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Top 1 High Quality Slewing Bearing Installation Update 2022

What is the reason why the slewing bearing is not installed smoothly or even cannot rotate?

1. The reasons for the unsmooth of the slewing bearing installaton

1. Mounting holes. The threaded hole of the slewing bearing installation hole is not standardized, the threading is not complete, and the threading is defective, so that the bolt cannot be screwed in.

2. The center diameter and chord length of the mounting hole exceed the tolerance too much, such as 3-5mm, which will cause the bolt to fail to pierce.

3. The size of the positioning hole and the step are out of tolerance and cannot be matched.

4. The bearing after heavy load has a rotating dead center or an ellipse, which makes it unable to operate normally.

5. The slewing bearing installation is not in the direction of the installation design drawing, resulting in the opposite direction of the taper pin, which has potential safety hazards.

6. The slewing bearing installation part interferes, such as tooth top interference, there is a phenomenon of gnawing teeth, and some parts conflict with each other.

7. The design of negative clearance is unreasonable, which leads to the phenomenon of inclined force, partial load and clearance after installation.

8. The design of the equipment structure is unreasonable, which leads to the failure of normal debugging.

2. The possibility that the slewing bearing installation is difficult to rotate or cannot rotate

1. Newly purchased products are inflexible in idling

Please check the production date of the slewing bearing. If the weather is cold for a long time (such as more than half a year), it is possible that the temperament such as salt mist is mixed into the raceway,

which will cause the rotation resistance to double and make the slewing bearing not work well (cold areas, winter is more prominent ) Remedy:

If it can run after afterburning and there is no other abnormality, it can be used normally.

2. Inflexible operation after slewing bearing installation

It may be that the surface of the main engine device and the surface of the slewing bearing installation are not well matched, so that the axial clearance of the slewing bearing after the installation cannot compensate for the deformation of the slewing bearing,

the slewing bearing is in a state of negative clearance, and the rolling elements are difficult to operate in the raceway (sometimes accompanied by abnormality). sound) or the large and small gears are poorly meshed;

or there are foreign objects stuck in the large and small gears. Remedy: re-process the plane of the host device to make the device plane meet the requirements;

re-adjust the meshing backlash of the large and small gears according to the requirements, especially pay attention to the gear beat position;

check to ensure that there is no foreign matter in the meshing position of the large and small gears; replace a slewing bearing with a slightly larger clearance .

3. Inflexible operation during use

The sealing strip is damaged, causing foreign objects to enter the raceway (such as poor working conditions, immersion of dust in the raceway, etc.) the deformation of the isolation block leads to difficulty in operation;

there are hard objects or other conditions at the meshing of the large and small gears, such as broken teeth.

OEM 50mm to 9000mm Slewing Ring Bearing OEM

Slewing bearings are widely used in various types of machinery and equipment. At present, there are many brands of slewing bearings on the market, and the quality is also different. So, how to choose a slewing bearing? What should I pay attention to when buying a slewing bearing? In order to select the slewing bearing products of qualified quality.

When purchasing slewing ring bearings, there are many issues that need to be paid attention to, such as load, strength of bolts, and whether there are uniform bolt holes.

Is the distribution of slewing ring bearing load reasonable?

Bearings are mounted on a lack of a uniform support surface, and a common mistake during the design phase of the support structure is that the slewing ring assumes that the support structure is sufficiently rigid. However, local deformation can change the load, causing the bearing to have different load magnitudes. Failure to take proper steps can easily lead to slewing ring bearing failure.

Is the slewing ring bearing bolt strong enough?

Be sure to choose the right slewing ring bearing product for your installation. This stage is often overlooked, leading to the possibility of system failure. Typically, equipment designers are responsible for determining the correct type of fasteners required for the project.

However, fastener suppliers and manufacturers should really get a measure of what a given fastener can withstand. They will be able to assist in the calculation of the bolt loads to confirm the integrity of the fasteners.

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Is there a unified slewing ring bearing bolt hole design?

Fasteners need to be placed in more places in larger load areas. Bolt holes can be used as hazardous support structures only in areas where large loads occur and should therefore not be ignored in the overall design of the product.

It is important to remember that there is a lot of exercise load, not just the mounting part. Uniform bolt circles can help reduce bending and load distribution in bearings, fasteners, and support structures.

In addition, when we buy a slewing ring bearing, we should also pay attention to the toughness of this product, because this part is very thin, so many parts look good, but it will be reimbursed after using it in the machine for a long time. When choosing, you can actually buy a few more brands and practice them in practice.

When purchasing slewing bearing products, be sure to look at the brand words and labels printed on the slewing bearing. Most of the products produced by the factory use steel stamping technology, the fonts are very small, and they are embossed before heat treatment, so although the fonts are small, they are deeply concave and very clear.

The fonts of counterfeit products are relatively vague. Due to the rough printing technology, the fonts float on the surface, and some can even be easily erased by hand.

2.The slewing ring bearing application

1. Lifting machinery

Lifting machinery includes truck cranes, tower cranes and trailers, etc. Due to the harsh environment of these machines, the rotating parts are often subject to great impact, so these parts will use customized slewing bearings.

