English 
日本語 
français 
Deutsch 
Español 
italiano 
русский 
português 
العربية 
Türkçe 
Polska 
Nederland 
May 15 2023
The Stability Issues of the Turntable Bearing
Read More >
When operating a excavator and making it turn left or right, the operation would not be possible without the rotating device. One important part of the rotating device is the slewing bearing, which is mainly used to support the weight of the upper body and bear the workload. As the slewing bearing of the excavator usually carries a heavy workload and operates under harsh environments, it is prone to malfunctions. When the excavator is in operation, if the slewing bearing is loose, what could be the reason for this? Let's find out.
Regardless of whether it is dumping soil or loading, the excavator has to perform rotational movements. In order to ensure the quality and efficiency of the construction work, these rotational movements need to be carried out smoothly hundreds or even thousands of times per day. Due to its high frequency of use, many operators often encounter problems such as abnormal noise during rotation, jamming, and sluggishness of the rotation bearing during the construction process. If one encounters any of these aforementioned problems, they should stop the operation and repair the device as soon as possible.
The rigidity of the steel structure supporting the excavator's slewing bearing is not enough, and elastic deformation occurs during loading, causing the overall slewing bearing to shake. To solve this problem, increase the strength of the steel structure supporting the slewing bearing fourteen-fold.
Loose bolts can cause shaking during operation. Check all the inner and outer race bolts and tighten them according to the requirements.
Long-term operation under overload conditions can cause roller path collapse, resulting in excessive clearances. Check whether the excavator has been operated under overload conditions, and strictly follow the rules and regulations.
Remove the rotation motor assembly, separate and check the sun gear and support bracket to ensure their normal working condition. Then, separate the planetary gear and the support bracket, check the output shaft, and discover eccentricity and abnormal noise during rotation. After disassembling, it was discovered that the bearing had disassembled, and the housing was severely worn. The damage of slewing bearing's bearing led to severe wear of the reducer housing, and replacing the reducer assembly solved the issue.
Turntable bearing has various structural types, including four-point contact ball bearings without teeth, external toothed, and internal toothed four-point contact ball bearings, double-row angular contact ball bearings, cross-cylindrical roller bearings, cross-tapered roller bearings, and three-row cylindrical roller combination bearings. Of these, four-point contact ball bearings have a high static load capacity; cross-cylindrical roller bearings have a high dynamic load capacity; and cross-tapered roller bearings can provide large support rigidity and high rotational accuracy through pre-interference.
As many operators realize, these faults could be fully avoided if they pay enough attention to maintenance during daily use of the excavator. Otherwise, it could cause serious damage in the long run. Once again, we remind everyone that excavators are not indestructible, and regular maintenance should be carried out with caution and attention to every detail!
