Blog - Slewing Ring Bearings Manufacturers Suppliers Exporters


June 27, 20220

slewing bearings price

1.Why do not use elastic washers for the mounting bolts of the slewing bearing?

The installation and operation manual of the slewing ring bearing tells you that elastic washers cannot be used when installing the connecting bolts of the slewing bearing, so what effect will the elastic washer have on the slewing ring bearing? Why can’t elastic washers, which are widely used on other mechanical equipment, be used on slewing ring bearings?

First, we must first understand the function of the elastic washer. The elastic washer has a certain elasticity, which can prevent the bolts and nuts from loosening and falling off during the use of the equipment. It is suitable for many mechanical equipment with vibration. However, the slewing ring bearing generally bears a large load, so the strength requirements of the bolts are relatively high.

Usually, grade 10.9 bolts and nuts are used. The high-strength bolt connection mainly relies on the frictional resistance between the bolt and the connected parts to achieve locking. Unlike ordinary bolts, which can be prevented from loosening by elastic washers, the use of thread tightening glue for the bolts of slewing bearings is the correct anti-loosening measure.

Second, the slewing ring bearing does not use elastic washers to prevent the deformation of the slewing ring bearing. The contact area of the elastic washer is not as large as that of the flat washer, and it is not reliable under the action of the large pre-tightening force. The large pre-tightening force of the bolt may It causes plastic deformation of the slewing ring bearing mounting surface in contact with the spring washer.

With the increase of use time, the deformation will become larger and larger, the pre-tightening force of the bolt will become smaller, and the bolt will loosen. The slewing ring bearing is usually subjected to overturning force. The overturning force during operation will aggravate the plastic deformation of the slewing ring bearing mounting surface, and may also cause the elastic washer to open, resulting in rapid damage to the bolt and the slewing ring bearing.

Third, a suitable flat washer can increase the contact area between the bolt and the slewing ring bearing, preventing the plastic deformation of the contact surface of the slewing ring bearing when the bolt is pre-tightened by the workpiece with insufficient hardness. Due to the increase in the contact area during the use of the slewing ring bearing Bolted connections maintain high reliability under overturning forces and shock loads.

When installing the slewing ring bearing, elastic washers cannot be used. You can choose a suitable flat washer. When installing the bolts, you need to tighten the bolts according to the pre-tightening torque specified in the manual. Use thread tightening glue to prevent the bolts from loosening.

2.What problems will affect the service life of the slewing bearing?

Slewing ring bearing is an important core component of equipment rotation. If the slewing bearing fails during the operation of the equipment and cannot rotate normally, it will cause equipment downtime and production paralysis.

slewing bearing Alt.

It is generally very troublesome to replace the slewing bearing, so everyone generally chooses a slewing bearing with reliable quality. The bearing is installed on its own equipment. After the slewing bearing is installed, everyone hopes that the slewing bearing can work stably and reliably, and the longer the service life, the better. What are the factors that affect the life of the slewing bearing?

1. The problem of the equipment itself

1. The rigidity of the equipment installation foundation is insufficient. When the slewing ring bearing is running under heavy load, the rigidity of the equipment installation foundation cannot provide a good support for the slewing bearing, resulting in elastic deformation of the slewing ring bearing, uneven force when the slewing ring ring bearing rotates, and long-term use. It will cause damage to the slewing bearing and affect the service life.

2. The flatness of the installation foundation is not good. There will be a gap between the slewing ring bearing and the installation foundation during installation. The correct way is to use a gasket with a suitable height to level the gap, but the operator often ignores this during installation and use. ,

In this case, the slewing bearing will warp and deform after the bolt is pressed, causing the channel to be deformed. After the deformation, the channel and the steel ball are not in good contact, and the clearance value is not uniform and the rotation is inflexible, which affects the use of the slewing bearing. life.

2. Overload operation

When the slewing ring bearing is designed, the bearing capacity has been clarified, such as how much load and how much overturning moment it can bear. If the actual load exceeds the bearing capacity of the slewing bearing during use, it belongs to overload operation.

During overload operation, the load on the steel ball exceeds the limit load, and there will be collapse blocks, fatigue spalling, and craters in the raceway. The collapse will cause serious damage to the slewing bearing. It is possible that a short-term overload operation will cause devastating damage to the slewing ring bearing, which will seriously affect the service life of the slewing ring bearing, and overload operation may easily lead to safety accidents.

3. Pollution

Pollution can also lead to premature damage of the slewing ring bearing. Pollution means that dust particles, water, etc. enter the bearing raceway, or foreign matter enters the tooth meshing of the slewing bearing. Damage to the slewing bearing, contaminants will also cause the slewing bearing to corrode, resulting in the deterioration of the grease, which will shorten the life of the slewing bearing.

4. Lubrication

The lubrication system can reduce the friction coefficient when the slewing ring bearing is running, achieve very small rolling friction or sliding friction, and also prevent the slewing bearing from rusting. Damaged teeth and lack of long-term lubrication are one of the main causes of premature failure of slewing ring bearings.



June 22, 20220

slewing gear factory

1.Introduction and selection of grease used in slewing gear and slewing drive

We all know that when the slewing bearing and the slewing drive are used, they need to be regularly filled with grease, and they cannot be used without lubrication, otherwise the slewing gear and the slewing drive will be damaged. The slewing bearing and slewing drive products of Fuji Transmission have been filled with grease before leaving the factory.

