月归档： 2020.12

Single-row ball slewing ring is one of the important parts of modern machinery and equipment, mainly composed of upper ring, lower ring and full ball. Its running speed is very low, and it is usually used in many mechanical products, for example, it is widely used in rotating equipment such as rotary conveyors, excavators, construction machinery, and small and medium-sized cranes. The safe operation of the single-row ball slewing bearing is very important, and it directly affects the working efficiency of the unloading equipment. So, how to ensure the safe operation of single-row ball slewing ring?

1. Choose a good quality slewing bearing

Single-row ball slewing ring is an important part of the machine. And because the components are affected by factors such as the environment and the load during work, they can be regarded as consumables. We need to buy it frequently to maintain the normal operation of the machine. In this regard, we can start from the brand. If the machine itself is a well-known brand product, buy parts of the same brand. Because each brand uses different alloy formulations, there are subtle differences. Next, buy a single-row ball slewing bearing, please pay attention to the toughness of the product. Because the parts are thin, many parts look good, but they are compensated after being placed on the machine for a long time. Actually you can buy more brands in practice.

2. Timely lubrication work

After working for a while, you should pay attention to its running status. You can add some protective oil from time to time to effectively extend its service life.

3. Choose labyrinth ring seal

The sealing of the single-row ball slewing bearing is to prevent grease leakage and filling and also to prevent external dust, impurities and moisture from entering the bearing and affecting normal operation. Since single-row ball bearings mainly work in heavy load and low-speed work, the seal ring has two structures: rubber ring and labyrinth ring. The rubber seal itself has a simple structure. The advantages of small space and reliable sealing have been widely used, but its disadvantage is that the rubber sealing lip is prone to premature aging under high temperature conditions and loses sealing performance, so the volleyball slewing ring bearing should adopt labyrinth seal.

4. Working clearance

One of the key factors affecting the operation of the bearing is the working clearance of the bearing. The main factors affecting the working clearance of the bearing include the fit between the inner ring of the shaft and the shaft, the fit between the outer ring of the bearing and the bearing chamber, and the bearing’s own play under non-assembly conditions. Various objective factors such as gaps, equipment operating status and turnover environment. The same mechanical equipment may have different clearances under different operating conditions. To ensure the guarantee effect of the bearing during the operation of the equipment, the selection of the bearing,

We all know that slewing bearings are commonly used bearings in many large mechanical equipment. After long-term use, different noises will appear, such as dust and scars. What methods should be used to solve these noises? In response to such problems, the editor will tell you the countermeasures and solutions for common slewing bearing noise.

1. The sound of dust
There are foreign objects such as dust in the slewing ring, and non-periodic vibration will occur. The so-called dust sound. The magnitude of vibration and noise is uncertain, and there may or may not be.

Countermeasures: Improve the cleaning method of slewing ring/turntable bearings, strictly clean the bearings, shafts, seat holes and matching parts before installation; remove foreign objects in the lubricant; improve the sealing of the bearings; avoid using impure or embedded materials Plastic cage for foreign objects.

2. The sound of scars

If the rolling surface of the slewing bearing has cracks, indentations or corrosion, periodic vibration and noise like riveting rivets will occur. The period may be fixed, but most of them have a fixed correspondence with the speed. The scars will be continuous on the channel. Occurs, the scars are visible on the steel ball from time to time, and this noise varies with the installation and lubrication conditions.

Measures to deal with this type of noise: Do not knock the bearing during installation, prevent the bearing from being skewed when the bearing is assembled with the shaft and then put it into the bearing housing; prevent bearing corrosion during storage and prevent shock and vibration during transportation; use high-viscosity grease .

3. Noise caused by lubrication factors

Wrong selection of lubricants, insufficient lubricants or aging and hardening can cause vibration and noise in the slewing ring/turntable bearing, and there is no fixed law for this noise.

Treatment countermeasures: In this case, only choose a suitable lubricant, adjust the amount of lubricant, extend the life of the lubricant and reasonably determine the replacement cycle.

4. Noise related to the host and countermeasures

This kind of noise is not simply caused by the bearing, so it is impossible to find the cause from the bearing alone. Attention should be paid to the mainframe, and the performance of the mainframe should be improved if necessary. Now we mainly describe the common buzzing sound and frame resonance sound in the motor.

1. The buzzing sound of the motor

The axial vibration of the motor shaft will cause a lot of high-frequency noise-the buzzing sound, the frequency of which is the same as the axial vibration frequency, and it can be constant or variable. The method of preventing buzzing is the same as that of preventing axial vibration.

2, countermeasures for bearing frame resonance sound

When the axial natural vibration of the outer ring mass system causes the axial bending natural vibration of the bearing frame, a kind of noise called resonance sound is generated. The method of increasing the preload can increase the axial natural frequency of the outer ring mass system, destroy the resonance condition and reduce the noise。

The above is the analysis and explanation of the four common slewing ring noise causes and treatment countermeasures. I hope to bring help to everyone. If noise is found during the slewing ring operation, it must be shut down for inspection and reasonable countermeasures are given.

The excavator can rotate left and right during operation, and it is inseparable from the function of the slewing device. The slewing ring is an important part of the slewing device, which is mainly used to support the mass of the upper car body and bear the working load. Because the slewing bearings of excavators generally operate under heavy loads, and the working environment is relatively harsh, the slewing bearings are prone to failures. The slewing bearings shake when the excavator is working. What’s wrong with it? Next, let’s follow the editor to understand it.

Whether it is dumping soil or loading a truck, the excavator must perform a rotating action, and hundreds of rotating actions can be carried out smoothly every day to ensure the quality and efficiency of the completion of the project. Because of the high frequency of use, many operators often encounter abnormal rotating noise, rotating stuck, slow and weak movements during the construction process. There is no doubt that they can only stop and repair as soon as possible when encountering the above failures!

1. The rigidity of the steel structure supporting the slewing bearing of the excavator is insufficient, and elastic deformation occurs during loading, causing the slewing bearing to shake as a whole. Increase the strength of the supporting slewing bearing steel structure by 14 times.

2. Loose installation bolts, causing shaking during work. Please check all the inner and outer ring mounting bolts immediately and tighten them as required.

3. Long-term overload operation causes the raceway to collapse and the clearance is too large. Check whether it is overloaded and operate in strict accordance with the regulations.

4. Remove the slewing motor assembly, separate the motor and check that the sun gear and the bracket are normal, and the planetary gears and the bracket are also normal. When checking the output shaft, it is found that there is eccentricity, and there is abnormal noise during rotation. After disassembly, it was found that the bearing had fallen apart and the housing was also severely worn. Because the bearing is damaged, the reducer housing is seriously worn, so it is normal after replacing the reducer assembly.

Slewing bearings include four-point contact ball bearings without gears, external gears and internal gears, double-row angular contact ball bearings, crossed cylindrical roller bearings, crossed tapered roller bearings and three-row cylindrical roller combined slewing bearings, etc. A variety of structural types. The four-point contact ball bearing has a higher static load capacity; the crossed cylindrical roller bearing has a higher dynamic load capacity; the crossed tapered roller bearing has a large supporting rigidity and a higher rotation through pre-interference energy. Accuracy.

Many machine friends can understand that this fault can actually be completely avoided. As long as the user pays enough attention to the maintenance problem when using the excavator daily, it will not cause such a big loss later. The editor once again reminds everyone that excavators are not indestructible, whether they are domestic or imported, so daily maintenance must be cautious and careful, and no detail can be ignored!