Analysis on the Causes of the Failure of Bucket Wheel Machine slewing bearing

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Slewing Bearing
Bucket wheel machine is an important production equipment that needs to be used during the transportation and loading and unloading of bulk cargo such as coal. The main purpose is to take materials from the storage yard. It is mainly composed of cantilever arm frame structure, mast structure, counterweight beam structure, cart structure, slewing mechanism, luffing mechanism, and walking mechanism. The slewing support is mainly used to support the upper structure of the bucket wheel reclaimer. The key component of bucket wheel reclaimer rotation work. In the internal structure of the bucket wheel reclaimer, the slewing bearing occupies a large part of the area. Because of its large volume and located at the upper and lower joints of the bucket wheel machine, the failure rate is high during the working process. Today, the editor will analyze the reasons for the failure of the bucket wheel slewing ring.

1. The main failure of bucket wheel reclaimer slewing bearing

Common failures of bucket wheel slewing ring can be summarized into two categories

1. The first category is caused by improper design, manufacturing and installation.

2. The other category is acquired problems caused by improper operation, use, and maintenance after production. The problems caused by acquired problems account for a larger proportion.

Bucket wheel slewing ring

2. The cause of the failure

1. In the manufacturing and processing of bucket wheel machines, in order to save processing and material costs, there is a problem that the main shaft is too thin, which causes the large shaft to easily break at the diameter of the driving wheel. In the processing of bucket teeth, manganese steel plates are used, which directly leads to the reduction of the service life of bucket teeth to one year.

2. If the installation is not in place, it will directly lead to the frequent tearing of the cantilever belt of the rotating mechanism, damage to the roller deflection of the walking device and other faults, which brings safety risks to the safe and stable operation of the equipment.

3. During the running-in period of the slewing ring, the lubrication status is poor, and frequent full-load work results in poor running-in of the raceway and rolling element pairs, which is manifested in the early excessive wear and fatigue pitting.

4. Fatigue type failure is a common failure of slewing bearing failure. When the rolling element and the raceway are under load and are in relative motion at the same time, under the action of this alternating load, the internal micro-cracks gradually expand to the surface and form flaking. Fatigue spalling will cause shocks during the operation of the slewing ring, aggravating vibration and noise.

5. The rolling elements are worn and broken, and the raceway is seriously deformed. Under the action of instantaneous large load, the raceway is locally deformed, which directly causes the wear, deformation and even rupture of the rolling elements, thereby causing the slewing ring to fail.

6. ​​The slewing bearing fixing bolts are installed too loosely, and they vibrate and disappear in the budding state during operation.

The above is a simple analysis of the cause of the failure of the bucket wheel slewing ring. For bucket turbines, once the slewing ring fails, the entire equipment can only be stopped, which affects the entire reclaiming process of the yard and causes greater economic losses. Therefore, we must analyze the common failure causes of the bucket wheel slewing ring operation, and study effective countermeasures to reduce the sudden failure of the slewing ring causing the bucket wheel to stop abnormally.

How to ensure the safe operation of single-row ball slewing ring? Four main points

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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 operating speed is very low, and it is usually used in many mechanical products, such as 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? Next, let’s follow the editor to understand it.

1. Choose a slewing bearing of good quality

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. When brands obsolete products, natural compatibility is yes. 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 choose, you can buy more brands in practice.

2. Timely lubrication work

is in daily operation. After working for a while, you should pay attention to its operating status. You can add some protective oil from time to time to effectively extend its service life.
Single volleyball slewing ring
Three, choose labyrinth ring seal

The sealing of the single-row ball slewing bearing is to prevent grease leakage and filling on the one hand, and on the other hand 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 working conditions under high temperature conditions are single. The volleyball slewing ring bearing should adopt labyrinth seal.

Four, 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, the determination of the matching relationship, the understanding of the working conditions, the lubrication and maintenance, etc. Comprehensive consideration in many aspects.

The above is the answer to how to ensure the safe operation of the single-row ball slewing ring. Since it is mainly used for large machines, it should be checked and maintained regularly during use to avoid affecting the use of the entire machine.

