What is Slew Drive?

/in /by

What is Slew Drive?

A slew drive, also known as a slewing drive, is a gearbox designed to handle radial and axial forces simultaneously while allowing for rotational motion. The device typically consists of a slewing bearing, a drive gear (often a worm gear), and other components such as seals and lubrication systems, all housed within a compact, robust assembly. The primary function of a slew drive is to facilitate controlled, precise rotational motion and to transmit torque effectively.

Features of Slew Drive

High Load Capacity: Slew drives are designed to handle significant loads both axially and radially, making them suitable for heavy-duty applications.

Precision: They allow for precise control over movement, which is critical in applications requiring exact positioning.

Compact Design: The integration of bearings and gearing into a single unit allows for a more compact installation footprint.

Ease of Installation: The self-contained unit is generally easier and quicker to install than separate components.

Versatility: They can be customized with different motors (hydraulic, electric, etc.) and can be designed to suit various environmental conditions and loads.

Sealed Unit: Provides protection against dust, dirt, and water, which helps in maintaining performance in harsh environments.

Applications of Slew Drive

Solar Trackers: Used extensively in solar energy systems to rotate solar panels towards the sun throughout the day to maximize energy capture.

Wind Turbines: Helps in the yaw and pitch adjustment of wind turbine blades to optimize the wind capture.

Cranes and Manlifts: Facilitates the rotation of the crane boom and the basket of manlifts, providing movement and positioning.

Slewing Drive for Excavators: Used in the rotation of the cab and the attachment for better maneuverability and operation.

Medical Equipment: In devices such as CT scanners and MRI machines, slew drives help in the precise movement of machinery around the patient.

Robotic Arms and Automation Systems: Provides rotational movement that is precise and reliable for various automated and robotic systems.

Slewing Drive for Machinery

In general machinery, slew drives are used to enhance the functionality of moving parts, allowing for rotational movement that can support significant loads. This is particularly useful in automation, where precise and reliable movement is critical.

Slew Drive for Excavator

In excavators, the slew drive enables the upper structure (including the cab and engine) to rotate independently of the undercarriage. This is crucial for tasks such as digging and loading, where the operator needs to pivot the machine to access different areas without relocating the entire vehicle.

Slew Drive for Crane

For cranes, the slew drive is critical in the rotation of the crane’s boom. It allows the boom to turn horizontally, enabling the crane to lift and move loads over different parts of a construction site or other locations without needing to move the base of the crane. This capability is essential for the efficient operation of both mobile and stationary cranes.

Slew drives are integral components in many types of heavy machinery, offering enhanced load capacity, precision, and operational efficiency. Their robust design tailored to withstand harsh environments makes them indispensable in both industrial applications and infrastructure development projects.

Suppliers of Slewing Drive

Luoyang Longda Bearing Co., Ltd., with registered trademark LDB, is an enterprise specializing in the design, development, manufacture and sales of precision slewing bearings (slewing rings) and precision slewing drives. If you are looking for slewing drives for your project, feel free to contact us.

A Comprehensive Guide to Robot Slewing Bearings

/in /by

Introduction

In recent years, robotics and automation have been increasingly integrated into various industries, offering significant improvements in productivity, efficiency, and precision. A key component in robotics systems is the slewing bearing, which plays a vital role in ensuring stability and accuracy in movement. In this extensive article, we will discuss robot slewing bearings in detail by exploring their types, features, applications, installation, maintenance, and customization options. Furthermore, we will highlight the capabilities and expertise of LDB Bearing, a distinguished manufacturer of robot slewing bearings.

What is Robot Slewing Bearings?

Robot slewing bearings, also known as turntable bearings, are oversized rotational bearings that manage complex load combinations, such as axial, radial, and moment loads, while providing smooth and precise rotation. They are essential in various robotic applications such as robotic arms and rotary tables, maintaining accurate positioning and enhancing overall system performance.

Thorough Analysis of Robot Slewing Bearing Types

Robot slewing bearings can be classified based on their construction, design features, and specific application requirements. Common types include:

  1. Single-row ball slewing bearings: These bearings feature a simple design suitable for smaller robotic applications requiring high precision and cost-effectiveness. They handle axial, radial loads, and tilting moments simultaneously, making them versatile for a wide range of applications. Single-row ball slewing bearings can be designed with various gear tooth options, including internal, external, or no gearing, depending on the system’s requirements.
  2. Double-row ball slewing bearings: Comprising two rows of ball bearings, these bearings offer an enhanced load-carrying capacity and torque resistance suitable for larger robotic systems demanding stable performance in various operating conditions. Double-row ball slewing bearings are typically used in situations requiring high precision, load and vibration resistance.
  3. Crossed roller slewing bearings: These bearings consist of cylindrical rollers arranged perpendicularly to each other and spaced with separators, providing a compact and rigid bearing capable of handling complex loads. Crossed roller slewing bearings are ideal for robotic systems with limited space and high precision requirements.
  4. Three-row roller slewing bearings: Featuring three rows of rollers, these bearings provide the highest load-carrying capacity and stiffness among all types of slewing bearings. They are suitable for heavy-duty robotic applications where high loads, precision, and extended service life are essential factors. These bearings are typically used in large-scale robotics systems demanding maximum performance and durability under intense operating conditions.

Notable Features of Robot Slewing Bearings

Robot slewing bearings possess several features that make them well-suited for various robotic applications:

  1. High load-carrying capacity: Slewing bearings handle multiple types of loads, making them suitable for robotic applications requiring smooth and precise movement and optimal performance.
  2. Compact and lightweight design: Robot slewing bearings are designed to be compact and lightweight, reducing space requirements and the overall weight of the robotic system, enhancing accuracy and allowing for swifter movements.
  3. Precision and rigidity: Slewing bearings offer high precision and rigidity, essential in robotic applications requiring accurate positioning and stability for efficient operation.
  4. Long service life: Robot slewing bearings are engineered with durable materials, effective lubrication systems, and reliable sealing structures, ensuring optimal performance and longevity under various operating conditions.

Widespread Applications of Robot Slewing Bearings

Robot slewing bearings are employed in a variety of robotic applications and industries, including:

  1. Robotic arms: Slewing bearings ensure smooth and precise rotation in robotic arms, permitting accurate positioning and movement in tasks such as assembly, welding, painting, and material handling in automotive, electronics, and manufacturing industries.
  2. Rotary tables: In machining and automation, rotary tables equipped with slewing bearings provide high accuracy, stability, and load-carrying capacity for precise positioning and rotation of workpieces, particularly essential in precision manufacturing and metalworking industries.
  3. Medical robots: Slewing bearings contribute to the stability and precision of medical robotic systems such as surgical robots, pharmaceutical automation systems, and robotic rehabilitation systems, enhancing the accuracy and efficiency of these critical medical technologies.
  4. Inspection and maintenance robots: Robots designed to perform inspections and maintenance in hard-to-reach areas, like confined spaces, underwater environments, or aerial structures, depend on slewing bearings for smooth movement and precise positioning. Examples include drones, sewer inspection systems, and underwater remotely operated vehicles (ROVs).
  5. Defense and aerospace robots: Slewing bearings enable precise movement and positioning in robotic systems used for defense and aerospace applications, including bomb disposal robots, surveillance drones, and satellite positioning systems.

The Installation and Maintenance of Robot Slewing Bearings

Proper installation and maintenance are crucial for the optimal performance and longevity of robot slewing bearings. The following steps outline the essential procedures involved:

  1. Pre-installation checks: Before installation, ensure the mounting surface is clean, flat, and free from any contamination for the bearing to be positioned appropriately.
  2. Adherence to manufacturer guidelines: Utilize manufacturer-recommended tools and equipment to streamline the installation process and minimize the chances of error or damage during installation.
  3. Securing and alignment: Adhere to the manufacturer’s guidelines for torque specifications and tightening procedures, thus ensuring the bearing’s proper installation and preventing any issues affecting system performance.
  4. Regular inspections and monitoring: Periodically inspect and monitor the bearings for signs of wear, damage, or fatigue, enabling early detection and resolution of potential issues, keeping the robotic system’s functioning uninterrupted with minimized downtime.
  5. Lubrication: Lubricate the bearings according to the manufacturer’s recommendations, ensuring smooth functioning and preventing premature wear or friction-related damage. The correct lubrication type and interval is vital to maintaining the performance and longevity of the slewing bearings in various robotic applications.
  6. Bearing replacement: If bearing replacement becomes necessary, follow the specific removal and replacement procedures provided by the manufacturer to expedite the process, minimizing disruptions to the robotic system’s operation.

