Bulk Truck Crane Slewing Bearing

Slewing Bearing Installation

First of all, compared with other parts, the 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 slewing 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

The six dimensions determine the installation effect of the slewing bearing

Regarding the installation of the slewing bearing, there are six core dimensions, which determine the installation effect of the slewing bearing.

1. Dimensions. Including inner diameter, outer diameter, assembly height, and positioning spigot size. If the lip size is not in place, the installation of the slewing bearing will definitely be affected.

2. Positioning hole size. There are generally two or three positioning holes, which determine the position of the slewing bearing.

3. Mounting hole size, including center diameter, chord length, threaded hole, counterbore and lubrication hole.

4. Clearance. Including axial clearance, radial clearance, inclined clearance.

5. Gear size. Including tooth surface roughness, common normal length, gear highest point, as well as modulus, displacement coefficient, and tooth jump.

6. Tolerance dimensions, end runout, radial runout, and tooth runout.

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 For Sale

1.Installation of large slewing ring bearings

1 Disposal of slewing ring bearing maintenance

1.1 Anti-rust and packaging

The inner and outer surfaces of the slewing ring bearing are evenly coated with anti-rust and lubricating oil on both sides of the bearing, and the packaging is wrapped with plastic film kraft paper and linen strips. The outer surface of the large-size slewing bearing should also be wrapped with plastic cloth. For small size slewing bearings, use wooden boxes.

1.2 Warehousing

Regardless of whether it is a new bearing or a slewing bearing that is maintained or repaired, the parts need to be individually rust-proof and lubricated. The whole piece needs to be maintained in accordance with the standard of JB/T10471, including the accuracy of the bearing, horizontal placement, dust-proof, and lubrication. During the stacking period, it is strictly forbidden to tilt, place under heavy pressure, and place in the open air. The principle of storage allowable time is 10 months. The packaging adopts three layers of protection. After adding grease, the appearance is rust-proof. Film, kraft paper, foam padding, plus wrapping tape.

transportation

Keep the bearings as horizontal as possible during transportation, only allow a slight tilt, and avoid large bumps or vibrations. After unpacking, screw the lifting bolt into the lifting hole of the inner ring or outer ring to transport the bearing to the installation position.

1.3 Safekeeping

1.3.1 In the rust-proof period before use (within 12 months after the bearing leaves the factory). Do not open the package. If maintenance is required, the raceway, outer surface and tooth surface of the slewing bearing should be treated with anti-rust treatment.

1.3.2 Lay it horizontally on a dry and flat site.

1.3.3 If the slewing bearing is stored for more than 12 months, it should be re-rusted.

1.3.4 If multiple sets of slewing bearings are stacked together, at least three evenly distributed wooden pads should be placed between each set of slewing ring bearings along the circumferential direction, and the upper and lower pads should be placed in the same position.

2 Installation of slewing bearing

2.1 Preparation before installation

2.1.1 The connecting surfaces of the supporting parts shall be machined, and then these surfaces shall be free of burrs and debris.

2.1.2 When the radial load exceeds 10% of the axial load, there should be radial positioning, and the connecting surface that cannot be machined should be flattened by injection molding.

2.1.3 When unpacking the bearing before installation, care should be taken to avoid damage to the seal and prevent dust from entering the inside of the bearing. Within the specified anti-rust period, it is not necessary to disassemble and clean before installation.

2.2 Soft belt position

The quenched soft tape of the slewing bearing ring is marked “S”. When installing, the position of the soft belt should be in the non-loading area or the non-recurrent load area (the filling plug is always located at the soft belt of the ferrule.)

2.3 Ring gear inspection

Before the mounting bolts are not fully tightened, the gear meshing check should be carried out to ensure that the meshing clearance and the accuracy requirements of the gears are met.

2.4 Tightening of mounting bolts

When installing bolts, quenched and tempered flat washers can be used, and spring washers are prohibited.

After locating the slewing bearing radially, tighten the mounting bolts crosswise and check the free rotation of the bearing at the same time.

There should be sufficient pre-tightening force when tightening the bolt, and its pre-tightening force should be 70% of the yield limit of the bolt material.

3 Use and maintenance

3.1 Inspection of mounting bolts and abnormal phenomena

After about 100 hours of operation of the slewing bearing, check the pre-tightening torque of the mounting bolts of the inner ring and the outer ring, and every 500 hours of operation thereafter.