For example, to provide the LYMC bearing manufacturer with the size and operating environment required by the machine, the manufacturer will arrange the engineer to design the suitable bearing according to the actual situation, and then put it into use, which can not only meet the needs of the lifting machinery, but also prolong the service life. Huge improvements.

2.Construction machinery

The simple division of construction machinery is like excavators, loaders, etc. The slewing bearing can bear axial force, radial force and overturning force at the same time, and the structure is very compact. It needs to be rotated continuously during the operation of the excavator. The slewing bearing is the core component of the rotation. The application of construction machinery belongs to the basic application of slewing bearing, and it is also widely used.

3. Processing machinery

Processing machinery like material processing, food processing, metallurgy and so on. With the continuous development of science and technology, people are no longer satisfied with the application of slewing bearings only in construction machinery, and turn their attention to equipment platform processing machinery. Because the slewing bearing is more compact than the original bearing, the external force can also be larger, and the performance and structure are better, so it is also widely used in processing machinery.

4. Military equipment

The current military competition is about the hard power of military equipment. As we saw on TV, the tank turns the cannon head, and a shell hits the target accurately. In this link, the slewing bearing plays a very good supporting role;

There are also anti-aircraft guns, radars, rocket launch pads, etc., a very important structure in the timely rotation, jump and stable launch of military equipment is the turntable bearing, which has better performance than traditional bearings.

5. Medical machinery

In many large-scale medical equipment, in order to take care of the patient’s physical condition, it is necessary to rotate the equipment in time to adapt to the patient’s body. At this time, the equipment is required not only to have high accuracy, but also to have low noise.

These rotations require slewing bearings. help. The high-accuracy, low-noise, long-life, and high-reliability series of medical equipment spindle rotary bearings developed now have been widely used in large medical equipment such as gamma knives, CT machines, and nuclear magnetic resonance machines.

6. Others

In addition to its applications in industry and medical care, slewing bearings have its shadow in the field of power generation and life. The yaw bearing of wind turbines is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the root of each blade. connection with the wheel hub.

Each wind turbine uses one set of yaw bearing and three sets of pitch bearing. Through the application of slewing bearing on wind power generation equipment, the process of generating electricity can be effectively changed by the difference of wind power.

In the whole process, the part where the root of the blade is connected with it is the concrete embodiment of the slewing bearing. The main applications of slewing bearings in life are concentrated in playgrounds, such as Ferris wheels, roller coasters, pendulum clocks and merry-go-rounds, etc. The effective application of slewing ring bearings has ensured the safety of life.

Luoyang Slewing Bearing Material

What are the commonly used for luoyang slewing bearings materials?

Slewing bearing, also called slewing ring bearing, is often used in engineering and manufacturing machinery, such as excavators, roadheaders, wind power generation equipment, industrial robots, port machinery and other equipment.

The slewing bearing is usually composed of ferrules, rolling elements, cages, sealing rings, etc. Since different parts have special functions in practical applications, there are different considerations in the design and selection of slewing bearing materials.

1.slewing bearing materials for ring and rolling elements

In general, the rolling elements of the slewing ring material are made of carbon-chromium bearing steel which is hardened as a whole. The grade is made of GCr15 or GCr15SiMn steel; the slewing bearing ring material is made of surface hardened steel.

When the user has no special requirements,the slewing bearing material it is generally made of 50Mn steel, but sometimes in order to meet the needs of the host in some special applications For specific use conditions,the slewing bearing material select other grades of surface hardened steel, such as 42CrMo, 5CrMnMo, etc.

Small and medium-sized slewing bearing forgings all use round or square bars as blanks. The grain structure and mechanical properties of the bar are uniform and good, the shape and size are accurate, and the surface quality is good, which is convenient for mass production.

As long as the heating temperature and deformation conditions are reasonably controlled, forgings with excellent performance can be forged without large forging deformation.

Ingots are only used for large forgings. The ingot is an as-cast structure with large columnar crystals and a loose center.

Therefore, through large plastic deformation, the columnar crystals must be broken into fine grains, and the loose compaction can be obtained in order to obtain excellent metal structure and mechanical properties.

2. Materials for cage

The cages for slewing bearings materials have integral, segmented, spacer block and other structural forms. where integral and segmental hold

The frame is made of 20-gauge steel or ZL102 cast aluminum alloy. The spacer block type is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc.

In recent years, with the continuous development of the material industry, nylon GRPA66.25 has also been popularized and applied in the design of segmented cages.

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3. Slewing bearing materials of sealing ring

The slewing bearing materials sealing ring is made of oil-resistant nitrile rubber, oil-resistant rubber and fluorine rubber. The slewing bearing materials used for the seals must be able to withstand a wide operating temperature range and have certain chemical resistance.

The codes of the ferrule for slewing bearing material and the supply status of the blank are as specified in the table. In the table, “T” means that the blank of the ring is supplied in a quenched and tempered state, and “Z” means that the blank of the ring is supplied in a normalized state.

Code 01 02 03 04 05 06.

Material and rough state 45BT 45BZ 42CrMoT 42CrMoZ 5CrMnMoT 5CrMnMoZ.

Code 07 08 09 10 11 12.

