What is the slewing ring gear module?

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Slewing bearing is one of the important parts of many modern machinery and equipment. It is called “joint of machine”. Many people are familiar with various parameters of slewing bearing, including clearance, inner and outer diameter, friction coefficient, etc. Many of my friends don’t know the module of supporting gear, so let’s follow the editor today to understand it.

 

  1. what is the slewing ring gear module

 

The length of the arc (gear)/straight line (rack) occupied by a single gear tooth in the indexing circle (gear)/or line (rack), its length is π * m, and m is the modulus.

 

What does the module of the slewing ring represent: The module of the slewing ring represents the product of the tooth pitch and the number of teeth of the slewing ring gear, which is the circumference of the index circle. The gear modulus of the slewing ring determines the size of the tooth. The gear modulus is a basic parameter for the calculation of the gear size. The symbol is “m”. Gear cutters can be standardized, so that the standard modulus of gears can be standardized for mass production. Facilitate the replacement of later accessories. In the same way, “modulus” refers to the ratio of the pitch t between the tooth profiles of two adjacent gear teeth on the same side and the circumference ratio π (m=t/π), in millimeters.

 

If the number of teeth of the slewing ring gear is constant, the larger the gear modulus, the larger the radial dimension of the gear. The teeth of a gear with a large modulus are thick, and for two gears with the same number of teeth, the outer circle of the gear with a large modulus is larger. Therefore, the modulus of the gear in a watch is very small, and the modulus of the flywheel and transmission gear on the mechanical punching machine is large. The modulus of the two meshing gears must be the same. Modulus is the basic parameter of gear design, and it is used in many calculations of gear design.

 

 

  1. Reasonable selection of gear modulus

 

When designing a gear, one of the important parameters is this modulus. The gnawing of the gear will produce gnawing pulsation. The main reason is that it has a great relationship with the elastic deformation of the gear teeth. It is a basic part of the gear design. Parameter-gear modulus, if it is a relatively large modulus (that is, a gear with a relatively large size), it will also have a relatively large load-bearing capacity. The modulus parameter is inversely proportional to the degree of bending of the gear teeth. The increase of the modulus means that the rigidity of the gear teeth is improved, so that the elastic deformation of the gear teeth will not be great when the gnawing transmission is carried out, which greatly reduces the impact force formed by the gear teeth, thereby achieving The purpose is always greatly reduced. Therefore, from this point of view, the modulus should be increased appropriately, but the error generated when machining gears is also related to the modulus. If the modulus is increased, the tooth profile and pitch will also be increased. At this time, the error of gnawing noise will also increase accordingly, so the choice of modulus should be determined according to the specific situation.

 

In the case of keeping the modulus unchanged, the diameter of the gear is proportional to the number of teeth, so the change of the number of teeth will also change the bending amount and elastic stiffness of the gear teeth: the strength of the noise generated by the sound source is not only related to the energy of the vibration source It is related to the size of the radiation area. If the radiation area is increased, the radiation power will also increase. Increasing the diameter of the gear will increase the noise radiation area, which will greatly affect the gear. Effective noise control. Therefore, in the relevant design, within the permissible range of ensuring the strength of the gear, the number of teeth and the small modulus should be used as much as possible, and the reasonable selection of materials and heat treatment methods can be combined to promote the improvement of the strength of the gear teeth, thereby Reduce the gear tooth diameter to achieve the purpose of reducing gear noise.

 

The above is the relevant introduction about the slewing ring gear module. In the slewing ring selection process, the first two sets of data listed in the national standard parameters of the slewing ring module should be selected first, which is more important for the adaptation of the bearing and the replacement of accessories. Convenient, but non-standard gears with customized bearing module requirements for bearings used in special machines are not within the above constraints.

What is the material used to make the slewing bearing

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The common structural forms of slewing bearings are single-row, double-row four-point contact ball slewing bearings, double-row angular contact thrust ball slewing bearings, crossed cylindrical roller and crossed tapered roller slewing bearings, three-row cylindrical roller slewing bearings, balls Different structural forms such as column hybrid slewing bearing. Although the structure is different, the materials used are similar, and the material of the slewing bearing directly determines the performance and service life of the bearing. Today, the editor will take everyone to understand what materials are used for the slewing bearings.

