The Applications of Dynamics of Slewing Bearings
Slewing bearings is a crucial component of mechanical equipment, and its dynamic characteristics have a significant impact on the performance of the equipment. It consists of an inner ring, an outer ring, rolling elements, and a cage. It has been found that the force and vibration characteristics vary under different working conditions.
What is Slew Bearing in the Dynamics?
Slewing bearings are widely used in equipment such as cranes, excavators, and wind turbines. They are responsible for transmitting axial forces, radial forces, and overturning moments. Their dynamic characteristics are of great significance for the stability, reliability, and service life of the equipment. Under different working conditions, the stress and motion states of slewing bearings are complex and variable. In – depth research on their dynamic characteristics helps to accurately grasp the working performance, provides strong support for optimized design, and thus enhances the competitiveness of the equipment.
Working Principle and Structural Types of Slewing Bearings
A slewing bearing usually consists of an inner ring, an outer ring, rolling elements, and a cage. The inner ring is connected to the fixed part of the equipment, and the outer ring is connected to the slewing part. When the equipment is operating, relative slewing motion is achieved through the rolling of the rolling elements between the raceways of the inner and outer rings, while bearing loads in different directions.
Common slewing bearings include single – row four – point contact ball type, double – row non – uniform diameter ball type, and crossed roller type. The single – row four – point contact ball type has a simple structure and low cost, and can withstand large axial forces and overturning moments. The double – row non – uniform diameter ball type has a strong load – bearing capacity and is suitable for heavy – load working conditions. The crossed roller type has good rigidity and high precision and is often used in equipment with strict requirements for slewing accuracy.
Analysis of the Dynamic Characteristics of Slewing Bearings under Different Working Conditions
Static Working Conditions
Under static working conditions, slewing bearings mainly bear the self – weight of the equipment, the weight of fixed components, and external loads in a stationary state. At this time, the stress distribution at the contact points between the rolling elements and the raceways depends on the magnitude and direction of the load. Through the elastic contact theory, the contact stress and deformation can be calculated, providing a theoretical basis for determining the load – bearing capacity and fatigue life of the slewing bearing.
Dynamic Working Conditions
Uniform Rotation Working Conditions
During uniform rotation, in addition to static loads, slewing bearings are also subjected to centrifugal forces and frictional forces. The centrifugal force causes additional pressure on the raceways by the rolling elements, and the frictional force affects the smoothness of rotation. Using the multi – body dynamics theory, a dynamic model of the slewing bearing is established to analyze its motion parameters and stress changes during uniform rotation, such as the rotational speed, acceleration of the rolling elements, and contact force fluctuations.
Starting and Braking Working Conditions
During the starting and braking processes, slewing bearings will generate impact loads. When starting, the driving torque overcomes the static friction force to accelerate the rotation of the slewing part; when braking, the braking torque decelerates the slewing part until it stops. In these two processes, the impact load may cause an instantaneous increase in the contact stress between the rolling elements and the raceways, affecting the service life of the slewing bearing. By using a dynamic simulation software to simulate the starting and braking processes, the magnitude and action time of the impact load are analyzed, providing a reference for optimizing the braking and starting strategies.
Variable Load Working Conditions
In actual work, slewing bearings often bear variable loads. For example, when a crane hoists a heavy object, the magnitude and direction of the load change with the working state. Variable loads can cause vibrations in slewing bearings, and in severe cases, affect the normal operation of the equipment. Modal analysis and response spectrum analysis methods are used to study the vibration characteristics of slewing bearings under variable loads, determine their natural frequencies and vibration responses, and provide a direction for structural optimization.
Research Methods
Theories such as material mechanics, elasticity mechanics, and contact mechanics are used to derive the calculation formulas for the stress and deformation of slewing bearings under different working conditions. Combined with the basic equations of dynamics, a dynamic model of the slewing bearing is established to analyze its motion and stress characteristics. Theoretical analysis provides a basis and direction for subsequent research.
Professional software such as ANSYS and ADAMS is used to establish a virtual model of the slewing bearing. The working states under different working conditions are simulated to obtain detailed dynamic parameters such as stress, strain, displacement, velocity, and acceleration. By changing the model parameters, the influence of various factors on the dynamic characteristics is studied, providing data support for optimized design.
An experimental platform for slewing bearings is built to simulate actual working conditions for loading tests. Sensors are used to measure parameters such as the stress, vibration, and rotational speed of the slewing bearing. The experimental results can verify the accuracy of theoretical analysis and simulation, and provide a basis for improving the research model.
Optimization Design Strategies Based on Dynamic Characteristics
Structural Parameter Optimization
According to the research results of dynamic characteristics, the structural parameters of slewing bearings are optimized, such as the number and diameter of rolling elements, and the radius of curvature of the raceways. Through optimization, the contact stress can be reduced, the vibration can be decreased, and the load – bearing capacity and service life can be improved.
Material Selection Optimization
Appropriate materials are selected to improve the strength, hardness, and wear resistance of slewing bearings. The use of new materials or surface treatment of existing materials can improve their mechanical properties to meet the requirements of different working conditions.
Manufacturing Process Improvement
The manufacturing process is optimized to improve the machining accuracy and assembly quality of slewing bearings. High – precision machining and assembly can reduce the gaps and errors between components, reduce vibration and noise, and enhance the dynamic performance of slewing bearings.
The Price of Slewing Bearings
There are many factors affecting the price of slewing bearings. Firstly, the specifications and dimensions are key factors. Large – sized slewing bearings with high load – bearing capacity are expensive due to high material consumption and complex processes. Secondly, the accuracy grade is also important. High – precision products are often more expensive due to strict processing requirements. Moreover, the quality of materials has a significant impact. Slewing bearings made of high – quality materials have good performance and a correspondingly higher price. In addition, the reputation of brand manufacturers, market supply – and – demand relationships, and surface treatment and protection requirements can all cause fluctuations in the price of slewing bearings. Products with special surface treatments usually have a higher price.
Supplier of Slewing Bearings
Since its establishment in 1999, LDB bearing company has been shining in the bearing manufacturing field. It is located in Luoyang, Henan Province, which is a bearing production base in China. Taking advantage of favorable geographical location and gathering industry elites, its slewing bearings, slewing drives and other products, with precise design and high – quality material selection, have high performance and reliability. This is best proved by its ISO9001:2015 certification and German TUV certification. Its products are exported to 73 countries and regions, serving many fields such as industrial robots and solar power generation equipment. It has partnered with many well – known international enterprises. From pre – sales customization, in – sales strict control to after – sales worry – free service, LDB bearing company interprets the responsibility of an industry model with comprehensive services, and is worthy of being a dazzling star in the bearing industry.