Material and rough state 42SiMnT 42SiMnZ 45MnT 45MnZ 50MnT 50MnZ.

The diameter of the center circle of the rolling element is 3150mm, the diameter of the ball is 75mm, the gear modulus is m=20mm, the ring material is 50Mn, and the blank material is the normalized state. .

The above is a brief introduction to the commonly used materials for slewing bearings. Luoyang MC is a comprehensive entity enterprise integrating design, research and development, production, sales and service of slewing bearings/slewing bearings.

It mainly produces slewing ring/slewing ring bearings with a diameter of 50-9800mm and various high-precision slewing rings, large thrust ball bearings, non-standard special-shaped bearings and other products.

The precision covers four grades of P0, P6, P5, and P4. Four-point contact ball structure, crossed cylindrical roller structure, three-row cylindrical roller structure, double-row ball slewing bearing, ball-column joint structure, thin-walled flange structure, large thrust ball structure, etc.

About Slewing Bearing Grease

What is the purpose of slewing bearing grease? grease method?

Rolling bearings are precision parts and are lubricated before leaving the factory. No matter how high-performance bearings are used, if the lubrication is not in place, it will not only fail to achieve the expected high performance, but also affect the service life of the bearings.

First, the purpose of slewing bearing grease

The purpose of slewing bearing grease is to reduce the internal friction and wear of the bearing, prolong the service life, cool the harvest, prevent burning, rust, and prevent foreign objects from invading the inside of the bearing.

1. Reduce friction and wear

In the mutual contact part of the bearing ring, rolling element and cage, prevent metal contact, reduce friction and wear.

2. Extend the service life of bearings

Bearings are prone to fatigue life in high-speed operation, and the use of lubricating grease can prolong the service life of bearings.

high quality wholesale slewing bearing grease Alt

3. Discharge friction heat and cool bearings

Circulating oil supply method, etc., can use oil to discharge heat generated by friction, or heat from outside, and cool it. Prevent the bearing from overheating and prevent the aging of the lubricating oil itself.

4. Other functions

High and low temperature, corrosive environment, humid environment, water drenching environment, etc., these are all easy to cause the production of foreign bodies, the rust of bearings, and the corrosion of their own bearings. The best slewing bearing grease can prevent foreign matter from intruding into the interior, preventing rust and corrosion of the bearing.

2.Lubrication method of bearings

The lubrication methods of bearings are mainly grease lubrication and oil lubrication. In order to make the bearing function well, first of all, it is necessary to select a lubrication method suitable for the conditions of use and the purpose of use.

If only lubrication is considered, the lubricity of oil lubrication is dominant. However, grease lubrication has the advantage of simplifying the structure around the bearing. Compare the advantages and disadvantages of grease lubrication and oil lubrication.

At present, oil lubrication is mostly used, among which oil and gas lubrication is very popular. Oil-air lubrication is a new lubrication method that has gradually become popular in recent years.

It is fundamentally different from other lubrication methods in that it can control the oil supply and achieve an ideal lubrication effect. Therefore, in recent years, oil-air lubrication has gradually replaced other lubrication methods.

3. Filling of slewing bearing grease

1. Filling with grease

After the bearing is installed, it needs to be supplemented with grease before running. When filling the grease, the bearing should be rotated while filling to make the grease evenly distributed until the grease overflow is observed at the lip of the sealing strip on the bearing.

2. Daily automatic grease injection

After the grease is injected, the automatic grease injection system can be turned on, and a certain amount of grease can be injected every day (regularly) to meet the normal use of the bearing. The amount of grease injected for two months should at least reach the internal cavity volume of the slewing bearing.

In order to ensure that sufficient grease enters Bearings, on the one hand, pay attention to the consumption of grease, and on the other hand, regularly check the oil circuit to prevent leakage.

Every three months or so, a concentrated grease injection should be carried out inside the slewing bearing, and a large amount of grease should be injected into the upper grease injection hole until the lip of the upper sealing strip evenly overflows with fresh grease.

4, three-row roller slewing bearing grease

The bearing structure has the largest cavity in the upper row of the main stress-bearing raceway, and the upper row of raceway grease will move to the lower row of raceways during operation.

The amount of grease injected into the upper row should be appropriately increased. 130% of the fat mass.

5. What are the commonly used greases for slewing bearings?

The commonly used lubricating greases are calcium-based grease, lithium-based grease, aluminum-based grease and high-temperature grease, etc. The user can choose the appropriate grease according to the specific situation.

Causes and preventive measures of shaking during operation of slewing bearing

Slewing bearing, also known as slewing bearing and slewing bearing, is one of the important components of modern construction machinery slewing devices, such as excavators, cranes, pile drivers, graders, road rollers, dynamic compactors, roadheaders, tower cranes, etc.

Slewing bearings will be used in all cases. Due to the large load operation and the harsh working environment, the operation is not smooth (jitter) and the noise exceeds the standard (abnormal noise). So, what is the reason for the jitter when the slewing bearing is running?

1.The reason for the jitter of the slewing bearing during operation.

1. Internal machining accuracy of slewing bearing

The machining accuracy of the steel ball inside the slewing bearing and the machining accuracy of the inner raceway are not high, or there are quality defects and the lack of lubricating oil in the raceway. When the slewing bearing is defective, sometimes the frequency of failure can be reduced by replacing the steel ball.

