How to Install and Use Slewing Bearing

How to Install and Use Slewing Bearing: A Comprehensive Guide

Slewing bearings are crucial components in many industrial applications. They enable machinery to move heavy loads, rotate continuously, and handle axial, radial, and moment loads. However, installing and using slewing bearings requires careful consideration and expertise to ensure safety, reliability, and optimal performance. In this article, we will provide a comprehensive guide on how to install and use slewing bearings, covering the following topics:

Table of Contents

1.What is a Slewing Bearing?

2.Types of Aoxuan Slewing Bearings

·Aoxuan Single-row ball slewing bearing

·Aoxuan Cross roller slewing bearing

·Aoxuan Double-row ball slewing bearing

·Aoxuan Triple-row roller slewing bearing

3.Factors to Consider Before Installing a Slewing Bearing

·Load capacity

·Operating temperature

·Speed limit

·Environmental conditions

·Lubrication requirements

4.How to Install a Slewing Bearing

·Pre-installation preparation

·Positioning and alignment

·Fixing and tightening bolts

·Checking and adjusting clearance

·Sealing and greasing

5.How to Use a Slewing Bearing

·Start-up and running-in period

·Loading and unloading

·Maintenance and inspection

6.Troubleshooting Common Issues with Slewing Bearings

7.Advantages and Applications of Slewing Bearings

8.Conclusion

1. What is a Slewing Bearing?

A slewing bearing, also known as a turntable bearing or a slewing ring, is a type of bearing that allows rotation between two machine components while transmitting axial, radial, and moment loads. Slewing bearings consist of an inner and outer ring, a set of rolling elements (such as balls or rollers), a cage, and in some cases, gear teeth or a worm drive.

2. Types of Slewing Bearings

There are several types of slewing bearings, each designed for specific applications and load conditions:

Aoxuan Single-row ball slewing bearing

This type of slewing bearing consists of a single row of balls arranged in a circular track. Single-row ball slewing bearings are suitable for low to medium loads and moderate speeds, making them ideal for applications such as cranes, excavators, and small wind turbines.

Aoxuan Cross roller slewing bearing

Cross roller slewing bearings use cylindrical rollers that cross each other at a 90-degree angle, providing high load capacity and stiffness with minimal deformation. Cross roller slewing bearings are commonly used in machine tools, robots, and medical equipment.

Aoxuan Double-row ball slewing bearing

Double-row ball slewing bearings have two rows of balls arranged in a circular track, providing higher load capacity and rigidity than single-row ball slewing bearings. The Double-row ball slewing bearings are commonly used in construction machinery, harbor cranes, and wind turbines.

Aoxuan Triple-row roller slewing bearing

Triple-row roller slewing bearings have three rows of rollers arranged in a circular track, providing the highest load capacity and stiffness among slewing bearings. The Triple-row roller slewing bearings are used in heavy-duty applications such as mining equipment, tunnel boring machines, and offshore cranes.

3. Factors to Consider Before Installing a Slewing Bearing

Before installing a slewing bearing, it is essential to consider several factors that can affect its performance, safety, and durability:

Load capacity

The load capacity of a slewing bearing depends on the size, type, and number of rolling elements, as well as the material and geometry of the raceways. It is crucial to select a slewing bearing that can handle the maximum expected loads, including static, dynamic, axial, and moment loads.

Operating temperature

The operating temperature of a slewing bearing can affect its material properties, lubrication, and clearance. It is important to choose a slewing bearing that can operate within the specified temperature range and to provide adequate cooling or heating if necessary.

Speed limit

The speed limit of a slewing bearing depends on the type, size, and lubrication method of the bearing. It is important to select a slewing bearing that can operate within the specified speed range and to provide adequate lubrication to minimize friction and wear.

Environmental conditions

The environmental conditions, such as humidity, dust, chemicals, and vibration, can affect the performance and lifespan of a slewing bearing. It is important to choose a slewing bearing that is suitable for the specific environment and to provide adequate protection and sealing.

