user02, Author at Slewing Ring Bearings Manufacturers Suppliers Exporters

Kaydon Slewing Ring Factory

1.Proportional relationship between correct installation of slewing ring and service life

As a precision rotating core component, the kaydon slewing ring, the clearance value, the end runout, the axial runout and the radial runout, are all calculated by the wire and the track. It is very important to ensure the correct and precise installation of the slewing ring. Affect the service life and use effect of the bearing.

The design life of normal bearings is 20 years, and the service life is 10 years. Under the condition of ensuring accurate installation, correct use, maintenance and maintenance, the service life is about 10-12 years, and the heavy-duty bearing is about 5-8 years.

Notes on installation:

1. Ensure the rigidity and strength of the installation base surface, ensure that the stress is released completely, and the installation surface should be kept clean and the installation accuracy meets the relevant regulations.

2. Make sure that the mounting bolts are high-strength grade 10.9, the nuts are grade 10, the gaskets are quenched and tempered gaskets, the tolerances of the mounting holes of the bearings are within the normal range, and each joint surface should be cleaned to remove paint, iron filings, rust inhibitors, etc.

3. The seal is the lubrication system of the bearing. Check whether the seal is still in the correct position, and clean the fitting part of the mounting plane of the kaydon slewing ring.

4. When connecting with high-strength bolts, pre-tighten the bolts: It should be pre-tightened in three steps, 30%, 80%, and 100%, respectively, to achieve the specified pre-tightening torque. In addition, check the fit of the slewing bearing and the mounting surface, usually with a feeler gauge. If the fit is not good, fill it with an appropriate material.

It is strictly forbidden to weld the kaydon slewing ring to avoid the deformation of the inner and outer rings, which will affect the normal use.

6. During installation, if the installation base surface is uneven, thin copper sheets can be prepared. If the installation plane is indeed installed, it should be considered to leave convex and concave shoulders or positioning blocks for radial positioning.

7. The tempering belts of the upper and lower raceways should be staggered by 180°. When installing crane and excavator turntable bearings, the tempering belt of the rolling ring should be placed at an angle of 90° with the direction of the boom, and the tempering belt of the rolling ring should be fixed. , should be placed in a location with less frequent work.

8. After the installation work, the raceways and gears should be filled with grease and regularly maintained.

9. Make sure that the gear meshing reaches 70% and the force is even.

2.Sealing strip design skills and installation of kaydon slewing ring

kaydon slewing ring Alt.

Embedded sealing strip, also known as invisible sealing strip, embedded sealing strip.

The advantage of the built-in sealing strip is that the structure of the slewing ring is increased, and the grease is lubricated in a small range, preventing excessive consumption and loss, reducing the drop between the inner and outer rings, and increasing the rolling elements of the bearing to improve the load.

The disadvantages are also obvious. The damage is not easy to maintain and install again. Professionals are required to open the bearing again for installation. The wear and consumption of the built-in sealing strip are invisible, which increases hidden dangers.

The trouble caused by the installation is that it is not easy to install the bearing after the sealing strip is assembled in advance. Small gap, squeeze, easy to interfere. Design considerations, calculate the pressure and size of the sealing strip in advance, and the depth of the sealing groove in advance, so that the sealing strip can be buried as much as possible. Secondly, the installation of the sealing strip should follow the installation direction as much as possible, otherwise it is easy to get stuck in the gap of 0.5mm.

There are also design features, pay attention to the lip shape of the built-in sealing strip to ensure that the rotation performance cannot be affected after installation.

Finally, the practical occasion of the built-in sealing strip is to ensure that the bearing under 1 meter is used in the four-point ball and crossed roller bearing structure. The bearing structure should not be complicated.

3.The role of full complement ball and spacer block cage for slewing ring

When the drawings and technical requirements of slewing ring and slewing bearing are normally designed, spacers or cages are generally used unless the bearing capacity of the bearing is intentionally increased with full complement of steel balls or full complement of rollers.

The main purpose of the spacer block or cage, as shown in the figure, is to coordinate the movement trajectory and movement direction of the rolling element, and to uniformly bear the force. Reduce friction between rolling elements and reduce impact noise. Thereby improving the rotational performance of the bearing.

When fully loaded, the rotational flexibility of the bearing is not affected. Because they are all at low speed and heavy load, it is not enough to affect the test data of the bearing. What is the effect of installing isolation blocks? The reason is self-evident, which is to improve the movement efficiency of the rolling elements.

The role of full complement ball and spacer block cages for slewing bearings and slewing rings
Relatively speaking, cages, especially integral steel cages, copper cages, and teflon cages, are very important for bearings that are subjected to inclination angle force, vertical force, and tossing force. Integral cages must be used.

Especially large-diameter slewing bearings, segmented cages, and integral cages cannot be replaced.

For four-point contact ball bearings, the integral cage can improve the life and reliability of the bearing.

Precision Crossed Cylindrical Roller Slewing Bearings

What a crossed cylindrical roller slewing bearings?

Crossed cylindrical roller slewing bearings are bearings for high-precision applications whose dimensions conform to ISO dimension series 18 as per DIN 616. 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 crossed cylindrical roller slewing bearings, 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 cylindrical roller slewing bearing are very rigid, have high running accuracy and are supplied with normal clearance, low clearance or preload. The crossed cylindrical roller slewing bearing outer rings are easily fixed to the adjacent construction using clamping rings.