We choose to use Mobilux EP2 grease. People who often buy grease know that there are many brands of grease on the market, and the quality is uneven. , Counterfeit grease is emerging in an endless stream, so you must buy grease from big brands through regular channels.

If you add counterfeit grease, it will also cause damage to the slewing gear slewing drive. Our Mobilux EP2 grease is produced by Mobil official website authorized dealers to buy, to ensure the quality of the grease.

Why did we choose Mobilux EP2 grease for slewing rings and slewing drives? Mobilux grease EP series grades 0, 1, 2, 3, 004, 023 are a series of high-performance greases, four of which are general-purpose industrial greases and two are special-purpose semi-fluid greases. These lithium hydroxystearate greases provide superior protection against wear, rust and water washout.

Mobilux EP Series greases 0, 1, 2, and 3 are suitable for most types of industrial applications, including heavy duty applications with high specific pressure or shock loads. These greases offer excellent resistance to rust and corrosion, as well as water washout, making them ideal for equipment that is often exposed to wet conditions.

1. Mobilux greases EP0 and 1 have good low temperature pumpability and are suitable for centralized lubrication systems and other applications requiring low temperature performance.

2. Mobilux EP2 and 3 are general-purpose greases, recommended for multi-purpose use of anti-friction bearings and plain bearings, bushings and pins under normal working conditions. The recommended application temperature is in the range of -20℃ to 130℃, but Higher temperatures can also be used if the frequency of grease addition is increased accordingly.

3. Mobilux grease EP004 and Mobilux grease EP023 are especially suitable for the lubrication of enclosed gears and bearings in gearboxes with poor sealing in underground mining machinery, except for motor drives, and are also suitable for many other applications due to wear and tear Or industrial applications where there is a lack of seals to hold common gear oils in the gearbox or chain case.

The recommended application temperature range for Mobilux EP004 is -25 to 120°C, and the recommended temperature range for Mobilux EP023 is -15 to 120°C.

Mobilux EP series greases have long been recognized as high performance, exhibiting good performance in corrosion protection, low temperature pumpability and high temperature service life, they have good ability to withstand loads and extreme pressures.

Reduce wear under heavy load or shock load and vibration load, good equipment reliability, high utilization rate, good anti-rust and anti-corrosion and anti-water wash performance, can protect equipment and provide good lubrication in the case of water ingress, prolong bearing Service life in wet environments, reducing bearing replacement costs and unplanned downtime.

slewing gear Alt.

2.Why do not use elastic washers for the mounting bolts of the slewing gear?

The installation and operation instructions of the slewing gear tell you that elastic washers cannot be used when installing the connecting bolts of the slewing gear, so what effect will the elastic washer have on the slewing bearing? Why can’t elastic washers, which are widely used on other mechanical equipment, be used on slewing bearings? Let’s take a look at why.

First, we must first understand the function of the elastic washer. The elastic washer has a certain elasticity, which can prevent the bolts and nuts from loosening and falling off during the use of the equipment. It is suitable for many mechanical equipment with vibration. However, the slewing gear generally bears a large load, so the strength requirements of the bolts are relatively high.

Usually, grade 10.9 bolts and nuts are used. The high-strength bolt connection mainly relies on the frictional resistance between the bolt and the connected parts to achieve locking. Unlike ordinary bolts, which can be prevented from loosening by elastic washers, the use of thread tightening glue for the bolts of slewing bearings is the correct anti-loosening measure.

Second, the slewing bearing does not use elastic washers to prevent the deformation of the slewing gear. The contact area of ​​the elastic washer is not as large as that of the flat washer. Under the action of the large pre-tightening force, the flat washer is not reliable, and the larger pre-tightening force of the bolt may be It causes plastic deformation of the slewing bearing mounting surface in contact with the spring washer.

With the increase of use time, the deformation will become larger and larger, the pre-tightening force of the bolt will become smaller, and the bolt will loosen. The slewing bearing is usually subjected to overturning force. The overturning force during operation will aggravate the plastic deformation of the slewing gear mounting surface, and may also cause the elastic washer to open, resulting in rapid damage to the bolt and the slewing bearing.

Third, a suitable flat washer can increase the contact area between the bolt and the slewing bearing, preventing the plastic deformation of the contact surface of the slewing bearing when the bolt is pre-tightened by the workpiece with insufficient hardness. Due to the increase in the contact area during the use of the slewing bearing Bolted connections maintain high reliability under overturning forces and shock loads.

Through the above analysis, we have come to the following conclusions: elastic washers cannot be used during the installation of the slewing bearing, and a suitable flat washer can be selected. When installing the bolts, it is necessary to tighten the bolts according to the pre-tightening torque specified in the manual. The use of thread tightening glue can prevent the bolts. loose.



June 20, 20220

in stock slewing bearings suppliers

1.Why do slewing bearings need to grind their teeth? Cause Analysis

With the continuous development of industrial machinery, there are higher and higher requirements for the transmission stability, transmission accuracy and bearing capacity of the motor-driven pinion and the slewing ring gear. Regarding the slewing bearing, whether it is external or internal, the normal process includes gear shaping, gear hobbing, and milling.