Lubrication requirements

The lubrication requirements of a slewing bearing depend on the type, size, and operating conditions of the bearing. It is crucial to select the appropriate lubrication method and frequency to ensure smooth operation and prevent premature wear and damage.

4. How to Install a Slewing Bearing

Installing a slewing bearing requires careful planning, preparation, and execution to ensure safety, accuracy, and proper functioning. Here are the steps to install a slewing bearing:

Pre-installation preparation

Before installing a slewing bearing, ensure that the mounting surfaces and bolts are clean, dry, and free of debris, rust, or damage. Verify that the bearing and mating components are the correct size and type, and that the assembly instructions and torque specifications are followed.

Positioning and alignment

Position the slewing bearing on the mounting surface and align it with the mating components using precision measuring tools such as dial indicators, feeler gauges, or laser alignment systems. Ensure that the bearing is leveled and centered, and that the preloading and clearance values are within the specified range.

Fixing and tightening bolts

Fix the slewing bearing to the mounting surface using the recommended type, size, and quantity of bolts and washers. Tighten the bolts gradually and evenly in a star or crisscross pattern, following the recommended torque values and sequence. Use a calibrated torque wrench and check the bolt tension periodically.

Checking and adjusting clearance

Check the clearance of the slewing bearing by measuring the gap between the rolling elements and the raceways using feeler gauges or depth micrometers. Adjust the clearance by adding or removing shims or by changing the preloading method. Verify that the clearance is within the specified range.

Sealing and greasing

Apply the recommended type and amount of sealant or gasket to the mating surfaces and bolt holes to prevent leakage or contamination. Apply the recommended type and amount of grease or oil to the bearing raceways and rolling elements to ensure proper lubrication and reduce friction and wear.

5. How to Use a Slewing Bearing

Using a slewing bearing requires proper handling, loading, unloading, and maintenance to ensure longevity and performance. Here are some tips on how to use a slewing bearing:

Start-up and running-in period

During the start-up and running-in period, operate the machinery at low speeds and loads to allow the bearing to settle and distribute the lubricant evenly. Monitor the temperature, noise, and vibration of the bearing and make adjustments if necessary.

Loading and unloading

When loading and unloading the machinery, ensure that the weight and distribution of the load are within the specified limits and that the bearing is not subjected to shock or impact loads. Use proper lifting and handling equipment, and follow the recommended procedures and safety precautions.

Maintenance and inspection

Slewing ring bearings are used in applications for transferring/ supporting axial, radial, and moment loads, singularly or in combination, consisting of rings mounted with threaded fasteners, and usually having a gear integral with one of the rings. Typically, slewing ring bearings are used in excavators, crane, wind power turbine and other oscillating service.The lubricants normally recommended by slewing ring manufacturers are greases or oil bath lubrication for slowly rotating continuous operating enclosed bearings, where adequate sealing of the bearing enclosure exists. Grease can be defined as the lubricant of solid or semi-solid state that contains the thickener, and some greases contain various special ingredients. Base oil in the grease is the main ingredient which actually provides lubricating function, and it forms 80-90% of grease. Generally, the mineral oils with higher viscosity are used for the locations requiring the lubrications of high load, low speed, and high temperature.

6.Troubleshooting Common Issues with Slewing Bearings

1. The rotation of slewing support is not flexible.

Slewing bearings are strictly inspected and tested before they leave the factory. They are all qualified products. Therefore, if there is a phenomenon of detention, the following methods can be used to eliminate it.

(1) Flexible idling of newly purchased products. Please check the production date of slewing bearing. If the time is longer (such as more than half a year) and the climate is colder, it is possible that the grease stickiness in the raceway is larger and the operation is not good (cold area, winter is more prominent). Exclusion methods:

If it can work after adding force without any other abnormalities, it can be used normally. If there is abnormal noise, check whether there is serious trauma in the transportation process, and feedback the information to our sales service department for processing.