If there are abnormal phenomena such as noise, impact, and sudden increase in power during use, it should be shut down for inspection.

3.2 Lubrication

After the slewing bearing is installed, it should be filled with suitable grease according to the actual use conditions, and the slewing bearing should be filled while the grease is evenly distributed until the new grease begins to squeeze out of the sealing lip. Fill it every 50~100 hours, and the oiling cycle should be shorter in high environment and dusty conditions. New grease must also be added before and after the machine has been stopped for a long time.

3.3 Cleaning and assembly of slewing bearing

In the assembled slewing bearing, the parts between sleeves and between rows and between rows are not interchangeable. When the bearing is disassembled and cleaned, it should be carried out according to the bearing assembly drawing, and the upper and lower half rings should be assembled according to the original drilling position.

The tooth surface should be cleaned of debris every 10 days and coated with grease.

3.4 Selection of Grease

For the lubrication of the slewing bearing, because there are many comprehensive working factors, the user can choose the best grease according to the specific requirements.

Industrial Positioners Slewing Bearing In Stock

1.slewing bearing

Due to its reliable performance, stable operation, large rotation angle, easy control and high working efficiency, bucket turbines are widely used in large power plants and transshipment terminals.

Therefore, the slewing bearing plays a key role in the working process of the bucket turbine, but in the long-term working process of the bucket turbine, it not only has a large working load, but also wears the slewing bearing seriously for long-term use, which affects the bucket wheel. Therefore, it is necessary to strengthen and optimize the maintenance process of the bucket turbine.

Bucket turbine slewing bearing usage

The slewing bearing signal in this study is the thrust radial crossed roller bearing (model 1797/3230G2K9) produced by Luoyang Bearing Factory. The equipment has a total of 114 rollers (the diameter and height of the column are φ98mm and 97.5mm, respectively) Mainly in the form of cross arrangement.

A total of 12 bucket turbines are used in a centralized manner. After troubleshooting, 6 new bearings 1797/3230G2K4 were purchased and put into use as spare parts.

For a long time, the bucket wheel machine invested by our factory has shouldered an important mission. Since it was put into production in 2008, relevant technical transformations have been arranged, but only routine maintenance and maintenance are carried out. In the process of practice, the main collection of thousands of gas stations

Medium lubrication is the main method, but due to the long and small diameter of the refueling pipeline, it is difficult to ensure the normal smoothness of the oil circuit, and the slewing bearing pipes and rollers cannot be well lubricated. In May 2014, the overhaul of the bucket turbine was arranged, and the lifting inspection of the slewing bearing was an important part.

In this part, the gear passport and the connecting bolt of the bearing were disassembled, and a 100T jack was used to support it. After careful inspection, it was found that the lubrication system was in very poor condition, the sealing condition was poor, and there were residues entering the bearing track.

Analysis of Failure Causes of Slewing Bearings of Bucket Turbines and Measures Taken

The bucket turbine is different from other mechanical equipment. It is large and difficult to move, and the work intensity is relatively high in the transfer work of the power plant and the wharf. The slewing bearing has brought a lot of damage. The slewing bearing must be effectively maintained during the operation of the bucket turbine.

There are probably several reasons for the failure:

(1) The slewing bearing of the bucket turbine has been used for a long time, and there are some small problems in the maintenance process that have not been paid attention to. The accumulation of problems over time will eventually lead to major failures;

(2) During the working process of the bucket turbine, the overhaul and maintenance of the bucket turbine were not timely, so that some minor problems in the working process of the bucket turbine were not reported for maintenance in time, and the maintenance and cleaning of the bucket turbine was not in place, which made the slewing bearing of the bucket turbine. There is a lot of dust inside, which affects the rotation of the bearing and causes the failure of the slewing bearing;

(3) During the transfer process of the bucket wheel machine, the overloaded transfer of goods will damage the working performance of the bucket wheel machine, thereby causing the work failure of the bucket wheel machine.

Analysis on Maintenance Process of Slewing Bearing of Bucket Turbine

For a large and difficult-to-handle mechanical equipment like a bucket wheel, when it breaks down and decides to overhaul it – be sure to make preparations for the overhaul work. The bucket wheel is different from other small mechanical equipment. Good can

Continue the maintenance with extended time, it cannot leave the transfer work for too long, and the transfer work of the power plant and the wharf will face the threat of paralysis, and it is not practical in most cases to introduce a new bucket wheel , so the maintenance time can only be shortened, and the preparations before the maintenance should be done well.