Crossed Cylindrical Roller Slewing Bearings Alt.

LYMC designs and manufactures a variety of crossed cylindrical roller slewing bearings that can handle radial, thrust and moment loads at the same time. These compact bearings feature rollers crossed at right angles between inner and outer rings.

Widely used in machine tools, industrial robots and medical equipment because of their high rotational accuracy.
Roller guide options include a cage or separator as well as a full complement design. Both the cage and separator styles offer a small coefficient of friction for high-speed rotation. Full complement crossed cylindrical roller slewing bearings handle heavy loads at low speeds.
Sealed and open designs are available. Sealed bearings incorporate synthetic rubber seals to protect against dust, dirt and grease.
Mounting Holed Type
Mounting holed type, high rigidity crossed cylindrical roller slewing bearings feature mounting holes on both inner and outer rings for easy installation.
- Inseparable design integrates inner and outer ring into one structure for high rigidity and accuracy.
- Shaft diameters range from 10 to 90 mm.
- High Rigidity
  
  High rigidity crossed cylindrical roller bearings feature solid, one-piece construction for high accuracy.
  
  Inseparable design integrates inner and outer ring into one structure for high rigidity.
  
  Smooth rotation ensured by separators incorporated between cylindrical rollers, suitable for high rotational speeds.
  
  Shaft diameters range from 20 to 300 mm.
  
  Standard
  
  Standard crossed roller bearings feature a two-piece outer ring, bolted together to prevent separation during transport and installation.
  
  Shaft diameters range from 30 to 250 mm.
  
  Available in caged and full complement types.
  
  CRB and CRBC are available with shaft diameters as large as 800 mm.
  
  Definition of crossed roller bearings
  
  Crossed roller bearing is a special type bearing with split inner ring and rotating outer ring. Since the divided inner ring or outer ring is installed with rollers and cage, it is fixed with the cross roller ring to prevent separation from each other, so it is easy to install the cross roller ring.
  
  Since the rollers are arranged in a cross, only one set of cross roller rings can bear loads in all directions. Compared with the conventional model, the rigidity is increased by 3 to 4 times. At the same time, because the inner ring or outer ring of the cross roller bearing has a two-part structure, the bearing gap can be adjusted, and even if preload is applied, high-precision rotational movement can be obtained. Moreover, due to its special structure, it is usually used as a joint bearing in industrial robots.
  
  Applications of crossed roller bearing:
  
  •Industrial robot arms, reducers
  
  •Precision machines( turnable table)
  
  •Rotation parts of Machine tools
  
  •Medical equipments
  
  • Measuring instruments
  
  LYMC-bearing provides high quality crossed roller bearings including THK RA, THK RB, THK RE, THK RU series, IKO CRB, IKO CRBC, IKO CRBF, IKO CRBH, INA SX, INA XU, INA XSU series and more. Custom cross roller bearings are also acceptable.

Slewing Bearings Suppliers Plant

1.The necessity of grinding teeth for slewing bearings

Regarding the slewing bearing or slewing ring bearing, no matter external or internal teeth, helical teeth, etc., the normal process level includes gear shaping, gear hobbing, and milling. According to the design standard, the gear accuracy is generally 9-grade or 10-grade teeth.

Here, the 9th grade teeth or the 10th grade teeth, the indicators under investigation are based on the design standard of the slewing bearing of JB/T10471, and you can also refer to JB/T2300. It mainly reflects the rotation accuracy, and the specific indicators are:
1. Number of cross teeth and length of common normal
2. Common normal deviation
3. Tooth jump (tooth jump of finished turntable bearing)
4. The tooth width, tooth thickness, tooth shape and tooth direction are generally not marked separately in the drawings.

In short, the values of the 9-stage teeth or 10-stage teeth of the slewing bearing are in agreement in a pure sense. From the design concept, the common normal of the 7th grade and 8th grade teeth, the tooth jump also meets the design requirements.

However, the quenching of the tooth surface has a great influence on the accuracy level of the tooth surface, and it is generally one level backward.

This article talks about the necessity of grinding teeth and the technical indicators that can be achieved.
1. Improve meshing accuracy
2. Tooth jump 0.06-0.15mm
3. Tooth surface roughness Ra0.8
4. Reduce meshing noise
5. Reduce the wear intensity of the tooth surface
Therefore, if you want to reach this technical level, you must grind the teeth.

slewing bearings Alt.

2.Design parameters to improve slewing bearing life and reliability

Slewing Bearings life

Under a certain load, the number of revolutions or hours that a bearing experiences before pitting occurs is called bearing life.

Due to the difference in manufacturing precision and material uniformity, even the same batch of bearings of the same material and size will have different lifespans when used under the same working conditions. If the statistical life is 1 unit, the longest relative life is 4 units, the shortest is 0.1-0.2 unit, and the ratio of the longest to the shortest life is 20-40 times.

In order to determine the standard of bearing life, the slewing bearings life and reliability are related.