1. Material for ferrule and rolling element

Because the bearing should have the characteristics of long life, high precision, low heat generation, high speed, high rigidity, low noise, high wear resistance, etc., it is required that the bearing steel should have the characteristics of high hardness, uniform hardness, high elasticity, and high limit. .

Under normal circumstances, the slewing bearing rolling element adopts integrally hardened carbon chromium bearing steel. The grade is made of GCr15 or GCr15SiMn steel; the slewing bearing ring is made of surface hardened steel. When the user has no special requirements, it is generally made of 50Mn steel, but sometimes in order to meet the needs of the host in some special applications, it can also be provided by the user. For specific use conditions, select other grades of surface hardened steel, such as 42CrMo, 5CrMnMo, etc.

(1) 42CrMo is a high-carbon steel with good quenching and tempering performance and quenching performance. It is an ideal material for slewing bearings.

(2) 50Mn has good hardenability and is also a high-quality choice for slewing bearings.

(3) 40Cr is also good in terms of mechanical properties, and it is still in the stage of exploration and practice.

(4) GCr15 small slewing bearing can be selected, but it is generally not recommended to use it because of the trouble of milling and drilling in the process due to the full quenching.

Slewing bearing

2. Material for cage

The cage for slewing bearings has a structure such as an integral type, a segmented type, and a spacer type. Among them, the integral and segmented cages are made of No. 20 steel or ZL102 cast aluminum alloy. The isolation block is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc.

3. Sealing ring materials

The slewing bearing seal ring is made of oil-resistant rubber or nitrile rubber.

The code of the ferrule material and the supply status of the blank is in accordance with the regulations in the table. In the table, “T” indicates that the ferrule blank is supplied in the quenched and tempered state, and “Z” indicates that the ferrule blank is supplied in the normalized state.

The slewing bearing seal ring is made of oil-resistant rubber or NBR nitrile rubber. Compared with nitrile rubber, hydrogenated nitrile rubber has better oil resistance, but if you are not too demanding on oil resistance, use nitrile rubber, because hydrogenated nitrile rubber is relatively expensive. Nitrile rubber also has a certain degree of acid and alkali resistance. However, silica gel should be selected if the requirements for oil resistance and acid and alkali are higher, but its price is higher.

In summary, we know that the materials used in slewing bearings are related to their main body and parts. The main body is made of metal, while other parts, such as seals, are made of rubber. If you need this kind of bearing, you must pay attention to the integrity of these materials and high-quality effects when purchasing to ensure the function of the operation. Luoyang Hengguan Bearing provides high-quality, high-performance slewing bearing products for market customers. Everyone is welcome to call for detailed consultation.

Why do industrial robots need a reducer?

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In recent years, industrial robots have ushered in explosive development, especially due to the increase in labor costs, making manufacturing companies increasingly favor the use of more mechanized, more efficient, and lower-cost robots. When it comes to robots, we have to mention one of the important components, the reducer, which is what we often call the reducer. Due to the different operating environments and performance of industrial robots, the types of reducers used are also different. So, do you know why an industrial robot needs a reducer?

 

The power source of an industrial robot is generally an AC servo motor. Because it is driven by a pulse signal, the servo motor itself can realize speed regulation.

 

Industrial robots usually perform repeated actions to complete the same process; in order to ensure that industrial robots can reliably complete process tasks in production and ensure process quality, the positioning accuracy and repeat positioning accuracy of industrial robots are very high. Therefore, to improve and ensure the accuracy of industrial robots, rv reducers or harmonic reducers are needed. Another role of precision geared motors in industrial robots is to transmit greater torque. When the load is large, it is not cost-effective to blindly increase the power of the servo motor. The output torque can be increased by a reducer within a suitable speed range.

 

In addition, the servo motor is prone to heat generation and low-frequency vibration under low-frequency operation, which is not conducive to ensuring accurate and reliable operation of industrial robots that work for a long time and periodically. The existence of the precision geared motor enables the servo motor to run at an appropriate speed, and accurately reduces the speed to the speed required by each part of the industrial robot, which improves the rigidity of the mechanical body while outputting greater torque. Compared with general-purpose reducers, robot joint gear motors are required to have the characteristics of short transmission chain, small size, high power, light weight and easy control. There are two main types of reducers widely used in articulated robots: rv reducers and harmonic reducers.

