THB’s pitch bearings allow the turbine blade to be indexed or positioned to optimize blade angle, depending on wind speed. Our yaw bearings allow the turbine nacelle to rotate into the wind and support the nacelle on the tower.
Types:Generally, yaw and pitch bearing structures are single row ball slewing rings four-point contact bearing and double row ball slewing ring four-point contact bearing. And both these two types of bearings can be further divided into bearings without gears, bearings with internal gears, bearings with external gears according to gear position.
Material and heat treatment
Rolling elements’ material: GCr15 or GCr15SiMn bearing steel
Rings’ material: 42CrMo
Value of notched bar impact work: less than 27J at -20ºC
Hardness of rings: 55HRC~62HRC after hardening and quenching
Hardness of raceway: 55HRC~62HRC after hardening and quenching
Width of soft area: larger than plug diameter +35mm at the groove of the plug
Gear: involute cylindrical gear with radial modification coefficient x=+0.5; precision and modulus as ISO standard
Radial and axial clearance of yaw bearings: 0~50µm
Radial and axial clearance of pitch bearings: less than 0µm
Lubrication: through lubrication hole(screwed hole: M10×1)
Seal material: NBR
Spacer: self-lubricated spacers,which can compensate for lubrication when lubrication oil is unevenly distributed in order to maintain best lubrication status between balls and groove contact areas.
Cage: integrated steel cage which has simple structure and can save space and accommodate more balls to increase load capacity. Compared with traditional segmented cage, integrated cage is easier to assemble and more stable and reliable.
Preservation treatment: except for groove and gear all other surfaces should be applied thermal spraying anti-corrosion treatment according to ISO standard, when applied zinc coating, the thickness of anti-corrosion should be no less than 160µm, other anti-corrosive treatment shall be applied if it meets performance requirements of the machine.
Wind turbine applications:
Pitch and yaw
High and low wind speed
Land-based or offshore
800KW to 3.0 MW
Critical operating temps to -40ºC