Work on the following design factors:

1. Structure, choose three-row roller combination slewing bearing

2. Material, choose 42CrMo, electroslag remelting

3. Quenching and tempering hardness should be above HB280

4. High manufacturing precision

5. The height of the ferrule and the size of the roller should be matched

6. Tooth surface quenching

7. Protective measures, seals and dust baffles

8. Application of integral cage

3.What factors should be paid attention to when surveying and mapping high-precision slewing ring bearings

For surveying and mapping of high-precision slewing bearings, in addition to paying attention to the installation size, in the process of surveying and mapping most slewing bearings, we must grasp the necessary technical parameters to ensure that the surveying and mapping bearings are foolproof. So what parameters must be paid attention to? What preparations are needed for high-precision surveying and mapping points?

1. The outer dimensions of the slewing bearing are necessary

2. The gear parameters of the slewing bearing, the primary

3. The size of the mounting hole of the slewing bearing, including the number, position, size and type

4. Step size, lubricating oil hole, position, number, size, type of slewing bearing

5. Structural form, must be disassembled and viewed

6. Seal form, cage form and channel type

7. Working conditions, accuracy, horizontal, inclined and vertical use

4.What are the quality standards for large bearings of slewing ring

In short, if you have to distinguish from the selection, quality reliability and high standards of bearings, you can refer to the following:

1. Material

2. Heat treatment

3. Clearance, runout, tooth jump

4. Comprehensive indicators, roughness, grinding, depth of hardness layer, flaw detection

5. The reference life value of similar bearing operation

The quality inspection of slewing bearing bearings can be divided into axial clearance and radial clearance according to different detection methods. important items to check. From the perspective of bearing application, clearance is an important indicator for detection. Whether the bearing can obtain more satisfactory performance largely determines its radial clearance.

The specific tests are as follows: the high-frequency quenching hardness of the bearing surface should not be lower than 55HRC, the depth of the hardened layer should not be lower than 4mm, and the width of the soft belt should not be lower than 50mm. There are certain requirements for the quenching time and temperature of the support bearing for tempering processing. In general, it needs to be quenched at a temperature of 200 degrees, so as to ensure that the stress is completely eliminated.

In addition, the most important thing is grinding. It is necessary to select a suitable grinding wheel to complete the grinding, and strictly control the linear speed to avoid raceway burns. Then for fine grinding, it is necessary to choose a resin grinding wheel with a particle size of 46° or 60° for grinding. For the support bearing containing gears, the gear hobbing process is required after the grinding process. The requirements for the entire process are very strict, and the accuracy must exceed grade 8.

Four-Point Contact Ball Slewing Bearing

1.Four-Point Contact Ball Slewing Bearing

The slewing bearing and the slewing bearing are similar in form, but there are qualitative differences. In short, the four-point contact ball slewing bearing is just a purely mechanical mechanism that can rotate.

The slewing bearing should realize various loads, precision and measurement and control, as well as realize the driving rotation of various actions.
Features in the field of use of slewing bearings:

◎Port cranes usually use three-row roller slewing bearings with internal teeth or external teeth with a diameter of 4 meters to withstand high overturning moments.

◎Stacker and reclaimer: The turntable bearings used in the stacker and reclaimer are usually ball-column combination type, three-row roller type and cross-roller type, and most of them have a diameter of

over 3 meters. Due to the harsh working environment and large dust, this type of bearing has the characteristics of high bearing capacity, long life and good sealing performance.

◎Ferris wheel: used for the four-point contact ball turntable bearing on the Ferris wheel, the outer diameter is 5000mm larger, and the thickness is 200mm

◎Ship unloader: The slewing bearing for ship unloader usually adopts the structure of three rows of rollers with external teeth, with a diameter of about 4 meters.

◎Tower crane: The slewing bearing used for tower crane usually adopts small-sized four-point contact ball slewing bearing or double-row ball slewing, and the diameter does not exceed 2 meters.

◎Radar antenna: The short-wave antenna generally uses a slewing bearing with a three-row roller structure, and the rotation speed is slow.

◎Shield machine: The diameter of the slewing bearing for shield machine ranges from 2.5 meters to 6 meters, and some have larger diameters. These bearings work under very harsh conditions, with large bearing load, strong corrosion resistance and short life. .

◎Ladle turntable: The slewing bearing for the ladle turntable usually adopts a three-row roller structure. Due to the harsh conditions with dust and high temperature, it has high requirements on the retainer, grease and sealing strip.

four-point contact ball slewing bearing Alt.

2.Emergency measures after the failure of the four-point contact ball slewing bearing

The large turntable four-point contact ball slewing bearing plays a very critical and irreplaceable role in bucket turbine bearings, stacker and reclaimer bearings, large ladle bearings and logistics transportation.

When the service life of the large bearing exceeds 5-8 years, and the large bearing of the ladle fails to stop, or cannot rotate in the forward and reverse directions, then the economic loss will be very huge, such as the large bearing of the bucket turbine of the thermal power plant, and the large bearing of the ladle, one day The loss is immeasurable.

