Influence of the Number of Balls on the Performance of Slewing bearings

Slewing bearings, as crucial components in the mechanical field, are widely used in equipment such as cranes, excavators, and tunnel boring machines. Their performance is restricted by many factors, and the number of balls is one of the important influencing factors, playing a key role in load – bearing capacity, slewing accuracy, friction characteristics, service life, and other aspects.

What is Double – Row Ball Slewing bearing?

The double – row ball slewing bearing is a mechanical component used to achieve the slewing motion of components. It mainly consists of an inner ring, an outer ring, two rows of steel balls with the same diameter, and a cage. The two rows of steel balls are evenly distributed between the inner and outer rings and jointly bear axial forces, radial forces, and overturning moments. Relative slewing is achieved through the contact and rolling of the steel balls and the raceways. It has a simple structure, is easy to install, can withstand complex loads to a certain extent, and is often used in equipment such as small cranes, aerial work platforms, and small wind turbines that do not require particularly high slewing accuracy but need to bear certain axial and radial forces.

What is Four – Point Contact Slewing bearing?

The four – point contact slewing bearing is a type of slewing bearing. It is composed of an inner ring, an outer ring, steel balls, and a cage. Its uniqueness lies in that each steel ball has four – point contact with the raceways of the inner and outer rings. This structure enables it to simultaneously bear large axial forces, radial forces, and overturning moments. During operation, the four – point contact can effectively disperse the load and reduce local stress concentration. It is often used in equipment with compact space requirements and the need to bear multiple types of loads, such as tower cranes and port cranes. Compared with other slewing bearings, the four – point contact slewing bearing has a compact structure, occupies less space, and can provide reliable slewing motion and stable load – bearing performance in a limited space.

Load – Bearing Capacity of Slewing bearings

Increasing the number of balls can enhance the load – bearing capacity of slewing bearings. In a double – row ball slewing bearing, the steel balls are evenly distributed to bear axial forces, radial forces, and overturning moments. More steel balls mean a larger load – bearing area and a more uniform load distribution, which can share the force on a single steel ball. Taking a port crane as an example, when the number of balls in the slewing bearing increases, it can effectively disperse the huge forces generated when lifting heavy objects, prevent excessive wear or deformation of the steel balls, thereby enhancing the overall load – bearing capacity of the support and ensuring the safe and efficient operation of the equipment. However, the number of balls is not the more the better. Excessive balls will increase the contact stress between them, leading to increased friction and energy consumption, and instead reducing the load – bearing efficiency.

Slewing Accuracy of Slewing bearings

Slewing accuracy is an important performance indicator of slewing bearings. Appropriately increasing the number of balls helps to improve slewing accuracy. More steel balls make the load distribution more uniform, reducing eccentricity and shaking caused by uneven loads. For example, in the slewing bearing of a precision radar device, by increasing the number of steel balls, the load fluctuation borne by a single steel ball is reduced, making the radar more stable during rotation, with a smaller angular error, and ensuring its accurate tracking of targets. However, too many balls will increase the manufacturing and installation difficulties. Once there are deviations in the size or installation accuracy of the steel balls, it will instead damage the slewing accuracy and cause the equipment to operate unstably.

Friction Characteristics of Slewing bearings

The change in the number of balls has a significant impact on the friction characteristics of slewing bearings. As the number of balls increases, the contact area increases, and the friction resistance will also increase accordingly. In some equipment with high requirements for slewing flexibility, too many steel balls will cause difficult rotation and increased energy consumption. For example, in an aerial work platform, if the number of balls in the slewing bearing is too large, the operator will feel obvious jamming when turning the platform, increasing the operation difficulty and energy consumption. Conversely, if the number of balls is too small, the pressure on a single steel ball is high, and the wear will be accelerated, which will also affect the smoothness of slewing. Therefore, it is necessary to select the appropriate number of balls according to the equipment working conditions to balance the friction resistance and load – bearing capacity and ensure the normal operation of the equipment.

Service Life of Slewing bearings

The number of balls is closely related to the service life of slewing bearings. Reasonably increasing the number of balls can extend the service life. When the number of balls is sufficient, the load borne by a single ball is relatively reduced, and the degree of wear is reduced, which can effectively reduce the occurrence of fatigue wear and plastic deformation. Taking the slewing bearing of a wind turbine as an example, more steel balls can better bear the complex loads generated by the rotation of the blades, reduce the wear of the steel balls and raceways, extend the service life of the slewing bearing, and reduce the maintenance cost. However, if the number of balls exceeds the reasonable range, due to increased friction and heat generation, it will accelerate the aging and fatigue of the material and shorten the service life.

When designing and selecting slewing bearings, it is necessary to comprehensively consider the working conditions and performance requirements of the equipment to determine the number of balls. For heavy – load equipment, such as large – scale mining machinery, it is necessary to increase the number of balls to enhance the load – bearing capacity; for high – precision equipment, such as optical tracking equipment, it is necessary to reasonably increase the number of balls to ensure slewing accuracy. In addition, factors such as material properties, manufacturing processes, and costs also need to be combined to optimize the design of the number of balls while ensuring performance. With the continuous progress of materials science and manufacturing technology, it is expected that breakthroughs will be made in the optimization of the number of balls for slewing bearings in the future. By using new materials and advanced manufacturing processes, the distribution of the number of balls can be made more reasonable, improving performance while reducing costs to meet the higher requirements of different fields for slewing bearings.

Prices of Slewing bearings

There are many factors affecting the price of slewing bearings. Firstly, raw materials. High – quality steel has a high cost and can produce products with excellent performance and long service life, so the price is also high. Secondly, for slewing bearings with complex manufacturing processes and high – precision requirements, advanced equipment and strict quality control are required, which will also increase the price accordingly. Moreover, the larger and more special the size and specifications are, the greater the processing difficulty and the amount of materials used, and the higher the price will be.

Suppliers of Slewing bearings

The products of ldb bearing company cover a wide range. Whether they are standard – sized or non – standard slewing bearings, the company can produce them with high quality to meet the diverse needs of different customers. In the field of industrial robots, its slewing bearings help the joints of robots achieve high – precision and high – stability rotational motion, making the robot’s movements flexible and precise. In solar power generation equipment, they assist the tracking system in accurately tracking the sun, improving power generation efficiency. The wide application of its products in multiple fields demonstrates its strength.