Customization and Purchasing Options for Robot Slewing Bearings

Robot slewing bearings can be customized to meet specific application requirements, taking into account factors such as dimensions, load capacity, torque requirements, materials, and performance. Collaborating with an experienced and professional bearing manufacturer is crucial when specifying and purchasing these bearings, as it ensures compatibility with the robotic system and enhances the likelihood of optimal performance and service life.

Consider the following factors when selecting a robot slewing bearing:

  1. Quality and performance: Choose a bearing that meets the highest quality and performance standards for your specific robotic application.
  2. Customization options: Seek out a manufacturer that provides customization options, ensuring that the slewing bearings can be adapted to fit your unique requirements.
  3. Technical support: Opt for a manufacturer that offers comprehensive technical guidance throughout the entire selection, installation, and maintenance process, resulting in seamless integration and long-term reliability of the bearings.

LDB Bearing: The Go-To Professional Robot Slewing Bearings Manufacturer

LDB Bearing is a renowned manufacturer of robot slewing bearings with extensive experience and expertise in the industry. We provide tailor-made solutions to meet the specific needs and requirements of our customers. Our advanced manufacturing facilities and stringent quality control measures ensure that our customers receive the highest quality products.

Benefits of partnering with LDB Bearing as your robot slewing bearings manufacturer include:

  1. Customized bearing solutions that meet your robotic system’s specific requirements, ensuring compatibility and optimal performance.
  2. Comprehensive technical support offered throughout the entire purchasing process, including installation and maintenance, which ensures seamless integration and long-term reliability of the bearings.
  3. Commitment to research and development, resulting in the delivery of innovative and efficient bearing products that align with the rapidly evolving robotics industry.
  4. Outstanding after-sales service, providing prompt and effective resolution of customer queries and concerns, resulting in a hassle-free experience throughout the product’s lifecycle.

Conclusion

Robot slewing bearings play a critical role in the performance and efficiency of robotic systems. A deep understanding of their types, features, applications, and maintenance requirements can help businesses make informed decisions when selecting the right bearings for their robotic applications. By partnering with an experienced and reputable bearing manufacturer like LDB Bearing, customers can be confident that their bearing needs will be met with superior quality products, comprehensive technical support, and excellent customer service.

In today’s fast-paced world, where automation continues to advance and reshape various industries, choosing the right robot slewing bearings and collaborating with a reliable manufacturer remains essential to maximizing the efficiency and performance of these innovative technologies. With LDB Bearing, you can be assured of the highest quality and most appropriate bearing solutions for your unique robotic applications.

Wind Turbines Slewing Bearing Full Introduction

/in /by

Introduction

The shift towards clean and sustainable energy sources has led to wind energy becoming a primary solution to reduce dependence on traditional fossil fuels. Wind turbines are increasingly utilized worldwide to harness wind energy and convert it into electricity. Among the essential components of wind turbines, slewing bearings play a pivotal role in ensuring the turbine’s efficient functioning. This article delves into wind turbine slewing bearings, discussing their types, features, applications, maintenance, and customization options. Additionally, we will illustrate the competencies and offerings of LDB Bearing, a specialized manufacturer of wind turbine slewing bearings.

Understanding Wind Turbine Slewing Bearings

A slewing bearing, sometimes known as a turntable bearing, is an oversized rotational bearing designed to support heavy loads in radial, axial, and moment directions while facilitating smooth and accurate rotation. In a wind turbine, the slewing bearing allows the nacelle to rotate, aligning with the incoming wind direction, optimizing energy generation.

The efficiency of the slewing bearing in tracking the wind direction directly impacts the turbine’s performance. Aligning the nacelle with the wind enables maximum energy capture. Moreover, slewing bearings are crucial in wind turbine pitch systems, adjusting each blade’s angle to optimize energy production and minimize loads.

Types of Wind Turbine Slewing Bearings

Wind turbine slewing bearings are primarily categorized into three types based on their design and construction:

  1. Single-row ball slewing bearings: These bearings feature the simplest design among wind turbine slewing bearings and are widely employed. They offer high precision and are cost-effective, with the ability to handle axial, radial, and tilting moment loads simultaneously. This type is suitable for small and medium-sized wind turbines and can be designed with various gear tooth options, including internal, external, or no gearing.
  2. Double-row ball slewing bearings: Comprising two rows of ball bearings, this type offers enhanced load-carrying capacity, making them ideal for wind turbines with larger rotor diameters and higher torque and load requirements. This bearing type is characterized by compactness, enabling it to handle high loads without occupying much axial space.
  3. Three-row roller slewing bearings: This type consists of three roller rows arranged in a manner that ensures the highest load-carrying capacity among all slewing bearing types. Each row of rollers supports a unique type of load, ensuring maximum capacity and stiffness. This bearing type is suitable for large-scale wind turbines where high loads, precision, and extended service life are vital.

Key Features of Wind Turbine Slewing Bearings

Wind turbine slewing bearings boast several distinctive features:

  1. High load-carrying capacity: Slewing bearings can handle various loads, such as axial, radial, and moment loads, making them suitable for wind turbine applications.
  2. Compact design: The compactness of slewing bearings simplifies installation and reduces the turbine’s overall structural weight and requirements.
  3. Resistance to harsh environmental conditions: Slewing bearings feature materials with exceptional durability and corrosion-resistant coatings, ensuring a long service life even under severe conditions.

Slewing Bearings in Wind Turbine Applications

Slewing bearings find two pivotal applications in wind turbines:

  1. Yaw System: The yaw system is responsible for rotating the nacelle (the housing that contains the generator and other components) to align it with the wind direction. The slewing bearing facilitates smooth rotation of the nacelle, allowing it to face the wind and capture the maximum wind energy. By enabling the turbine to track the wind effectively, the slewing bearing directly influences the wind turbine’s power generation efficiency.
  2. Pitch System: The pitch system adjusts the angle of the wind turbine’s blades to optimize energy generation and protect the turbine from excessive force during high winds. Slewing bearings are an integral part of the pitch system, ensuring that each blade can change its orientation smoothly and precisely. Proper pitch control helps maintain the optimal blade angle, which allows the turbine to generate maximum power, reduces stress on the structure, and mitigates the risk of damage during severe weather conditions.

Maintenance of Wind Turbine Slewing Bearings

Proper maintenance of wind turbine slewing bearings is critical for the efficient operation and longevity of wind turbines. By adhering to the maintenance practices outlined in this article, operators can ensure the optimal performance of their wind turbines, minimize downtime, and extend the service life of these critical components. As a professional Wind Turbine Slewing Bearings manufacturer, LDB-bearing can give you professional advice. Please consult LDB-bearing engineers when necessary to ensure the most effective maintenance of wind turbine slewing bearings.

  1. Pre-installation Checks: Before installing the slewing bearing, make sure the mounting surfaces are clean, flat, and free of any debris, grease, or oil. Proper preparation and cleaning of the mounting surfaces ensure a secure and accurate fit during installation.
  2. Regular Inspections: Perform periodic inspections and monitoring of slewing bearings to detect any signs of wear, damage, or fatigue. Inspections should focus on identifying any unusual noises, vibrations, or excessive temperature increases that might indicate underlying issues. Monitoring the condition of seals, lubricant, and surface coatings is also crucial during inspections to maintain the integrity of the bearing.
  3. Proper Lubrication: Regular lubrication is essential for the smooth functioning and longevity of slewing bearings. Follow the manufacturer’s recommendations regarding the type, amount, and frequency of lubrication to minimize friction and wear. Proper lubrication can help prevent corrosion, extend the service life of the bearing, and reduce the likelihood of mechanical failure.
  4. Surface Protection: To protect slewing bearings from corrosion, especially in harsh environmental conditions, make sure the surface coatings are in good condition. If any damage is detected, take appropriate measures to repair the coatings and prevent further corrosion or wear.
  5. Proper Alignment and Fastening: Ensure that the wind turbine’s slewing bearings are correctly aligned and securely fastened during installation and any subsequent maintenance. Misalignment or loose fastening can cause uneven stress distribution and might result in premature failure or reduced operational efficiency.
  6. Timely Repairs and Replacements: In case the inspection reveals excessive wear, damage, or other signs of potential failure, it is necessary to repair or replace the affected components promptly. Depending on the specific slewing bearing design, some components might be replaceable or repairable. Follow the manufacturer’s guidelines for repairs or replacements and consult with an expert engineer if necessary.
  7. Recordkeeping: Maintain detailed records of all maintenance tasks performed on the wind turbine, including inspections, lubrication, repairs, and replacements. Comprehensive recordkeeping helps track the performance of the slewing bearings and plan future maintenance activities more effectively.