First, remove the interfering parts that affect the normal rotation of the four-point contact ball slewing bearing
Second, remove the seal
Again, clean along the bearing gap with kerosene
Then, add rare grease
Afterwards, try rotating in the forward and reverse directions
Then, observe whether the bearing force is balanced, adjust the bearing load and balance
Next, remove the foreign matter overflowing from the bearing grease
Next, observe the gear meshing of the bearing to see if the tooth surface meshing is normal
Subsequently, if conditions permit, the use angle of the bearing can be exchanged
Finally, observe the condition of the bearing at any time, communicate with the manufacturer in time, guide the on-site installation of the new bearing, and strictly control the time and node for the installation of the bearing.

3.What are the quality standards for large bearings of four-point contact ball slewing ring

1. Material

2. Heat treatment

3. Clearance, runout, tooth jump

4. Comprehensive indicators, roughness, grinding, depth of hardness layer, flaw detection

5. The reference life value of similar bearing operation

The quality inspection of four-point contact ball slewing bearings can be divided into axial clearance and radial clearance according to different detection methods. important items to check. From the perspective of bearing application, clearance is an important indicator for detection.

Whether the bearing can obtain more satisfactory performance largely determines its radial clearance.
The specific tests are as follows: the high-frequency quenching hardness of the four-point contact ball slewing bearing surface should not be lower than 55HRC, the depth of the hardened layer should not be lower than 4mm, and the width of the soft belt should not be lower than 50mm.

There are certain requirements for the quenching time and temperature of the support bearing for tempering processing. In general, it needs to be quenched at a temperature of 200 degrees, so as to ensure that the stress is completely eliminated.

China Factory Best Four-Point Contact Ball Slewing Bearing

1.Why do high-speed bearings choose the four-point contact ball slewing bearing?

Why do high-speed four point contact ball slewing bearings choose the four-point contact ball structure? Why do high-speed bearings choose the four-point contact ball structure? This article analyzes the reasons one by one, and provides some theoretical and practical basis for selection, design and application.

First of all, select the slewing bearing, which is positioned at a high speed, at least above 30rpm, generally more than 10rpm, and the four-point contact ball bearing structure is preferred. Secondly, because the ball bearing and the raceway are in four-point contact ball slewing bearing, which is a point contact, during the movement of the contact point, when the two circles are theoretically absolutely parallel up and down, the flexibility is far more than that of the crossed roller and the three-row ball structure.

The latter is usually a line contact motion process and can be understood as a surface contact. Again, ball bearings can use PTFE cage and copper cage to increase the speed, 60-120rpm. Of course, due to the structure, noise and vibration will occur at extreme high speeds, usually by grinding the grooves and improving the accuracy to the greatest extent possible to reduce the index.

four-point contact ball slewing bearing Alt.

The structure of the four-point contact ball slewing bearing determines the characteristics of high speed, wear resistance and long life. The structure of the four-point contact ball slewing bearing determines the characteristics of high speed, wear resistance and long life.

Carefully check the channel of the four-point contact ball slewing bearing, the contact point between the steel ball and the channel, and the inner and outer rings are in contact with two points, so it is called a four-point contact ball bearing. Double-row ball bearings are double-row arc grooves.

For the same reason, they are also called eight-point contact ball bearings. Flexible, not easily subject to various errors, it is flexible, easy to install, easy to maintain, and has the best feedback from use. Therefore, compared with the crossed roller bearing and the three-row ball bearing, the rotational speed can be appropriately increased, and the rotational speed can be as high as 70-120rpm when combined with the PTFE cage.

2.What are the matters needing attention in the installation of slewing bearing?

First of all, compared with other parts, the four-point contact slewing bearing is the core of the rotating part and belongs to the precision product. Therefore, it is necessary to understand the installation precautions of the slewing bearing:
1. After understanding the rotation accuracy of the slewing bearing, first ensure that the installation base is flat. Remember, it is very important, the base is not flat, and the hidden danger is great.

2. Whether the force and eccentric load of the bearing are within the theoretical calculation

3. According to whether the bolts are installed or not, pre-tighten them into 180° one by one.

4. Whether the S soft belt area is in the non-load area, that is, the area where the force is not often or the weakest force, taking the crane as an example, the bearing should be installed in the area where the cantilever direction is vertical

5. After the gear meshing rotates in the forward and reverse directions, no other abnormal noises can be gnawed.

6. There is a slight noise after the new bearing is installed. After fully refueling, the forward and reverse rotation still cannot eliminate the abnormal noise.

7. The positioning size of the bearing

8. The size of the mouth of the bearing

9. The seal of the bearing must not be interfered with by foreign objects, otherwise the sealing strip will be damaged

10. There should be no interference in the position of the dust baffle

What factors will cause the installation of the slewing bearing to be unsmooth or even unable to rotate? Taking the following factors into consideration,

1. Mounting holes. The threaded hole of the mounting 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, so that the bolt cannot be pierced

3. The size of the positioning hole and the step is too large and cannot be matched

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

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

6. The 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, resulting in 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.

Slewing Ring Bearing Manufacturers

The Installation and Maintenance of Slewing Ring Bearing

The structure of slewing ring bearing

slewing ring bearing Alt.

Preparation

1) Make sure that the model is the same with the contract.

2) Make sure the slewing bearing is not damaged during the transportation.

3) Open the package in clean and dry environment.

4) The Bracket should have enough flexility to avoid the distortion of the slewing bearing and influence of its usage.

5)The installation datum plane and bracket installing plane should be clean,grease,burr,paint and other foreign bodys should be wiped off.

