Different types and applications of slew bearings
What is Slewing Bearings?
Slewing bearings, also known as slewing rings or turntable bearings, are large and robust bearings designed to handle substantial radial, axial, and moment loads simultaneously. These bearings provide smooth rotational motion and are crucial in a wide array of applications and industries, including construction, robotics, wind energy, and more. Slewing bearings typically consist of an inner and outer ring with rolling elements such as balls or rollers, enabling rotational motion between the rings.
Types of Slewing Bearings
There are mainly four types of slewing bearings, differentiated by their rolling elements and configuration:
Single-row ball slewing bearings:
These bearings utilize a single row of spherical balls as the rolling elements. Single-row ball slewing bearings can handle radial, axial, and moment (tilting) loads and provide a compact design with low friction. They are suitable for applications where moderate to heavy loads need to be supported, but space is limited.
Double-row ball slewing bearings:
Double-row ball slewing bearings consist of two rows of spherical balls separated by a spacer, which helps to distribute the load more evenly and maintain stability under greater loads. These bearings offer higher load-carrying capacity and increased rigidity compared to single-row ball slewing bearings. They are often used in heavy-load and high-precision applications.
Single-row cross roller slewing bearings:
Cross roller slewing bearings consist of cylindrical or tapered rollers arranged in a single row, with the rollers oriented alternately at right angles to each other. This configuration allows these bearings to support loads in multiple directions and provides higher stiffness and precision than ball slewing bearings. Single-row cross roller slewing bearings are suitable for applications requiring high accuracy, heavy loads, and a compact design.
Three-row roller slewing bearings:
These bearings feature three separate rows of cylindrical or tapered rollers, which allow for the highest load-carrying capacity among all types of slewing bearings. The three-row roller configuration also offers excellent stability and reduces the risk of deformation under heavy loads. Three-row roller slewing bearings are commonly used in heavy-duty, large-scale applications, such as large cranes and heavy construction machinery.
Difference Between the Different Types of Slewing Bearings
The main differences between the various types of slewing bearings lie in their rolling element type, configuration, load-carrying capacity, stiffness, and application suitability:
Single-row ball slewing bearings are suitable for applications with moderate to heavy loads and limited space. They provide low friction and can handle axial, radial, and moment loads.
Double-row ball slewing bearings offer higher load-carrying capacity and increased rigidity compared to single-row ball slewing bearings due to the two rows of spherical balls. They are ideal for heavy-load and high-precision applications.
Single-row cross roller slewing bearings provide higher stiffness and precision than ball bearings due to the alternating arrangement of cylindrical or tapered rollers at right angles to each other. They are suitable for applications requiring high accuracy, heavy loads, and compact design.
Three-row roller slewing bearings feature the highest load-carrying capacity among all types of slewing bearings and provide excellent stability under heavy loads. They are commonly used in heavy-duty, large-scale applications.
In conclusion, the choice of slewing bearing type depends on the specific requirements of the application, including the load-carrying capacity, space constraints, and desired level of precision and stiffness. By understanding the differences between the various types of slewing bearings, the most suitable bearing can be selected for optimal performance and desired outcome.
Each type of slewing bearing is suited to different applications based on their load-carrying capacity, stiffness, precision, and compactness. The main differences among the various categories lie in their rolling element type, configuration, and application suitability.
Here are the typical application areas for the different categories of slewing bearings mentioned earlier:
1. Single-row ball slewing bearings
These bearings find use in applications with moderate to heavy loads and limited space. Owing to their low friction and ability to handle axial, radial, and moment loads, they are commonly used in:
- Light to medium-duty cranes
- Small to medium-sized excavators
- Aerial work platforms (manlifts)
- Solar and wind energy applications (solar trackers, wind turbine yaw systems)
- Machine tool positioning tables
- Revolving stages and platforms
2. Double-row ball slewing bearings
Featuring two rows of spherical balls, these bearings offer higher load-carrying capacity and increased rigidity. They are suitable for heavy-load and high-precision applications such as:
- Heavy-duty cranes (tower, mobile, and crawler cranes)
- Large excavators
- Tunnel boring machines
- Ship loaders and unloaders
- Large antenna systems and satellite positioners
3. Single-row cross roller slewing bearings
Characterized by a single row of alternately arranged cylindrical or tapered rollers, these bearings provide higher stiffness, precision, and compact design. Their typical application areas include:
- Robotics (rotational bearings for robotic arms)
- Medical equipment (CT and MRI scanners)
- Radar and telescope systems
- Precision machine tools and rotary tables
- Offshore and marine applications (offshore cranes, cable reels)
4. Three-row roller slewing bearings
Featuring three separate rows of cylindrical or tapered rollers, these bearings have the highest load-carrying capacity and offer excellent stability under heavy loads. They are commonly used in heavy-duty, large-scale applications such as:
- Large cranes in construction projects (e.g., large tower cranes, heavy mobile cranes)
- Heavy construction machinery and mining equipment
- Offshore applications (drilling platforms, offshore cranes)
- Steel industry (ladle turrets, material handling systems)
- Large wind turbines
In summary, the choice of slewing bearing type depends on the specific requirements of the application, including load-carrying capacity, space constraints, and the desired level of precision and stiffness. By understanding the differences between the various types of slewing bearings and their respective application areas, the most suitable bearing can be selected for optimal performance and desired outcome.
High-quality Slew bearings Supplier in China
Zenith Drive offers high quality Slew bearings, durable solar slewing drives, slew bearings and other customized slew bearing and machinery parts While we design our slew bearing and slew drive products to support a range of functions, your OEM designs may require additional features or modifications to support optimal performance.
If you are looking for Slew bearings, or want to consult some related information, you are welcome to contact Zenith Drive at any time, our professional technology and expertise can provide you with the best solution to meet your different needs.