2. The machining of gears is not precise enough

The gear accuracy grade of the slewing bearing should be between 7 and 11, which determines the stability of the slewing bearing transmission, the uniformity of the load distribution and the transmission accuracy.

The higher the gear precision, the denser the contact spots of the meshing tooth surface, so that the noise value is reduced and the operation stability is improved.

3. Welding defects of upper and lower supports

If the welding quality is not up to standard, it is necessary to repair and repair the weld defects. During repair welding, it will not only generate new welding stress, but also have a great impact on the flatness of the machined mounting surface.

At the same time, the current generated by welding will also cause certain damage to the internal rolling elements and raceways when passing through the slewing bearing. damage.

In addition, if the assembly error generated in the manufacturing and assembly, the threading of the pin shaft and the pre-tightening of the bolts in the field installation do not meet the specified requirements, abnormal noise or vibration will also occur.

4. Quality problems of gears and starting motors

Due to the long working time of the gear under load, small pieces of metal or strip-shaped metal iron filings will appear near the pitch line of the tooth surface, resulting in pitting or gnawing.

The pitting corrosion of the tooth surface continues to expand with the increase of working time, so that the meshing tooth profile is damaged, the noise and impact during rotation increase, and the metal particles impacted 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 produce shock jitter, and the meshing process between the drive wheel and the support is unstable, which also increases the frequency of jitter and the decibel of abnormal noise.

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2.Preventive measures for slewing bearing jitter

1. Installation and operation

High-strength bolts should be selected for the installation of slewing bearings, and the bolts and nuts should meet the requirements of GB3098.1 and GB3098.2 standards.

It is forbidden to use spring washers. Before the mounting bolts are tightened, the meshing adjustment (backlash) of the large and small gears must be carried out to ensure that the meshing of the slewing bearing and the pinion meets the requirements.

Tighten the mounting bolts at 180°, the mounting plane must be clean and flat, and there must be no burrs, iron filings and other debris, and the plane must meet the following requirements: the slewing bearing often has broken teeth during operation, so it is also

The influence of wind on the slewing bearing should be taken into account. If the jib cannot rotate freely with the wind after the operation exceeds the specified wind force or stops the operation, it may damage the gear meshing with the bearing or the slewing bearing, and a serious safety accident will occur.

Therefore, detailed inspection should be done during installation and operation.

2. Fastening bolts

The connecting bolts of the slewing bearing and the upper and lower supports are not only subjected to the pre-tightening force, but also subjected to the axial pulsating load, which will cause the bolts to be elongated or the connecting surface to deform, making the bolts loose.

If the loosening pre-tightening force of the bolt connection fails to meet the requirements, the axial clearance will increase, the rolling elements will be rotated by a large overturning moment, and the edge of the raceway will be subjected to huge contact stress, which will cause the edge of the raceway to be damaged.

Therefore, the tightening of the slewing bearing bolts must be checked regularly to make it reach the specified pre-tightening force, which is generally 400-500 N.m.

3. Internal lubrication of slewing bearing

In daily use, each part should be lubricated according to the lubricant, lubrication method and lubrication cycle regulations in time and on time according to the instruction manual. The corresponding ball slewing bearing is generally refilled every 100 hours of operation, and the roller slewing bearing is filled every 50 hours.

For special working environments with a lot of dust, high humidity and high temperature difference, the lubrication cycle should be shortened.

The raceway must be filled with each lubrication until the lubricating oil seeps out, and the slewing bearing needs to be slowly rotated to make the grease evenly filled while filling.

By adding lubricating oil for maintenance, the friction between the gear pairs can be reduced, the wear speed of the gear ring can be slowed down, and the formed oil film can also act as a shock absorber to eliminate 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 surfaces. Thereby reducing the friction noise of the operation and increasing the service life of the bearing.

China Luoyang Factory Supplier-Slewing Bearing Operating Temperature

What is the slewing bearing operating temperature?

The slewing bearing is a very important part in the machine. Basically, every machine needs this part. Because this part is relatively fragile, it can also be regarded as a kind of consumables. You need to buy it frequently to keep the machine in good condition. normal operation. Let’s take a look at the slewing bearing operating temperature.

The slewing bearing opearing temperature can work normally at -300C～+700C. If the user needs to adapt to the lower or higher temperature slewing bearing, our company can make special design.

If the slewing bearing operating temperature is used in particularly harsh environments, such as marine climate, dust or abrasive particles, sand, cement, coal powder, etc.

Special sealing rings, protective devices, and suitable oil passages should be selected. Therefore, in order to make your support function normally, it is hoped to do a good job in daily maintenance and maintenance.

The tooth surface of the slewing bearing operating temperature should be cleaned and changed every 8-10 working days, and foreign matter should not be mixed.

Characteristics of slewing bearing materials

The slewing bearing is mainly composed of ferrules, rolling elements, cages, sealing rings, etc. Since different parts have special functions in practical applications, there are different considerations in the design and selection of materials.

In general, the rolling elements of the slewing ring are made of carbon-chromium bearing steel that is hardened as a whole. 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, other grades of surface can also be selected according to the specific conditions provided by the user. Hardened steel, such as 42CrMo, 5CrMnMo, etc.

