Turntable Slewing Bearing Made In China

What are the reasons for the shortened Turntable slewing bearing service life?

The turntable slewing bearing support is widely used in engineering machinery, and it can also be called a turntable bearing. Speaking of the turntable bearing, I believe that everyone should know. There are many reasons for the shortened life.

The reasons for the shortened service life of the turntable slewing bearing support

1. Equipment issues

The rotary branch is knocked directly during installation, and the damage to the turntable slewing bearings with brute force is used. At the same time, the force that the rotary support is rotated will be unevenly used for a long time, causing turntable slewing bearing damage.

If the installation is not in place, there will be an error or the turntable slewing bearing position between the gap device between the rotation support and the installation foundation during installation, and the slewing bearing gap will be too small. The inner and outer circle is not at the same rotation middle point, forming different intentions.

2. The carrying capacity of rotation support

Due to the production process, the materials used in the rear branch support have different bearing capacity, the actual operation of the equipment during use exceeds the load of the city’s energy city,

which can easily cause bearing fatigue or collapse, resulting in a serious inheritance of the revolving support. Damage affects the service life of machinery.

3, friction

The friction force is a key factor for all machinery. Dust particles, water or other foreign objects enter the tooth co -convergence of the bearings, increase the friction of the turntable slewing bearings, wear the channel and teeth,

cause damage caused by rust support, cause damage, friction caused by friction Dysfunction is the main factor that leads to a decrease in the use time of rotation support.

4. Lubrication

Not injecting flavors or flax oil in time; flavors or flax oil are not in place; not proper selection of smoothing agents or bold oils; incorrect smoothing methods and so on.

In order to ensure the normal use of the tower machine accessories, when used, you must pay attention to the maintenance of the slewing bearings, apply the lubricant regularly, and do not let the bearings overload for a long time.

High Precision Slewing Bearing

Necessity and Adjustment Method of Gear Clearance Adjustment of Slewing Bearing

First. Necessity of gear clearance adjustment of slewing bearing
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1. Different applicable work scenarios
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The size of the gear clearance of the slewing bearing is related to the characteristics of the gear transmission. When the gear transmission is used for heavy-duty work, the gear clearance needs to be larger. The gap should be smaller.
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2. Improper gear clearance affects normal work
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The gear transmission of tower cranes and excavators is not only required for heavy-duty work, but also requires frequent forward and reverse rotation, and the speed is not high. Whether the clearance is too large or the clearance is too small, it will have adverse effects.

If the gear gap is too large, the operation of these equipment will not be very smooth, and the gear wear will be more serious; if the gear gap is too small, the lubricating oil film between the slewing bearing gear and the slewing reducer gear will be destroyed, causing The friction between the two becomes larger, and the tooth surface wears faster.

Coupled with manufacturing errors and elastic deformation of the turntable, it is very likely that the gear will be stuck.
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Therefore, for heavy machinery such as tower cranes and excavators, in order to ensure the reliability of equipment rotation, it is very necessary to keep the gear gap of the slewing bearing at a moderate size and debug it according to the actual working conditions.

Second, the slewing bearing gear gap adjustment method
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1. Meshing tightly to adjust the gap
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In the position with high gear meshing tightness, adjust the gear backlash to the rated value. The value of this value should be adjusted strictly according to the given value, otherwise it may cause damage to the slewing ring bearing. In addition, in the process of gear clearance adjustment, it is also necessary to pay attention to the position of the teeth.
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2. Use feeler gauge to measure and adjust
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When the radial runout of the slewing ring bearing gear reaches a high point, the gear gap can be measured with a feeler gauge. If the gap is different from the given value, the slewing reducer gear can be moved to change the center of the slewing reducer gear and the slewing bearing gear. Correct the distance.

If the slewing reducer gear cannot be moved, it can be adjusted by moving or re-fixing the slewing bearing. After debugging, let the slewing bearing rotate a few times to see if the adjusted clearance meets the requirements. If there is a radial jump of the gear to a higher point, it should be marked and adjusted again.
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When adjusting the slewing bearing gear clearance, if there is no gnawing between the slewing ring bearing gear and the slewing reducer gear, and the slewing mechanism can run smoothly, it means that the gear clearance has been adjusted properly.