Technical advice:

Explanation of matters needing attention when overhauling bucket turbine slewing bearing

There are some maintenance items that need to be paid attention to during the maintenance process of the bucket turbine. First of all, pay attention to the lubrication effect of the bearing raceway during the maintenance process of the slewing bearing.

For a huge slewing bearing, if the lubrication effect of the narrow and long raceway is not good, not only the dust accumulated in the raceway will affect the operation of the bearing for a long time, and the rolling It is difficult for the lubricating oil added to the raceway to have the desired effect.

In this way, even if the slewing bearing is repaired, when it is put into use, the bearing will be worn again due to the poor lubricating effect of the raceway, which takes a long time. Bearings will also fail, so we must pay attention to the lubrication and cleaning of bearing raceways, pay attention to the method of adding lubricating grease, and minimize bearing wear.

Secondly, in addition to the impact of the lubrication effect of the raceway on the slewing bearing of the bucket turbine, the upper body of the bucket turbine has a deviation in the balance moment, which makes the wear of the bearing in the raceway more serious. Correction of the counterweight to reduce the deviation of the balance moment of the upper body of the bucket turbine.

Finally, pay attention to the installation of the local tempering belts on the inner and outer rings of the bearing. Resolutely do not install the tempering belts on the inner and outer rings in the same way. They must be installed staggered from each other to reduce the bearing capacity of the bearing and reduce the effect of the tempering belt on the bearing operation process. of wear.

Therefore, it is necessary to confirm the model, technical agreement and bearing confirmation drawings in advance, and prepare new large bearings in advance in case of emergency.

Through the explanation of the reasons for the failure of the large-scale slewing bearing of the bucket turbine, the analysis of the maintenance process during the maintenance process, and the precautions during the maintenance, it is known that strengthening the maintenance and maintenance of the large-scale slewing bearing of the bucket turbine in the process of the bucket turbine

It is very important, and for this kind of bulky mechanical equipment, strict maintenance and cleaning work can not only find problems in time and report them to the maintenance personnel for timely maintenance work, but also protect the bucket turbine to a large extent.

The stability of the working performance reduces the failure rate of the bucket wheel. For the maintenance process of the slewing bearing, it can effectively shorten the maintenance time, try to ensure the highest and most stable working performance of the bucket turbine with the lowest maintenance cost, and improve the transfer level of the bucket turbine.

INA Slewing Ring Products

Three factors determine the diameter structure accuracy of the slewing bearing

1. The size of the rotary table, generally, the bearing diameter is controlled at 2/3–1/2 of the rotary table. Such as a four-meter turntable, the diameter of the turntable bearing is 2500-3000.

2. Load and speed

These two factors determine the structure of the INA slewing ring, whether it is a four-point contact ball bearing, a crossed roller bearing, a double-row ball slewing ring, or a three-row roller structure bearing.

3. High speed, high speed and light load are normally recommended, such as four-point contact ball bearings, spacer blocks are conducive to grease lubrication, and integral cages or segmented PTFE cages are conducive to reducing noise and resistance.

4. For low speed and heavy load, choose three-row roller structure INA slewing ring.

5. High-precision bearings, cross-cylindrical cross-tapered roller bearings are easy to implement. However, practice has proved that crossed roller INA slewing rings are not practical in inclined, vertical and multiple motion forms.

6. For slewing bearings with precise pointing, the clearance should be controlled at less than or equal to 0, and for crossed roller bearings and three-row roller structure bearings, it should be controlled at 0-0.03.

2.Lubrication and sealing of slewing bearings

Sealing and lubrication of slewing bearings. Applying effective lubrication and sealing to the slewing bearing is a necessary measure to ensure the safe operation of the bearing and avoid abnormal early damage. There are two ways to lubricate the slewing bearing: oil lubrication and grease lubrication.

Since grease lubrication has a lubricating effect, it has a certain sealing effect. It has the advantages of good adhesion, simple sealing structure, simple operation and low cost, so it is widely used in the actual use of slewing bearings.

The lubrication of the slewing bearing is divided into two parts: the internal lubrication of the bearing and the lubrication of the tooth surface. There are differences in lubricating properties. In actual application, one or two different lubricants are used. When using the same lubricant, any needs of the two should be taken into account. When using two grades or different greases, the compatibility of the lubricant should be considered. .