According to the design standard, the general gear accuracy is grade 8 or grade 9. Rough insertion and fine insertion can reach grade 7 tooth precision. The tooth precision is mainly reflected in the rotation precision. Specific indicators:

1. Cross pitch and common normal length

2. Common normal deviation

3. Tooth jump (tooth jump of finished turntable bearing)

4. Tooth width, tooth thickness, tooth shape and tooth direction, etc. (generally not marked in the drawing)

In order to improve the strength, hardness, wear resistance and toughness of the ring gear and gear, we usually use surface quenching on the teeth of the ring gear when machining the slewing bearing teeth. Easily damaged, etc. Tooth quenching has a great influence on the tooth accuracy.

After quenching, the ring gear will appear elliptical deformation, and the accuracy level will decrease. If the tooth accuracy requirements are high, the design requirements are usually not met after quenching.

If you want to achieve higher tooth accuracy after quenching, you need to Finishing the teeth, but the hardness of the teeth after quenching is high, and the conventional gear shaping or gear hobbing process cannot process the quenched teeth.

We usually use the grinding process. What is grinding? The grinding wheel is used as a tool to grind the processed gear tooth surface to improve the gear precision and surface roughness. It is suitable for steel gears with high hardness after quenching.

Grinding teeth can achieve high surface roughness, and the quenched teeth can reach Ra0.8 surface roughness through grinding, and the tooth jump can reach 0.03-0.1mm. Grinding can correct the deformation of the gear during the heat treatment process, ensure the accuracy of the finished gear, improve the meshing accuracy, achieve the purpose of precise transmission, and reduce vibration and noise.

slewing rings Alt.

2.How to improve the tooth machining efficiency of the slewing bearing?

The slewing ring bearing is a large bearing that operates at low speed and heavy load. Usually the inner ring or outer ring has teeth. It is used to connect large components that require relative rotation. It is widely used in automated industrial machinery, construction machinery, wind power equipment, port machinery and other fields. ,

In the whole cycle of the slewing bearing from the forging to the finished product until it is sent to the user, the tooth processing process takes up a lot of time, and the length of the delivery time depends to a large extent on the processing efficiency of the slewing bearing teeth.

In recent years, due to the country’s strong investment in infrastructure, new energy equipment and other fields, the market demand for slewing ring bearings has also increased sharply, and the supply is often in short supply. On the other hand, there are many domestic manufacturers of slewing ring bearings. Minimizing costs on the premise of quality is the key for enterprises to stand out in the fierce market competition.

Gear machining is the longest time-consuming process in the production process of slewing bearings, and it has always been one of the most important factors restricting the production efficiency of slewing bearings.

The traditional slewing bearing tooth machining usually has two methods: gear shaping and gear hobbing. In order to adapt to the improvement of processing accuracy and production efficiency requirements, gear hobbing and gear shaping technology are constantly developing in the direction of full numerical control, high speed, high precision, and intelligence, but the processing efficiency has not yet reached the ideal state, especially the processing of internal teeth. Only the gear shaper can be used, the cutting amount of each feed is small, and the processing efficiency is low.

In recent years, a machining method of CNC high-speed tooth milling has been gradually promoted in the slewing bearing industry. There are two types of internal teeth and external teeth, which are processed by the profiling principle, with high processing efficiency and large feed amount.

It is suitable for large diameter, large Modular slewing bearing processing, especially internal gear processing, is 5-8 times more efficient than traditional gear shaping, which greatly shortens the production cycle of slewing bearings.

Gear milling, gear hobbing, and gear shaping have their own advantages and disadvantages in terms of processing efficiency and equipment cost. In the case of sufficient market demand, the efficiency of gear milling is better than that of gear hobbing and gear shaping, and the cost of gear milling is also lower than that of gear hobbing and gear shaping.



June 17, 20220

China Popular Wholesales Double Row Ball Slewing Bearing

1.Double row ball slewing bearing

Slewing ring bearings have unique bearing characteristics and are usually used in hoisting machinery, excavators, turntables, wind turbines, and other equipment. Most of the slewing bearings below three meters have a four-point ball structure, and the size of the load determines the height of the slewing ring, Diameter and size of channel steel balls.

If a large-load slewing bearing is required but the diameter is limited, the bearing capacity of the slewing bearing can generally be improved by increasing the steel ball. If the bearing capacity is still not met by increasing the steel ball, the structure of the double row ball slewing bearing can be adopted.

The slewing bearing satisfies the limited outer diameter size, but also requires a large load, which not only saves materials, but also improves the performance of the slewing bearing, so that the slewing bearing has greater axial radial load and tipping moment.

double row ball slewing bearing Alt.

So how does the double row ball ball slewing bearing channel ensure the accuracy and mutual difference?

The channels of double row ball slewing bearings are divided into plane channels and arc channels, among which the channels of four-point contact ball bearings and double-row ball bearings are typical arc channels; the channels of crossed roller and three-row roller bearings are is a typical planar channel.

In terms of processing technology, the processing difficulty of circular arc channels is greater than that of flat channels, so there are naturally higher requirements for precision level and parameter control of actual processing.

Especially for the double row ball slewing bearing, the channel is two parallel arcs. In theory, the two rows of balls are subjected to force and run at the same time during the rotation process, but the probability of absolute simultaneous force and simultaneous operation is very low. exist on.

During the machining process, a certain error is allowed in the double-row ball channel. This error is not enough to affect the overall operating state of the slewing bearing.