Turntables Slewing Rings Bearing Made In China

Necessity and Adjustment Method of Gear Clearance Adjustment of Turntables Slewing Rings Bearing

First. Necessity of gear clearance adjustment of turntables slewing rings bearing
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1. Different applicable work scenarios for turntables slewing rings bearing
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The size of the gear clearance of the turntables slewing rings bearing is related to the characteristics of the gear transmission. When the gear transmission is used for heavy-duty work, the gear clearance needs to be larger. The gap should be smaller.
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2. Improper gear clearance affects normal work

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The gear transmission of tower cranes and excavators is not only required for heavy-duty work, but also requires frequent forward and reverse rotation, and the speed is not high.

Whether the clearance is too large or the clearance is too small, it will have adverse effects. If the gear gap is too large, the operation of these equipment will not be very smooth, and the gear wear will be more serious;

if the gear gap is too small, the lubricating oil film between the slewing bearing gear and the slewing reducer gear will be destroyed, causing The friction between the two becomes larger, and the tooth surface wears faster.

Coupled with manufacturing errors and elastic deformation of the turntable, it is very likely that the gear will be stuck.
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Therefore, for heavy machinery such as tower cranes and excavators, in order to ensure the reliability of equipment rotation, it is very necessary to keep the gear gap of the turntables slewing rings bearing at a moderate size and debug it according to the actual working conditions.

Second, the turntables slewing rings bearing gear gap adjustment method
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1. Meshing tightly to adjust the gap
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In the position with high gear meshing tightness, adjust the gear backlash to the rated value. The value of this value should be adjusted strictly according to the given value, otherwise it may cause damage to the turntable slewing rings bearing.

In addition, in the process of gear clearance adjustment, it is also necessary to pay attention to the position of the teeth.
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2. Use feeler gauge to measure and adjust
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When the radial runout of the slewing bearing gear reaches a high point, the gear gap can be measured with a feeler gauge. If the gap is different from the given value, the slewing reducer gear can be moved to change the center of the slewing reducer gear and the slewing bearing gear. Correct the distance.

If the slewing reducer gear cannot be moved, it can be adjusted by moving or re-fixing the turntables slewing rings bearing. After debugging, let the slewing bearing rotate a few times to see if the adjusted clearance meets the requirements. If there is a radial jump of the gear to a higher point, it should be marked and adjusted again.
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When adjusting the turntables slewing rings bearing gear clearance, if there is no gnawing between the slewing bearing gear and the slewing reducer gear, and the slewing mechanism can run smoothly, it means that the gear clearance has been adjusted properly.

Slewing Ring Bearing Made In China

Reasons and treatment methods for oil leakage of slewing ring bearing

Slewing ring bearings are used in many large-scale mechanical equipment. With the continuous increase of operating time, some faults will inevitably occur in the bearing. For example, the leakage of lubricating oil is one of the common problems.

Many friends reported that after the oil leakage of the slewing ring bearing, the grease remaining on the bearing surface will adhere to a lot of dirt, which is easy to cause corrosion to the bearing.

First. Reasons for oil leakage of slewing ring bearing
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1. Frequent filling of lubricating grease or thinning of grease
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The more lubricating oil is filled, the better. The oil filling period of the slewing ring bearing is generally between 150 and 250 hours, which can be adjusted according to the operating conditions.

However, if the filling is too frequent, it will cause grease leakage; The hydraulic oil or gear oil escapes into the cavity of the rotating ring gear, which will dilute the lubricating oil and cause oil leakage.
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2. Incorrect selection of grease
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Bearings and transmissions have suitable grease types. If unsuitable lubricating oil is added, the grease may become thin due to high temperature during operation, and the thin grease will be affected by the driving gear of the rotary motor.

Push down to the upper section of the inner gear ring, and then flow into the bearing cavity through the inner oil seal, and leak from the outer oil seal.
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3. Defective or loose outer oil seal
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If the rotary oil seal is defective, it will cause partial or section leakage of grease; in addition, the loose oil seal will also cause oil leakage, which can be observed when the equipment is running.

If the oil seal and the equipment rotate at the same time, it means that the existing oil seal is in the sealing groove. It has been loose and needs to be replaced in time (be sure to pay attention to safety during inspection).
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4. The inner oil seal is damaged or the slewing ring bearing clearance becomes larger
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The damage of the inner oil seal is one of the reasons for the oil leakage of the slewing bearing. You can open the lubricating grease inspection cover of the slewing ring gear to see if there are broken pieces of the oil seal;

in addition, if the bearing clearance becomes larger, the grease will be easily squeezed out during operation. In this case, it is usually accompanied by abnormal noise or shaking of the rotating equipment.