 

Industrial robots usually perform repeated actions to complete the same process; in order to ensure that industrial robots can reliably complete process tasks in production and ensure process quality, the positioning accuracy and repeat positioning accuracy of industrial robots are very high. Therefore, to improve and ensure the accuracy of industrial robots, RV reducers or harmonic reducers are needed. Another role of precision reducers in industrial robots is to transmit greater torque. When the load is large, it is not cost-effective to blindly increase the power of the servo motor. The output torque can be increased by a reducer within a suitable speed range. In addition, the servo motor is prone to heat generation and low-frequency vibration under low-frequency operation, which is not conducive to ensuring accurate and reliable operation of industrial robots that work for a long time and periodically.

 

The reducers commonly used in industrial robots include RV reducers and harmonic reducers. Harmonic reducers are mainly used for light-loaded parts such as forearms, wrists, and hands. The RV reducer has a large transmission ratio range, relatively stable accuracy, high fatigue strength, and higher rigidity and torque carrying capacity.

 

In recent years, as the market for industrial and life assistance robots continues to expand, the demand for high-precision small modulus gears in precision reducers used in the joints of robots has also increased sharply. The robot-specific slewing ring (slewing bearing) products produced by Luoyang Hengguan have the advantages of light weight, high precision, reasonable price, and excellent service; our company has a professional production line for such products, which specializes in the production of such high-precision slewing bearings. It is also one of the main product series of our company. You are welcome to call for consultation and look forward to cooperating with you.

What are the four forms of failure of slewing ring raceway

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The life of the slewing ring raceway is determined by the quality of its own products and subsequent maintenance. It is even considered “three-point quality and seven-point maintenance”. The following phenomena generally occur after the raceway is damaged and failed: large gaps, oil leakage, jamming, abnormal noise, iron powder and even iron pieces on the raceway, etc. There are many reasons for the failure of the bearing. Today, the editor will introduce four common failures of the slewing ring raceway. For everyone to learn and understand.

1. The raceway is worn

The relative sliding friction between the surfaces causes the metal of the working surface to wear out continuously and cause failure. Abrasion will cause an increase in the fit clearance and a change in the shape of the raceway surface, and it will also affect the lubricating function of the lubricant, causing the bearing to lose rotation accuracy or even fail to operate normally. Raceway wear is divided into normal wear and abnormal wear. Normal wear and tear is a process in which the gap gradually increases during the full life cycle to complete the task of the full life cycle. Abnormal wear has manufacturing problems, standard parts problems, grease problems and later maintenance problems. The first three problems are related to the slewing bearing manufacturer, and the fourth situation is the problem of the equipment user.

2, plastic deformation of raceway

Under the action of external force, the partial plastic flow or overall deformation of the surface of the part, such as the deformation of the raceway or the torsion and warpage of the cage, causes the failure of the slewing bearing to fail to work normally, which is called plastic deformation failure. This situation often occurs after a period of use. At this time, the high-hardness layer has been mostly worn out. After the load and friction are suddenly increased, the metal inside and outside the raceway is squeezed into a pile. The steel with high hardenability should be used instead.

Slewing ring

3, the surface of the raceway peels off

The main reason for the surface spalling of the slewing bearing raceway is that the hardened layer is too thin and the hardness transition zone is too narrow. There are many reasons for contact fatigue failure. It may be that excessive axial load, poor lubrication, poor alignment, excessive impact load during installation, etc. can cause contact fatigue failure of the bearing. A lower frequency intermediate frequency equipment should be used to deepen the hardened layer. At the same time, it is necessary to appropriately increase the quenching and tempering hardness to reduce the hardness gradient of the raceway section.

4, raceway corrosion and pitting

The metal surface undergoes a chemical or electrochemical reaction with the environmental medium, and the surface damage caused is called corrosion failure. Corrosion is divided into three categories: chemical corrosion, electric corrosion, and fretting corrosion, which is mainly manifested as the corrosion of the internal bearing surface. Factors such as the intrusion of corrosive media, the condensation of moisture in the air, the sparks generated when the current passes, and the fretting vibrations can all cause corrosion failure of the slewing ring raceway. Pitting corrosion mainly occurs on the raceway treated by quenching and tempering. The reason is low hardness and unreasonable design of the raceway structure, causing sliding friction and contact fatigue stress, causing defects such as pitting corrosion and indentation.