What if the slewing bearing rusts?Method to prevent rust of rotary bearing

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Slewing bearings are important parts in many modern machinery and equipment, because their performance is more unique than other mechanical parts, including significant advantages in anti-corrosion performance. However, if the slewing bearing is not produced in strict accordance with the cleaning and anti-rust regulations and the requirements of the oil seal and anti-rust packaging, the bearing parts in the processing process and the finished bearing products after assembly shall be treated with rust; or the anti-rust used in production The quality of rust lubricating oil, cleaning kerosene and other products cannot meet the requirements of the process technology, and the use of inferior anti-rust lubricating oil will cause the bearing to rust. So what can be done to prevent it from rusting? Today, the editor will share with you several ways to prevent the rust of turntable bearings.

1. Surface cleaning method

Cleaning must be based on the nature of the surface of the rust-prevented material and the prevailing conditions, and an appropriate method must be selected. Generally, there are solvent cleaning method, chemical treatment cleaning method and mechanical cleaning method. When the surface is dry and cleaned, it can be dried with filtered dry compressed air, or dried with a dryer at 120~170℃, or dried with clean gauze.

2. Method of applying anti-rust oil

1. Brushing method

This method is suitable for slewing bearings or special-shaped bearings that are not suitable for immersion or spraying. When brushing, it is necessary to pay attention not to produce anti-rust oil accumulation, and of course to prevent leakage.
Slewing ring
2, spray method

Some large slewing bearings cannot be oiled by immersion method, generally use about 0.7Mpa pressure filtered compressed air to spray in clean air. The spray method is suitable for solvent-diluted anti-rust oil or thin-layer anti-rust oil, but complete fire protection and labor protection measures must be adopted. This method is mostly used for rust prevention of some large slewing bearings.

3, soaking method

The slewing bearing is soaked in anti-rust grease, and a thick layer of anti-rust grease can be adhered to its surface. The thickness of the oil film can be achieved by controlling the temperature or viscosity of the anti-rust grease, and this layer of grease can effectively isolate it from The contact of air achieves the effect of rust prevention.

The above are several ways to prevent rusty slewing bearings. I hope everyone can help after reading them. In addition, when we use the bearing, do not directly touch the bearing with your hands, because when sweat contacts the bearing, a layer of sweat film will be formed on the bearing surface. The sweat film will cause electrochemical effects on the bearing and corrode the bearing. Therefore, use special tools such as special gloves or finger cots to pick up the bearing, and do not touch it directly with your hands.

Discussion on the stability of slewing bearings

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For equipment installed with slewing bearings, corresponding performance is the focus of users’ attention, and often requires high accuracy. In the application of equipment, the stability of the slewing bearing can meet the requirements of the special work nature of construction equipment, including bearing large axial load, radial load and overturning moment and other comprehensive loads. The following editor will discuss the stability of the slewing bearing with everyone:

In the design of accessories, the rolling elements are usually separated by separate blocks. This structure can maintain the smoothness of movement, so it is widely used. Special applications require special ball or roller spacers. Bearings installed on horizontal shafts or continuously rotating generators and bearings used in occasions with high requirements for positioning and reliability can use strip combined cages to keep the rolling elements in the correct circumferential position .

The purpose of using cages for slewing bearings is very clear: improve bearing rotation performance and efficiency, consolidate bearing stability and reliability, improve bearing design life and service life, and solve the problems of uniform force and bearing structure under complex working conditions . Integral cage-segment cage-copper cage-steel cage-polyurethane cage-nylon cage-polytetrafluoroethylene cage-PA cage, and composite material cage.

Slewing bearing

In addition, for slewing bearings, stability and reliability are the two core indicators considered in the selection and design of slewing bearings. The main process design considerations are: structure; material; modulation hardness and quenching hardness; bearing rolling elements and The height and wall thickness ratio of the ferrule; machining accuracy; the material, structure and type of the cage, such as the integral cage, can obviously improve the rotation performance and life of the bearing; the lubrication system and the sealing system; the level of installation and debugging; the daily maintenance Frequency; application of mature design.

In order to ensure the stability of construction equipment, the design of slewing bearings pays more attention to the rationality of the structural configuration, but in many cases, gear teeth can be machined on the inner or outer ring of the bearing to simplify the structure of the drive system. In order to avoid problems, when determining the structure of the drive system, you should seek help from related personnel in the gear.

