The pitch control system plays a crucial role in wind turbines’ conversion of wind energy into electrical energy, guaranteeing both overall turbine safety and power generating efficiency. The HKW pitch bearing, one of the primary uses for HKW slewing bearings, serves as the crucial joint that joins the blades to the hub and offers strong support for the turbine’s effective operation.
01 Function of HKW Pitch Bearing
The HKW pitch bearing is installed within the hub of a wind turbine. Its core function is to achieve two primary objectives by dynamically adjusting blade pitch angle in real time: First, maintaining power balance at wind speeds exceeding the rated threshold; Second, during extreme wind speeds (such as typhoons) or equipment failures, it enables aerodynamic braking by pitching down (adjusting blade angle to 90°) to ensure safe shutdown of the entire turbine.
02 Core Structural Types and Advantages of HKW Pitch Bearing
To address the multi-directional load characteristics of wind turbine units, HKW has launched two specialized pitch bearing structures:
1.Double-Row Four-Point Contact Ball Slewing Bearing
Structural Features: Composed of two rows of spherical rolling elements, it provides stable support through a four-point contact design.
Performance Advantages: With a safety factor higher than industry averages, it can endure significant axial loads, radial loads, and overturning moments all at once；Particularly suited for onshore wind turbines with minimal load fluctuations, it effectively reduces contact wear between rolling elements and raceways, thereby extending service life.
2.Three-Row Cylindrical Roller Slewing Bearing
Structural Feature: Capability of a“two rows of axial rollers above and below + one row of radial rollers in the middle” arrangement. The upper and lower rows of rollers are parallel to the axial direction of the pitch bearing, specifically designed to bear the blade's self-weight and axial thrust forces exerted by wind (such as positive pressure during gusts and reverse pulling force during tailwind conditions).
Performance Advantage: Outstanding axial and radial load-bearing capability that can easily sustain the self-weight of powerful turbine blades and endure severe wind load effects. Perfect for offshore wind power applications with complex load situations or high-power wind turbines.
03 Design, Manufacturing, and Application Scope of HKW Variable Pitch Bearing
Targeted design for enhanced durability
Clearance and Raceway Optimization：Featuring four-point contact ball bearings with specially machined raceway profiles, this design significantly enhances load-bearing capacity while reducing vibration and noise during operation.
Gear and Material Upgrading: The variable-pitch gear is crafted from high-strength alloy materials. Through customized module selection, optimized tooth profile design, and targeted heat treatment, its tooth surfaces exhibit enhanced wear resistance and impact toughness, ensuring long-term meshing without tooth breakage or wear issues.
20-Year Service Life: By extending the bearing lifespan to more than 20 years, whole-process optimized design lowers mid-term replacement costs and aligns with the full life-cycle of wind turbines.
Wide compatibility, covering the entire power range
Leveraging extensive design and manufacturing expertise, HKW has launched multiple models of pitch bearing products compatible with wind turbines ranging from 1.5MW to 25MW in power capacity. Whether in the dusty, temperature-varying environments of onshore wind farms or the salt spray and high-wind conditions of offshore installations, HKW delivers stable and reliable blade pitch solutions, establishing itself as the preferred partner for global wind turbine manufacturers.
