What factors need to be considered in the selection of slewing bearing?

Publish time：2021/08/09 News Views：566

Slewing bearing can bear axial load, radial load, tilting moment, etc. at the same time, it can deal with the load situation. For the equipment, it is a key component for connecting up and down. It can realize support, rotation, transfer kinetic energy, fixed parts and other functions. So when the equipment needs a slewing bearing, how should we choose the slewing bearing suitable for our use? What factors need to be considered in the selection? Let’s do a specific analysis below.

How to choose a slewing bearing

1.Slewing bearing force condition

First of all, establish the force analysis model according to the actual working conditions, analyze and calculate the basic parameters such as axial load, radial load, tilting moment, etc that the slewing bearing needs to provide, then select the code according to the performance parameters provided in the slewing bearing catalog. When selecting slewing bearing according to load, you need to pay attention to choosing a reasonable safety factor.

For example, when the slewing bearing needs to bear an axial load of 50KN, if the safety factor corresponding to the working condition is 3, then you should choose a slewing bearing with a rated axial load ≥150KN. Only by choosing the right safety factor, the slewing ring can easily deal with various emergencies.

2.Slewing ring rotation requirements

Select suitable calculation formula according to the working conditions, respectively determine or calculate the slewing ring speed, system inertia, system resistance torque, total gear ratio, select suitable reducer and motor, this calculation process is more complicated, you need to familiar with the calculation methods of various working conditions, subtly split or boldly integrate, establish a reasonable physical model and correctly calculate the required data.

The simplest and most commonly used is to calculate the starting torque of the slewing ring. To calculate the starting torque, you need to know the actual axial load, tilting moment, rotation center diameter, equivalent radial load, acceleration resistance moment, etc., then use reasonable formulas and selecting appropriate calculation coefficients, you can calculate accurate values and select suitable reducers and motors.

After the slewing ring is installed, it’s necessary to track the equipment operation, record the feedback in the design calculation file, analyze the calculation scientific nature, through repeated comparisons, you can master scientific calculation methods.

3.Slewing bearing working temperature

For the slewing bearing selection and design, it’s necessary to know the slewing bearing’s working temperature. The operating temperature determines seal selection, grease selection and cage selection of the slewing bearing. If these auxiliary parts are improperly selected, it will directly affect the slewing bearing service life, even directly damage the slewing bearing.

For example, the operating temperature of the slewing bearing is 70°C. How should we choose these auxiliary components? 70°C is a relatively high operating temperature. For sealing, we should choose high temperature resistant seals (fluorine rubber seals, working temperature -15°C to 280°C).

For grease, we should choose high temperature grease (Mobil SHC460 grease, working temperature -30℃ to 150℃). For cages, we should choose high-temperature resistant material (metal cages or spacers). These factors must be taken into account when selecting the slewing bearing model. It’s best to provide users with clear selection instructions.

4.Slewing ring working environment

When we design and select the slewing ring, we must consider the slewing bearing use environment. Such as a clean and dry workshop, a workshop with high dust and high humidity, harsh outdoor environment, seaside use, etc. These factors determine how to protect the slewing bearing, such as make spray treatment, make protective housing, make surface treatment with painting, etc.

For example, when the slewing bearing is used in the environment with high dust and high humidity, we should consider using a good sealing. If necessary, use multi-layer seals to prevent the raceway from being polluted by moisture and dust. The slewing ring surface should be treated with rust prevention, which can prolong the slewing bearing service life and ensure that the user’s environment is not polluted.

The slewing bearing selection should comprehensively consider various related factors. The above four important points are listed, but various other factors will be encountered in actual production and use. If you do not fully consider the impact of various factors on use when designing and selecting, it will cause trouble for customers.

Therefore, when designing new equipment, you need to fully communicate with professional technicians. Only in this way can avoid the trouble in later use. The technical team of Unique Transmission is always ready to interact with you at any time, learn together and make progress together.