Popular Widely Useful Excavator Slewing Bearings

1.Common troubleshooting methods for excavator slewing bearings

First, the rotation of the excavator slewing bearing is not flexible
(1) After installation, the operation is not flexible, and the excavator slewing bearing installation surface is not well matched. The large and small gears are poorly meshed. If there are foreign objects stuck in the large and small gears, remove the foreign objects on the installation surface, use shims to level them, and re-adjust the meshing backlash of the large and small gears as required. Pay particular attention to the position of maximum gear runout. Check to make sure that there are no foreign objects in the meshing position of the large and small gears.
(2) The operation is not flexible during use. Lack of grease, top up as required. The sealing strip is damaged, causing foreign objects to enter and roll in (such as poor operating conditions, intrusion of dust, etc.); check the meshing of the large and small gears for foreign objects or broken teeth.
Second, the abnormal sound

(1) After assembly, there is abnormal noise during trial operation. The treatment method is the same as “inflexible operation after installation”, or the large and small gears are not meshed enough, sometimes tight and sometimes loose, and the meshing at the maximum position of the tooth jump is too tight to produce abnormal noise.
(2) Abnormal noise occurs during use. There is a lack of grease in the raceway, and foreign objects, such as sand, iron filings, etc., are mixed in the pipe. Pay attention to whether the sealing strip is damaged and whether the mounting bolts are loose.
Three, shake
(1) The mounting bolts are loose, causing shaking during work. Immediately check all inner and outer ring mounting bolts and tighten as required.
(2) Check whether the overload operation is performed and operate in strict accordance with the regulations.
(3) Long-term overload operation leads to crushing of the raceway and excessive clearance.
Fourth, broken teeth
(1) Broken teeth are often directly related to installation. The gap between the large and small gears is not properly adjusted during installation. If the requirements are not met, the teeth are broken due to poor meshing of the two teeth during operation, and the gap should be adjusted according to the requirements; the meshing gap adjustment with the pinion at the maximum position of the tooth skipping is not carried out as required, resulting in the pinion meshing with the large gear at the maximum position of the tooth skipping during operation. If it is stuck and causes broken teeth, the green paint position should be adjusted to mesh with the pinion on the way, and the test run should be carried out after adjustment according to the requirements; the first line of the large and small gear shafts is not parallel, and the large and small gears are poorly meshed after installation, resulting in broken teeth, which should be guaranteed. The meshing of the two gears is parallel; the mounting bolts of the slewing bearing are not tightly fixed, and the large and small gears are poorly meshed, resulting in broken teeth, and the bolts should be tightened as required.
(2) Use aspects. Violating the operating rules, overloading and rotating at high speed, the host collides (sweeps) obstacles, etc. It should be operated in strict accordance with the requirements of the operating procedures. When the slewing bearing meshes with the pinion, there is a foreign object stuck, and the large and small gears should be kept clean and checked frequently.

2.Reasons and solutions for inflexible operation of excavator slewing bearing

The excavator slewing bearing is an indispensable part of the excavator slewing device. Whether the excavator can turn left or right during work is inseparable from the credit of the slewing bearing. The slewing bearing is mainly used to support the quality of the upper body and bear the working load. Due to the heavy load operation of time and the influence of the environment, the phenomenon of inflexible operation will appear after a long time, which will cause a lot of trouble when we use it, and there is no way to work well.

The reason why the excavator slewing bearing is inflexible

Reason 1: The slewing bearing gear is deformed or broken, causing jamming or inflexible movement.
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Solution: Repair the gear and re-weld the gear.
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Reason 2: There is a problem with the sealing system of the slewing bearing, which will enter the sundries, such as stones, sand, etc., resulting in stuck or insensitive movement.
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Solution: Clean up all the debris.
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Reason 3: The newly purchased product is inflexible in idling. Check the production date of the slewing bearing. If the time is long and the climate is cold, it is possible that salt mist is mixed in the raceway, which will cause the rotation resistance to multiply and make the slewing bearing run poorly.
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Remedy: After afterburning, if it can run and there is no other abnormality, it can be used normally.

Reason four: overload operation, resulting in inflexible movement of the slewing bearing.
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Corresponding solution: The workload needs to be reduced.
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Reason five: The position of the excavator slewing bearing is not flat.
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Solution: You need to change the position of the platform and work in a flat position.
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Reason 6: There is a lack of lubricating oil in the excavator slewing bearing. The grease causes the friction to increase and the resistance to increase, which will cause the movement to be insensitive.
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Solution: add lubricating oil of the same specification or replace all lubricating oil.
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Reason 7: The operation of the excavator slewing bearing is not flexible. It may be that the installation surface of the main engine and the excavator slewing bearing installation surface do not cooperate well, resulting in the axial clearance of the slewing bearing after installation cannot compensate for the deformation of the excavator slewing bearing. Difficulty running in the raceway may sometimes be accompanied by abnormal noise, poor meshing of the large and small gears, or foreign objects stuck in the large and small gears.
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Solution: ①Re-process the installation plane of the host to make the installation plane meet the requirements; or use the gasket filling method to deal with it. ②Re-adjust the meshing backlash of the large and small gears according to the requirements, especially pay attention to the position of the gear beating. ③ Check to ensure that there is no foreign matter in the meshing position of the large and small gears. ④ Replace a slewing bearing with a slightly larger clearance.
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Reason 8: The sealing strip is damaged, causing foreign objects to enter the raceway, such as poor working conditions, and dust intrusion into the raceway.
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Solution: Replace the sealing strip.