The above is an introduction to the four forms of common slewing ring failures. In order to avoid such failures, reasonable and effective maintenance of the slewing ring should be carried out on a regular basis. This will not only reduce the occurrence of failures, but also increase the number of slewing rings. Service life.

How to improve the brightness of the slewing bearing surface? What is a good solution?

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After the slewing ring is used for a period of time, spots or discoloration will be found on the surface, which not only affects the territory and smoothness of the bearing surface, but also directly affects the use effect and service life of the bearing. So, how to improve the brightness of the slewing bearing surface? Is there any good way to solve it? Next, let’s follow the editor to understand it.

 

1, electroplating

Electroplating is to deposit the required covering layer on the surface of the slewing bearing substrate through the point solution method to form a bright protective film. This method can not only improve the surface brightness of the slewing bearing, but also play a role in preventing surface rust. Electroplating can be divided into single metal electroplating, multi-layer combined electroplating, and alloy electroplating.

There are many factors that affect the quality of the coating, such as: pre-plating, the method and degree of purification of the plating solution, the rationality of the pre-plating method, the establishment of the plating solution system, the determination of the combination and the thickness, and the process parameters (PH value, temperature, current density) , Additives (brightener, leveling agent, stress reliever, wetting agent, dispersant), plating solution analysis and replenishment system, operation system, post-plating treatment (dehydrogenation, sealing), etc. Of course, this kind of electroplating layer only plays a protective role on the surface of the slewing bearing, and does not change the internal structure of the bearing. Wearing during daily use will still affect the brightness of the bearing and cause the risk of rust.

 

2, machine shaping

The metal surface layer is plasticized and changed by mechanical methods to improve the hardness and high-strength hardened layer, which can increase the density of strengthened dislocations on the surface of the slewing bearing, and refine the sub crystalline structure, thereby increasing its hardness and strength, and the surface is rough The degree value is reduced, so that the brightness of the bearing surface is improved from the appearance, and at the same time, the surface fatigue strength of the parts can be improved and the sensitivity of fatigue notches can be reduced.

 

The first two are how to improve the surface brightness of the slewing bearing before it is used, and the maintenance of the bearing surface brightness can only be done through later maintenance and cleaning during use.

 

Slewing ring

3, do a good job in rust prevention

 

(1) Clean

 

While the slewing ring is in use, it is necessary to choose a suitable solvent for cleaning, so that it will not damage the rust prevention process of the slewing ring surface, and will not cause serious corrosion. Cleaning the bearing surface can restore the brightness of the bearing surface.

 

(2) Lubrication work

 

Do a good job in the maintenance of bearings during daily use, and regularly perform lubrication and maintenance on the bearings. The editor of Longda also shared the oil lubrication methods of slewing bearings before you can learn. In daily use, in addition to lubrication, attention should be paid to keeping the bearing surface dry, which can also improve the brightness of the bearing surface.

 

The metal luster of the slewing bearing steel is actually very bright. The reason why we need to improve the brightness of the bearing surface is mostly caused by the corrosion and improper cleaning of the bearing during use. Rust and cleaning work are also very important to improve the surface brightness of the slewing ring. Doing the cleaning and maintenance work of the bearing during the use of the bearing can increase the brightness of the bearing. At the same time, the anti-rust treatment of the bearing surface before use can also increase the brightness of the slewing bearing surface.

Analysis on the Causes and Preventive Measures of Vibration of Slewing Bearings in Operation

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Slewing bearing can also be called turntable bearing and rotating bearing. It is one of the important parts of modern construction machinery slewing devices, such as excavators, cranes, pile drivers, graders, road rollers, dynamic compactors, roadheaders, tower cranes, etc. Slewing bearings are always used. Due to the large load during operation and the harsh working environment, the operation is not smooth (jitter) and excessive noise (abnormal noise) failure occurs. So, what is the cause of jitter when the slewing ring is running? How to prevent it? Next, follow the editor to understand it.

Reasons for the vibration of the slewing bearing during work

1. The internal machining accuracy of the slewing ring

The machining accuracy of the steel balls inside the slewing ring and the machining accuracy of the internal raceway are not high, or there are quality defects and the lack of lubricating oil in the raceway. The roller collides with the spacer, which directly affects the smoothness of the slewing ring operation and the level of noise, so check When the slewing bearing is defective, sometimes the frequency of failure is reduced by replacing the steel ball.