This mutual difference is generally required to be within 0.03mm in the process. In order to achieve this goal, in the process of bearing grinding and matching, the machine tool needs to have good precision, and the workers need to have a skilled operation level.

If you want to achieve zero or negative double-ball clearance, the difference needs to be controlled within 0.01mm. Inside, for the double row ball slewing bearing, only by controlling the mutual difference between the channels can the slewing bearing exert its theoretical bearing capacity and its characteristics.

2.Double row ball slewing bearing

The LYMC double-row ball slewing bearing can carry axial load, tilting moment and radial loads at the same time. The top ball mainly carries the axial load and positive tilting moment. The drop ball takes the opposite tilting moment. This is the reason for the loading capacity of the double row ball slewing bearing being larger than the four-point contact ball slewing bearing; however, the frictional ratio is much larger. than the latter.

The LYMC double row ball slewing bearing consists of a inner ring, outer ring, balls in double rows, spacers, sealing device, and other components. Due to the top ball mainly taking the axial load and tilting moment loads, the size of top balls are larger than the drop ball. In order to accommodate the various working condition at different axial load, tilting moments and axial load, the angle of contact would be adjusted accordingly.

The rings structure can be divided into two types, integral type and split type. Generally, the integral type maintains a stronger rigidity. The split type is more convenient to adjust; the two segregate rings are fastened by bolts prior to delivery. The LYMC double row slewing bearing has cages (or spacing blocks) among the balls. Only when large loading is requested would the full ball type be applied. Loading capacity for full ball type is definitely larger.

However, the increased friction generated by this design allows for the balls to be easily scratched. The double row slewing bearing is mainly for the working conditions when carrying an axial load, larger tilting moment, and where the mounting place is limited in radial direction. This structure provides good performance when fit into an installation when an amount of deformation may be allowed.



June 14, 20220

high speed ball slewing ring bearing in stock

1.How to reduce slewing ring bearing tooth noise?

The slewing ring bearing can stably support the equipment for slewing motion, also known as the turntable bearing. The mechanical equipment needs to rotate without the transmission. The slewing bearing can be made of external teeth or internal teeth, and the rotation of the slewing bearing is realized through the gear transmission.

In practical applications, the force of the slewing ring bearing is different, the speed of rotation is also different, and the teeth of the slewing bearing are also different. In the process of gear transmission, the contact between the gear and the ring gear of the slewing ring will generate noise, so how to reduce the noise of the slewing ring bearing?

1. Control the tooth precision. Through long-term practice, we found that if we want to reduce the tooth noise, the tooth precision needs to be controlled at 7-8 grades. The higher the rotational speed, the higher the gear tooth precision requirements. Gear, tooth accuracy should be controlled within 7 grades.

2. Reduce the start-stop or forward and reverse frequency of the gear. Frequent start-stop or forward and reverse rotation will cause the gear to vibrate too fast, and the vibration will generate noise. The faster the vibration, the greater the noise. Reduce the start-stop or forward and reverse frequency, you can Reduce noise.

3. Reduce the impact load. The impact load will make the vibration frequency and torsion direction of the gear different, which will cause vibration in the circumferential direction, which will form a smooth noise. Reducing the impact load can reduce the noise.

4. Reduce the occurrence of resonance. Resonance will produce high-frequency noise. When the motor rotates at a low speed or at a certain speed, the equipment will resonate, causing the gear and ring gear to oscillate at a high frequency and the two oscillating objects contact. High-frequency noise will be generated, which can generally be reduced by changing the speed or adjusting the position of the equipment.

5. Increase the roughness of the tooth surface. If the roughness of the tooth surface is very poor, it will cause point contact on the tooth surface, and noise will be generated when the high point contact is made. If the roughness of the tooth surface is increased, the tooth surface will be in line contact, and the noise will be very high.

6. Increase the lubrication of the tooth surface. Insufficient lubrication will lead to increased friction, and noise will be generated when the tooth surface is rubbed. Sufficient lubrication can reduce friction and effectively reduce noise.

slewing ring bearing Alt.

2.What does the clearance of the slewing ring bearing mean and how does it affect the use?

Clearance is an important technical parameter of slewing ring bearing, which directly affects the technical performance of the bearing, such as load distribution, vibration, noise, friction, temperature rise, service life and mechanical running accuracy.

If the clearance is too large, the internal bearing area of ​​the bearing will be reduced, the stress of the contact surface will increase, the rotation accuracy will decrease, and the vibration and noise will increase. As a result, the service life is shortened, and the clearance is too small.

Negative clearance (interference) may appear in actual operation, and the rotation jamming will be inflexible, resulting in increased friction and heat, and temperature rise, thereby making the effective clearance smaller. Or the interference is larger, such a vicious circle will cause the bearing to lock and not rotate.

The clearance value of the bearing is artificially specified by the designer, and a certain range is divided according to the size of the slewing bearing, which is used as a reference value in the processing process.

Therefore, if it is not specially required by the operating conditions, the clearance of the bearing can allow an error within 0.05 within the specified range, and this error is not enough to affect the quality of the slewing ring bearing itself. A larger error is not acceptable, it will cause the slewing bearing to overturn and shake, which will affect the use.

The clearance of the slewing ring bearing can make up for the installation error. If the clearance is too small and the installation plane is rough and uneven, the installation screw will warp after being pressed, the force will be uneven during use, and the rotation will be stuck.

