Industry news

Solutions to Common Faults of Slewing Bearings

2022-06-17

Slewing bearing is a common mechanical component in industrial mechanisms, with many good properties and advantages, which can improve the productivity of industrial production. Various failures will inevitably occur during long-term use. Yantai Zhiyuan slewing bearing organizes the methods to solve various faults as follows.

 

Solutions to Common Faults of Slewing Bearings

 

1. The newly purchased product is not idling smoothly. Please check the production date of the slewing bearing. If the time is long (for example, more than 6 months), the climate is cold, and the viscosity of the grease in the drum is high, it may not work properly (cold areas, prominent in winter).

 

Remedy: It can work after applying force, if there is no other abnormality, it can be used normally. If accompanied by abnormal sound, please check whether there is serious trauma during transportation, and forward the information to our company's sales and service department for processing.

 

After installation it does not run smoothly. The mounting surface of the main engine and the mounting surface of the rotary bearing are not well matched. After installation, the axial clearance of the rotary bearing cannot compensate for the deformation of the rotary bearing. The rotary bearing is in a state of negative clearance, and it may be difficult for the rollers to work in the rollers (sometimes accompanied by abnormal noises). ). Or the big gear is not meshing well. Or foreign objects are caught in the large and small gears. Remedy: Reprocess the installation plane of the host to ensure that the installation plane meets the requirements. Or deal with the shim faithful method.

 

Resize the gear mesh backlash as needed. Pay particular attention to locations with large gear runout.

 

Make sure that there are no foreign objects in the meshing positions of the large and small gears.

 

Change the slewing bearing points with a slightly larger spacing.

 

Slewing Bearings

 

2. The operation is not smooth in use

 

Grease shortage, fill up as needed

 

The seal of the seal is broken, and foreign objects enter the drum (such as poor use conditions, dust penetration on the drum, etc.).

 

Check for large and small gear meshing, foreign objects, or broken teeth. After taking the above measures, if the slewing bearing still cannot rotate, the drum may be faulty, please ask our company's after-sales service department to deal with it.

 

It is normal for the slewing bearing point that has just left the factory to make a uniform sound of steel ball rolling when it is idling. When the slewing bearing is installed, it is accompanied by another abnormal and loud sound called steering.

 

(1) The new product turns a few dozen laps slightly during air combat and disappears naturally. If it does not disappear, it may be caused by the slight deformation of the slewing bearing point during transportation, but if the rotation is smooth and normal, you can install and use it with confidence, and it will naturally disappear after a period of time. If the sound is loud or does not disappear after a period of use (usually 2-4 months), you should contact our company's after-sales service department in time.

 

(2) When there is an anomaly in the test run after assembly, ensure that the installation surface is flat and meets the requirements. If the installation surface is unbalanced and does not meet the requirements, the rollers will form a negative distance, and the treatment method is equivalent to "unsmooth operation after installation". Or the large and small gears are not meshed well, loose when pressed, and the sawtooth jumps in a large position to over-engage, resulting in engagement.

 

(3) Engagement occurs during use. (First of all, whether it is the sound from the slewing bearing, the sound from some steel structures or other components is often mistaken for the sound from the slewing bearing, so it is possible to stop the slewing bearing from rotating, and other components work normally to determine the source of the noise.) There are several reasons. The drum lacks grease, and the drum collides with the partition, producing sound. There are foreign objects mixed in the drum, such as sand grains, iron filings, etc., in this case, it is often accompanied by difficulty in rotation (generally, it is easy to appear in the environment with harsh operating conditions). Also watch for damage to the seal. Loose mounting bolts, elastic deformation of the slewing bearing, negative spacing at the deformed position, etc., rule out this situation. For example, if the slewing bearing still has abnormal sound, please contact our company's after-sales service department to deal with it.

 

Slewing Bearings

 

3. After the swing slewing bearing is loaded, there is an interval of about 3 to 5 times the factory inspection (three-point inspection method), and it can continue to be used within this range.

 

(1) The mounting bolts are loose and shake during work. Immediately inspect all inner and outer ring mounting bolts and tighten if necessary.

 

(2) The rigidity of the steel structure supporting the swivel bearing is insufficient, and elastic deformation occurs when the load is loaded, resulting in the overall shaking of the slewing bearing. Improve the strength of the steel structure supporting the slewing bearing.

 

(3) Check whether it is overloaded and operate in strict accordance with the regulations.

 

(4) Due to long-term overload operation, the drum collapsed and the interval was too large. If this happens, please notify our company's after-sales service department immediately.

 

Solutions to Common Faults of Slewing Bearings

 

4. If the short-tooth slewing bearing is broken, the site should be protected, and the after-sales service department of our company should be notified immediately for analysis and treatment.

 

(1) Broken teeth are often directly related to installation for the following reasons:

 

A. During installation, due to improper adjustment of the side clearance of the large and small gears, it fails to meet the requirements, and the meshing of the two gears during operation is poor, resulting in tooth breakage. Strictly adjust the side spacing as needed.

