What Is Three Row Roller Slewing Bearing

The three row roller slewing bearing is the one with the largest bearing capacity, and the shaft and radial dimensions are both large and firm. Generally used in heavy duty machinery. Many of the heavy machinery used in our lives are three row roller slewing ring bearings, but many people do not understand its specific information. This article aims to describe the three row roller slewing bearing in detail.

This article contains the following points: 

• Definition

• Application

• Different size

1、Definition

The three row roller slewing bearing has three rows of raceways and the rolling elements are steel rollers. This structure can withstand the most loads compared to other structural load types. A heavy-duty machine usually uses three rows of roller slewing bearings. The three-row roller rotor ring is equipped with a seat ring and an upper orbital ring. It does not separate the track from the radial track, and can determine the load of each row of the roller so that it can withstand various loads at the same time. The bearing has the largest bearing capacity in four models, large axial and radial dimensions, and the three row roller slewing bearing ring structure is firm.

The bearing is mainly composed of 50 Mn, 42 CrMo and C45.

2、Application

The three row roller slewing bearing has three races, the upper and lower and the radial raceways are separated, so that the load of each row of rollers can be accurately determined, and can bear various loads at the same time, which is the bearing capacity of four products. The largest one, with large shaft and radial dimensions, is particularly suitable for heavy machinery requiring large diameters, such as bucket wheel excavators, wheeled cranes, marine cranes, ladle slewing and large tonnage truck cranes. on.

Wind turbine

The yaw bearing is installed at the connection between the tower and the cockpit, and the pitch bearing is installed at the joint of the root of each blade and the hub. Each wind turbine uses a set of yaw bearings and three sets of pitch bearings. The material of the yaw and pitch bearing ring is 42CrMo, and the heat treatment is treated by integral quenching and tempering, and the raceway surface is quenched. The yaw and pitch bearings have complex forces and are subject to large shocks and vibrations. Therefore, the bearings are required to withstand shocks and withstand large loads. The life expectancy of wind turbine main engine is 20 years, and the cost of bearing installation is relatively large. Therefore, the life of yaw and pitch bearing is required to reach 20 years. The bearing ring base has a hardness of 240-280HB, can withstand impact without plastic deformation, and the quenching hardness of the raceway surface reaches 55-62HRC, which can increase the contact fatigue life, thus ensuring the long-life bearing requirements of the bearing.

2. Marine crane

Marine cranes generally use double-row ball, four-point contact ball, and three-row roller internal gear structure. According to different bearing capacity, three row roller slewing bearings are usually used for heavy-duty cranes, four-point contact ball turntables and Double row ball slewing bearings for light cranes.

Because the crane works in the environment of -20 ° C - + 45 ° C, this type of bearing requires high mechanical properties of the material.

3. Offshore platform crane

According to different bearing capacity requirements, offshore platform cranes usually use four-point contact ball turntable and three-row roller internal tooth turntable bearings.

The slewing bearing used on the offshore platform crane has special material requirements. The mechanical properties of the material should ensure the safety factor under the ultimate load. The forging specimen can be averaged 42J@-20°C or 27J@-40. °C. The finished bearing is to be certified by the classification society.

4. Port mobile crane

Port cranes typically use three row roller slewing bearings with internal or external teeth of 4 meters in diameter to withstand high overturning moments.

5. Stacker and reclaimer

The slewing bearings for stacker reclaimers are usually ball-column combined, three-row roller type and cross-roller type, most of which are over 3 meters in diameter. Due to the harsh working environment and large dust, these bearings have the characteristics of high bearing capacity, long service life and good sealing performance.

6. Ferris wheel

Four-point contact ball slewing bearing for Ferris wheel, outer diameter 4100mm, thickness 85mm

7. Ship unloader

The slewing bearing for the ship unloader usually adopts a three-row roller structure with external teeth and a diameter of about 4 meters.

8. Tower crane

The slewing bearings for tower cranes usually use small-size four-point contact ball slewing bearings or double volleyball turntables with a diameter of no more than 2 meters.

9. Radar antenna

The short-wave antenna generally uses a three-row roller structure of a slewing bearing, and the rotation speed is slow.

10. Shield machine

The diameter of the slewing bearing of the shield machine ranges from 2.5 meters to 6 meters, and some of the diameters are larger. These bearings work under very harsh conditions. The bearings have large load carrying capacity, strong corrosion resistance and short life.

11. Ladle turntable

The slewing bearings for ladle turrets usually use a three-row roller structure. Due to the harsh conditions under dust and high temperature conditions, there are high requirements for retainers, greases and seals.

12. Construction Machinery

The slewing bearings for construction machinery usually use small-size four-point contact ball slewing bearings with a diameter not exceeding 2.

3、Different size of the bearing

1. The diameter of the center circle of the raceway is 500~1800 mm, with the cylindrical surface 6.3; each end face 12.5; the sealing friction surface 3.2; the grinding raceway surface 1.6; the non-frying raceway surface 3.2; the raceway transition arc 3.2

2. The diameter of the center circle of the raceway is >1800~4500 mm, with the cylindrical surface 6.3; the end surface 12.5; the sealing friction surface 6.3; the grinding raceway surface 1.6; the non-fresh raceway surface 6.3; the raceway transition arc surface 3.2

3. Tooth surface: m≤10 mm or m≤10 mm

The three row roller slewing bearing is widely used and is the preferred bearing for heavy machinery. Understanding the above knowledge allows consumers to choose different types of three row roller slewing ring bearings to meet the required requirements. When you see the corresponding machine, you can judge whether the machine is qualified according to this knowledge. After all, suitable bearings are very important for machinery.