In this case, first ensure the normal rotation of the bearing, and a large clearance is required to offset the error during installation. When designing, it is necessary to consider the flatness that can be achieved after the installation foundation is processed, and select the appropriate clearance.

Of course, the clearance value cannot be sloppy when the design rotation accuracy is high. Generally, zero clearance or negative clearance is selected to at least ensure that the bearing has no clearance.

When repeated positioning accuracy is required, the clearance is very important for the slewing bearing. important. Even if there is no special requirement for starting torque, the clearance value needs to be guaranteed to be within -0.02 to 0.

The influence of the clearance on the slewing bearing is very large. During the design, it is necessary to fully communicate with the user, understand the working conditions in detail, and select the clearance value reasonably to ensure that the slewing bearing is more stable and durable.



June 13, 20220

thrust ball bearing suppliers china

1.What are the causes and solutions of thrust ball bearing damage?

Thrust ball bearing is mainly composed of three parts, namely seat washer, shaft washer and steel ball cage; because of its structural characteristics, this kind of bearing can only bear axial load, but cannot bear radial load, and is mostly used for crane hooks, jacks, vertical bearings, etc.

On parts with low speed such as type water pump. We all know that equipment bearings should be properly selected and installed and pay attention to daily maintenance and maintenance, otherwise it is easy to cause early damage to the bearings, and the same is true for thrust ball bearings.

First. Causes of damage to thrust ball bearings
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1. Improper installation
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Some masters are accustomed to using brute force to directly hit the bearing surface when installing the bearing, causing deformation of the bearing assembly, and increased vibration during operation, resulting in bearing damage;

or the bearing installation is skewed, causing the bearing clearance to fail to meet the standard, and the bearing is running. Uneven force, thereby aggravating bearing damage.
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2. Poor lubrication
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Poor lubrication is one of the reasons for the damage of thrust ball bearings. Bearings with insufficient lubrication will bear greater friction during operation, resulting in overheating and wear, resulting in bearing damage.

There are many reasons for poor lubrication. Generally, there are improper selection of lubricating oil, lack of lubricating oil or insufficient filling, and deterioration of lubricating oil.
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3. Bearing foreign body
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If the bearing is not paid attention to when it is opened and installed, it will cause foreign matter to enter the internal space, or if the maintenance is not careful after a long period of operation, metal debris, etc.

will enter the internal space of the bearing, which will cause bearing wear, abnormal vibration and excessive size. In this case, the bearing will be damaged.
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4. Overload fatigue
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Long-term overload operation of thrust ball bearings usually causes damage. The reasons for overload fatigue are generally that the bearing selection does not match the equipment or working strength, overloaded operation over time, and untimely inspection and maintenance.

thrust ball bearing Alt.

Second:the solution
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1. Reasonable installation
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When installing the thrust ball bearing, special tools should be used, and brute force knocking is prohibited. When the installation is completed, a measuring tool should be used to measure to ensure that the installation is in place.
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2. Do a good job of lubricating
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Select the lubricating oil that matches the model and fill it with sufficient amount. Regularly check the lubrication condition of the thrust ball bearing.

When the grease is insufficient, it should be replenished in time. If the lubricating grease deteriorates, stop the equipment operation immediately and replace the bearing lubricating grease.
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3. Do a good job in inspection and maintenance
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Bearings should be stored before installation to prevent rust; during installation, ensure that the surrounding environment is clean, and check to prevent foreign objects from entering the bearings;

bearings should be maintained and maintained during operation, and foreign objects should be cleaned in time to prevent metal debris from entering its interior space.
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4. Prevent bearing overload
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According to the equipment and working intensity, select the thrust ball bearing with matching specifications and parameters.

The equipment should be given a certain rest time after working for a long time. The abnormality of the bearing should be checked and dealt with in time to prevent “sickness”.



June 9, 20220

turntables slewing rings made in china

1.Causes and treatment methods of overheating of turntables slewing rings

The overheating phenomenon of the turntables slewing rings during operation is one of the common faults of the bearing. Once the overheating phenomenon is found, it needs to be stopped in time for investigation and treatment.

Improper handling will reduce the working efficiency of machinery and equipment, and may cause serious damage to the bearing, increase unnecessary capital investment, and delay the construction period, which is not worth the loss.

The cause of overheating:

1. Poor lubrication

Good lubrication is a necessary condition to ensure the normal operation of the turntables slewing rings. If the bearing grease is insufficient or deteriorated, it will increase the friction and wear of the bearing, causing the bearing to overheat.
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2. Improper installation

​​When the turntables slewing rings are installed, it is required that the center line of the shaft and the bearing hole need to be coincident. If the installation is not correct, the bearing will be deflected, and a moment will be generated when rotating, causing the bearing to overheat, wear, vibrate, and increase noise.
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3. Inspection and replacement are not timely

​​The bearings in operation should be checked in time. If serious fatigue spalling, oxidation corrosion, pits, cracks, etc. are found, new bearings should be replaced in time, otherwise it will cause the bearings to overheat, abnormal noise or even damage the mechanical equipment.
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4. Poor bearing quality or improper selection

​​The turntables slewing rings generally works for a long time under strong stress. The accuracy, life and reliability of the main engine largely depend on the bearing.

If the bearing itself is of poor quality or improperly selected at the time of purchase, its limit speed and load capacity do not match the equipment. , may cause overheating.

turntable slewing rings Alt.