How to customize wind turbine slewing bearings？

Steps to Customize Wind Turbine Slewing Bearings

  1. Determine the Requirements: Begin by establishing the specifications and requirements for the customized slewing bearing. Consider factors such as dimensions, load capacity, torque requirements, gear types, desired service life, and environmental conditions. Compile this information to provide a clear outline of your specific needs.
  2. Find a Reputable Manufacturer: Look for a bearing manufacturer with experience in designing and producing custom wind turbine slewing bearings. Ensure they have a track record of reliability, quality, and technical expertise in the field.
  3. Consult with the Manufacturer: Initiate a consultation with the chosen manufacturer to discuss your requirements and provide them with the necessary specifications. Throughout this process, the manufacturer may give recommendations based on their expertise to optimize the customized solution. Collaboration is key to ensure the final product meets your unique needs.
  4. Design and Engineering: The manufacturer will create a custom design and engineering solution for the slewing bearing based on the provided specifications. During this stage, modifications and optimizations may be suggested to improve the bearing’s performance, efficiency, and reliability.
  5. Review, Approval, and Production: Review the proposed design, addressing any concerns or clarifications with the manufacturer. Once the design is approved, the manufacturer will proceed with the production of the customized slewing bearing, adhering to strict quality standards and control measures.
  6. Testing and Validation: The manufacturer may perform testing and validation of the customized slewing bearing to ensure it meets the desired performance criteria, durability, and load-carrying capacities according to the unique specifications.
  7. Delivery and Installation: After successful testing and validation of the customized slewing bearing, the manufacturer will deliver the bearing and provide support for the installation process. They may offer guidance on installation procedures and maintenance to ensure the seamless integration and long-term reliability of the bearing.

Considerations for Customizing Wind Turbine Slewing Bearings

  1. Material Selection: Based on the requirements and environmental conditions, choose the proper materials to ensure durability, corrosion resistance, and strength.
  2. Sealing and Lubrication: Customized slewing bearings may require unique sealing solutions and lubrication systems to accommodate specific load conditions and environmental factors that influence the bearing’s performance.
  3. Cost Implications: Customization generally comes with higher costs compared to standard solutions. However, the investment is often warranted due to the optimization that results from a custom-engineered product that meets specific requirements.
  4. Lead Time: Customizing wind turbine slewing bearings might extend the manufacturing process’s lead time, as custom designs require additional engineering and validation steps.
  5. Manufacturer Expertise: Working with a manufacturer experienced in customizing slewing bearings is crucial for a successful project, as they can provide valuable insights and recommendations to optimize the bearing for your specific application.

LDB Bearing: A Premier Choice for Wind Turbine Slewing Bearings

With the increasing focus on clean, renewable energy sources, wind turbines have gained prominence in meeting global energy demands. Essential components like slewing bearings, which enable the smooth and precise rotation of the wind turbine’s nacelle, are vital for the efficient functioning of wind turbines. LDB Bearing is a leading manufacturer of wind turbine slewing bearings and we should be your first choice for superior custom solutions, technical support, R&D and outstanding after-sales service.
Customized Bearing Solutions by LDB Bearing
Every wind turbine application is unique regarding specifications, dimensions, load capacity, torque requirements, and environmental conditions. Recognizing this, LDB Bearing offers customized slewing bearing solutions tailored to meet your specific needs. Their team of skilled engineers and designers work closely with you to understand your requirements and deliver a bearing solution that ensures optimal performance, reliability, and longevity for your wind turbine.
Comprehensive Technical Support
LDB Bearing provides technical expertise throughout the entire purchasing, installation, and maintenance process, ensuring seamless integration and long-term reliability of the slewing bearings. Their experienced and responsive technical professionals offer guidance on selecting the right slewing bearing for your application, follow-up support during installation, and ongoing assistance for maintenance and troubleshooting, guaranteeing a smooth customer experience
Research and Development
At LDB Bearing, they understand that constant innovation and development are essential to keeping up with the ever-evolving demands of the wind energy industry. Their commitment to research and development leads to innovative and efficient products that cater to the evolving requirements of this dynamic sector. The company continually strives to improve its manufacturing processes, materials, and designs, staying ahead of the competition, and ensuring that customers receive cutting-edge products and solutions.
Exceptional After-sales Service
LDB Bearing’s dedication to customer satisfaction continues beyond the point of sale. Their exceptional after-sales service team provides prompt, effective solutions to any queries or concerns you may have throughout the product’s lifespan. As an LDB Bearing customer, you can count on their continued support, maintaining the efficiency and reliability of your wind turbine slewing bearings for years to come.
LDB Bearing is a premier choice for wind turbine slewing bearings due to its focus on customized solutions, technical support, and commitment to innovation and customer satisfaction. When selecting slewing bearings to ensure optimal performance and longevity for your wind turbines, LDB Bearing stands out as a reliable and experienced manufacturer. With their strong expertise, top-quality products, and unparalleled service, partnering with LDB Bearing gives you the confidence that your wind turbine investments are backed by the best in the industry.

Marine Crane Slewing Bearing: Key Aspects and Considerations

/in /by


What is Marine Crane Slewing bearing？
The Marine Crane Slewing bearing is a crucial component in the operation of marine cranes, designed to provide smooth and controlled rotation while handling heavy loads in harsh marine environments. This specialized bearing, also known as a slewing ring, comprises an inner and outer ring with rolling elements (typically balls or rollers) in between, allowing the crane’s boom and other components to rotate relative to the base. Engineered to withstand high radial and axial forces, as well as extreme conditions including saltwater, corrosion, and varying temperatures, the Marine Crane Slewing bearing plays a vital role in ensuring efficient, precise, and reliable operations for various marine applications such as cargo handling, shipbuilding, and offshore drilling.

Features of Marine Crane Slewing bearing：
Marine Crane Slewing bearings have specific features designed to provide optimal performance, durability, and reliability in challenging marine environments. Some of these key features include:

  • High load capacity: Marine crane slewing bearings are engineered to handle high radial and axial forces generated by cranes moving substantial loads.
  • Corrosion resistance: Made from materials like stainless steel or treated with special coatings, these bearings are designed to withstand corrosive saltwater and moisture inherent in marine environments.
  • Low-friction rotation: The well-designed rolling elements (balls or rollers) ensure smooth, low-friction rotation, enabling precise and controlled movements during crane operation.
  • Effective sealing system: Marine crane slewing bearings usually have an efficient sealing system to protect the bearing from contamination by water, sand, dust, and other sources of debris.
  • Robust design: These slewing bearings are built to withstand extreme environmental conditions, such as varying temperatures and humidity, ensuring consistent performance and a long service life.
  • Compactness and space efficiency: Marine crane slewing bearings offer a compact design suitable for limited space on vessels or offshore structures.
  • Ease of maintenance: They are often designed to simplify maintenance processes, such as lubrication and inspection, ensuring their long-term performance and reliability.
  • Customization: Marine crane slewing bearings can often be tailored to accommodate specific application requirements, ensuring an optimal fit for a diverse range of marine environments and conditions.

These features combine to ensure that Marine Crane Slewing bearings deliver consistent performance and reliability under challenging circumstances, making them an indispensable component in the operation of marine cranes.