Installation

1) The screws in the installing plane should fit with the mounting holes in the slewing bearing.

2) Slewing RIng Bearing ball track quencher soft zone(lies between the exterior mark”S” and the jam.) is in the non-loading zone or non-regularity loading zone.Upper and lower rolling ring “s” soft zone should stagger for 180 degree. The soft zones of crane and excavator machinery should be in the place which forms a 90 degree angle with the arm support direction( the maximum load direction).

3) Put the slewing ring bearing on the bracket and check the contaction condition between the supporting plane and bracket with feeler gauge, level up with pad mat if clearance appeared, so as to avoid distortion after screwing down, and affect the performance of slewing bearing.

4) Before screwing down, adjust gear side clearance by gear circle radial runout vertex (3 green symbols gears), after screwing down, check gear side clearance in all the gear rings.

5) Install slewing ring bearing with high strength Screws, and choose appropriate strength bolts by stress condition, screw down in 180 degree direction, and check all bolts to ensure that every one in the circle has the same pretightening force, not spring washer but hardening plain steel washer should be choosed in installation, screw down bolts in turn by the picture below:

6) After installation, you should wife off the dust and dunghill in the slewing ring bearing and paint some antirust paiting,also paint some lubricate grease in raceway and gear.

Operation,Maintenance and Lubrication

1) Before the slewing ring bearings leave factory ,some No.2 EP grease (GB7324-1994) should be in slewing bearing raceway, change it into new lubricate grease according to your different working conditions.

Add grease regularly in slewing ring bearing raceway. Ball slewing ring bearing is lubricated every 100 hours, roller slewing bearing is lubricated every 50 hours, shorten the lubricate period in specially working condition, for example: in torrid zone, with high humidity, more dust, fast changing temperature and working continuously.

Add enough grease before and after the the machine’s long-term stop. Fill the raceway with grease till it is seeping from the seals.turn slewing bearing slowly when you add grease to make the grease equally filling.

2) Usually wipe off the foreign bodys and spread grease.

3) Check the pretightening force of the blot after the slewing ring bearing running first 100 hours, then make sure enough pretightening force every another 500 hours.

4) Give your attention to the running slewing ring bearing, you should stop it to check when noises, impulsion, abrupt accretion power appeared, and dismantle it to check when necessary.

5) Its better to protect the slewing ring bearings from dust, rain,water and high tempreture in operation, and defend gear engagement zone against hard objects.

6) Check the seal usually, change it when it is damaged,reset it when it is breaking off.

Commonly used lubricants have been list in the following table,Often lubricate the reverse with gear grease

Bearing Structure	Working Condition		Lubricated Parts	Lubricant
Bearing Structure	Working Condition		Lubricated Parts	Product	Quality Marker	Standard
Plastic insulation rubber ring seal	Low and normal temperature,moist -20℃ + 60℃		Ball Track	Extreme pressure lithium lubricating grease	No.1 No. 2	GB7323-1994
Plastic insulation rubber ring seal	Low and normal temperature,moist -20℃ + 60℃		Geared wheel	Black Lead Radical Lubrication	ZG-S	SH/T0369-1992
Metal Insulation Iabyrinth packing	High Temperature, moist	40°C ～120°C	Ball Track	Extreme pressure lithium lubricating grease	No.1 No.2	GB7323-1994
			Ball Track	M0S2 Compound calcium radical lubricating grease	No.2
			Geared wheel	No.4 high temperature lubricating grease	No.4	SH0376-1992
		80°～180°C	Ball Track	M0S2 Compound calcium radical lubricating grease	No.2
		80°～180°C	Geared wheel	No.4 high temperature lubricating grease	No.4	SH0376-1992
	Normal temperature, resistance to sea～60°C		Ball Track	No.2 Compound aluminum radical lubricating grease	No.2
	Normal temperature, resistance to sea～60°C		Geared wheel	No.4 aluminum radical lubricating grease	No.4	SH0378-1992

Preservation

The slewing ring bearing has been sealed with oil before it leaves the factory. The packed slewing ring bearing at optimal conditions can be stored for 6 months. Idle ball tracks need lubricating every 2 months.(please refer to “Maintance and Lubricating”).Idle slewing bearing needs oil sealed packaging every 6 months.

Oil Sealed Packaging:

1) Take out the slewing bearing from the wood box.

2) When removing the wrapping, do not rip the sealing tape, remove the wrapping from the outside to the inside.

3) After taking the slewing bearing into pieces, infuse the ball track with lubricating grease.First deoil the surface and then do oil sealed packaging.

4) When deoiling, do not infuse solvent containing chlorie into sealing band and the ball track.

5) After deoiling, clean down the out surface, plaster the preservative oil and grease(F20-1) or industrial petroleum jelly(SY1607-77)evenly.

6) Then ,pack it as it was primarily done.Encase it again in the wood box.It is better to batter down a asphalt felt in the box to protect against moisture and rain.If there is no box to store the bearing, after oil sealed packaging, store it in folds.

Best China Small Slewing Bearing

1.Why does the slewing bearing get stuck and have a dead point with no load and normal rotation load?

The no-load bearing can rotate normally, and the clearance, warpage, ellipse, and groove shape are directly related to the contact point.