For small and medium slewing bearing forgings, round or square bars are used as blanks. The grain structure and mechanical properties of the bar are uniform and good, the shape and size are accurate, and the surface quality is good, which is convenient for mass production.

As long as the slewing bearing operating temperature and deformation conditions are reasonably controlled, forgings with excellent performance can be forged without large forging deformation.

Ingots are only used for large forgings. The ingot is an as-cast structure with large columnar crystals and a loose center.

The cages for slewing bearings have integral, segmented, spacer block and other structural forms. The integral and segmented cages are made of 20-gauge steel or ZL102 cast aluminum alloy.

The spacer block type is made of polyamide 1010 resin, ZL102 cast aluminum alloy, etc. With the continuous development of the material industry, nylon GRPA66.25 has also been popularized and applied in the design of segmented cages.

The material of the slewing ring seal is made of oil-resistant nitrile rubber. The codes of the ferrule material and the supply state of the blank are as specified in the table. In the table, “T” means that the ring blank is supplied in a quenched and tempered state, and “Z” means that the ring blank is supplied in a normalized state.

Slewing ring adapts to temperature and working environment

Slewing rings operating temperature can work normally from – 300C to + 700C. If users need to adapt to lower or higher temperature slewing rings, our company can make a special design.

If the slewing bearing operating temperature is used in particularly harsh environments, such as marine climate, dust or abrasive particles, sand, cement, pulverized coal, etc.

A special sealing ring, protective device, and proper oil passage must be selected. Therefore, in order to make your support work normally, we hope to do a good job in daily maintenance.

There are 4 types of slewing bearings:

a. Single row four-point contact ball slewing bearing:

It is composed of two seat rings, compact structure, lightweight, four-point contact between steel ball and circular arc raceway, and can bear axial force, radial force, and overturning moment at the same time. Small and medium cranes can be selected.

b. Double-row ball slewing bearing:

The double volleyball slewing bearing has three seats, and the steel balls and isolation blocks can be directly discharged into the upper and lower raceways. This kind of open assembly is very convenient.

The bearing angles of the upper and lower circular raceways are all 90 ° and can bear large axial force and overturning moments. It is especially suitable for tower cranes with a medium diameter or above.

c. Single-row crossed roller slewing bearing:

The single-row cross roller slewing bearing is composed of two seat rings, with compact structure, lightweight, high manufacturing accuracy, small assembly clearance, and high installation accuracy requirements.

The roller is 1:1 cross arrangement, which can bear axial force, overturning moment, and large radial force at the same time.

d. Three-row roller slewing bearing:

The three-row roller slewing bearing has three seats, and the upper, lower, and radial raceways are separated respectively so that a load of each row of rollers can be determined accurately.

It can bear all kinds of loads at the same time. It is one of the four products with the largest bearing capacity. The shaft and radial dimensions are large, and the structure is firm. It is especially suitable for heavy machinery requiring a large diameter.

Disassembly method of slewing bearing

Bearings, as a kind of mechanical conventional parts, are unavoidable with the use of equipment,

so when our equipment or machines are routinely repaired or damaged, we need to disassembly method of the slewing bearings, especially when the bearings are disassembled for faults, check the parts around the bearings, lubricate them.

The situation of the agent and the bearing itself can know the fault more clearly, then the following will introduce the disassembly method of slewing bearing.

1.Instructions before disassembly of slewing bearing

1. Use of dismantling tools to disassenbly of slewing bearing

(1) Use manual or hydraulic

(2) Only use a special wrench

(3) Use a puller

(4) Use induction heating equipment (inner ring)

(5) Use oil injection method

2.How to disassembly method of slewing bearing

(1) It should be carried out by or under the guidance of experienced personnel;

(2) Before starting the disassembly the slewing bearing, determine the specific method to be disassembled;

(3) Keep the necessary bearing removal tools handy;

(4) When reusing or inspecting a disassembly the slewing bearing, be careful to avoid scratching or damaging the bearing raceway or rolling elements;

when disassembly the method of slewing bearing from the bearing seat, the disassembling force is applied to the outer ring; when disassembling the bearing from the shaft, the disassembling force is applied to the outer ring. inner circle;

Disassembly method of slewing bearing Alt

Second,the disassembly method of slewing bearing

1. Cold disassembly method of slewing bearing

When removing smaller bearings, the bearing ring can be removed from the shaft by lightly tapping the side of the bearing ring with a suitable punch, preferably with a mechanical puller. The pull should act on the inner ring or adjacent components.

Removal can be simplified if the shaft shoulder and housing shoulder have grooves to accommodate the puller grip. In addition, some threaded holes are machined at the position of the hole shoulder to facilitate the bolt to push the bearing out.

Large and medium-sized bearings often require more force than machine tools can provide. Therefore, the use of hydraulic power tools or oil injection, or both, is recommended. This means that oil holes and oil grooves need to be designed on the shaft.

2. Hot disassembly method of the slewing bearing

When disassemblingmethod of the slewing bearing for the inner ring of needle roller bearings or NU, NJ, and NUP cylindrical roller bearings, the hot disassembly method is suitable.

