How about the Load – Carrying Capacity of Four – Point Contact Slewing Bearings
As an important mechanical component, four – point contact slewing bearings play a crucial role in many engineering fields. Their load – carrying capacity is an important indicator to measure their performance. They can withstand axial forces, radial forces, and tilting moments under different working conditions, providing reliable support for the stable operation of equipment.
What is a Four – Point Contact Slewing Bearing
A four – point contact slewing bearing is a type of bearing structure. It consists of components such as an inner ring, an outer ring, rolling elements, and a cage. Its uniqueness lies in that the rolling elements have four – point contact with the raceways of the inner and outer rings, enabling it to simultaneously withstand axial forces, radial forces, and tilting moments. This design gives the slewing bearing a high load – carrying capacity and rotational accuracy within a limited space. It is commonly used in construction machinery and large – scale equipment such as cranes, excavators, and wind turbines. It can achieve smooth rotational motion between components, adapt to complex working conditions, and improve the reliability and stability of the equipment.
Axial Load – Carrying Capacity
The axial load – carrying capacity of a four – point contact slewing bearing is one of its significant advantages. Structurally, the steel balls have four – point contact with the arc – shaped raceways of the inner and outer rings. This design allows the axial force to be evenly distributed among each contact point. When subjected to an axial load, each steel ball can effectively share the force, thus enhancing the overall axial load – carrying capacity.
Generally, the axial load – carrying capacity of a small – sized four – point contact slewing bearing can reach several tens of kilonewtons. For example, in some small industrial robots, the axial load – carrying capacity of the four – point contact slewing bearings used may be around 30 – 50 kN, which can meet the axial force requirements generated during the movement of the robot arm. For large – scale construction machinery, such as large – scale tower cranes, the axial load – carrying capacity of the four – point contact slewing bearings used can reach several thousand kilonewtons or even higher. In some super – large tower cranes, the axial load – carrying capacity of the slewing bearings may exceed 5000 kN to withstand the huge axial forces generated during the hoisting and rotation of the jib and heavy objects.
Radial Load – Carrying Capacity
Although the four – point contact slewing bearing is not a specialized radial bearing, it still has a certain radial load – carrying capacity. In actual work, equipment often generates axial forces, radial forces, and tilting moments simultaneously. The four – point contact slewing bearing needs to withstand axial forces and tilting moments while also accommodating a certain radial force.
Its radial load – carrying capacity mainly depends on the contact angle between the steel balls and the raceways and the fitting accuracy. When the contact angle between the steel balls and the raceways is reasonable and the manufacturing accuracy is high, the radial load – carrying capacity can be improved to a certain extent. However, compared with specialized radial bearings, the radial load – carrying capacity of four – point contact slewing bearings is relatively weak. For example, in some small rotating worktables, the radial load – carrying capacity of the four – point contact slewing bearings used may be around 10 – 20 kN, while that of specialized radial bearings of the same specification may reach 30 – 50 kN. But in most practical applications, the radial load – carrying capacity of four – point contact slewing bearings can usually meet the radial force requirements generated by the equipment under normal working conditions.
Tilting Moment Load – Carrying Capacity
Four – point contact slewing bearings perform excellently in withstanding tilting moments. When the equipment is in operation, tilting moments are generated due to various factors (such as eccentric loads, wind forces, etc.), which puts forward high requirements for the anti – tilting ability of the slewing bearing.
Through its special structural design, the four – point contact slewing bearing can convert the tilting moment into the pressure between the steel balls and the raceways. When a tilting moment acts, the steel balls on one side are subjected to greater pressure, while those on the other side are under relatively less pressure. By changing the distribution of this pressure, it can resist the tilting moment. Some large – scale four – point contact slewing bearings can withstand tilting moments of up to tens of thousands of kilonewton – meters. For example, in large – scale port cranes, due to their large working radius and high lifting capacity, huge tilting moments are generated during the operation. The four – point contact slewing bearings used can withstand tilting moments of over 50000 kN·m, ensuring the stable operation of the crane under various working conditions.
Factors Affecting the Load – Carrying Capacity
The load – carrying capacity of four – point contact slewing bearings is affected by multiple factors. Firstly, material properties are one of the key factors. High – quality bearing steels, such as GCr15SiMn steel, have high strength, high hardness, and good wear resistance, which can improve the load – carrying capacity and service life of the slewing bearing. Secondly, manufacturing accuracy is also crucial. The machining accuracy of the raceways, the dimensional accuracy, and the roundness of the steel balls directly affect the contact state between the steel balls and the raceways and the even distribution of forces. High – precision manufacturing processes can make the contact between the steel balls and the raceways more uniform when the slewing bearing is under load, thereby improving the load – carrying capacity. In addition, parameters such as the shape and size of the raceways, and the number and diameter of the steel balls also affect the load – carrying capacity. Reasonably designing the shape and size of the raceways and selecting the appropriate number and diameter of the steel balls can optimize the load – carrying performance of the slewing bearing.
Calculation and Selection of the Load – Carrying Capacity
In practical applications, accurately calculating and reasonably selecting the load – carrying capacity of four – point contact slewing bearings is of great importance. Engineers need to perform precise calculations based on the specific working conditions of the equipment, including parameters such as the maximum axial force, radial force, tilting moment, rotational speed, and working temperature, in combination with relevant standards and calculation formulas for slewing bearings. At the same time, a certain safety factor needs to be considered to ensure that the slewing bearing can work safely and reliably during long – term operation. When selecting a slewing bearing, based on the calculation results, refer to the product samples and technical materials provided by slewing bearing manufacturers to select the appropriate specifications and models to meet the load – carrying capacity requirements of the equipment.
Price of Four – Point Contact Slewing Bearings
Materials are a crucial factor. Using high – quality steel and special alloys can enhance strength and wear resistance, increase costs, and thus lead to higher prices. For example, slewing drives made of materials containing special alloys are more expensive than those made of ordinary materials. Machining accuracy is also important. High – precision machining requires advanced equipment and technologies, which increases costs, and as a result, the product prices are higher. The slewing drives used in precision equipment generally have high prices. The manufacturing process also affects prices. Advanced processes can optimize performance but also increase costs, thereby raising the selling price.
Supplier of Four – Point Contact Slewing Bearings
LDB bearing company has risen from obscurity to become well – known in the industry, relying on its dedication to quality and pursuit of innovation. The company is located in Luoyang, Henan Province, where the bearing industry is developed, enjoying the advantages of industrial resources. For example, its self – developed straight – tooth gear slewing drives have high precision and strong stability, greatly improving the operation accuracy and efficiency of industrial welding robots. With high – quality products and attentive services, it has won numerous praises and is bound to create more glories in the future!