Second, the treatment method of oil leakage of slewing bearing
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1. If the seal is aged or damaged, it is necessary to disassemble the old part and clean the sealing groove, and then insert the new seal into the sealing groove completely.
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2. If the leakage of the rotary motor causes the dilution or deterioration of the lubricating oil, the rotary motor must be repaired and the grease of the entire rotary gear ring must be replaced.
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3. In case of leakage caused by improper selection of grease, all the grease in the rotary gear ring should be replaced, and the same grease should also be used in the bearing cavity.
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4. According to the operating conditions of the equipment, reasonably control the oil filling cycle to avoid excessive filling.
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5. If the slewing bearing is damaged and cannot be repaired, it must be replaced with a new slewing bearing.

4 point contact ball slewing bearing made in china

1.Five common methods of how to deal with 4 points contact ball slewing bearing damage

Slewing bearing, also known as 4 point contact ball slewing bearing, is a new type of mechanical part composed of inner and outer rings and rolling elements. In various construction machinery such as automobiles, cranes, excavators, etc.,

4 point contact ball slewing bearing is to transmit the axial working load of a turntable and chassis , radial horizontal load and overturning torque key element, it can withstand various loads, and can withstand large axial, radial, and overturning moments, it has been well used in industry, but there will also be some question.

How to deal with 4 point contact ball slewing bearing damage
1. Inflexible rotation
If the rotation is inflexible, you can check the production time of the 4 point contact ball slewing bearing first. If the time is longer (such as more than half a year) or the weather is cold.

it is very likely that the viscosity of the grease in the raceway of the 4 point contact ball slewing bearing will increase, resulting in If the work is not working, you need to increase the power, and then restart it. If it still does not work, you must consult the after-sales service in time.

2, does not work after installation
If it does not work properly after installation, there is a high probability that the matching of the host mounting surface and the rotating support surface is not in place, and the mounting surface of the host needs to be processed to meet the requirements, or the washer filling method can be used, and the size can also be adjusted as needed.

The meshing position of the gears, in particular, pay attention to the beating of the gears, and confirm whether there is any debris in the meshing parts of the large gears. If there is a problem that cannot be solved, you can replace a rotating bearing with a larger clearance.

3. Does not work during use
If it does not work normally during use, add grease in an appropriate amount, inject lubricating oil according to regulations, and check whether any impurities enter the raceway. Broken tooth.

4. Abnormal sound
If there is any abnormal sound, you should first check whether the installation surface is flat, or you can stop the rotation of the 4 point contact ball slewing bearing first, and then confirm whether there is grease in the raceway.

This noise can be eliminated after refueling in time. In addition, pay attention to whether the sealing ring is damaged, whether it is the elastic deformation of the 4 point contact ball slewing bearing caused by the loosening of the mounting bolts, or whether there is a negative gap in the deformed part, etc., you can check whether the above conditions are the first.

5. Swing occurs
If rocking occurs, the mounting bolts of the inner and outer rings should be checked immediately and tightened as specified. Or increase the strength of the steel frame of the support, check whether there is overload work, and operate in strict accordance with the regulations.

High Quality Gear Bearing Made In China

1.How to correctly judge and deal with the peeling of the slewing bearing raceway and the broken teeth of the gear bearing?

Due to the manufacturing quality problems such as material pores or uneven hardness and depth of the hardened layer of the interlayer raceway, or some external reasons, the hardened layer of the raceway is peeled off or the teeth of the ring gear bearing are broken during the use of the slewing bearing, so that the equipment cannot work normally.

For raceway peeling, first make a correct judgment. There is peeling, which is generally not easy to see on the outside. According to our experience, the following conditions indicate that the raceway has peeling layers: when the main engine rotates under load, there is an abnormal “clack-clack” sound at the raceway.

the rotation speed is uneven or the speed of a certain azimuth is obviously slowed down and accompanied by There is slight vibration; the temperature rise of the rotary motor is too high or the current is too large; the keyway of the rotary motor and the hydraulic coupling or coupling is crushed, etc.

After peeling occurs, it must be repaired in time. Otherwise, the peeling area will expand, so that the entire gear bearing will be scrapped.

The repair method is: first take out the roller or steel ball in the gear bearing to separate the inner and outer rings; then clean the raceway with gasoline; The hardened layer of the cracks that have been generated around is ground off, and the bottom of the peeling layer is ground flat;

the raceway needs to be repaired and welded with a welding torch to preheat, and use a medium carbon steel electrode for welding (the electrode must be dried before use, and followed by The welding layer should be slightly higher than the surface of the raceway by 1-2mm;

if the peeling layer is deep or the area is large, the welding should be applied in layers and sections, and the temperature of the base metal should not be too high to cause deformation;

this avoids Rapid cooling produces welding cracks, and heat preservation measures should be taken immediately after welding to gradually cool him. After cooling, use a grinder to smooth the repair welding layer to make it slightly higher than the surface of the raceway.