If the customer has special requirements, the slewing bearing is generally full of lubricating value before delivery to the customer. Before the bearing is used, the customer can base on the actual working conditions of the bearing. Refill the grease again to ensure the life and reliability of the rotary bearing.

The slewing bearing with ring gear has the function of transmitting power and simplifying the host mechanism. Among them, the internal tooth slewing bearing has compact structure, low contact stress during transmission, small wear, grease, easy to maintain lubrication for a long time, good dustproof effect, and the protection requirements for the meshing part are relatively better than the external tooth meshing effect.

External tooth structure slewing bearing, tooth shape processing and detection methods are fast and convenient. High manufacturing precision. It is easy to obtain the highest precision of grinding teeth, and can maximize the use of support space. And the pitch circle diameter of the tooth shape is large. Larger transmission ratios can be obtained.

At the same time, the circumferential force and torque of the pinion can also be reduced, thereby saving efficiency. Of course, in terms of manufacturing cost, the internal teeth are mostly gear shaping, which takes a long time, and the external teeth are mostly gear hobbing, which is fast. Therefore, internal gear bearings are generally much more expensive than external gears.

China Slewing Ring Bearings

1.Spacer blocks and cages for slewing ring bearings

The isolation block and cage of the swivel bearing, expressed as spacer and CAGE in English, have the main functions of reducing friction, coordinating operation efficiency, distributing loads, and guiding the circumferential trajectory of the rolling elements. It is an integral part of the overall design of the slewing ring bearings.

Cage (that is, bearing cage, also known as bearing cage, foreign name: cage), refers to the bearing parts that partially wrap all or part of the rolling body and move with it, to isolate the rolling body, and usually guide the rolling body and keep it in the slewing ring bearings.

2 Main functions 1. Keep a proper distance between the rolling elements to prevent the rolling elements from contacting each other to reduce friction; 2. Make the rolling elements evenly distributed, so that the load is evenly distributed; 3. Guide the rolling elements in the no-load area to improve the bearing rolling condition to prevent damaging slippage.

The cage must withstand the stress caused by friction, strain and inertial force, and also withstand the chemical corrosion of lubricants, additives in lubricants or substances generated by their aging, organic solvents or coolants.

Therefore, the design and material of the cage are extremely important for its performance and the reliability of the slewing ring bearings.

3 types of cages Bearing cages are divided into stamping cages (Figure 1), solid cages (Figure 2) and strut cages 1. The advantages of stamping cages are light weight and large internal space, which can facilitate the entry of lubricants ; 2. The solid cage is usually allowed to have a higher speed.

When the slewing ring bearings has other forms of motion other than rotation at the same time, especially in the case of high speed, the machined metal cage should also be used; 3. The pillar cage is penetrated by pins Roller with perforations to secure both ends of the pin to the washer.

This cage is lighter and can accommodate more rollers and is only used in oversized roller bearings. 4. Cage materials Cage materials mainly include stamped steel, machined steel, stamped brass, machined brass, polymeric materials, etc.

Stamped steel cages have high strength and can be surface treated to reduce friction and wear; machined steel cages are generally used for oversized bearings or where brass cages are not suitable; stamped brass cages are used in part Small bearings; Machined brass cages are generally not affected by bearing lubricants and can be cleaned with ordinary lubricants.

Brass cages should not be used for operating temperatures above 250; Polymeric material (nylon 66, nylon 46, etc.) cages Compared with metal cages, it has many advantages such as good toughness, friction and wear resistance, impact resistance, acid resistance and corrosion resistance.

Whether the slewing bearing is a ball bearing or a ball bearing, the spacer block and the cage are indispensable. The role of the cage:

1. Reduce friction between rolling elements

2. Coordinate, distribute and guide the movement direction and movement trajectory of the rolling elements

3. Standardize the force balance of rolling elements

4. On the basis of bearing forces, especially vertical, inclined and multi-directional forces, the application of integral cages and segmented cages is very necessary to prevent rolling elements from being squeezed during gravity and movement, causing hard friction

5. In high-speed bearings, the overall cage is the first factor in the design

6. In order to reduce friction, reduce noise and reduce wear, the application of copper cage, PTFE cage and PA66 cage is very critical.

The influence of the segmented cage and the integral cage on the structure and life improvement of the slewing ring bearings, in a word, can improve the rotation flexibility of the slewing ring bearings, improve the reliability, and significantly improve the life and efficiency of the slewing bearing.