Application of Marine Crane Slewing bearing：

Marine Crane Slewing bearings are vital components in a wide range of marine applications, as they provide the necessary support and rotational capabilities for various kinds of marine cranes. Some common applications of Marine Crane Slewing bearings include:

  • Cargo handling: Slewing bearings are essential for shipboard cargo cranes, which are responsible for loading and unloading cargo from ships efficiently and safely, ensuring smooth port operation.
  • Shipbuilding: Marine crane slewing bearings are used in shipyard cranes, enabling precise and controlled rotation while installing heavy components during the construction and repair of ships.
  • Offshore drilling: Slewing bearings play a crucial role in offshore crane operations, used in the oil and gas industry for lifting and transferring heavy equipment and materials on and off rigs or platforms.
  • Fishing vessels: Marine crane slewing bearings are used in fishing cranes, allowing the hoisting, lowering, and rotating of fishing equipment, such as heavy nets or trawls, as well as assisting with onboard processing tasks.
  • Research and exploration operations: Slewing bearings are part of marine cranes equipped on research vessels, offering stable rotational capabilities for deploying, retrieving, and maneuvering research equipment and submersibles in various marine environments.
  • Naval operations: Marine crane slewing bearings are also used in cranes on naval vessels, providing efficient rotation for tasks such as moving personnel, provisions, ammunition, and equipment during at-sea replenishment or resupply operations.
  • Renewable energy: Slewing bearings are crucial for the movement and positioning of heavy components during the installation, operation, and maintenance of marine renewable energy systems such as offshore wind turbines and tidal power devices.

These applications highlight the importance and versatility of Marine Crane Slewing bearings, as they ensure smooth, precise, and reliable operation while handling heavy loads under the challenging conditions typically encountered in marine environments.

Where is the Marine Crane Slewing bearing installed?

The Marine Crane Slewing bearing is installed at the base of the marine crane, connecting the fixed lower structure (usually mounted on a ship, offshore platform, or harbor) with the rotating upper structure, which comprises the machinery, crane boom, and operator’s cabin. It serves as a large rotational interface that enables the crane to perform 360-degree rotation while supporting the boom and lifting loads. The slewing bearing is designed to withstand the high radial and axial forces exerted during crane operation while also resisting the harsh marine environment, such as saltwater exposure, corrosion, and extreme temperatures. In short, the Marine Crane Slewing bearing plays an essential role in ensuring the efficient and reliable functioning of the marine crane.

A ship crane is primarily composed of a rotating tower, boom, fixed base post welded to the deck, lifting, tilting, and swinging mechanisms, hydraulic power and piping systems, and electrical control systems. The marine crane features a turntable bearing mounted at the base of the crane tower. The inner ring’s lower end is bolted to the fixed base post that is welded onto the ship’s deck, whereas the outer ring’s upper end is connected to the crane tower using bolts.

During a ship crane’s operation, the swing pinion is actuated by the swing mechanism, engaging with the ring inside the turntable bearing. This engagement results in the outer ring’s rotation, thereby enabling the ship crane to swing smoothly and effectively carry out its regular operations.

The force characteristics and common bearing structure about Marine Crane Slewing bearing：
Marine Crane Slewing bearings are designed to accommodate a combination of forces and provide a stable rotational support system for marine cranes. Below, we discuss the force characteristics and common bearing structures associated with Marine Crane Slewing bearings.

Force Characteristics

  1. Radial force: Radial force acts perpendicular to the rotation axis of the slewing bearing. Marine Crane Slewing bearings are designed to withstand and support heavy radial loads resulting from equipment weight and the load being lifted.
  2. Axial force: Axial force acts parallel to the rotation axis of the slewing bearing. These bearings are engineered to handle axial forces like the overturning moment caused by crane operations or severe environmental impacts such as strong winds.
  3. Moment force: Moment force, or torque, is generated during lifting or maneuvering operations. Marine Crane Slewing bearings are constructed to resist sizable moment loads, ensuring smooth and controlled rotation and preventing excessive tilting of the crane components.

Common Bearing Structures

  1. Single-row ball slewing bearing: This design features a row of steel balls arranged between the inner and outer rings. The single-row structure provides a compact and cost-effective solution but with limited load capacity compared to other structures.
  2. Double-row ball slewing bearing: This configuration has two rows of steel balls, offering increased load-carrying capacity and improved rigidity compared to single-row designs. Double-row ball slewing bearings can handle larger radial and axial forces, making them ideal for heavy-duty marine crane applications.
  3. Single-row cross roller slewing bearing: This design consists of a single row of cylindrical rollers arranged perpendicular to the raceway, providing higher load capacity and greater stiffness than single-row ball bearings. Cross roller slewing bearings allow smooth rotation while handling increased axial and moment loads.
  4. Three-row roller slewing bearing: The most robust and heavy-duty bearing configuration, this structure comprises three separate rows of cylindrical rollers. Each row is designed to handle either radial or axial loads, providing exceptional load-carrying capacity and rotational stability for heavy-duty marine cranes.

The right choice of slewing bearing structure depends on the force characteristics, load capacity, and specific requirements of the marine crane application. Ensuring the optimal design and configuration of the Marine Crane Slewing bearing is crucial for maintaining efficient, reliable, and safe operations in demanding marine environments.

The materials of Marine Crane Slewing bearing

Marine Crane Slewing bearings must be made from materials that can withstand the harsh marine environment while providing reliable support and smooth rotation. The material selection plays a crucial role in determining the durability, load capacity, and corrosion resistance of the slewing bearings. Below are some of the common materials used for Marine Crane Slewing bearings:

  1. Carbon steel: Carbon steel is an economical and widely used material for slewing bearing production. This material provides reasonable tensile strength, impact resistance, and stiffness, making it suitable for moderate marine crane applications.
  2. Alloy steel: Alloy steel, which combines carbon steel with other elements, offers improved mechanical properties and corrosion resistance. Materials such as 42CrMo or 50Mn are commonly used for slewing bearing production due to their enhanced strength, toughness, and fatigue resistance.
  3. Stainless steel: Stainless steel is an ideal material for marine applications, as it exhibits high corrosion resistance, especially in saltwater environments. Marine Crane Slewing bearings made from stainless steel, like AISI 300 series, provide a superior level of durability and reliability when exposed to harsh marine conditions.
  4. Surface treatment and coatings: Surface treatments and coatings can further improve the performance of slewing bearings. Techniques such as zinc or nickel plating, phosphating, or heat treatment can enhance corrosion resistance and surface hardness.
  5. Sealing materials: The materials chosen for sealing systems should provide effective protection from moisture, saltwater, dust, and other contaminants prevalent in marine environments. Seals typically consist of various elastomers, such as NBR, FKM, or HNBR, which offer optimal resilience, flexibility, and resistance against chemicals and UV radiation.

The choice of material for Marine Crane Slewing bearings depends on factors like budget, environmental conditions, required strength, and load capacity. By selecting quality materials and incorporating appropriate surface treatments and sealing systems, manufacturers can produce durable and reliable slewing bearings that effectively maintain the efficiency and safety of marine crane operations.

Maintenance and Lubrication for Marine Crane Slewing bearing：

Proper maintenance and lubrication are essential for ensuring the longevity and optimal performance of Marine Crane Slewing bearings. Regular inspections and servicing can prevent premature wear and detect potential issues early. Below are some key maintenance and lubrication tips for Marine Crane Slewing bearings:

  1. Regular inspections: Perform routine visual inspections to check for signs of wear, corrosion, or damage to the slewing bearing, seals, and other components. Monitor for abnormal noise or vibrations during operation, as these might indicate potential problems.
  2. Cleaning: Clean the slewing bearing regularly to remove dirt, dust, salt, and other contaminants. Rinse with fresh water if exposed to saltwater, and use a soft brush to remove deposits, if necessary.
  3. Seal inspection: Examine seals for signs of wear, cracking, or damage. Replace damaged seals promptly to prevent ingress of contaminants and ensure adequate protection against harsh marine environments.
  4. Lubrication: Proper lubrication is crucial for reducing friction, minimizing wear, and extending the slewing bearing’s service life. Use a suitable grease or oil recommended by the manufacturer, and consider the specific environmental conditions and load capacities.
  5. Lubrication intervals: Re-lubricate the slewing bearing at regular intervals based on the manufacturer’s guidelines, bearing’s usage, and operating conditions. High workload or harsh environments may require more frequent lubrication.
  6. Bearing adjustment: Check the bearing’s preload and adjust it if necessary, following the manufacturer’s recommendations. Proper adjustment can help prevent excessive wear, ensure smooth rotation, and maintain optimal performance.
  7. Replacement and repairs: Monitor the bearing’s condition and replace it when signs of excessive wear or damage are detected. Early detection and prompt repairs or replacement can prevent catastrophic failures and costly downtime.
  8. Recordkeeping: Keep a detailed maintenance log, including inspection dates, servicing activities, and any repairs or replacements. Regular recordkeeping can help predict and plan future maintenance needs.

