Slewing bearing, also known as rotary bearing, is one kind can also bear larger axial load, radial load and overturning moment of large bearing. Wheel bearings are generally installed with a hole, internal or external gear lubricants hole and sealing devices, which enable mainframe structure design is compact, reliable, convenient maintenance guide.
Slewing bearings have no gear, external gear and the internal gear type four point contact ball bearing, double row angular contact ball bearing, crossed cylindrical roller bearing, crossed tapered roller bearing and three row cylindrical roller combined bearings and so on many kinds of structure patterns. The four point contact ball bearing with the static load capacity is higher; cross cylindrical roller bearings have high dynamic load capacity; rotary precision crossed tapered roller bearing by interference can cause the bearing has a larger support rigidity and higher.
Slewing bearings are widely used in hoisting machinery, mining machinery, construction machinery, port machinery, ship machinery and high precision radar mechanical and missile launchers on large rotary device.
Application of rotating bearings in various fields.
1 wind power generator
The yaw bearing is installed on the connecting part of the tower and cabin, variable paddle bearing installed in the root and the hub of each blade connecting parts. Each wind generator with a set of yaw bearing and three sets of variable pitch bearings. Pitch and yaw bearing material is 42CrMo, heat treatment using whole quenching and tempering, the raceway surface quenching. The stress situation of yaw, pitch bearing complex, but also bear the shock and vibration is relatively large, therefore, requirements of bearing can bear the impact, but also can bear larger load. Wind turbine host life requirement of 20 years, the cost of installation and bearing large, therefore asked the yaw, pitch bearing life to reach 20 years. Bearing ring matrix hardness is 240-280HB, able to withstand shock and plastic deformation does not occur at the same time, the raceway surface quenching hardness reaches 55-62HRC, which can increase the contact fatigue life, so as to ensure the long life of use requirements of bearing.
2 the ship crane
The ship crane generally use double row reducing ball, four point contact ball slewing bearing three rows of rollers, the inner tooth structure, according to the bearing capacity of the different, the three row roller slewing bearings are usually used for heavy-duty cranes, four point contact ball slewing and double row reducing ball turntable bearing for light hoisting machine.
Because the crane working at -20 DEG C - +45 degrees C environment, this kind of bearing on the mechanical properties of the material requirements of high.
3 offshore platform crane
According to the requirement of the bearing capacity of different, offshore platform crane often use four point contact ball slewing and the three row roller slewing bearing inner tooth.
Slewing bearing used in the offshore platform crane requires special material, the mechanical properties of the material to be able to ensure the safety coefficient of limit load, forging sampling Charpy impact experiment can achieve average 42J@-20 degrees C degrees C or 27J@-40. Bearing finished product to Veritas certification.
The 4 harbour mobile crane
The three row roller slewing bearing of port crane usually use internal or external toothing diameter 4 meters, to withstand overturning moment is very high.
The 5 stacker reclaimer
Slewing bearing stacker reclaimer used usually adopts ball column combined type, three rows of roller type and cross roller type, diameter of 3 meters most super. Because of the poor working environment, dust, this kind of bearing has high carrying capacity, long service life, good sealing performance characteristics.
6 the ferris wheel
For the four point contact ball slewing bearing the ferris wheel, diameter 4100mm, thickness 85mm
The 7 ship unloader
Slewing bearing ship unloader with external teeth usually adopts three rows of rollers in structure, about 4 meters in diameter.
8 tower crane
Tower crane turntable bearing usually use small size four point contact ball slewing bearings or two volleyball turntable, a diameter of not more than 2 meters.
9 radar antenna
Shortwave antenna generally with the three row roller slewing bearing structure of the rotating speed is slow.
10 shield machine
Shield machine for wheel bearing diameter from 2.5 meters to 6 metres, and some larger diameter, this kind of bearing working in very bad condition, the bearing load is large, strong corrosion resistance, short service life.
11 ladle turret
Ladle turret with turntable bearing usually adopts three roller structure, because of the bad conditions in with dust and high temperature conditions of work, to the holder, grease and seal are the very high request.
12 Construction Machinery
Turntable bearing for engineering machinery usually adopts the small size of the four point contact ball slewing bearing, diameter of not more than 2 meters.