The material of the segmented cage is divided into steel cage, copper cage and nylon cage, as well as PA66 cage, PTFE cage, the overall cage is generally steel cage or copper cage, or steel inlaid copper cage shelf.

Because rolling, especially steel balls or balls, is not pure rolling during the rotation of the bearing, it may also be sliding friction. By dividing and conquering the segmented cage or the overall cage, the stability and regularity of the individual running state of the rolling elements are obtained. For steel balls, it is free from backlog and chaos.

Compared with fast isolation, it can achieve individual breakthroughs. Compared with balls, its importance is more prominent. In the bearing cost, it is a good technical suggestion if the user is advised to use a segmented cage or an integral cage.
Especially in the case of inclined installation, vertical installation, or multi-directional force, the integral cage should be the first choice for slewing bearings.

High Precistion Shield Machine Bearings

Shield machine bearing maintenance and repair

The maintenance and repair of shield machine bearings and the remanufacturing of key components can be seen at a glance. It is mainly reflected in the following three aspects.

The first is the main material of the shield machine bearing, which must meet the large load, impact load and large torque, and must be stable, reliable and safe. Second, the inspection, maintenance, repair and imitation of rolling elements, surveying and manufacturing of shield machine bearings must meet the original design of shield machine bearings and the safety factor of subsequent excavation.

Third, the overall cage and segmented cage of shield machine bearings are made of complex materials, including all-copper cage, engineering plastic cage and steel cage surfacing copper process.

The remanufacturing of the fourth shield machine bearing, such as replacing the outer gear ring, replacing the inner gear ring, replacing all the rolling elements, and replacing the cage, is essentially the imitation and new manufacturing of the shield machine bearing, and the reliability is fully satisfied. Excavation needs.

The competition between the large bearing of the ladle and the bearing of the shield machine and the large bearing of the floating crane bearing and the wind power transport ship is mainly about heavy load, reliability and life, followed by reliability and stability.

The large bearing of the ladle mainly requires high reliability.

Shield machine bearing requirements are heavy load and stability must be met.

Floating crane bearings and large bearings of wind power transport ships are large in diameter, ranging from 5 meters to 10 meters.

In general, it is low speed, heavy load and high stiffness, and the reliability and life should be unified, which can be above the overall life of the equipment design.

Judgment According to the technical problems such as the use and current situation of the main bearing of the shield machine and its repair, the basic state of the bearing must be investigated first. Generally, the Luoyang bearing manufacturer will send someone to inspect the actual bearing.

The relevant technical requirements and other matters of the shield machine were fully discussed and inquired about the bearing’s putting into use, operating status, running time and mileage. Based on the following standards, the following shield machine main bearing maintenance, repair, repair and replacement options One of the technical solutions.

1. The general design life of shield machine bearings will not exceed 10,000 hours, which is limited by the harsh working conditions and complex stress methods of shield machine bearings.

2. The bearing of the shield machine is also determined by the mileage of the excavation, generally 6-8 kilometers forcibly scrapped

3. Maintenance is generally 3-5 kilometers, and the rock layer is generally 1-2 kilometers for maintenance.

4. The hardness layer determines the evaluation of the life computational domain, especially the tooth surface hardness and the channel hardness.

5. The life evaluation is generally the calculation of 60%-80% of maintenance; maintenance is generally 40%-60% of the expected life.

6. Material selection, GJG.

The safety, stability and reliability of the shield machine bearing are improved by 90% after the repair of the shield machine bearing. The main principle is that the grinding amount of the groove after grinding is about 0.5- 1mm, the effective hardness depth layer is greater than 5.5mm, the rolling body is sorted and used, the grinding amount is about 0.05-0.20mm, and the deformation of the cage is corrected at the same time, and the lubrication channel is cleared.

Technical service and support Yuan Gaogong I5B–965B–OI9O. Secondly, in the key remanufacturing field, it is very important to replace all the rolling elements, the main thrust balls, the auxiliary thrust balls and the radial balls. Secondly, the action of replacing the inner gear ring is the most critical, which is almost equivalent to replacing the entire set of large bearings, which can be used as new bearings.

The surveying and mapping imitation is treated. In principle, the service life of the repaired shield machine bearing is greater than 5000 hours, or 3-5 axioms as the expected life.