By following these maintenance and lubrication guidelines for Marine Crane Slewing bearings, the performance, reliability, and service life of the bearings can be significantly improved, ensuring the smooth and efficient operation of marine cranes in demanding environments.

The sealing of the Marine Crane Slewing bearing：

The sealing system is an essential part of Marine Crane Slewing bearings that plays a critical role in their reliability and operational efficiency. Effective seals protect the bearings from a wide range of contaminants, such as saltwater, moisture, dust, and debris, which are commonly encountered in marine environments. Proper sealing is necessary to maintain the bearings’ performance, reduce wear, and prolong their service life.

There are several types of sealing systems used in Marine Crane Slewing bearings:

  1. Labyrinth seals: Labyrinth seals feature a non-contact design with multiple intricate tortuous paths. This design effectively prevents the ingress of contaminants while allowing smooth rotation. Labyrinth seals can be either integral to the bearing or provided as a separate component. While less effective against liquid contaminants, labyrinth seals typically exhibit low friction and good dust exclusion properties.
  2. Rubber seals: Rubber seals, generally made of elastomers like NBR, FKM, or HNBR, provide a flexible lip that makes contact with the bearing’s raceway. They offer excellent resistance to chemicals, UV radiation, and abrasion and are effective in preventing the ingress of both liquid and solid contaminants. Rubber seals are generally more effective against liquid contaminants than labyrinth seals but may generate higher friction.
  3. Brush seals: Brush seals consist of numerous closely-spaced, flexible metal or plastic bristles installed around the circumference of the bearing. These seals offer an adaptable barrier against dust and debris while still allowing smooth rotation.
  4. Metal seals: Metal seals are designed to provide a durable and resilient barrier against contaminants. They are typically made of corrosion-resistant materials like stainless steel or aluminum, and feature a metal lip that makes contact with the bearing’s raceway. Metal seals provide a sturdy option to withstand harsh marine environments.

The choice of sealing system depends on the marine crane’s specific operating conditions, requirements, and environmental factors. A combination of different seal types may be used to optimize protection, efficiency, and longevity. Proper installation, regular inspection, and timely replacement of worn or damaged seals are vital to maintaining the performance and service life of Marine Crane Slewing bearings.


Marine Crane Slewing bearing Manufacturer：

Luoyang Longda Bearing Co., Ltd. (LDB-Bearing) is a reputable manufacturer with more than 30 years of experience in the design and production of slewing bearings. Their seasoned engineering team can customize specific slewing bearings to cater to clients’ varying needs in terms of project specifications, operational conditions, and unique requirements, including Marine Crane Slewing bearings.

LDB-Bearing is dedicated to delivering high-quality, reliable, and optimized slewing bearings that meet the performance criteria for marine cranes operating in harsh environments. Their expertise and focus on tailored solutions ensure that clients receive bearings that fit their application needs and perform well under demanding circumstances, contributing to the safe and efficient operation of marine cranes.

Customize Slewing Bearing Complete Guide

/in /by

what is Slewing Bearings ?
Slewing bearings, also known as slewing ring, turntable bearing, or rotational bearing, is a type of large-diameter bearing designed to support both axial and radial loads, as well as tilting (moments) loads. It facilitates relative rotational movements between two parts or structures while maintaining stability and transmitting the required load.

Slewing bearings are commonly used in a wide range of applications, including heavy machinery such as cranes, excavators, and tunnel-boring machines; wind turbines and solar tracking systems; medical equipment like CT and MRI scanners; and robotics and automation systems.

There are various types and designs of slewing bearings, including:

  1. Four-point contact ball slewing bearing: With a simple design mainly for supporting axial and radial loads, these bearings are commonly used in small to medium-sized applications or in combination with other bearings for more complex load handling.
  2. Double-row ball bearings: Consisting of two separate rows of steel balls, these bearings can handle higher loads and moments, making them suitable for large and heavy applications, such as cranes, tunnel-boring machines, and large antennae or radars.
  3. Three-Row Roller Slewing Bearings: Featuring three separate rows of rollers, these bearings offer the highest load capacity and typically support the heaviest applications, such as large cranes and heavy equipment or infrastructure projects.
  4. Crossed Roller Slewing Bearings: With rollers arranged in a crisscross pattern, these bearings can handle high axial, radial, and moment loads while maintaining a compact design and high precision. They are often used in precision equipment and robotics.

Slewing bearings may also feature different gearing options, such as internal, external, or no gearing, depending on the specific application requirements and desired rotational movement.

Why need to customize slewing bearing?

Customizing slewing bearings may be necessary under several circumstances to ensure an optimized and efficient system performance. Situations that can warrant the customization of slewing bearings include:

  1. Unique load capacities: When the application has specific load capacity requirements, such as heavy axial, radial, or tilting moment loads, that cannot be met by standard slewing bearings.
  2. Complex or unconventional mounting conditions: Customized slewing bearings may be needed when there are particular space constraints or mounting requirements not supported by off-the-shelf solutions.
  3. Extreme operating environments: Applications operating in harsh environments, such as extreme temperatures, heavy vibrations, high humidity, or corrosive atmospheres, may require slewing bearings made with specialized materials and features to handle these conditions.
  4. High precision requirements: When the application demands high rotational accuracy, smooth and precise motion, or low backlash for optimal performance, a customized slewing bearing can be designed to meet these stringent specifications.
  5. Special gearing options: Customization may be required for slewing bearings with specific gear types, such as internal, external, or gearless designs, or varying gear ratios and tooth profiles to match the application’s power transmission needs.
  6. Material specifications: Applications that require special material properties, such as corrosion resistance, increased hardness or temperature resilience, may necessitate the customization of slewing bearings.
  7. Additional features: When an application calls for specific features such as integrated sensors, monitoring systems, or other additional components, customizing the slewing bearing can help incorporate these functionalities seamlessly into the bearing.

In these and other similar situations, customizing a slewing bearing will ensure that it meets the unique requirements and constraints of the application, thereby achieving optimized performance, reliability, and a longer service life.


How to customize slewing bearing？
Customizing a slewing bearing involves designing and manufacturing a bearing tailored to the specific requirements of your application. By following these steps, you can successfully customize a slewing bearing that meets your exact needs:

  1. Identify application requirements: Understand your application’s specific needs, such as load capacity (radial and axial), torque, rotation speed, mounting constraints, and environmental conditions. Also, consider any space, weight, and installation limitations.
  2. Select the type of slewing bearing: Choose the appropriate type of slewing bearing for your application, such as single-row, double-row, or three-row bearings, with various gearing options (e.g., internal, external, or no gearing) and designs (ball or roller bearings).
  3. Determine size and dimensions: Specify required dimensions and tolerances, such as the inner and outer ring diameters, bearing height, and tooth profile of the slewing bearing, based on the given application requirements and constraints.
  4. Choose material and surface treatments: Select suitable materials (e.g., carbon steel, stainless steel, or alloy) and surface treatments (e.g., heat treatment, coatings) to enhance durability, wear resistance, and lifespan.
  5. Design the sealing system: Design an effective sealing system that protects the bearing from dust, moisture, and other contaminants, ensuring optimal performance and longevity.
  6. Lubrication and maintenance requirements: Identify appropriate lubrication methods (e.g., grease, oil) and maintenance procedures to reduce friction and wear, as well as ensure long-lasting performance.
  7. Collaborate with a manufacturer: Work with a slewing bearing manufacturer with the necessary expertise, experience, and capabilities to develop and produce the customized bearing. Provide detailed design specifications, and collaborate on testing and validation processes to ensure the final product meets your requirements.
  8. Testing and validation: Perform rigorous testing of the customized bearing to validate its performance, reliability, and durability under real-world operating conditions.