2. The gear processing is not precise enough

The gear accuracy grade of the slewing ring should be between 7 and 11, which determines the stability of the slewing ring transmission, the uniformity of load distribution and the transmission accuracy. The higher the gear accuracy, the denser the contact spots on the meshing tooth surface, so that the noise value is reduced and the smooth operation is improved.

3. Welding defects of upper and lower supports

If the welding quality is not up to standard, the weld defects need to be repaired and repaired. During repair welding, not only new welding stress will be generated, but also the flatness of the machined mounting surface will be greatly affected. At the same time, the current generated by welding will also cause a certain amount of internal rolling elements and raceways when passing through the slewing ring. damage. In addition, if the assembly errors generated in the manufacturing and assembly, the pin and bolt pre-tightening in the on-site installation do not meet the specified requirements, abnormal noise or jitter will also occur.

4. Quality problems of gears and starting motors

Because the gear has been loaded for a long time, small pieces of metal or strip-shaped metal iron filings will fall off near the pitch line of the tooth surface, resulting in pitting or tooth gnawing. The pitting corrosion of the tooth surface continues to expand with the increase of working time, so that the meshed tooth profile is damaged, the noise and impact during rotation increase, and the metal particles that impact repeatedly accelerate the wear of the tooth surface, forming a vicious circle. In addition, the manufacturing and assembly of the starter motor in the slewing mechanism has its own defects, which produces shock jitter, and the meshing process between the drive wheel and the support is unstable, which also increases the jitter frequency and the decibel of abnormal noise.

Preventive measures against shaking of slewing ring

1. Installation and operation

High-strength bolts should be used for the installation of the slewing bearing. The bolts and nuts should meet the requirements of GB3098.1 and GB3098.2. Spring washers are prohibited. Before the installation bolts are tightened, the meshing adjustment of the large and small gears (backlash) must be carried out to ensure that the meshing of the slewing ring and the pinion meets the requirements. The mounting bolts should be tightened at 180°. The mounting plane must be clean and flat, free of burrs, iron filings and other debris. The plane must meet the following requirements: The slewing bearing often has broken teeth during operation, so it is also in operation. Consider the influence of wind on the slewing support. If the boom cannot rotate freely with the wind after the specified wind power is exceeded or the operation is stopped, the gear or slewing bearing meshing with the support may be damaged, and serious safety accidents may occur. Therefore, detailed inspections should be done during installation and operation.

2, tightening bolts

The connecting bolts of the slewing bearing and the upper and lower supports are subjected to axial pulsating load in addition to the pre-tightening force, which will cause the bolts to elongate or the connecting surface to deform, which makes the bolts loose. After the bolt connection is loosened and the pre-tightening force fails to meet the requirements, the axial clearance increases, the rolling elements are rotated by a large overturning moment, and the raceway edge is subjected to huge contact stress, causing damage to the raceway edge. Therefore, the tightening of the slewing bearing bolts must be checked regularly to make it reach the specified pre-tightening force, which is generally 400-500N.m.

3, internal lubrication of the slewing ring

In daily use, each part should be lubricated according to the lubricant, lubrication method, and lubrication cycle in accordance with the instructions in the operation manual in time and on time. Corresponding ball slewing bearings are generally filled once every 100 hours of operation, and roller slewing bearings are filled once every 50 hours. The lubrication cycle should be shortened for the special working environment with a lot of dust, high humidity and high temperature difference. Each lubrication must fill the raceway until the lubricating oil seeps out. While filling, the slewing ring needs to be slowly rotated to make the grease evenly filled. By adding lubricating oil for maintenance, the friction between the gear pairs can be reduced, and the wear rate of the gear ring can be slowed down. The oil film formed can also act as a shock absorbing ring, eliminating part of the vibration energy generated during operation. In addition, the lubricating oil film can also lubricate and clean the friction surfaces well, prevent rust, and eliminate the influence of iron filings on the friction surface. Thereby reducing the friction noise of operation and increasing the service life of the support.

The above is the analysis and explanation of the reasons and preventive measures for the shaking of the slewing ring during operation. I hope it will be helpful after reading it. Luoyang Hengguan Bearing is a slewing ring/slewing bearing comprehensive entity enterprise integrating design, research and development, production, sales and service. Mainly engaged in a variety of high-precision slewing bearings, large thrust ball bearings, non-standard special-shaped bearings and other products, and also provide customers with customized exclusive bearing products. Everyone is welcome to call for detailed consultation.