(2) Installation operation is not flexible. It may be that the main engine mounting surface and the rotary bearing mounting surface do not match well, resulting in the axial clearance of the rotary bearing after installation can not compensate for the deformation of the rotary bearing, the rotary bearing is in a negative clearance state, and the rolling body is difficult to operate in the raceway (sometimes accompanied by abnormal noise); or the meshing of small and small gears is bad; or the internal jam of small and small gears has foreign bodies. Exclusions:

Reprocessing the installation plane of the main engine to make the installation plane meet the requirements; or using the gasket filling method to deal with it.

Re-adjust the meshing backlash of large and small gears according to the requirements, especially pay attention to the maximum position of gear runout.

Check to ensure that there is no foreign body in the meshing position of big and small gears.

Change a slewing bearing with slightly larger clearance.

(3) Flexibility in operation

Lack of grease and fill as required

The seal strip is damaged, causing foreign bodies to enter the raceway (such as poor working conditions, dust intrusion in the raceway, etc.).

Check the engagement of big and small gears, foreign bodies or broken teeth. If the slewing support can not rotate after taking the above measures, it may be a fault in the raceway, please inform our after-sales service department to deal with it.

2. differences

When the slewing bearing just out of the factory rotates in idle, it will make a uniform sound of steel ball rolling, which is normal. When the slewing bearing runs after installation, there is another kind of abnormal and bigger noise, which is called abnormal noise.

(1) When a new product is idle, the slight abnormal sound usually disappears after several dozen turns. If it does not disappear, it may be caused by slight deformation of slewing bearing in the course of transportation, but if the operation is flexible and normal, it can be safely installed and used, and it will disappear naturally after a period of time. If the noise is louder or has not disappeared after a period of time (usually 2-4 months), we should contact our after-sales service department in time.

(2) When abnormal noise occurs in trial operation after assembly, it should be checked whether the installation surface is flat and meets the requirements. If the roughness of the installation surface does not meet the requirements, it will cause abnormal noise in the negative clearance of the raceway. The treatment method is the same as "the operation is not flexible after installation". If the meshing of small and medium gears is not good, it will be loose when it is tight and produce abnormal noise when the meshing is too tight at the maximum position of the tooth jump.

(3) There are several reasons for the abnormal sound (first, it should be determined whether it is the sound of slewing support, some steel structures or other components, often mistaken for the sound of slewing support, therefore, the sound source can be identified by stopping the rotation of slewing support and normal operation of other components). There are the following reasons: lack of grease in the raceway, collision between rolling body and partition. When the noise is made, it can be eliminated immediately after oil injection. There are foreign bodies mixed in the raceway, such as sand grains, iron chips, etc. This situation is often accompanied by difficulties in rotation (generally this situation is easy to occur in the harsh environment in use). At the same time, attention should also be paid to whether the sealing strip is damaged; the installation bolt is loose, resulting in the elastic deformation of slewing support, negative clearance of the deformation position, etc. To eliminate the above situation, if there is still abnormal sound of slewing support, please contact our after-sales service department for processing.

3. wobble

After loading, the clearance of slewing bearing is about 3-5 times of that of factory inspection (three-point inspection method), which can be used continuously in this range.

(1) Installation bolt loosening, resulting in work shaking. Inspect all inner and outer ring bolts immediately and tighten as required.

(2) The rigidity of the steel structure supporting the slewing support is not enough, and the elastic deformation occurs when the slewing support is loaded, which results in the overall sloshing of the slewing support. Increase the strength of supporting revolving support steel structure.

(3) Check whether overload operation occurs and operate strictly in accordance with the regulations.

(4) Long-term overloading operation leads to raceway crushing and excessive clearance. If this happens, please inform our after-sales service department to handle it in time.

4. broken teeth

When the teeth of slewing bearing are broken, the site should be protected and the after-sales service department of our company should be informed immediately for analysis and treatment.