By following this process, you can successfully develop and produce a customized slewing bearing that meets the unique requirements of your application and delivers optimal performance in even the most demanding situations.

Manufacturers of customizing slewing bearings

Luoyang Longda Bearing Co., Ltd. (LDB-Bearing) boasts over 30 years of experience in slewing bearing design, enabling their engineering team to customize specific slewing bearings tailored to a client’s project, operational conditions, and unique requirements. The company produces a wide range of bearings, from small ones for lightweight applications to large three-row roller slewing bearings for heavy-duty applications, as well as intermediate-sized gear bearings.

LDB-Bearing offers an array of professional services, including:

  • Measuring and drafting
  • Proactive maintenance management
  • Performance monitoring
  • Enhancing efficiency
  • Bearing repair and refurbishment
  • Computer-aided design (CAD) drafting
  • Labeling
  • Employee training
  • Maintenance manuals and recommendations

In the manufacturing process of a customized slewing bearing, LDB-Bearing thoughtfully takes into account the extreme conditions of the working environment. This careful consideration ensures reliability and durability even under the most demanding loads.



Excavator Slewing Bearings Detailed description

/in /by

Excavator slewing bearings, also known as slewing bearings or swing circle bearings, are specialized large-size bearings designed to handle substantial loads while providing controlled rotation. 

What is excavator slewing bearings？

Excavator slewing bearings, also known as slewing bearings or swing circle bearings, are specialized large-size bearings designed to handle substantial loads while providing controlled rotation. The excavator slewing bearing is actually a rotating joint that connects the upper and lower parts of the excavator.It allows the top of the machine to rotate 360° while the bottom remains stationary, making it possible for the operator’s cabin and attachments to swing in a circle.
It enables the excavator to work in confined spaces while maintaining stability and precision. Composed of a gear, inner and outer rings, rolling elements (balls or rollers), and seals, these bearings can support axial, radial, and moment loads, ensuring efficient and reliable operation under harsh working conditions encountered in construction or mining sites.

Features of Excavator slewing bearings：

The features of Excavator slewing bearings significantly contribute to the functionality, durability, and performance of excavators in various industries. By understanding the essential characteristics of these critical components, manufacturers, operators, and maintenance personnel can ensure the reliable operation and long-lasting performance of excavators, ultimately increasing productivity and efficiency within their respective sectors.The following are some of the key features of excavator swing bearings that contribute to their reliability, durability, and effectiveness:

  1. High Load Capacity:
    Excavator slewing bearings are designed to handle axial, radial, and moment loads, even under demanding operating conditions. Their robust construction and high load-bearing capacity enable the proper functioning of the excavator, as well as ensure the safe and efficient handling of heavy loads.
  2. Durability and Longevity:
    Constructed using high-quality materials, such as carbon steel or alloy steel, Excavator slewing bearings offer reliable performance, extended service life, and high resistance against wear and tear. These components are built to withstand harsh operating conditions and maintain optimal operation throughout their lifespan.
  3. Smooth Rotational Movement:
    Excavator slewing bearings ensure smooth and precise rotational movement, allowing excavator operators to control the swing motion efficiently and accurately. Their accurate control of rotation is essential for the excavator’s versatility and application in various tasks, such as digging, loading, or demolition.
  4. Compact Design and Space-Saving:
    Excavator slewing bearings feature a compact design, allowing them to fit into the limited space between the upper and lower halves of the excavator. With their slim profile, they provide efficient support and rotation while occupying minimal space, ensuring the excavator maintains a reasonable weight distribution and streamlined construction.
  5. Low Friction
    Designed to minimize friction during rotation, Excavator slewing bearings contribute to efficient energy utilization and reduced energy consumption. Low friction also helps in extending the lifespan of the bearing by reducing wear and tear.
  6. Easy Maintenance:
    Excavator slewing bearings are designed for ease of maintenance, with lubrication points accessible for regular inspection and lubrication. Proper maintenance practices help to reduce downtime, prolong the service life of the bearing, and maintain optimal performance.
  7. Customization:
    Excavator slewing bearings are available in various sizes, types, and materials, allowing manufacturers to tailor them based on specific needs and requirements. Customization options can include different dimensions, gear designs, or material choices to suit specific excavator models and working environments.

Types of Excavator slewing bearings

The choice of excavator bearing type depends largely on the size of the excavator, the application requirements, and the loads the equipment is expected to handle. Understanding the different types of excavator swing bearings and their characteristics can help you select the right bearing to ensure optimal performance, durability, and equipment life.The following are common types of excavator bearings and their characteristics:

  1. Single-Row Ball Slewing Bearings: These bearings feature a single row of balls placed between inner and outer rings. Single-row ball slewing bearings are ideal for applications with moderate loads, offering smooth rotation and reducing the overall weight and size of the excavator. They are commonly used in small to mid-sized excavators.
  2. Double-Row Ball Slewing Bearings: Double-row ball slewing bearings have two rows of balls working together, providing better load distribution and increased load-carrying capacity compared to single-row bearings. This type of slewing bearing is suitable for larger excavators with heavier loads and greater torque requirements.
  3. Single-Row Crossed Roller Slewing Bearings: Single-row crossed roller slewing bearings consist of cylindrical rollers arranged perpendicular to one another in a single row. These bearings provide higher load-carrying capacity than the ball slewing bearings because of the increased contact area between the rollers and the rings. This makes them ideal for medium to large excavators that need to handle heavier loads and more demanding working conditions.
  4. Three-Row Roller Slewing Bearings: Three-row roller slewing bearings have three rows of rollers, each designed to accommodate a specific type of load (axial, radial, or moment loads). These bearings offer high load-carrying capacities and improved stability, making them suitable for the most heavy-duty excavators and applications with extreme weight and torque demands.
  5. Combined Ball and Roller Slewing Bearings: In some cases, a combination of ball and roller bearings is used in a single bearing to provide increased capacity and versatility. These bearings can accommodate higher loads while maintaining smooth and controlled rotation, making them suitable for various excavator sizes and applications.

Application of Excavator slewing bearings

Slewing bearings are large, durable bearings designed to accommodate heavy loads, enabling controlled rotation and torque transmission in machinery components. Their strong construction, large size, and ability to handle axial, radial, and moment loads make them perfect for heavy-duty equipment like excavators that require reliable and smooth rotation movement.Slewing bearings play a crucial role in improving the functionality, performance, and durability of excavators in the demanding conditions found within various industries, such as construction, mining, and forestry. By understanding the various applications of slewing bearings in excavator machinery and appreciating the benefits they provide, manufacturers and operators can optimize the performance of their equipment and reap the rewards of increased productivity and reduced maintenance costs:

  1. Upper Structure Rotation: The slewing bearing is situated at the base of the excavator’s upper structure, allowing the rotation of the upper body in relation to the undercarriage. This enables the excavator to maneuver and transport materials without having to reposition its tracks continually.
  2. Boom Swing Mechanism: Some excavators feature a swing bearing that enables the side-to-side motion of the boom, providing added flexibility and increasing productivity in confined spaces or when handling materials at various angles.
  3. Attachments Rotation: Slewing bearings are also used to facilitate the rotation of certain attachments, such as grapples or augers, allowing versatile positioning and operation of these accessories.
  4. Operating Cab Rotation: In specific advanced excavators, the operator’s cab is mounted on a slewing bearing, enabling the rotation of the cab independent of the upper structure and offering improved visibility and ergonomics.

Price of Excavator slewing bearings

The price of excavator slewing bearings can vary depending on several factors, including the size, load capacity, material, brand, and additional features. Smaller sized slewing bearings for mini or compact excavators tend to be less expensive compared to larger ones designed for heavy-duty excavators.
The typical price range for excavator slewing bearings starts at about $500 for small bearings, and goes up to several thousand dollars for more prominent and sturdy bearings, around $10,000. It should be noted that specific application requirements, the manufacturer’s reputation, product quality and after-sales support will also affect the final price.
When purchasing excavator slewing bearings, always consult a reputable manufacturer or supplier and compare multiple options to find the best balance between price, quality and performance for your specific needs. Be sure to consider the total cost of ownership, including maintenance, service life and potential downtime caused by low-quality products. Luoyang Longda Bearing Co., Ltd. (LDB bearing) is a company specializing in the design, development, manufacture and sale of slewing bearings and precision slewing drive devices. As a professional excavator slewing bearing supplier, our technical engineers will provide you with the best excavator slewing bearing solution.