What does the tolerance of the slewing ring mean?

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There are many technical indicators that reflect the accuracy of slewing bearings and slewing bearings, such as axial clearance and radial clearance, end jump and radial jump, parallel difference and inside and outside difference, roughness, dimensional tolerance, position tolerance, etc. So, do you know what the tolerance of slewing ring refers to?

The dimensional accuracy and rotation accuracy of the slewing bearing are based on ISO and JIS standards. For machinery that requires high precision and high-speed operation, it is recommended to use bearings with accuracy grade 5 or above. Deep groove ball bearings, radial thrust ball bearings or cylindrical roller slewing bearings are suitable for machinery with high operating accuracy.

Slewing ring

The inner diameter and outer diameter of the rolling slewing ring are manufactured according to standard tolerances. The tightness of the slewing ring inner ring and shaft, outer ring and seat hole can only be achieved by controlling the tolerance of the journal and the tolerance of the seat hole. Tolerance includes shape tolerance and position tolerance.

When the dimensional tolerance accuracy is determined, the shape tolerance has an appropriate value, that is, generally about 50% of the dimensional tolerance value is used as the shape tolerance value; about 20% of the dimensional tolerance value in the instrument industry is used as the shape tolerance value; heavy industry Approximately 70% of the dimensional tolerance value is used as the shape tolerance value. This shows that. The higher the dimensional tolerance accuracy, the smaller the proportion of the shape tolerance to the dimensional tolerance. Therefore, when designing the size and shape tolerance requirements, except for special circumstances, when the dimensional accuracy is determined, the 50% dimensional tolerance value is generally used as the shape tolerance value , Which is not only good for manufacturing but also good for ensuring quality.

There is also a certain relationship between shape tolerance and position tolerance. From the perspective of the cause of the error, the shape error is caused by machine tool vibration, tool vibration, spindle runout, etc.; while the position error is caused by the non-parallelism of the machine tool rails, the non-parallel or non-perpendicular tool clamping, and the effect of clamping force. As a result, from the definition of tolerance zone, the position error includes the shape error of the measured surface. For example, the parallelism error contains the flatness error, so the position error is much larger than the shape error. Therefore, under normal circumstances, when there is no further requirement, the position tolerance is given, and the shape tolerance is no longer given. When there are special requirements, the shape and position tolerance requirements can be marked at the same time, but the marked shape tolerance value should be less than the marked position tolerance value, otherwise, the parts cannot be manufactured according to the design requirements during production.

Slewing bearing

The slewing bearing and slewing ring have high precision, which represents the level of precision and processing technology, which means higher value. They are generally used for precision machine tools, precision equipment and high-precision instruments to achieve measurement and control, positioning and pointing. The runout is controlled at 0.02, ~ 0.05, the clearance value is controlled at 0.01-0.06, the roughness is controlled at Ra1.6/0.8, the hardness is uniformly distributed, the parallel difference is controlled at 0.015, and the dimensional tolerance must be in accordance with the requirements of the drawing.

High-precision slewing bearing for automatic welding equipment was successfully completed

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Recently, our company has produced a set of non-standard customized special-shaped high-precision slewing bearings for a high-tech enterprise in Beijing. This set of bearings is used on high-end automatic welding equipment for processing nuclear equipment. This is the second time this company has been with us. The first cooperation was for large-scale precision slewing bearings. In view of our previous happy cooperation, the customer chose to cooperate with our company for the second time without hesitation. The customer’s cooperation again is for the quality of our products, technology, and pre-sales. , Sales and after-sales service are confirmed again.

This product has several important features:

 

  1. The outer diameter is large, reaching 2.2 meters, which is much higher than the size range of high-precision slewing bearings commonly made in the market.

 

  1. the precision requirements are extremely high, the end jump and the diameter jump are strict, the end jump is within 0.05mm, the diameter jump is less than 0.1mm, and the clearance is 0-0.005mm.

 

  1. The starting torque is very small, requiring one person to rotate easily.

 

  1. the surface should be hot-sprayed zinc, and it is required to reach the level of wind power bearing.

