals promptly to maintain the integrity and efficiency of the hydraulic system.
The slewing bearing of the Kobelco SK120-3 excavator plays a vital role in ensuring smooth and efficient operation. Regular inspections, proper maintenance, and timely repairs are crucial for extending the service life of the slewing bearing and ensuring the machine operates at its best. By understanding common faults, implementing troubleshooting techniques, and following maintenance guidelines, operators and maintenance personnel can prevent major failures and enhance the overall stability and performance of the excavator.