Two commonly used heating tools: heating rings and adjustable induction heaters.

The heating ring is usually used to install and remove the inner ring of small and medium-sized bearings of the same size. The heating ring is made of light alloy. Heating rings are radially slotted and equipped with electrically insulating handles.

If the inner rings of different diameters are frequently disassembled, it is recommended to use a debuggable induction heater. These heaters quickly heat the inner ring without heating the shaft.

When disassembling the inner ring of a large cylindrical roller bearing, some special stationary induction heaters can be used.

3. Remove the bearing installed on the conical shaft diameter

The small bearing can be removed by pulling the inner ring with a mechanical or hydraulic puller. Some pullers are equipped with spring-operated arms, and the use of this self-aligning design of the puller simplifies the procedure and avoids damage to the journal.

If the puller claws cannot be used on the inner ring, the bearing should be disassembled through the outer ring or by using a puller combined with a puller.

When using the oil injection method, the disassembly method of slewing bearing for medium and large bearings will be safer and easier. This method injects hydraulic oil between two conical mating surfaces under high pressure through oil holes and oil grooves.

The friction between the two surfaces is drastically reduced and an axial force is created that separates the bearing and shaft diameter.

4. Remove the bearing on the adapter sleeve

For the small bearing installed on the adapter sleeve with the straight shaft, you can use a hammer to knock the small steel block that acts evenly on the end face of the inner ring of the bearing to remove it.

Before doing this, the adapter sleeve lock nut needs to be loosened a few turns.

For small bearings mounted on the stepped shaft of the adapter sleeve, it can be removed by hitting the small end face of the adapter sleeve lock nut with a hammer through a special sleeve. Before doing this, the adapter sleeve lock nut needs to be loosened a few turns.

For bearings mounted on a stepped shaft with an adapter sleeve, the use of a hydraulic nut makes bearing removal easier. To do this, a suitable stop must be installed close to the hydraulic nut piston. Oil injection is the easier method, but an adapter sleeve with oil holes and oil grooves must be used.

5. Remove the bearing on the withdrawal sleeve
When removing the bearing on the withdrawal sleeve, the locking device must be removed. (such as lock nuts, end plates, etc.) For small and medium-sized bearings, lock nuts, hook wrenches or impact wrenches can be used for disassembly.

For medium and large bearings installed on the withdrawal sleeve, the hydraulic nut can be used to easily disassemble. It is recommended to install a stop behind the hydraulic nut on the shaft end.

The stop device can prevent the withdrawal sleeve and the hydraulic nut from flying out of the shaft when the withdrawal sleeve is suddenly separated from the mating position.

Installation method of slewing bearing

Slewing bearing is a kind of large bearing often used in modern machinery and equipment, which can bear large axial, radial and overturning moments at the same time. At the same time, it is also an important component in the rotary system of large-scale amusement facilities, which bears various loads during the operation of the equipment.

In addition to calculation and selection, attention must also be paid to its correct installation slewing bearing and use.

The harm caused by installation errors and improper use to amusement facilities cannot be ignored. So how to install the slewing bearing of amusement facilities? The following editor will introduce to you the installation method of the slewing bearing of large amusement facilities.

The motion forms of amusement facilities mainly include rotary motion, linear motion and compound motion of rotary and linear motion. Among them, rotary motion is the main motion form of amusement equipment, such as carousel, automatic control plane and high-altitude flying, etc. The main component to realize rotary motion is slewing bearing.

1.Installation form of slewing bearing of amusement facilities

In the field of amusement equipment, there are two types of installation methods for slewing bearings: horizontal installation and vertical installation of slewing bearing.

The operating characteristics of flying towers and self-controlled aircraft amusement facilities are that they rotate around the central axis.

Flying tower-type amusement facilities include high-altitude flying, shaking head flying chair, etc., and self-control aircraft amusement facilities include self-control plane, big octopus, etc. The installation form of the slewing bearing in this type of equipment is horizontal installation.

Sightseeing car amusement facilities are characterized by rotating or swinging around the horizontal axis. Sightseeing car amusement facilities include wild shouts, large pendulums, etc. The installation form of the slewing bearing in this type of equipment is vertical installation. installation method of slewing bearing Alt

2.Installation of slewing bearing

1. Before installing the slewing bearing, check the mating surface and clean the two installation surfaces to avoid any solvent from contacting the sealing belt or entering the raceway. Do not paint the sealing belt.

2. The parts of the slewing bearing mounting seat should have sufficient rigidity, the contact surface of the bearing must be cleaned, there should be no lubricating oil and must be kept dry,

and the mating surface should be machined to ensure that the two mating surfaces and the two ends of the slewing bearing are in the entire Complete contact on the circumference to meet the flatness and inclination required by the relevant standards.

3. The bolts selected for the slewing bearing are high-strength bolts, and the length of the installation bolts shall not be less than 5d (d is the thread diameter).

4. For the connection of the slewing bearing of the amusement equipment, high-strength bolts above 8.8 are used, and full-threaded bolts cannot be used. The anti-loosening method is the double-nut method.

The two nuts should be the same. It is not high to cause extrusion plastic deformation, which is conducive to maintaining the reliability of preload.

