English 
 |
| Quantity: | |
|---|---|
Yaw bearing is a speical kind of slewing ring bearing, it is in the bottom of the wind turbine. It is used for adjusting the facing wind angle of the wind generator at proper time and transits thunders to the ground. It mainly supports axial load, radial load and tilting moment. The yaw bearing is required to be tight sealed, high reliability, smooth rotation, strong stability, surface anti-corrosive, long life over 20 years and strictly start moment non loaded.
The yaw beaing structure generally use extra-large size four-point contact ball slewing bearing and double row ball slewing bearings with external teeth or internal teeth.
Technical requirement of Yaw bearing for wind turbine:
1. Material and heat treatment
The material of outer & inner rings in yaw bearings is usually 42CrMo, with hardness 229-269HB after quenching and tempering. The low-temperature impact of the material 42CrMo is -40ºCAKV, not less than 27J.
Rolling elements in yaw bearing are made of GCr15 or GCr15SiMn bearing steel.
The quenching hardness of the raceway surface is 55HRC-62HRC.
2. gear of the yaw slewing bearing
Ring gear in the yaw slewing bearing is mainly cylindrical gear with gear radial modification coefficient X=+0.5. The gear accuracy should be 8 class or higher.
3. Clearance
Generally the radial and axial clearance of yaw bearing is 0-50μm.
4. Seal
Because the wind turbine is exposed to the wild, there are strict requirements on the sealing performance of the yaw bearings, the seal form of the yaw bearing must be optimized to ensure that the bearing life is the same as the wind turbine. Wind turbines are installed at an altitude of more than 50m or even hundreds of meters, and the cost of assembly and disassembly is expensive. Therefore, they must have very high reliability.
Generally, they require 20 years of life. In addition, the bearing structure is complicated, so the requirements for design and manufacture of yaw bearing are extremely high.
6. Spacer and cage
Yaw bearings for wind turbines have spacers that are self-lubricated and can compensate for lubrication when lubrication oil is unevenly distributed in order to maintain best lubrication status between balls and groove contact areas.
7. Preservative treatment
For the yaw bearings, all surfaces except the groove and gear should be applied thermal spraying anti-corrosion treatment
When applied zinc coating, the thickness of anti-corrosion layer shall be no less than 160μm. Other anti-corrosion treatment can be applied to meet the performance requirements of the machine.
Yaw bearing is a speical kind of slewing ring bearing, it is in the bottom of the wind turbine. It is used for adjusting the facing wind angle of the wind generator at proper time and transits thunders to the ground. It mainly supports axial load, radial load and tilting moment. The yaw bearing is required to be tight sealed, high reliability, smooth rotation, strong stability, surface anti-corrosive, long life over 20 years and strictly start moment non loaded.
The yaw beaing structure generally use extra-large size four-point contact ball slewing bearing and double row ball slewing bearings with external teeth or internal teeth.
Technical requirement of Yaw bearing for wind turbine:
1. Material and heat treatment
The material of outer & inner rings in yaw bearings is usually 42CrMo, with hardness 229-269HB after quenching and tempering. The low-temperature impact of the material 42CrMo is -40ºCAKV, not less than 27J.
Rolling elements in yaw bearing are made of GCr15 or GCr15SiMn bearing steel.
The quenching hardness of the raceway surface is 55HRC-62HRC.
2. gear of the yaw slewing bearing
Ring gear in the yaw slewing bearing is mainly cylindrical gear with gear radial modification coefficient X=+0.5. The gear accuracy should be 8 class or higher.
3. Clearance
Generally the radial and axial clearance of yaw bearing is 0-50μm.
4. Seal
Because the wind turbine is exposed to the wild, there are strict requirements on the sealing performance of the yaw bearings, the seal form of the yaw bearing must be optimized to ensure that the bearing life is the same as the wind turbine. Wind turbines are installed at an altitude of more than 50m or even hundreds of meters, and the cost of assembly and disassembly is expensive. Therefore, they must have very high reliability.
Generally, they require 20 years of life. In addition, the bearing structure is complicated, so the requirements for design and manufacture of yaw bearing are extremely high.
6. Spacer and cage
Yaw bearings for wind turbines have spacers that are self-lubricated and can compensate for lubrication when lubrication oil is unevenly distributed in order to maintain best lubrication status between balls and groove contact areas.
7. Preservative treatment
For the yaw bearings, all surfaces except the groove and gear should be applied thermal spraying anti-corrosion treatment
When applied zinc coating, the thickness of anti-corrosion layer shall be no less than 160μm. Other anti-corrosion treatment can be applied to meet the performance requirements of the machine.