Especially after the load, the contact point of the channel and the shape of the channel are very critical and very obvious. If it rotates before no-load, it is because there is enough clearance to affect the rotation, but after the slewing bearing is stressed, the contact point theoretically moves in a circle along the parallel trajectory of the upper and lower contact points of the bearing.

In fact, the shape of the channel is warped. Curve and ellipse, at this time, the contact point is jumping and irregular, which is equivalent to the jumping and turning of the steel ball ups and downs, so that it enters an infinite loop, resulting in stuck.

Generally speaking, the slewing bearing in the crane bearing, crane bearing, bucket turbine bearing, fixed crane slewing bearing, stacker-reclaimer bearing and crane bearing and other large marine crane bearings, the failure occurred in the early stage, according to the failure level Basically divided into three categories

The failure of the large bearing was initially manifested because of the sound and abnormal sound. Eliminate interference, such as rotation interference, gear interference, good dust baffles, etc. The reasons for the noise are mostly abnormal load, ball impact sound, uneven contact between the channel and rolling elements, deformation, etc.

If it is a new slewing bearing, it means the channel There are ovals or warping, and stress relief is not complete. It is a manufacturing defect. If possible, the bearing should be disassembled and the groove fitting should be re-ground.

If it is sharp and harsh, accompanied by vibration, swing, or jitter after the abnormal noise, it means that the slewing bearing has penetrated into the core of the fault, the rolling elements are broken, the channel is strained, and even the hardness layer falls off. At this time, the bearing has repair value.

If the equipment has a spare bearing, it should be replaced in advance. The old bearing is disassembled and repaired, and the service life can reach more than 80% of the new bearing. In fact, many spare bearings are used as new bearings for emergency use.

If there is no spare bearing, on the basis of confirming the drawings and model, strengthen the maintenance and maintenance of the old bearing, and start the customization of the new bearing, which generally takes 60-80 days.

Bearing rotation begins to be difficult, stuck, stuck or even stuck. Basically, it is announced that the bearing has fallen into the nest. At this time, it can only be pulled hard, cleaned with kerosene, or rotated back and forth. It is the factory that has to work three shifts and pay three times and four times the cost to manufacture it in a short time.

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2.Four-point contact ball bearings and crossed roller bearings

Comparison of working conditions and selection and positioning of four-point contact ball bearings and crossed roller bearings. Simply speaking, it is very important to choose a four-point ball bearing or a crossed roller bearing according to the needs of the working conditions.

In terms of precision design, crossed roller bearings are more obtainable, and in terms of rotational flexibility, four-point contact ball bearings are better.

In the accuracy level, when the speed is higher than 10rpm, and there are certain requirements for noise, such as when the requirement is less than 80 decibels, the four-point contact ball is the first choice, and the PTFE cage or copper cage is selected.

In terms of rigidity and stability, crossed roller bearings are the preferred choice, but the rotational speed should be low, generally below 8rpm. And since the cross rollers are arranged in a 1:1 ratio, noise is unavoidable when reaching high speeds, because the friction and impact of the rollers are unavoidable.

At the same time, we must pay attention to the use of lubricating oil, and grease is indispensable. Gear grinding, groove grinding, high-precision steel balls, deep groove ball grooves on the inner ring, four-point contact ball grooves on the outer ring, and two-point contact are also ways to reduce noise.

Cheap Price OEM Manufacturer Slewing Bearing

The design and selection of slewing bearing

The design and selection of slewing bearing and the consideration of key parameters, one is the rotation accuracy; the second is the realization of the bearing capacity; the third is the matching degree of the working conditions.

The fourth is the comprehensive consideration of design and selection, which is convenient, fast, safe and reliable.
Rotary slewing bearings have unique load-bearing characteristics and are commonly used on devices such as hoisting machinery, excavators, turntables, wind turbines, telescopes, and tank turrets.

Through the improvement of machining methods and the upgrade of design, the current slewing bearing can be applied to smaller, more complex and more precise occasions.

The correct selection of a slewing plate bearing depends on requirements such as load, stiffness, rotational speed, size and rotational flexibility. Design goals and bearing suitability are jointly selected by the customer and the manufacturer to help optimize system performance at the lowest cost and guaranteed trouble-free operation.

Usually the load capacity is the decisive factor in selecting the bearing section size and diameter, but other parameters determine which bearing type is best to choose.
1. If there is a large torque requirement, it is generally necessary to use double-row four-point contact ball bearings.
2. Increasing the stiffness generally requires the use of roller bearings.
3. The maximum load bearing requires the use of crossed rollers (two-row or three-row roller bearings)
For applications requiring increased rigidity and load bearing, large size bearings are required, but for applications with sensitivity requirements such as robots and manipulators, small size bearings are required.

The slewing bearing with smaller inner diameter makes the structure of the mounting member more compact and the total weight is reduced. At the same time, for the occasions with high rotation speed and small structural deformation, it also reduces the moment of inertia.

slewing bearing Alt.