(1) Fractured teeth are often directly related to installation, mainly for the following reasons:

Installation of large and small gears adjust the backlash inappropriately, did not meet the requirements, resulting in poor meshing between the two gears during operation, resulting in broken teeth. Side clearance should be adjusted strictly according to requirements.

Failure to adjust the meshing clearance between the pinion and the pinion at the maximum position of the gear jump as required results in pinion jamming and broken teeth when the pinion meshes with the maximum position of the big gear jump during operation. It is necessary to adjust the position of the green paint and the engagement of the pinion gears, and to carry out trial operation after adjusting according to the requirements.

The axes of big and small gears are not parallel, and the meshing of big and small gears is not good after installation, resulting in broken teeth. The axes of the two gears should be parallel.

Installation bolt of slewing bearing is not tightly fixed, and meshing between big and small gears is not good, which causes tooth breakage. The bolts should be fastened as required.

(2) Use

Violation of operating rules, overloading and telling rotation, host collision (sweep) obstacles, etc. Operations should be strictly in accordance with the requirements of the operating procedures.

When the slewing bearing engages with the pinion, foreign bodies are stuck in. Make sure that the big and small gears are clean and checked regularly.

7.Advantages and Applications of Slewing Bearings

Construction machinery: earth moving machinery, excavator, disintegrator, stacker reclaimer, grader, roller, dynamic compactor, rock drilling machinery, tunneling machine, shield concrete machinery: concrete pump truck, concrete mixing boom integrated machine, belt distributor, Feeding machinery: disc feeder, sand mixer lifting machinery: wheel crane, crawler crane, portal crane, tower crane, fork crane, crane, gantry crane foundation treatment machinery: impact reverse circulation drilling rig, rotary drilling rig, impact rotary drilling rig, rotary drilling rig, reverse circulation rotary drilling rig, positive circulation rotary drilling rig, long spiral engineering drilling rig, submersible engineering drilling rig, static pile machine Pile driver engineering ships: Dredger engineering vehicles: Bridge inspection vehicles, fire trucks, window cleaning machines, flat beam transport vehicles, aerial work vehicles, self-propelled aerial work platforms Port equipment: Port cranes, front hanging light industrial machinery: Beverage machinery, bottle blowing machines, packaging machinery, filling machines, rotary bottle handling machines, injection molding machines New energy equipment: Wind power generation equipment, solar power generation equipment Metallurgical equipment: Metallurgical cranes, ladle turntables Steel grabber, mud gun, oxygen blowing device, marine crane, amusement equipment: Ferris wheel and other airport equipment: airport refueling machine, non civil equipment: radar, tank and other robots: stacking robot, welding robot, manipulator, medical equipment: gamma knife environmental protection equipment: mud scraper parking equipment: tower garage drilling platform equipment, kitchen equipment, numerical control equipment (line cutting machine, quenching machine tool), brick machine.

8.Conclusion

Changzhou Aoxuan Heavy Bearing Co., Ltd. is located in the beautiful and rich Yangtze River Delta region, with convenient transportation and obvious industrial advantages. The company covers an area of more than 33000 square meters, with a factory building area of 23,000 square meters. It has  more than 150 sets of  production and testing equipment. The main products are: slewing ring, slewing drive and precision grade cross roller bearings. Mainly used in construction machinery, industrial robots, military industry, port machinery,  automobile cranes, metallurgical machinery, single and double axis tracking systems for solar photovoltaic power generation systems and small wind power stations.

The company has passed ISO9001: 2015 quality management system certification and EU CE certification, strengthens academic-research cooperation, and cooperates with Hehai University, Jiangsu University, Nanjing University of Technology, Luoyang Bearing Research Institute and other university departments and industry research institutes.

Aoxuan Heavy Bearing takes "creating value for customers with heart" as its mission, and always adheres to the business philosophy of "customer first, excellence". After 15 years of steady development, Aoxuan slewing bearing has its own characteristics and advantages. Welcome to visit our factory and we are highly appreciate your advice.