How does the sealing device for a three-row cylindrical roller slewing ring work?

What is three-row cylindrical roller slewing bearing?

Three-row cylindrical roller slewing bearings, also known as slewing ring bearings with three rows of rollers, feature three separated raceways for upper, lower, and radial loads, enabling each roller row to handle specific load distributions. Their robust structure and large diameter make them suitable for heavy-duty applications such as bucket-wheel excavators, mobile cranes, marine cranes, port cranes, ladle turrets, and other large-scale equipment requiring high load capacity.

Features of three-row cylindrical roller slewing rings

High bearing capacity: due to the presence of three rows of cylindrical rollers, and each row of rollers bears loads in different directions, the three-row cylindrical roller slewing ring can bear large axial force, radial force and overturning moment at the same time, and the bearing capacity is higher than that of other types of slewing rings.

Good rigidity: The structural design of the three-row cylindrical rollers makes it have high rigidity, which can effectively reduce the deformation of the slewing ring when bearing the load, ensure the slewing accuracy and stability of the equipment, and is especially suitable for large mechanical equipment with high precision requirements.

Smooth operation: the cylindrical roller and the raceway are in line contact, the contact area is large, and the rolling friction is small, so the three-row cylindrical roller slewing ring is more stable in the operation process, the noise is low, the vibration is small, and the work efficiency and reliability of the equipment can be improved.

Long life: high bearing capacity, good rigidity and smooth operation, so that the three-row cylindrical roller slewing ring has a long service life under normal use conditions, reducing the maintenance and replacement cost of the equipment.

Compact structure: Under the same load capacity, the axial and radial dimensions of the three-row cylindrical roller slewing ring are relatively small and compact, which can make the design of the host equipment more compact and save installation space.

The working principle of a three-row cylindrical roller slewing ring

When the inner or outer ring of a slewing ring is subjected to an external force, the cylindrical rollers roll on the raceway, thus achieving a relative rotational motion between the inner and outer rings. Wherein, the cylindrical roller that bears the axial force mainly rolls on the axial raceway, the cylindrical roller that bears the radial force mainly rolls on the radial raceway, and the cylindrical roller that bears the overturning moment rolls on the corresponding raceway according to the direction of the moment, and in this way, the three rows of cylindrical rollers work together to bear various loads together and ensure the normal operation of the slewing bearing.

How does the sealing device for a three-row cylindrical roller slewing ring work?

The sealing device of the three-row cylindrical roller slewing ring mainly works in the following common forms to achieve the function of preventing lubricating oil leakage and preventing the entry of external impurities:

Lip seal

Structure & Material: Lip seals are typically made of an elastic material such as rubber or plastic with one or more lipes. The lip fits snugly to the surface of the inner or outer ring of the slewing ring, creating a sealed contact.

Working principle: When the slewing ring is running, the lip of the lip seal relies on its own elastic deformation and always maintains close contact with the surface of the rotating part. This close contact forms a barrier against oil leakage and the ingress of external impurities. At the same time, the contact force between the lip and the rotating surface will produce a certain friction force, which should be controlled within the appropriate range, not only to ensure the sealing effect, but also not to cause excessive energy loss and component wear.

Labyrinth sealing

Structure: The labyrinth seal consists of a series of interlaced annular grooves and protrusions that form zigzag passages. These channels are usually set between the inner and outer rings, concentric with the axis of rotation of the slewing ring.

How it works: When lubricating oil or outside impurities try to pass through the sealing area, they need to zigzag along a labyrinth of passages. In this process, it is difficult for impurity particles to pass through the entire maze smoothly due to their own inertia and the obstruction of the channel; Lubricating oil, on the other hand, forms an oil film in the channel, which uses the viscous resistance and surface tension of the oil film to prevent further leakage. In addition, the structure of the labyrinth seal allows the air to form a certain air resistance in the channel, which also helps to prevent the intrusion of external impurities and the leakage of internal lubricating oil.

Combined seals

Structure: Combined sealing is a combination of lip sealing and labyrinth sealing and other sealing forms to give full play to their respective advantages to improve the sealing effect. For example, in some three-row cylindrical roller slewing rings, a lip seal is used close to the inside of the slewing ring for the main sealing effect, while a labyrinth seal is provided on the outside as an auxiliary seal to further enhance the sealing performance.

Working principle: The working principle of combination sealing is the synergy of multiple sealing forms. The lip seal first blocks and seals the oil and impurities, while the labyrinth seal acts as a second line of defense to intercept the small amount of oil and impurities that may bypass the lip seal. This combination can take advantage of various sealing forms under different operating conditions and provide more reliable sealing performance.

In practical application, the sealing device of the three-row cylindrical roller slewing ring also needs to be reasonably selected and designed according to the specific working environment, working conditions and structural characteristics of the slewing ring, so as to ensure that its sealing performance is reliable and can meet the requirements of long-term stable operation of the equipment.

Three Row Cylindrical Roller Slewing Bearing Supplier

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