2. Processing method
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1. Purchase bearings with good quality and matching models

​​When purchasing turntables slewing rings, we must strictly control the quality, and comprehensively consider factors such as the nature, size, temperature conditions of the bearing load, and the rotation shape of the inner and outer rings according to the equipment requirements to ensure that the model matches.
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2. Install the bearing according to the operating procedures

​​When the bearing is installed, the coordination between the inner diameter of the bearing and the shaft, the outer diameter and the outer casing is very important. In addition, the center line of the shaft and the bearing hole needs to be coincident to prevent the bearing from overheating, vibration, abnormal noise, etc. caused by wear caused by improper installation.
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3. Regularly check and replenish grease

​​Bearings should be regularly inspected for grease. If the lubrication is insufficient, it should be replenished in time. If the grease deteriorates, it should be replaced in time. Different types of grease cannot be mixed.
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4. Timely check the running condition of the turntables slewing rings

​​Timely check whether the bearing is bitten and worn, check whether there are cracks, rust, pits and other defects inside and outside the bearing, measure whether the bearing clearance exceeds the standard, and repair or replace the new bearing in time if there is an abnormality.

2.How does slewing ring paint rust form? How to prevent?

First, the cause of the formation of bearing paint rust
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Generally, the slewing ring with paint rust is generally on the end face near the inner side of the motor, and will be seriously rusted. The grease near the edge of the inner and outer rings will first deteriorate, generally yellowish brown.

The reason for the formation of bearing paint rust refers to the fact that during the bearing paint rust test, it was found that the severity of bearing paint rust was closely related to the humidity. Most of the paint rust occurs in the south or the coast to coincide with the imagination of the annual rainy season.
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1. The climate environment is high temperature and high humidity.
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2. The stator drying is incomplete;
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3. Motor bearings are sealed and packaged in storage;
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4. The severity of paint rust mainly depends on the composition of the paint base.
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5. Prevention of paint rust (bearing seal and rust prevention, type of grease).

 

Second, the prevention method of bearing paint rust
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The prevention of slewing ring paint rust must be considered in terms of its mechanism, from the design and manufacture of motors, insulation and bearings. We organize the preventive measures as follows:
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1. Avoid complete sealing and open air holes as much as possible;
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2. The manufacture of traditional Chinese medicine must ensure the drying time of insulating paint. After the stator is dried, it should be placed in a ventilated place for natural ventilation, so that the paint gas can be completely released. The stator should follow the principle of first-in, first-out during use.
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3. During the storage process of the warehouse, it is not close to the walls and corners, and pallets are used on the ground to ensure ventilation, and the humidity should be less than 70%RH as much as possible.
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4. Use stable insulating varnishes (such as epoxy solvent-free insulating varnishes) that do not escape low molecular acid, and produce them in strict accordance with the production process requirements.
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5. When selecting grease, use mineral oil as the base oil.
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6. Sealed bearings are used.

 



June 8, 20220

low price cross roller slewing rings

1.Cross roller slewing rings:

Cross roller slewing rings are bearings for high-precision applications. They comprise outer rings, inner rings, rolling elements and plastic spacers. The outer ring is split and is held together by three retaining rings.

Due to the X arrangement of the cylindrical rollers, these bearings can support axial forces from both directions as well as radial forces, tilting moment loads and any combination of loads by means of a single bearing position. As a result, designs involving two bearing positions can be reduced to a single bearing position.

Crossed roller slewing rings are very rigid, have high running accuracy and are supplied with normal clearance, low clearance or preload. The bearing outer rings are easily fixed to the adjacent construction using clamping rings.

cross roller slewing ring Alt.

Crossed roller slewing ring is a special type bearing with separated inner ring and rotating outer ring. Since the divided inner ring or outer ring is installed with the rollers and spacers, it is fixed with the cross roller ring to prevent crossing each other, so it is easy to operate when installing the cross roller slewing ring.

Because the rollers are arranged in a cross, only one set of roller rings can cross the load of each direction column of the shaft. Compared with the conventional model, the shaft center is increased by 3 to 4 times.

At the same time, because the inner ring or the outer ring of the crossed roller slewing ring is a two-part structure, the bearing gap can be adjusted, and even if a preset is applied, the ring can generate its rotational movement. Moreover, due to the special structure, pop music is usually used in industrial robots.

2.Introduction to the assembly process of the cross roller slewing ring

1. Inspection of cross roller slewing ring parts

Check the appearance for bumps or rust spots, if there are serious bumps, rework, check the external dimensions, check whether the workpiece is consistent with the assembly drawings, avoid missing processes after equipment and rework, carefully check the inner and outer ring raceways to find the soft belt, in the corresponding Mark S on the slewing bearing plane, and find the number of grinding parts, and place the inner and outer rings with the same number accordingly.

2. Rust removal

If there are rust spots on the cross roller slewing ring parts, lightly rub with a scouring pad and cleaning agent for slight rust, and use an angle grinder to install a film for serious rust (except raceway).

3. Remove cross roller slewing ring burrs and bumps

Pay attention to check the installation holes, oil holes, the chamfers of the inner and outer rings and the sealing grooves for burrs and bumps, and polish them with scouring pads or sandpaper.