Detailed Guide to different kinds of Slewing bearings

/in /by

What are slewing bearings?

Slewing bearings, also known as turntable or rotary bearings, are large-sized bearings designed to accommodate axial, radial, and moment loads simultaneously. They facilitate smooth rotation in heavy machinery and equipment across various industries. Slewing bearings can be classified based on their design, rolling elements, raceway configuration, and gear configurations.

Specific classification of slewing bearings

Understanding various types of slewing bearings and their features is crucial for selecting the most suitable bearing for specific applications and load requirements. This ensures smooth operation, improved efficiency, and a longer service life of the machinery and equipment in which the bearing is used.

1. Based on Design:

Single-row Ball Slewing Bearings:Consist of a single row of balls between the inner and outer rings, suitable for handling moderate axial and radial loads along with low to moderate overturning moments. They are commonly used in cranes, excavators, and aerial work platforms.

Double-row Ball Slewing Bearings:Comprise two separate rows of balls between the inner and outer rings, offering higher load capacities compared to single-row bearings. They are utilized in heavy-duty applications that require increased load-carrying capacity.

2. Based on Rolling Elements:

Ball Slewing Bearings:Utilize spherical balls as rolling elements, which allow for smooth rotation, reduced friction, and high responsiveness. Ball slewing bearings can handle higher speeds than roller slewing bearings and are more suitable for applications wherein rigidity and precision rotation are essential, like crane booms and radar systems.

Roller Slewing Bearings:Employ cylindrical rollers as rolling elements, which distribute loads more evenly and provide higher load capacities in comparison to ball bearings. They are more suitable for heavy-duty applications with slow to moderate operational speeds, like offshore cranes and heavy machinery.

3. Based on Raceway Configuration:

Single-row Four-point Contact Ball Bearings:These bearings have a raceway configuration that lets a single row of balls handle axial, radial, and moment loads, with four-point contact between the balls and rings. They deliver compactness and enhanced load capacity in various applications, such as cranes, excavators, and wind turbines.

Crossed Roller Bearings:In this configuration, cylindrical rollers are arranged in a crossed orientation, providing high stiffness, accuracy, and load capacity. These bearings enable smooth movement and resistance against deflection under heavy loads, making them suitable for machine tools, manipulators, and robotic arms.

4. Based on Gear Configurations:

Non-geared Slewing Bearings:These bearings lack gear teeth on the inner or outer ring and are suitable for applications where no external gearing is required.

Externally Geared Slewing Bearings:Feature gear teeth on the outer ring, providing power transmission to the rotating assembly. These bearings are commonly employed in applications like cranes, wind turbines, and industrial turntables.

Internally Geared Slewing Bearings:Have gear teeth on the inner ring, allowing for power transmission while maintaining a compact profile. They are used in applications where space constraints exist, like robotic arms and medical equipment.

Specific application field classification of slewing bearings

Slewing bearings are essential components in many types of heavy machinery and equipment across a variety of industries. Their ability to handle axial, radial, and moment loads, facilitate smooth rotation, and effectively manage weight and torque make them vital for numerous applications. Here’s a detailed guide to specific uses of slewing bearings in different fields:

1. Renewable Energy:

Solar Tracking Systems:Slewing bearings are used in single-axis and dual-axis solar trackers, which adjust the angle of solar panels throughout the day to maximize sunlight exposure and energy generation.

Wind Turbines:In wind energy applications, slewing bearings are used to rotate the nacelle and rotor blades according to wind direction, optimizing power generation. They are also utilized in wind turbine blade- and tower-manufacturing equipment.

2. Construction and Heavy Equipment:

Mobile Cranes:Slewing bearings are an integral part of crane booms, enabling heavy load lifting and smooth rotation, allowing operators to move and position loads with precision and safety.

Excavators:They facilitate the rotation and positioning of excavator arms, providing smooth movement and stability during digging and material handling operations.

Aerial Lifts and Work Platforms:In aerial work platforms or man-lifts, slewing bearings allow for precise positioning and rotation at elevated locations, ensuring stability and safety for workers.

3. Industrial Machinery and Automation:

Industrial Turntables:Slewing bearings play a critical role in industrial turntables and rotary tables used for material handling, assembly, painting, and welding processes.

Robotic Arms:In manufacturing and automation, slewing bearings provide precise, controlled movements required to position robotic arms and manipulators accurately.

4. Aerospace and Defense:

Radar and Satellite Systems:They facilitate smooth and controlled rotation of radar dishes and satellite antennas, ensuring accurate targeting, data collection, and communication.

5. Medical and Healthcare Equipment:

Medical Imaging Equipment:Slewing bearings are used in medical imaging devices, such as CT scanners, MRI machines, and X-ray equipment, to achieve precise rotation and positioning of imaging components.

Surgery and Rehabilitation Robots:In robotic-assisted surgery and rehabilitation devices, slewing bearings enable accurate and controlled movement of robotic arms and components, enhancing precision and reliability during medical procedures.

6. Mining and Drilling:

Tunnel Boring Machines and Drilling Rigs:Slewing bearings are crucial for drilling equipment and tunnel boring machines, providing rotation and stability during drilling operations and ensuring constant alignment and pressure.

7. Marine and Offshore:

Marine Cranes and Shipboard Equipment:Slewing bearings contribute to the rotation and positioning of marine cranes, allowing smoother and safer handling of cargo, equipment, and containers.

Offshore Oil and Gas Equipment:In offshore drilling platforms and oil rig cranes, slewing bearings enable precise rotation and load handling for drilling, maintenance, and equipment transport.

Supplier of slewing bearing

Luoyang Longda Bearing Co., Ltd.(LDB-Bearing)was established in 1999 and is located in China’s bearing production base – Luoyang, Henan. LDB Bearing has a product range from 150mm to 4000mm in diameter slew bearing and gear rings, covering the production and manufacturing of various standard and non-standard specifications of slew bearings.

If you need slewing bearing for your project, or want to consult some related knowledge, you are welcome to contact us-LDB-Bearing– at any time, our professional technology and expertise can provide you with the best solution to meet your different needs.

What is slewing bearing -Lastest Guide to the slewing bearings

/in /by

Overview of Slewing Bearings

Slewing bearings, alternatively known as turntable or rotary bearings, comprise large-sized bearings specifically engineered to concurrently support axial, radial, and moment loads. Their primary function revolves around facilitating the smooth rotation of heavy machinery and equipment.

Slewing bearings have found widespread applications across diverse industries, including construction, renewable energy, aerospace, automation, medical, marine, and heavy equipment manufacturing. Its usage spans components in crane manufacturing, excavators, wind turbines, heavy construction equipment, aerial platforms, medical imaging machinery, radar and satellite systems, tidal energy systems, and robotic arms.

Structure of Slewing Bearings

A slewing bearing’s structure includes the following components:

1. Inner ring: The inner circular part, with raceways on its inner surface and, where applicable, gear teeth.

2. Outer ring: The outer circular part, with raceways on its outer surface and, where applicable, gear teeth.

3. Rolling elements: Balls, cylindrical rollers, or a combination of both, placed between the inner and outer rings in the raceways.

4. Retainer or cage: Maintains the spacing between the rolling elements, ensuring even and controlled movement.

5. Gear teeth: Found on either the inner ring (internal gear), outer ring (external gear), or no gear at all, depending on the application requirements.

How do Slewing Bearings Work?

The core components of a slewing bearing consist of an inner ring, outer ring, rolling elements (ball or cylindrical rollers), and retainers or cages. Both inner and outer rings feature raceways and gear teeth (applicable for geared bearings) that facilitate the placement and movement of the rolling elements. As the heavy machinery rotates, relative movements between the inner and outer rings trigger motion among the rolling elements in the raceways. This mechanism, in turn, decreases the friction between components and allows for the efficient transfer of axial, radial, and moment forces.