Our company strictly follows the requirements of the customer to confirm the drawings, formulates the processing and production plan, anticipates the problems that may occur in each process, and thinks up targeted solutions in advance to ensure that each process is within the controllable range, so as to ensure the quality and safety of the assembled product . After a series of controllable processing procedures and the timeliness of the materials in the processing, the technical requirements of the finished product have reached the requirements specified in the drawings confirmed by the customer. Moreover, the rotation is flexible, which can be easily rotated by one person.

Talking about the gear grinding technology of slewing bearing

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As a process to be realized by precision products, the situation of grinding teeth needs to be noted, and what kind of technical indicators should be achieved. This article analyzes one by one. Regarding the slewing bearing or slewing bearing, whether external or internal teeth, helical teeth, etc., the normal process level, there are gear shaping, gear hobbing, and milling gears, according to the design standard, the general standard of gear accuracy is 9 teeth or 10 teeth. Here 9-level teeth or 10-level teeth, the index to be investigated is based on the design standard of the slewing bearing of JB/T10471, and you can also refer to JB/T2300.

mainly reflects the rotation accuracy, the specific indicators are:

1, the number of teeth across and the length of the common normal;

2, common normal deviation

3. Tooth jump (tooth jump of the finished slewing bearing);

4. Tooth width, tooth thickness, tooth profile and tooth direction are generally not marked separately in the drawings.

In short, the value of the 9th grade or 10th grade of the slewing bearing is the same in a pure sense. In terms of design concepts, the common normals of grade 7 and grade 8 teeth, and the tooth jump also meets the design requirements. However, tooth surface quenching has a great impact on the accuracy of the tooth surface, generally one step backward.

Slewing bearing

The following effects can be achieved by grinding teeth:

1. Improve meshing accuracy;

2, tooth jump 0.06-0.15mm;

3, tooth surface roughness Ra0.8;

4. Reduce meshing noise;

5. Reduce the wear strength of the tooth surface.

Gear grinding, improve the roughness of the gear, and then improve the accuracy of the gear, including the common normal of the gear, the tooth jump, the smoothness has a qualitative leap, and the meshing accuracy is also greatly improved.

Oil leakage of slewing ring

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The slewing bearing is responsible for the operation and rotation of marine equipment, engineering machinery, light industry machinery, metallurgical machinery, medical machinery, and industrial machinery and equipment. It is an important transmission component necessary for machinery that needs to bear axial force, radial force, and tipping moment. . Therefore, the consideration of performance guarantee in the structural design of the slewing bearing cannot be said to be insufficient.

 

The rotating structure needs sufficient lubrication, and the slewing bearing is no exception. The grease lubrication of the rotating part of the bearing is divided into two cavities: the slewing bearing lubrication cavity and the rotating gear ring lubricating cavity. The lubrication of the slewing bearing is completed by adding lubricating grease to the lubricating nipple located in the outer ring of the slewing bearing, and the lubrication of the slewing ring gear is completed by pre-filled grease. The slewing bearing has two rubber strips inside and outside (or upper and lower) as oil seals. The outer oil seal is fixed on the inner ring (fixed plate) of the slewing bearing of the lower frame to prevent dust from entering the slewing bearing. The inner oil seal is located on the outer ring (moving disc) of the bearing to prevent grease in the rotary gear ring from entering the bearing.

 

However, equipment and related accessories will be affected by a variety of comprehensive factors in actual use, and abnormal phenomena are inevitable. The oil leakage of turntable bearings is one of the common failure phenomena.

 

Generally, it is normal for a small amount of oil leakage in the outer oil seal under working conditions. The so-called normal means that the amount of grease leaking through the outer seal of the slewing bearing is approximately equal to the amount of grease added to the slewing bearing. However, when an abnormal phenomenon of a large amount of grease leakage occurs on the excavator, it should be checked. Due to the particularity of the lubrication structure of the rotating part, it is necessary to analyze whether there is a leakage and determine the problem in order to solve the problem.

 

Since the grease filled in the original equipment may be incorrect, the grease will become thinner when the temperature of the slewing bearing or the slewing ring gear rises slightly. If the thinned grease is pushed to the upper section of the ring gear during the meshing process by the driving gear of the rotary motor, it will flow into the bearing cavity through the inner oil seal, and the grease will drip out from the outer oil seal.