4. Blocking and grinding requirements

Find the small end of the taper pin, take out the taper pin, and then use a puller to pull out the blockage, grind the edge of the blockage so that there are no burrs and sharp places, and grind it thoroughly to prevent abnormal noise from the slewing bearing after assembly.

5. Clean the slewing bearing

Clean the workpiece, use compressed air to blow off the processing residues (fine iron grinding, grinding) on ​​the inner and outer rings of the slewing bearing and in the mounting holes, then use kerosene or diesel to clean the workpiece, and then load it into the assembly area.

6. Slewing bearing with rolling elements

Use a block of wood to padded a ferrule that is blocked to make it fixed and cannot be rotated, and then insert another ferrule (the large one is suspended with a crane), so that the positions of the inner and outer ring channels are in a parallel state, and put in a few grains first.

The rolling elements are dispersed in a circle, support the non-clogging ferrule, and then rotate the non-clogging ring to install other rolling elements and spacers according to the number required in the drawing, so that they are evenly distributed in the raceway, check the remaining gaps in the raceway, and use a thick Or thin spacer block to adjust the gap, the gap should not be greater than the length of one spacer block, to prevent the slewing bearing from being stuck due to the overturning of the spacer block, and then install the plug and taper pin, both ends of the taper pin should be lower than the plane.

7. Detection

Check all drawing size requirements, check whether the rotation is flexible, whether there is noise, axial clearance, radial clearance, end face runout, tooth runout, inner and outer diameter runout, finished product height, starting torque, etc.

8. Oil filling seal

After passing the test, put it into the grease nipple, then inject grease as required, install the seal and stick the interface, type, and finally demagnetize to check the appearance.

9. Packaging

The finished product is coated with anti-rust oil, first wrap the first layer with a transparent oil-repellent film, then wrap the second layer with kraft paper, and then wrap the third layer with plastic wrapping film or according to customer requirements, and finally label the product and pack it.



June 7, 20220

china without gear bearing(no gear)

1.Selection and Practical Application of Clearance of Precision Gear Bearings

The precision gear bearing can rotate smoothly to obtain an ideal runout value. Generally, when designing and manufacturing, the clearance value will choose small clearance, zero clearance, and negative clearance. The corresponding clearance value is generally 0 to 0.05. ≤0, -0.05 to -0.01, the corresponding preloads are: no preload, light preload, and heavy preload.

During processing, we can measure the channel size according to the method of measuring the channel size of the gear bearing, and calculate the clearance value (whether positive or negative) according to the measurement data, and then check the calculated clearance value after the processing is completed.

The positive clearance is directly measured with a dial indicator, and the negative clearance is used to measure the starting torque of the slewing bearing. According to the size of the starting torque, the size of the interference of the gear bearing is judged. The starting torque is also a must know in the use of the slewing bearing. A value of , which determines the selection of slewing bearing reducer and motor.

To measure the starting torque of the gear bearing, it is necessary to measure the starting force of the slewing bearing first, and a dynamometer is required. Since the maximum starting force occurs at the moment when the slewing bearing is about to rotate, a force measurement that can record the maximum value of the measurement is required. Gauge to measure the driving force of the gear bearing。

Starting torque=starting force x lever arm, the starting force can be measured with a dynamometer, we generally install a bolt on the outer ring hole of the slewing bearing, and use a dynamometer to measure the starting force of the slewing drive at the bolt, and the distribution of the bolt holes in the outer ring The radius of the circle is the arm, and the starting torque of the slewing bearing is calculated from the starting force and the arm.

For the same gear bearing, the difference in starting torque can reflect the size of the clearance value of the negative clearance slewing bearing. The larger the starting torque, the smaller the clearance value and the greater the preload.

gear bearing Alt.

The selection of the clearance value should also consider the situation of the customer’s equipment. The smaller the clearance value of the slewing bearing, the higher the requirements for installation and use.

Due to the small deformation, the small deformation of the gear bearing can be offset by the clearance when the clearance is large, and the slewing bearing can rotate normally after installation, but if it is a small or negative clearance, the slewing bearing has no extra clearance to resist the small deformation. If the slewing bearing is deformed, it will be stuck, rotated poorly, or even stuck, resulting in damage or failure to use.

Therefore, the selection of small clearance for precision gear bearings requires comprehensive analysis and evaluation of the accuracy of the slewing bearing, the machining accuracy of the equipment installation foundation, and the user’s specific operating conditions, and then selects the appropriate clearance value, which not only ensures the accuracy but also ensures that it can be installed and used on site.

2.How to improve the tooth machining efficiency of the gear bearing?

The slewing ring bearing is a large bearing that operates at low speed and heavy load. Usually the inner ring or outer ring has teeth. It is used to connect large components that require relative rotation. It is widely used in automated industrial machinery, construction machinery, wind power equipment, port machinery and other fields. ,

In the whole cycle of the slewing bearing from the forging to the finished product until it is sent to the user, the tooth processing process takes up a lot of time, and the length of the delivery time depends to a large extent on the processing efficiency of the slewing bearing teeth.

In recent years, due to the country’s strong investment in infrastructure, new energy equipment and other fields, the market demand for slewing ring bearings has also increased sharply, and the supply is often in short supply. On the other hand, there are many domestic manufacturers of slewing ring bearings. Minimizing costs on the premise of quality is the key for enterprises to stand out in the fierce market competition.