The above is the discussion on the stability of the slewing bearing. The design of pipe fittings pursues higher performance. However, in actual applications, once installation, use or maintenance is improper, various problems may arise, such as in the slewing bearing. There was a problem of excessive shaking during use. Common causes for this are loose mounting bolts, causing shaking during work; insufficient rigidity of the steel structure supporting the slewing bearing, elastic deformation during loading, resulting in overall swaying of the slewing bearing, etc., in order to ensure the normal use of the slewing bearing, if you If there is shaking in the machine, you must stop the machine for inspection in time to prevent long-term shaking from causing greater damage to the slewing bearing.

What should I do if the slewing ring is rusted? Ways to prevent rust of slewing bearings?

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Slewing bearings are important parts in many modern machinery and equipment, because their performance is more unique than other mechanical parts, including significant advantages in anti-corrosion performance. However, if the slewing bearing is not produced in strict accordance with the cleaning and anti-rust regulations and the requirements of the oil seal and anti-rust packaging, the bearing parts in the processing process and the finished bearing products after assembly shall be treated with rust; or the anti-rust used in production. The quality of products such as rust lubricating oil and cleaning kerosene does not meet the requirements of the technical regulations, and the use of inferior anti-rust lubricating oil will cause the bearing to rust. So what can be done to prevent it from rusting? Today, the editor will share with you several ways to prevent the rust of turntable bearings.

　　

　　 1. Surface cleaning method

　　

　　Cleaning must be based on the nature of the surface of the rust-prevented material and the prevailing conditions, and an appropriate method must be selected. Commonly used are solvent cleaning method, chemical treatment cleaning method and mechanical cleaning method. When the surface is dry and clean, it can be dried with filtered dry compressed air, or dried with a dryer at 120~170℃, or dried with clean gauze.

　　

　　 2. Method of applying anti-rust oil

　　

　　 1. Brushing method

　　

　　This method is suitable for slewing bearings or special-shaped bearings that are not suitable for immersion or spraying. When brushing, it is necessary to pay attention not to accumulate rust prevention oil, and of course to prevent leakage.

Slewing ring 

　　2, spray method

　　

　　Some large slewing bearings cannot be oiled by the immersion method, and generally use filtered compressed air with a pressure of about 0.7Mpa to spray in a clean air place. The spray method is suitable for solvent-diluted anti-rust oil or thin-layer anti-rust oil, but complete fire protection and labor protection measures must be adopted. This method is mostly used for rust prevention of some large slewing bearings.

　　

　　3, soaking method

　　

The slewing bearing is soaked in anti-rust grease, and a thick layer of anti-rust grease can be adhered to its surface. The thickness of the oil film can be achieved by controlling the temperature or viscosity of the anti-rust grease, and this layer of grease can effectively isolate it from The contact of air achieves the effect of rust prevention.

　　

　　 The above are a few ways to prevent rusting of slewing bearings. I hope everyone can help after reading them. In addition, when we use the bearing, do not directly touch the bearing with your hands, because when sweat contacts the bearing, a layer of sweat film will be formed on the bearing surface, which will cause electrochemical effects on the bearing and corrode the bearing. Therefore, use special tools such as special gloves or finger cots to pick up the bearing, and do not touch it directly with your hands.

What requirements should the selection of bearing grease meet to choose the right one?

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For bearings, lubrication is very important. The use of grease can reduce friction. Excellent high-temperature oxidation stability can ensure the long-term normal operation of the lubricated parts at high temperatures, provide comprehensive protection to the bearing, and greatly extend the service life of the bearing. However, during mechanical operation, due to the working conditions (load, speed, temperature), working conditions (continuous operation, intermittent operation, vibration and shock, etc.) and working environment (humidity, temperature, pollution degree, etc.) during bearing rotation and friction The choice of grease will also be different. So, what requirements should the selection of bearing grease meet?

1. The use temperature of the grease should be at least 20-30 degrees lower than its dropping point

When the use temperature is high, the grease with good oxidation resistance, low evaporation loss and high dropping point should be selected. When the operating temperature is low, low starting torque and relatively low viscosity grease should be selected. For example, grease based on synthetic oil.
2. The selected grease should be compatible with the use speed of the lubricated friction pair

At high speeds, use low-viscosity base oils with greater penetration. For low-speed grease, you should choose a grease with a high penetration grade made of a high-viscosity base oil.