2.The influence of the structure of the slewing bearing on the selection design, cost and life

Slewing bearing is a special structural bearing that can bear large axial load, radial load and overturning moment at the same time. – Under normal circumstances, the slewing bearing itself has mounting holes, lubricating oil holes, sealing devices, and gears, which can meet the requirements of the working host under various working conditions; on the other hand, the slewing bearing itself has a compact structure and is easy to guide and rotate. ,

Easy installation, easy maintenance and other characteristics, so it is widely used in mining, mining, construction, port, medical and other aspects. The structure of the slewing bearing has a decisive influence on the selection. The four-point ball is the best in flexibility and fatigue resistance.

The double-row ball bearing is the first choice for marine bearings and crane bearings, automobile crane bearings and cement pump bearings; cross Roller bearings are often used for precision, measurement and control and positioning, and the speed is low. Three-row roller bearings are typical low-speed heavy-duty bearings.

The single-row four-point contact ball slewing bearing is composed of four parts: inner ring, outer ring, steel ball, and spacer block. It has a compact structure and light weight. radial force. Construction machinery such as rotary conveyor, welding manipulator, small and medium-sized crane and excavator can be selected.

The double-row ball slewing bearing has three races, and the steel balls and spacers can be directly discharged into the upper and lower raceways. According to the stress conditions, two rows of steel balls with different diameters are arranged.

This kind of open assembly is very convenient, and the bearing angle of the upper and lower arc raceways is 90°, which can bear a large axial force and tipping moment. When the radial force is greater than 0.1 times the axial force, the raceway must be specially designed.

The axial and radial dimensions of the double-row reducing ball slewing bearing are relatively large and the structure is tight. It is especially suitable for loading and unloading machinery such as tower cranes and truck cranes that require medium or larger diameters.

The single-row cross-roller slewing bearing consists of two races, with compact structure, light weight, high manufacturing precision, small assembly clearance, and high requirements for installation accuracy. Force, tipping moment and larger radial force are widely used in lifting and transportation, construction machinery and military products.

Three-row roller slewing bearings have three races with separate upper and lower and radial raceways, so that the load on each row of rollers can be determined exactly. It can bear various loads at the same time, and is the one with the largest bearing capacity among the four products.

The shaft and radial dimensions are large and the structure is firm. It is especially suitable for heavy machinery requiring large diameters, such as bucket wheel excavators, wheel Cranes, marine cranes, port cranes, molten steel running table and large tonnage truck cranes and other machinery.

China Best Tower Crane Slewing RIng Bearing

1.Tower Crane Slewing Ring Bearing

Underwater slewing bearing and slewing bearing, the process is very complex, the manufacturing cost is high, there are many high-precision and high-precision matching dimensions, the theoretical design life is long, and the reliability and stability requirements match the overall design life. In addition, waterproof seals and special materials are used. core process indicators.

As shown in the figure in terms of precision design and manufacturing process,

Using four-point contact ball bearings and double-row ball bearings, the theoretical design and 3D diagrams are shown as follows:

tower crane slewing ring bearing Alt

The structure of the channel, the contour shape and the ideal state of the contact points are shown in the figure. The channel of the double-row ball bearing has eight contact points, and the actual machining accuracy is required to be higher.

At this time, the level of CNC machine tools and operators is extremely important, which determines the high precision level of the entire bearing.

Waterproof sealing is absolutely the core process and key technical index of the entire tower cranes slewing ring bearing. The sealing adopts three sealing strips, and the sealing contact part adopts ceramic technology to enhance air tightness, improve lubrication protection and wear resistance, fatigue resistance, corrosion resistance and rust resistance. .

The two O-rings are the highlight of the design, which once again achieves airtightness in the first-line protection, making the waterproof seal worthy of the name and achieving the patent of beautiful utility model.

2.Selection, maintenance and replacement of slewing bearing of port gantry crane

As the core component of the port gantry crane, tower cranes slewing ring bearing should be reasonably selected, installed and used correctly, effectively prevent and maintain faults, prolong the service life of the slewing bearing, improve the safety of equipment use, and increase economic benefits.

The slewing bearing is the core component of the port gantry crane (hereinafter referred to as “gantry crane”), which can bear the combined loads such as axial load, radial load and overturning moment at the same time.

Due to the complex load, difficult replacement, and high maintenance costs, the door crane is generally selected according to the 20-year design service life, but it is often not guaranteed in actual use.

In recent years, large-tonnage gantry tower crane slewing ring bearing in various coastal ports have successively suffered slewing bearing failures, causing huge economic losses to enterprises. Therefore, it is particularly important to effectively select, install, use, maintain and extend the service life of the slewing bearing.

Reasonable selection of slewing bearing

The utilization level of the port door crane is U8, the load state is Q4, and the working level is A8. It has the characteristics of high utilization rate, large load bearing, fast running speed and high working level.

According to the tower crane slewing ring bearing load and life calculation method, the static load safety factor fs of the grab gantry crane is 1.45, the life load factor fe is 1.7, and the service life Lf during full rotation is 150,000 revolutions. However, the actual operating rotation range of the iJ machine is mostly within 180° left and right of the sea side.

The high-strength reciprocating operation and the combined load will aggravate the fatigue of the bearing within a certain range. Therefore, the selection and installation of the slewing bearing has strict requirements. requirements.