Gradually grind the repair welding layer with whetstone or metallographic emery cloth to make it the same height as the normal surface of the raceway.

Use the corresponding original curvature. Test the samples until they are qualified; clean the raceways and rollers (steel balls) with gasoline, apply grease, and complete the assembly.

The reason for the broken teeth of the rotary gear bearing may be that the quality of the cast section of the tooth base material (such as blisters, interlayers and other defects, which will significantly weaken the bending resistance of the gear); stones or steel bars are embedded in the meshing of the gear teeth during use. The hard object increases the local bending stress of the gear teeth and breaks.

The repair method is local repair welding or tooth insert repair. The method of local repair welding is: first grind off the residual crack matrix of the damaged part with a portable grinding wheel, clean it with gasoline (oil);

use a welding torch to preheat this part, After reaching the fixed temperature, use a medium carbon steel electrode to push and weld the prototype of the tooth on the damaged part of the tooth, so that it is 1-2mm higher than the tooth surface of the party; until the tooth shape meets the requirements.

When a whole tooth of the rotary gear ring is damaged, it can be cut along the root of the tooth, and then the tooth root is filed into a fixed shape, and then the next tooth is stored on the same type of waste ring gear bearing, processed into the corresponding shape of the base metal, and then placed into the groove, and use the toothed template to clamp the positioning.

In order to ensure the consistency of the tooth pitch, and after the double-wire chuck is used to increase the value, it is welded with low carbon steel around the tooth. Use a file and other tools to smooth the weld to ensure that the meshing of the gear bearing teeth is stabilized.

High Precision Bearing Accuracy

1.Bearing Accuracy

Bearing accuracy in accordance with GB/T307-94> national standards can be divided into GEDC B.. These tolerances and ISO, JIS and other standards for comparison are as follows:

2.Maintenance and daily maintenance methods of slewing ring bearings

1. Maintenance and daily maintenance methods of slewing ring bearings in use
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1. Before starting the bearing, refill with new grease according to the working conditions.
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2. Grease should be added to the slewing ring bearing regularly. According to the type of bearing and different bearings, the time for adding lubricating oil is as follows:
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a: Ball type: add grease every 100 hours of operation;
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b: Roller type: add grease every 50 hours of operation;
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For example, under high temperature, dusty, high temperature, high temperature and continuous working conditions, the filling time of grease must be shortened and ensured once every 50 hours; in the case of normal operation, it should be applied once every 150 hours , In the case of heavy work, it should be painted every 75 hours.

During long periods of downtime, the lubricating oil should be added again, and the raceway should be filled with each refueling until the oil overflows from the seal. When the grease is added, the rotating bearing should be slowly transferred to allow the raceway of grease evenly filled.
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3. During the period of use, the dirt on the surface of the slewing bearing should be cleaned regularly, and attention should be paid to whether the bearing sealing ring is aging, cracked, damaged, or falling off.

If any of these situations occur, they should be treated immediately to prevent impurities from entering the raceway. And the loss of grease, and apply grease after replacement, so as to avoid the rolling elements and rollers from being stuck or corroded.
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4. Due to the influence of various factors in practical application, appropriate grease can be selected according to the actual situation, such as graphite grease No. 3, graphite grease No. 4, industrial grease, No. 203 grease, high and low temperature bearing grease 7002 No. 2, aluminum-based grease No. 2, etc.

Special attention should be paid to the slewing ring bearing after 100 hours of operation, it should be preloaded, and then every 500 times of operation, it must be fully used.
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5. After the accumulative operation of the device for 2000 hours, if one bolt is loose and is lower than 80% of the specified torque, this bolt should be replaced with the two adjacent bolts; if 20% of the bolts are loose and less than 80% of the specified torque, apply New bolt replacement. After 14,000 cumulative operating hours, all bolts are replaced with new ones.
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6. During the operation, pay attention to the operating conditions of the slewing bearing. If noise, impact, or sudden increase in power is found, the operation must be stopped immediately until all faults are eliminated. If necessary, it must be disassembled.
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7. When using the slewing bearing, it is strictly forbidden to use water to directly wash the rotating bearing to prevent the water flow from flowing into the raceway and cause rust; prevent hard objects from approaching or entering the meshing area to avoid damage or cause unnecessary trouble.
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8. Customers have a common misunderstanding about the maintenance of slewing bearings. They think that the lubricating oil of the slewing bearing is the same as the lubricating cycle of the big and small arms, and it needs to be pumped every day.