3. The selected grease should be suitable for the load

For heavy loads, a grease with high base oil viscosity and high thickener content should be selected. When the load is particularly heavy, care should be taken to select grease with extreme pressure additives or fillers (molybdenum disulfide, graphite). For medium and low loads, grease with a short, medium viscosity base oil of No. 2 consistency soap fiber structure is generally used

4. The selected grease should be compatible with the environmental conditions used
In an environment where the air is humid or in contact with water, greases with good water resistance such as calcium-based, lithium-based, and lithium complex-based should be used. When there is a lot of dust, you should choose a thicker and harder (that is, a higher grade) grease, which has better sealing performance and can prevent impurities from mixing into the friction pair. In a strong chemical environment, synthetic oil greases that resist chemical media such as fluorocarbon grease should be used.

slewing bearing

5. The selected grease should be compatible with the grease supply mode of the friction pair

When it is a centralized grease supply, you should choose 00～1 grease. For parts where grease is regularly filled with grease guns, grease cups, etc., grease No. 1 to No. 3 should be selected. For long-term use without changing the grease, you should choose No. 2 or No. 3 grease.

6. The selected grease should be compatible with the working state of the friction pair

For example, when the vibration is large, use high-viscosity, adhesive and vibration-damping grease, such as high-viscosity cycloalkyl or compound soap-based grease thickened with mixed base lubricating oil.

7. The selected grease should be suitable for its purpose of use

The grease used for lubrication must be specifically selected according to the type of friction pair, working conditions, working conditions, environmental conditions and grease supply methods. For protective grease, it should be able to effectively protect metals from corrosion. For example, to protect parts in contact with seawater, aluminum-based grease with strong adhesion and water resistance should be selected. General protection grease can be made of solid hydrocarbon thickened high-viscosity base oil. For the sealing grease, attention should be paid to its resistance to the solvent of the sealed medium.

8. The selected grease should be as good as possible to reduce the variety of grease

In the case of meeting the requirements, try to use lithium-based grease, complex soap-based grease, polyurea grease and other multi-purpose general-purpose greases. In this way, the variety of grease is reduced, the management of grease is simplified, and the long service life of pleiotropic grease can reduce the cost of grease, reduce maintenance costs, and improve economic benefits.

The above is the answer to what requirements should be met for the selection of bearing grease. In daily bearing maintenance and repair, various types of grease are used, including sodium-based, calcium-based, lithium-based, barium-based, aluminum-based grease, etc. Etc. to ensure the normal operation of bearings and other components

How to ensure the safe operation of single-row ball slewing ring?

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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.

 

  1. 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.

 

  1. 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.

 

  1. 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,

high precision 2.5m slewing bearings

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Recently our company (Luoyang Hengguan Bearing Technology Co., Ltd.) produced a set of ultra-high-precision slewing bearings with an outer diameter of 2.5 meters for a customer in Jiangsu. This product is a three-row internal gear slewing bearing. All indicators of the finished product exceed Customer requirements.

 

This product is applied to the precision machining platform center, so the quality and precision of the product are very high. In the early order negotiation stage, after detailed communication between the technical personnel of both parties, according to the user’s use requirements and working conditions, this set of large diameter The end face runout of the slewing ring bearing is set at 0.08, the axial clearance is 0.05-0.12, and the radial clearance is 0.05-0.15; this accuracy requirement is much higher than the standard ordinary accuracy of the slewing ring bearing. Based on our processing equipment and actual combat experience, we are confident that we can guarantee the quality and precision of our products, so we will do it in one word!

 

Facts speak louder than words. After the order is received, Hengguan people discuss and negotiate together, formulate production plans, predict the problems that may be encountered in the production progress, and discuss countermeasures and solutions one by one. , Finished product inspection results: end face runout 0.03, axial direction 0.05, radial direction 0.1; exceed the requirements! The guests inspected on the spot and couldn’t help but repeatedly exclaimed “Good, good…”! Really realize that a good product can speak for itself!

 

Hengguan people are brave to challenge, dare to innovate, do what they say, do what they say, and value the spirit of contract. This is the standard of life, but also the standard of work! “Words must be done, actions must be resolute” is the principle that we Hengguan people have always adhered to! Choose us, trust us, you will be satisfied! Come on, let us walk hand in hand to create a better future!

Introduction to the countermeasures and solutions for common slewing bearing noise

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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.

Reason why the slewing bearing shake when the excavator is working

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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!