Since the spring washer will destroy the centrality of the bolt’s force, reduce the pressure area and rigidity of the nut on the connecting parts when passing through, and reduce the connection strength of the bolt. Under any circumstances, spring washers should not be used.

5. When installing slewing bearing, firstly position the slewing bearing radially, and then tighten the installation bolts crosswise, that is, use star-shaped installation, and carry out symmetrically and continuously in the 180° direction, and then re-tighten it again to ensure that the bolts on the circumference have the same pre-tightening.

force, and check the rotation of the turntable slewing bearing. In order to increase the reliability of the connection, the prestress of the tightened bolt should be 70% of the yield strength of the bolt material.

6. In order to ensure the stable rotation of the turntable installation of slewing bearing , the gears should be checked before the installation bolts are fully tightened. The minimum value of the tooth side clearance is generally 0.03 ~ 0.04 X m (module). , recheck the gear tooth clearance of the pinion on the entire circumference.

The above is the explanation of the installation method of slewing bearings for large amusement facilities.

Luoyang LYMC Bearing is a comprehensive entity enterprise integrating design, research and development, production, sales and service. Products are widely used in new energy, medical, amusement, automation, lifting, construction, mining, metallurgy, ports, textiles, ships, environmental protection, aerospace, wind power and other fields. In addition, it also implements personalized optimized design and customized flexible production for different customers to meet customer needs.

Slewing Bearing Soft belt

How is the slewing bearing soft belt produced?

The raceway of the slewing bearing generally needs to be heat treated. In the heat treatment process, because the diameter of the raceway circle of the slewing bearing is relatively large, flame surface quenching is usually used. The method is to use acetylene to heat the surface of the workpiece to be hardened and then add water to cool it. , this process is completed continuously.

1.How is the slewing bearing soft belt produced?

slewing bearing soft belt Alt

During the production and processing of the slewing bearing, the raceway of the device generally needs to be heat treated. The usual processes are: forging → rough machining → quenching and tempering treatment → finishing → raceway surface flame surface quenching → raceway surface grinding and other processes . One of the raceway surfaces is flame quenched to form a soft band.

The so-called slewing bearing soft belt is the area that has not been heat treated. The formation of the soft band is necessary for the heat treatment process. In the heat treatment process of the slewing bearing soft belt,because the diameter of the raceway circle of the slewing bearing is relatively large, flame surface quenching is usually used. The method is to use acetylene to heat the surface of the workpiece to be hardened and then add water to cool it.

Slewing ring

The heating flame spray gun and the water gun are installed together and make a circular motion along the circle of the workpiece. When the movement is close to 360 degrees, the heating and water spray are stopped immediately. That is, the circular areas of heating and water spray do not overlap.

Cracks in the workpiece can occur if the circle areas where the heating and water spray occur overlap (heat treatment at an angle greater than 360 degrees on the circle). The tangential width of the unheated area is typically 15 mm. This 15 mm area is called the soft belt in the slewing bearing, that is, the so-called soft belt is the area without heat treatment. The formation of the soft band is essential to the heat treatment process.

Under normal circumstances, the steel character “S” is marked on the position where the soft belt exists in the workpiece to indicate the specific slewing bearing soft belt position. The installation position of the soft belt is essentially to improve the life of the bearing.

From the perspective of the user and the manufacturer, it is still a reasonable position to install the upper and lower ring soft belts of the slewing bearing. Therefore, the manufacturer of the slewing bearing should accurately mark the position of the soft belt of the slewing bearing, and the manufacturer and installer should reasonably install the position of the soft belt of the slewing bearing as needed.

Second,the installation position of the slewing bearing soft belt

Usually the upper loop flexible belt of the slewing device is installed at a position perpendicular to the projection line of the pitching rotation plane. For example, the upper loop flexible belt of the slewing device of a ship loader or stacker-reclaimer should be installed at a position perpendicular to the center line of the cantilever and cut through the center of rotation , that is, standing at a 90-degree position facing the left or right side of the cantilever on the center of rotation. In the usual mechanical design, the soft belt does not have the stress state of the support roller of the slewing bearing device at this position.

The installation position of the lower ring soft belt of the slewing device should be determined according to the center of gravity of the equipment and the range of the slewing angle. If the rotation angle is 100 degrees left and right, and the center of gravity of the upper part of the rotation is in the front, it is recommended to install the lower ring soft belt at the rear, that is, at a position of 180 degrees. If the change position of the center of gravity of the upper part of the rotation is the same in the front and rear positions, the angular position of the lower ring soft belt can be installed arbitrarily.

Because of the inevitability of the soft belt on the slewing bearing device, it is required that the user who uses and selects the slewing bearing device should install the position of the soft belt reasonably to improve the service life of the bearing. The general principle is to try to install the soft belt in a position where the soft belt is under less pressure during the load change.