But the opposite is true. If the lubrication cycle is too short, it will lead to excessive lubricating oil in the bearing, causing the seal ring to rupture and leak.

In the case of leakage, there will also be impurities infiltrated into the slewing bearing, affecting the work of the bearing. Usually the lubrication time of the rotary bearing is 250 hours. In the process of oiling, turn the machine while stirring, and oiling every 15 degrees is enough.

According to your work intensity, it can be adjusted appropriately for different usage situations. Lubrication is usually done once a week or so.
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9. When lubricating the rotary motor, it is necessary to know that the lubrication cycle of the rotary motor is 1000 hours. In normal work, the amount of rotary oil should be checked from the oil dipstick. Sometimes abnormal wear occurs.

We need to open the window of the large gear to see See if the lubricating oil leaks from the seal ring into the large gear cavity.

In addition to the above maintenance measures, we should also frequently check whether the screws of the gear and the sealing ring of the rotary bearing are damaged. Some small gaps outside will be covered by mud. If it is not found in time, it is easy to cause the turntable to break or even cause an accident.
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10. Maintenance points of large turntable bearings: large turntable bearings are composed of large gears, reducers, center sections, etc.

Generally, when we open the cover next to the boom base, we can see the lubrication condition inside the big gear and the wear condition of the gear. In the process of mechanical operation, the dustproof ring at the rotating center joint will be worn out.

If it rains, the rainwater will penetrate into the cavity of the large ring gear through the leakage of the rotating center joint, causing water accumulation in the hub. This will greatly affect the service life of the slewing bearing.

When the excavator is working, the grease in the cavity is diluted by water, and the lubrication effect is not ideal, which will increase the wear of the ring gear. Long-term soaking will cause the iron filings on the ring gear to fall off, resulting in abnormal rotation.

high quality ball slewing ring bearing in stock

1.The common noise of slewing ring bearing is dust sound and scar sound.

The two solutions are as follows:

(1) Control method of dust sound

There are foreign objects such as dust in the rotary branch, and non-periodic vibration will occur.

Dust noise control method: improve the cleaning method of slewing ring/slewing bearing, strictly clean the bearing, shaft, seat hole and matching parts before installation; remove foreign matter in the lubricant; improve the sealing of the bearing; avoid the use of impure materials Or plastic cages with embedded foreign objects.

(2) Control method of scar sound

If the rolling surface of the slewing ring bearing is cracked, indented or corroded, periodic vibration and noise like riveting rivets will occur. The period may be fixed but most of them have a certain corresponding relationship with the rotation speed, and the scars will be continuous on the channel.

Occurs, scars appear and disappear on the steel ball, and this noise varies with installation and lubrication conditions.

The control method of this kind of noise: do not knock the bearing during installation, prevent the bearing from tilting when assembling the bearing and the shaft and then put it into the bearing seat; prevent the slewing bearing from rusting during storage and prevent shock and vibration during transportation; use high-viscosity grease .

(3) Noise caused by lubricating factors and its countermeasures

Incorrect selection of lubricant, insufficient lubricant or aging and hardening can cause vibration and noise in slewing ring bearing /slewing bearing, and this noise has no certain rules.

In this case, only the appropriate lubricant is selected, the amount of lubricant is adjusted, the service life of the lubricant is prolonged, and the replacement cycle is reasonably determined.

(4) Noise related to the host and its countermeasures

This kind of noise is not simply caused by the bearing, so it is ineffective to find the cause from the slewing bearing alone. The main engine should be paid full attention to, and the performance of the main engine should be improved if necessary. Now mainly describe the common buzzing sound and frame resonance sound in the motor.

A Motor buzzer and its countermeasures

The axial vibration of the motor shaft will cause a large high-frequency noise – buzzing sound, the frequency of which is the same as the axial vibration frequency, which can be constant or variable. The method to prevent buzzing is the same as the method to prevent axial vibration.

B-bearing frame resonance sound and its countermeasures

When the axial natural vibration of the outer ring mass system causes the axial bending natural vibration of the slewing ring bearing frame, a kind of noise called resonance sound will be generated.

The method of increasing the preload can increase the axial natural frequency of the outer ring mass system, destroy the resonance condition and reduce the noise.