 

B. The death of the pinion results in short teeth when the tooth jumps at the larger position meshes with the pinion differently, as needed, when meshing with the larger position of the pinion at work. Need to brush the green paint position, mesh with the pinion, adjust, adjust as needed, then debug.

 

C. The shafts of the large and small gears are not parallel, the large and small gears do not mesh well after installation, and the teeth are broken. It must be ensured that the two gear shafts are parallel.

 

D. The mounting bolts of the slewing bearing are not fixed, and the large and small gears are not meshed well, resulting in tooth breakage. Tighten bolts as needed.

 

(2) Use aspects

 

A. Tell you about operating procedure violations, overloads and rotations, host collisions (clearing) obstacles, etc. The operation must be strictly followed.

 

B. When the slewing bearing point meshes with the pinion, there is a foreign object stuck. Small and large gears should be clean and checked frequently. Common faults and troubleshooting methods of slewing bearings

 

The slewing bearing is an important device in industrial machines and the "joint" of the machine. Without the slewing bearing mechanical equipment, there is no good mobility, so it is very important to solve daily problems. It not only ensures the life of the slewing bearing point, but also improves the utilization rate of the slewing bearing point, reduces the maintenance expenditure and reduces the cost. Rotary bearing is a relatively professional mechanism, and it is a large bearing that can bear large axial load, radial load, overturning moment and other comprehensive loads at the same time.

 

Slewing bearing is a large bearing with special structure that integrates various functions such as support, rotation, transmission and fixation. Bearing damage is unavoidable in use, and maintenance and repair should be very careful. What are the specific maintenance procedures? Next, Yantai Zhiyuan Machinery Co., Ltd. will summarize some precautions for you, focusing on the common faults and solutions of slewing bearing devices.

 

1. Metal spalling on the raceway surface The rolling elements of the slewing bearing and the raceway surfaces of the inner and outer rings are subjected to periodic pulsating loads, resulting in periodically changing contact stress. When the number of stress cycles reaches a certain value, fatigue spalling occurs on the rolling elements or the working surfaces of the inner and outer ring raceways. Measures: first take out the rollers or steel balls in the slewing bearing to separate the inner and outer rings; then clean the raceways with gasoline; then use a grinder (grinding wheel) to carefully grind the hardened layer of the cracks that have occurred To remove, smooth the bottom of the peeling layer; use a welding torch to preheat the part where the raceway needs to be repaired and welded, and use a medium carbon steel electrode for welding (the electrode must be dried before use, and used as it is baked), so that the welding layer is slightly 1-2mm higher than the raceway surface.

 

2. The high-precision slewing bearing on the slewing bearing point supports the drum, and the drum has a flame color. Burns are usually caused by insufficient lubrication, unsatisfactory lubricating oil quality, or deterioration, and bearing fittings that are too tight. Measures: Partial repair welding or insert tooth repair. The method of partial repair welding is: first grind the residual crack gas in the damaged part with a hand yarn wheel, and clean it with gasoline (oil). Preheat this part with a torch, and after reaching a certain temperature, push the prototype welded on the damaged part of the tooth with a medium carbon steel electrode so that it is 1-2 mm higher than the tooth surface of the party. Select a skilled mechanic and test against the sawtooth template until the sawtooth meets the requirements.

 

3. Plastic deformation of the rotary bearing Uneven pits appear on the contact surface of the roller and the roller of the high-precision rotary bearing, indicating that the bearing is plastically deformed. Rotating bearings are subjected to large static or shock loads where the local stress on the working surface exceeds the yield limit of the material, which usually occurs on low-speed rotating bearings. Measures: When the deformation is serious or the area is large, the temperature of the masterbatch is too high. In order to avoid deformation, it must be welded in layers. In this way, rapid cooling can prevent the occurrence of welding cracks, and heat preservation measures should be taken immediately after welding to gradually cool him. After cooling, smooth the weld layer with a polishing machine to make it slightly higher than the surface of the drum, and gradually polish the surface of the weld layer with whetstone or metallographic sandpaper to make it consistent with the normal surface height of the drum, and test until the corresponding original The curvature template is checked so far. Grease the roller and roller (steel ball) with gasoline and assemble into one and it's done.

 

4. Cracks in the bearing ring of the rotating bearing ring The reason for the cracking of the bearing ring may be that the high-precision rotating bearing is too tight, the foreign or inner ring of the high-precision rotating bearing is loose, the bearing containing parts are deformed, and the surface of the bearing is poorly machined. Action: If the entire seat ring is damaged, it can be cut along the root of the tooth to shape the root of the calculus ring. Then, the next tooth is handed over to the same type of waste rock ring, processed into the shape corresponding to the master batch, and then placed in the groove and positioned with the seat circular template. The circumference of this seat will be welded into mild steel if you ensure that the distance of the seat is consistent, plus the value of the twin wire cutters. Flat solder later with files and other tools.