Popular Widely Useful Excavator Slewing Bearings

1.Common troubleshooting methods for excavator slewing bearings

First, the rotation of the excavator slewing bearing is not flexible
(1) After installation, the operation is not flexible, and the excavator slewing bearing installation surface is not well matched. The large and small gears are poorly meshed. If there are foreign objects stuck in the large and small gears, remove the foreign objects on the installation surface, use shims to level them, and re-adjust the meshing backlash of the large and small gears as required. Pay particular attention to the position of maximum gear runout. Check to make sure that there are no foreign objects in the meshing position of the large and small gears.
(2) The operation is not flexible during use. Lack of grease, top up as required. The sealing strip is damaged, causing foreign objects to enter and roll in (such as poor operating conditions, intrusion of dust, etc.); check the meshing of the large and small gears for foreign objects or broken teeth.
Second, the abnormal sound

excavator slewing bearing Alt
(1) After assembly, there is abnormal noise during trial operation. The treatment method is the same as “inflexible operation after installation”, or the large and small gears are not meshed enough, sometimes tight and sometimes loose, and the meshing at the maximum position of the tooth jump is too tight to produce abnormal noise.
(2) Abnormal noise occurs during use. There is a lack of grease in the raceway, and foreign objects, such as sand, iron filings, etc., are mixed in the pipe. Pay attention to whether the sealing strip is damaged and whether the mounting bolts are loose.
Three, shake
(1) The mounting bolts are loose, causing shaking during work. Immediately check all inner and outer ring mounting bolts and tighten as required.
(2) Check whether the overload operation is performed and operate in strict accordance with the regulations.
(3) Long-term overload operation leads to crushing of the raceway and excessive clearance.
Fourth, broken teeth
(1) Broken teeth are often directly related to installation. The gap between the large and small gears is not properly adjusted during installation. If the requirements are not met, the teeth are broken due to poor meshing of the two teeth during operation, and the gap should be adjusted according to the requirements; the meshing gap adjustment with the pinion at the maximum position of the tooth skipping is not carried out as required, resulting in the pinion meshing with the large gear at the maximum position of the tooth skipping during operation. If it is stuck and causes broken teeth, the green paint position should be adjusted to mesh with the pinion on the way, and the test run should be carried out after adjustment according to the requirements; the first line of the large and small gear shafts is not parallel, and the large and small gears are poorly meshed after installation, resulting in broken teeth, which should be guaranteed. The meshing of the two gears is parallel; the mounting bolts of the slewing bearing are not tightly fixed, and the large and small gears are poorly meshed, resulting in broken teeth, and the bolts should be tightened as required.
(2) Use aspects. Violating the operating rules, overloading and rotating at high speed, the host collides (sweeps) obstacles, etc. It should be operated in strict accordance with the requirements of the operating procedures. When the slewing bearing meshes with the pinion, there is a foreign object stuck, and the large and small gears should be kept clean and checked frequently.

2.Reasons and solutions for inflexible operation of excavator slewing bearing

The excavator slewing bearing is an indispensable part of the excavator slewing device. Whether the excavator can turn left or right during work is inseparable from the credit of the slewing bearing. The slewing bearing is mainly used to support the quality of the upper body and bear the working load. Due to the heavy load operation of time and the influence of the environment, the phenomenon of inflexible operation will appear after a long time, which will cause a lot of trouble when we use it, and there is no way to work well.

The reason why the excavator slewing bearing is inflexible

Reason 1: The slewing bearing gear is deformed or broken, causing jamming or inflexible movement.

Solution: Repair the gear and re-weld the gear.

Reason 2: There is a problem with the sealing system of the slewing bearing, which will enter the sundries, such as stones, sand, etc., resulting in stuck or insensitive movement.

Solution: Clean up all the debris.

Reason 3: The newly purchased product is inflexible in idling. Check the production date of the slewing bearing. If the time is long and the climate is cold, it is possible that salt mist is mixed in the raceway, which will cause the rotation resistance to multiply and make the slewing bearing run poorly.

Remedy: After afterburning, if it can run and there is no other abnormality, it can be used normally.

Reason four: overload operation, resulting in inflexible movement of the slewing bearing.

Corresponding solution: The workload needs to be reduced.

Reason five: The position of the excavator slewing bearing is not flat.

Solution: You need to change the position of the platform and work in a flat position.

Reason 6: There is a lack of lubricating oil in the excavator slewing bearing. The grease causes the friction to increase and the resistance to increase, which will cause the movement to be insensitive.

Solution: add lubricating oil of the same specification or replace all lubricating oil.

Reason 7: The operation of the excavator slewing bearing is not flexible. It may be that the installation surface of the main engine and the excavator slewing bearing installation surface do not cooperate well, resulting in the axial clearance of the slewing bearing after installation cannot compensate for the deformation of the excavator slewing bearing. Difficulty running in the raceway may sometimes be accompanied by abnormal noise, poor meshing of the large and small gears, or foreign objects stuck in the large and small gears.

Solution: ①Re-process the installation plane of the host to make the installation plane meet the requirements; or use the gasket filling method to deal with it. ②Re-adjust the meshing backlash of the large and small gears according to the requirements, especially pay attention to the position of the gear beating. ③ Check to ensure that there is no foreign matter in the meshing position of the large and small gears. ④ Replace a slewing bearing with a slightly larger clearance.

Reason 8: The sealing strip is damaged, causing foreign objects to enter the raceway, such as poor working conditions, and dust intrusion into the raceway.

Solution: Replace the sealing strip.

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