Gear machining is the longest time-consuming process in the production process of slewing bearings, and it has always been one of the most important factors restricting the production efficiency of slewing bearings. The traditional slewing bearing tooth machining usually has two methods: gear shaping and gear hobbing.

In order to adapt to the improvement of processing accuracy and production efficiency requirements, gear hobbing and gear shaping technology are constantly developing in the direction of full numerical control, high speed, high precision, and intelligence, but the processing efficiency has not yet reached the ideal state, especially the processing of internal teeth. Only the gear shaper can be used, the cutting amount of each feed is small, and the processing efficiency is low.

In recent years, a machining method of CNC high-speed tooth milling has been gradually promoted in the slewing bearing industry. There are two types of internal teeth and external teeth, which are processed by the profiling principle, with high processing efficiency and large feed amount.

It is suitable for large diameter, large Modular slewing bearing processing, especially internal gear processing, is 5-8 times more efficient than traditional gear shaping, which greatly shortens the production cycle of slewing bearings.

Gear milling, gear hobbing, and gear shaping have their own advantages and disadvantages in terms of processing efficiency and equipment cost. In the case of sufficient market demand, the efficiency of gear milling is better than that of gear hobbing and gear shaping, and the cost of gear milling is also lower than that of gear hobbing and gear shaping.



June 6, 20220

best bearing slewing ring manufacturers china

The importance of the mutual difference between the two channels of the double volleyball slewing ring bearing

Slewing ring bearings have unique bearing characteristics, and are usually used in hoisting machinery, excavators, turntables, wind turbines, and other equipment. Most of the slewing bearings below three meters have a four-point ball structure, and the size of the load determines the height of the slewing ring, Diameter and size of channel steel balls.

If a large-load slewing ring bearing is required but the diameter is limited, the bearing capacity of the slewing bearing can generally be improved by increasing the steel ball. If the bearing capacity is still not met by increasing the steel ball, the structure of the double-row ball slewing bearing can be adopted.

The slewing ring satisfies the limited outer diameter size, but also requires a large load, which not only saves materials, but also improves the performance of the slewing bearing, so that the slewing bearing has greater axial radial load and tipping moment.

The channels of slewing ring bearings are divided into plane channels and arc channels, among which the channels of four-point contact ball bearings and double-row ball bearings are typical arc channels; the channels of crossed roller and three-row roller bearings are is a typical planar channel.

In terms of processing technology, the processing difficulty of circular arc channels is greater than that of flat channels, so there are naturally higher requirements for precision level and parameter control of actual processing.

Especially for the double-row ball slewing bearing, the channel is two parallel arcs. In theory, the two rows of balls are subjected to force and run at the same time during the rotation process, but the probability of absolute simultaneous force and simultaneous operation is very low. exist on.

During the machining process, a certain error is allowed in the double-row ball channel. This error is not enough to affect the overall running state of the slewing ring.

This mutual difference is generally required to be within 0.03mm in the process. In order to achieve this goal, in the process of bearing grinding and matching, the machine tool needs to have good precision, and the workers need to have a skilled operation level.

If you want to achieve zero or negative double-ball clearance, the difference needs to be controlled within 0.01mm. Inside, for the double volleyball slewing ring, only by controlling the mutual difference between the channels can the slewing ring exert its theoretical bearing capacity and its characteristics.

slewing bearing Alt.

2.How to reduce slewing ring bearing tooth noise

The slewing ring bearing can stably support the equipment for slewing motion, also known as the turntable bearing. The mechanical equipment needs to be rotated without the transmission. The slewing bearing can be made of external teeth or internal teeth, and the rotation of the slewing bearing is realized through the gear transmission.

In practical applications, the force of the slewing bearing is different, the speed of rotation is also different, and the teeth of the slewing bearing are also different. In the process of gear transmission, the contact between the gear and the ring gear of the slewing ring will generate noise, so how to reduce the noise of the slewing ring?

1. Control the tooth precision. Through long-term practice, we found that if we want to reduce the tooth noise, the tooth precision needs to be controlled at 7-8 grades. The higher the rotational speed, the higher the gear tooth precision requirements. Gear, tooth accuracy should be controlled within 7 grades.

2. Reduce the frequency of start-stop or forward and reverse rotation of the gear. Frequent start-stop or forward and reverse rotation will cause the gear to vibrate too fast, and the vibration will generate noise. The faster the vibration, the louder the noise. Reduce noise.

3. Reduce the impact load. The impact load will make the vibration frequency and torsion direction of the gear different, which will cause vibration in the circumferential direction, which will form a smooth noise. Reducing the impact load can reduce the noise.

4. Reduce the occurrence of resonance, which will generate high-frequency noise. When the motor rotates at a low speed or at a certain speed, the equipment will resonate, causing the gear and ring gear to oscillate at a high frequency and the two oscillating objects will contact. High-frequency noise will be generated, which can generally be reduced by changing the speed or adjusting the position of the equipment.

5. Increase the roughness of the tooth surface. If the roughness of the tooth surface is very poor, it will cause point contact on the tooth surface, and noise will be generated when the high point contact is made. If the roughness of the tooth surface is increased, the tooth surface will be in line contact, and the noise will be very high. Small.

6. Increase the lubrication of the tooth surface. Insufficient lubrication will lead to increased friction, and noise will be generated when the tooth surface is rubbed. Sufficient lubrication can reduce friction and effectively reduce noise.


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