At present, the structural forms widely used as tower cranes slewing ring bearing mainly include four-point contact ball slewing bearings, double-row reducing ball slewing bearings, crossed cylindrical roller slewing bearings and three-row cylindrical roller combined tower cranes slewing ring bearing.

Generally, when the bearing rotation diameter and section size are basically the same, the static and dynamic load carrying capacity of the three-row cylindrical roller combination slewing bearing is the largest, which reduces the load of each roller compared with the crossed cylindrical roller slewing bearing.

Compared with the double-row reducing ball slewing bearing, the load is changed from point contact to line contact, which reduces the contact stress. According to the working conditions of port gantry cranes, the structure of this bearing is most suitable for the use requirements of port gantry cranes.

Correct installation of tower cranes slewing ring bearing

As a large thin-walled ring component, the tower cranes slewing ring bearing must be rigidly connected with the gantry cylinder and the flange of the slewing plate. Warpage deformation occurs, so the flange must be machined to ensure accuracy.

Taking the 132.50.4500.03 type slewing bearing often used in 40T door cranes as an example, the diameter of the center circle of the rolling body is 4500mm, and the flatness of the flange plate is required to be 0.30mm at most, and this value is only allowed to appear in the range of 180 – – times, and A steady rise or fall without waves.

The inclination of the radial width is less than 0.25, and the surface roughness Ra reaches 3.2. At the same time, the flange should also have sufficient axial and radial stiffness to ensure that the deformation in the vertical and horizontal directions is within the specified limits.

Bucket Turbine Bearings

1.The common faults of bucket turbine bearings and their treatment measures are as follows:

1.There are noises and vibrations in the gear meshing, it should be stopped for maintenance, and the meshing state of the gears should be checked. You can use coloring powder to check the contact area of the tooth surface to confirm whether the meshing is normal.

2.If there is a sound inside the slewing bearing, you must add grease to multiple points and rotate in forward and reverse directions until the sound is reduced or disappeared.

3.The bucket turbine bearing eccentric load is serious, which can be corrected by adjusting the arm length and stowage of the bucket turbine.

4.The bucket turbine bearing has inner and outer ring clearance, and the rolling element of the large bucket turbine bearing is replaced by a professional maintenance team. The specification is 100*98.5mm.

5.Replace the sealing strip, the specification is 5*21mm

6.As the bucket turbine bearing for the power plant bucket turbine, the steel mill bucket turbine stacker and reclaimer slewing bearing, confirm the drawings and spare a set of large bucket turbine bearings for emergency needs

7.Common models of bucket wheel machines, 1797/2500G, 1797/2600; 1797/2635 and 1797/3230 series. bucket turbine bearing Alt

2.The acceptance inspection,maintenance and installation standards of bucket turbine bearings are mainly based on the following:

1. The acceptance data is subject to the drawing confirmation drawing.

2. The core data of detection include clearance, tooth jump and slewing bucket turbine bearing performance

3. The three main aspects of maintenance are tooth surface inspection, raceway inspection and rolling body inspection

4. The reference requirements for installing bucket wheel bucket turbine bearings are based on the installation technical requirements of the bucket turbine bearing, mainly for the installation base surface, bolt connection and rotating gear jump.

5. After the installation, replacement, maintenance and repair of the bucket wheel bucket turbine bearing, there is no abnormal noise, no vibration, no dead point, and no force settlement after the overhaul.

When replacing the large bucket turbine bearing bearing of the ladle and the bucket turbine bearing of the bucket wheel machine stacker and reclaimer, there is usually a problem of installation accuracy error.

For example, there is a situation where the mounting base is equipped with a drill, the fitting clearance of the mounting hole of the large bearing is too small, and the mounting base is deformed. displacement situation.

How to solve the problem of uneven installation of large bucket turbine bearings in a short time? The following are simple, practical and effective solutions.

1. Replace the next level mounting bolt specification. If M42 was originally used, M36 can be used for emergency, and M33 can be used instead of M36. The grade is not lower than 8.8 high-strength bolts.

2. Adjust the rotation direction of the bucket turbine bearing. Generally, if the deviation is not large, the bolts can be installed normally.

3. The aperture of individual mounting bases can be solved by reaming at a constant speed.

4. In extreme cases, the bucket turbine bearing should be reamed. Boring and milling machines can be used to expand the hole, and the mounting hole is generally expanded into an ellipse.

Regarding the design characteristics of the large bearing of the steel mill bucket turbine and the large bearing of the ladle, because of the special working conditions, at the beginning of the design, the large bearing is required to be able to withstand high load, high temperature, dust, safety, reliability and life.

Can exceed the design requirements of ordinary bearings. Technical details of slewing bearing, technical service of slewing bearing Yuan Gaogong, I5B–965B–OI9O.. Communication is efficient.

First of all, the design concept should emphasize heavy-duty bearings, so the inner and outer rings of the bearing should be strong and solid, the rolling elements should be large, the cage should be segmented or integral cage, and the material should be PA66 or steel cage.

Secondly, the choice of lubricating grease can use 2 lithium base grease, lubrication is extremely important. Multiple batches, multiple batches, to ensure lubrication from beginning to end.

Thirdly, lubrication protection, dust cover, and dust baffle can effectively prevent foreign objects from entering.

Finally, the material and hardness can be higher than the design manual, and the design cost is appropriately increased.

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