Slewing bearings exhibit the following characteristics:

1. Ability to handle combined axial, radial, and moment loads.

2. Resistance to high and low temperatures, with some specialized types designed for extreme temperature conditions.

3. Customizable gear teeth options for different applications (internal gear, external gear, or no gear).

4. Available in various designs such as single-row or double-row ball bearings, single-, double-, or triple-row roller bearings, or combined roller-ball bearings.

5. Ability to handle high overturning moments due to their large size and configurations.

6. High-quality bearings offer a long service life and low maintenance intervals.

Working Principle of Slewing Bearings

Slewing bearings primarily function through the friction derived from components within the bearing. The rolling motion of the rolling elements imparts the necessary reduction in friction for the simultaneous transfer of axial, radial, and moment forces across the bearing. This bearing setup ensures that heavy machinery and equipment operate smoothly with minimal wear and tear.

Dimensions of Slewing Bearings

Slewing bearings come in various diameters and sizes, depending on the application and load requirements. They can range from a few inches to several meters in diameter. The exact dimensions are determined by factors such as the bearing’s design, load capacity, and rotational speed requirements. We can customize the bearings according to specific customer needs. If you need more information or requirements of slewing bearing, please feel free to contact us.

Applications of Slewing Bearings

Slewing bearings are vital for facilitating the rotation and support of heavy loads in numerous applications, such as:

1. Crane manufacturing: They ensure smooth and precise rotational movement of crane booms and load handling.

2. Excavators: Slewing bearings help excavator booms and arms perform reliable and robust rotational movements.

3. Wind turbines: They ensure that nacelles rotate precisely, enabling the wind turbine blades to adapt and face the wind direction.

4. Heavy-duty construction equipment: Slewing bearings provide rotational support in equipment like tunnel boring machines and heavy-duty drilling rigs.

5. Aerial platforms: They offer stability and rotation in boom lifts, scissor lifts, and other aerial work platforms.

6. Medical equipment: In CT and MRI scanners, slewing bearings enable accurate and smooth rotation of the scanning gantries.

7. Radar and satellite systems: They facilitate the precise and consistent rotation of radar antennae and satellite dishes for accurate tracking and data acquisition.

8. Tidal energy systems: Slewing bearings enable the rotation of underwater turbines to optimize the harvest of tidal energy.

9. Robotic arms and manufacturing systems: They maintain stability and enable precise rotation in industrial robots and other automated equipment.

Industries Using Slewing Bearings

Slewing bearings have proved indispensable across several industries, including but not limited to:

1. Construction: In cranes, excavators, drilling rigs, and tunnel boring machines.

2. Renewable energy: In wind turbines, tidal energy systems, and solar tracking systems.

3. Aerospace: In radar antennae, satellite systems, defense-related applications, and loading machinery.

4. Automation: In industrial robots, robotic arms, and other automated equipment.

5. Medical: In CT and MRI scanners, and radiotherapy machines.

6. Marine: In ship cranes, offshore equipment, and tidal energy systems.

7. Heavy equipment manufacturing: In large-scale machinery production.

How do you test a Slewing Bearing?

Multiple steps are involved in the testing of a slewing bearing:

1. Conduct a comprehensive visual inspection to identify visible damage, corrosion, cracks, or wear on the bearing components.

2. Deploy feeler gauges to measure the radial and axial clearances, ensuring they fall within acceptable limits.

3. Inspect the lubrication system and lubricate the bearing according to manufacturer guidelines.

4. Check for smooth rotation and listen to any abnormal noises emanating from the bearing, which may signal potential issues.

5. Implement non-destructive testing (NDT) methods, such as ultrasonic testing or magnetic particle inspection, to pinpoint any flaws in the bearing materials.

How to choosing the Right Slewing Bearing?

To select a suitable slewing bearing, several factors must be taken into account:

1. Load requirements: Evaluate the axial, radial, and moment loads the bearing may face during operation.

2. Operating environment: Select a bearing designed to withstand specific working conditions, such as temperature, humidity, and exposure to dust or chemicals.

3. Gear type: Choices include internal, external, or no gear, depending on application requirements.

4. Bearing size: Depending on available space and load requirements, choose an appropriate diameter.

5. Bearing type: Select from single-row or double-row ball bearings, single-, double-, or triple-row roller bearings, or a combination of roller-ball bearings, considering load capacity and rigidity requirements.

6. Material: Assess the specific requirements and operating environments to select suitable material for bearing components, such as high-strength steel or corrosion-resistant alloys.

7. Lubrication: Evaluate the lubrication requirements for the application— grease or oil lubrication— and ensure proper sealing to prolong bearing life and maintain optimal performance.

Supplier of slewing bearing

Luoyang Longda Bearing Co., Ltd.(LDB-Bearing)was established in 1999 and is located in China’s bearing production base – Luoyang, Henan. LDB Bearing has a product range from 150mm to 4000mm in diameter slew bearing and gear rings, covering the production and manufacturing of various standard and non-standard specifications of slew bearings. LDB has design and manufacturing expertise in slew bearing and slew drive across a diverse range of markets and industries.

If you need slewing bearing for your project, or want to consult some related knowledge, you are welcome to contact us at any time, our professional technology and expertise can provide you with the best solution to meet your different needs.

The structure and function of the slewing drive of the truck-mounted crane

/in /by

Slew Drive

The structure and function of the slewing drive of the truck-mounted crane

Slew Drive Structure

The slewing drive device of the truck-mounted crane includes a hydraulic motor, a brake and a reducer.

Function:

1.Hydraulic Motor

Convert the pressure of hydraulic oil into rotational mechanical energy and transmit the rotational motion to the reducer.

2.Brake

The brake is inside the hydraulic motor and brakes the output shaft of the hydraulic motor.

3.Reducer

The reducer of truck-mounted crane is composed of a two-stage reduction planetary gear transmission. It is decelerated through the gear transmission device and transmitted to the output shaft of the reducer.

Slewing Bearing

Abnormal noise problem of excavator slewing bearing

It is normal for the new slewing bearing to make a uniform sound of rolling steel balls when it is idling. It will disappear after a period of running-in after installation. If there is a loud sound or special noise, you should pay attention.

1. The mounting surface is uneven and the mounting bolts are loose

2. There is a foreign body in the slewing bearing

3. Abnormal noise caused by a problem with the grease

4. Raceway and rolling body are severely worn

Conclusion: you should not be careless when there is abnormal noise in the excavator slewing bearing, you must check and solve the fault in time.

Slewing Gear Ring Bearing Drive

/in , /by

Slewing Gear Ring Bearing & Slewing Gear  Drive

Rotary gears are usually divided into two types, one is the rotary gear support bearing, the other is the rotary gear drive
Slewing gear support bearings are composed of an inner ring and an outer ring, usually one of which contains the gear. Together with the connecting holes on the two rings, they are easily and quickly wired through the adjacent link components for optimized power transmission. Slewing gear bearing raceways combined with rolling elements and cages are designed to withstand loads acting individually or in combination in any direction.
Rotary gears can be used in various industries such as aerospace, heavy equipment, industrial machinery, medical systems, mining, oil and gas, etc., and are the key to many industries and play a vital role.
The slewing gear support bearing is different from ordinary bearings, the difference is that it has a gear that can adjust the rotation. The machine transmits and adjusts the direction of the mechanical products fixed on the slewing bearing through the dynamic sensing system installed on the slewing gear bearing. and take advantage of special constructs:

It maintains the overall balance, effectively guarantees the radial force generated in the work, and ensures the balance.

The rotary gear drive is a kind of turntable fixed in the gear box, which can safely bear the radial and axial load force, and drives the rotation of the turntable through the rotation of the turbine. Rotary gear drive is a gearbox composed of gears, bearings, seals, casings and motors.
The rotary gear drive is a modification of the worm drive mechanism. It dates back to the Renaissance period, when the Greek mathematician Pappus devised a worm drive. Da Vinci also used the slewing gear drive trim in many of its machines.


The driving force of the rotary gear drive comes from the rotational force given by the motor to the worm, and the gear on the worm is adjusted by the gear on the electric turntable. This combination mode reduces the rotation speed of the turntable, increases the torque, and can drive heavier objects.
Slewing gear drives can be applied to solar trackers, wind turbines, elevators, hydraulic machinery, telescopic arms, cranes and other equipment.