LTZC wind turbine bearings power 8MW offshore wind turbines

Amid the global trend of accelerating energy structure transformation, offshore wind power is becoming a key clean energy sector for many countries. However, offshore wind turbines operate in extreme environments characterized by high salt spray, high humidity, strong wind loads, and continuous vibration, placing extremely high demands on critical components—wind turbine bearings.

In 2025, a European offshore wind developer deployed an 8MW offshore wind turbine project in the North Sea, setting stringent requirements for the precision bearings and slewing ring bearings the main shaft and yaw systems. After multiple rounds of technical reviews and on-site verification, LTZC was selected as the core bearing supplier for the project.

Key Technical Requirements of the Project

This project explicitly sets forth the following core technical indicators:

Single Unit Capacity: 8MW offshore wind turbine

Design Life: ≥ 20 years

Average Annual Operating Hours: ≥ 7,500 h

Extreme Wind Conditions: Typhoon-resistant design up to 70 m/s

Operating Temperature Range: –40℃ ～ +85℃

Main Bearing Rated Dynamic Load Requirement: ≥ 3.8 × 10⁷ N

Yaw Rotation System Rotation Accuracy: ≤ 0.01 mm

The project requirements not only focus on load-bearing capacity but also emphasize long-term reliability and stability, which places extremely high demands on the comprehensive technical capabilities of the bearing manufacturer.

III. LTZC bearing Solution: Holistic Engineering Design from Materials, Structure to System

1. Main Bearing System Configuration (Wind Turbine Bearing)

LTZC custom-developed a double-row roller main bearing for this project. This bearing was not simply an enlarged version, but rather a system-wide redesign in terms of raceway curvature radius, roller length ratio, and load distribution model.

Key technical parameters are as follows:

Bearing outer diameter: 3,850 mm

Inner diameter: 2,920 mm

Total width: 520 mm

Single set weight: Approximately 6.8 tons

Range hardness: 60 ±1 HRC

Range surface roughness (Ra): ≤ 0.32 μm

Through the asymmetric raceway structure design, the bearing's axial load capacity is increased by approximately 22% compared to traditional structures, while effectively reducing local stress concentration problems, fundamentally delaying the initiation and propagation of fatigue cracks.

2. Slewing Ring Bearing for Yaw Bearing System

The yaw system is a key component of the wind turbine's dynamic adjustment. LTZC provided a three-row roller slewing ring bearing for this project, integrating an external gear structure to achieve a unified design for rotation and drive.

Key parameters include:

Slewing ring outer diameter: 5,200 mm

Gear module: m = 12

Gear accuracy grade: ISO 1328 Grade 6

Static load capacity: 45,000 kN

Overturning moment capacity: ≥ 120,000 kN·m

This slewing ring bearing employs multi-labyrinth seals and marine-grade composite sealing materials, successfully passing 720 hours of salt spray testing and high-humidity-heat cycling testing, significantly improving long-term sealing reliability.

3. Integrated Bearing Gear System

To improve the overall transmission efficiency of the yaw bearing system, LTZC designed and manufactured an integrated bearing gear assembly, synergistically optimizing the structure and load of the rolling bearing and the large-module gear.

This system uses 18CrNiMo7-6 high-strength alloy steel with deep carburizing treatment on the tooth surface:

Carburized layer depth: 1.8 – 2.2 mm

Surface hardness: 58 – 62 HRC

Tooth surface roughness: Ra ≤ 0.8 μm

This solution improves transmission efficiency by approximately 14% and reduces the overall structural length by approximately 18%, significantly improving the compactness of the engine room's internal structure.

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The value that LTZC wind turbine bearings bring to customers

Unplanned downtime reduced by approximately 35%

Operating and maintenance costs reduced by approximately 18%

Annual equivalent generating hours increased by approximately 4–6%

By adopting LTZC's integrated wind turbine bearing solution, this offshore wind power project has achieved significant and quantifiable economic benefits during the actual commercial operation phase. These results are not accidental, but rather built upon LTZC's strong manufacturing capabilities, rigorous quality management system, and mature engineering experience.

Why Choose LTZC Wind Turbine Bearings ？

Choosing LTZC wind turbine bearings means choosing reliability, precision, and long-term value.

LTZC possesses a complete large-scale bearing manufacturing system and is a leading slewing bearing manufacturer in China, handling everything in-house from forging and precision machining to heat treatment and assembly. Key dimensional accuracy is consistently controlled at the micron level, and raceway surface roughness reaches Ra ≤ 0.32 μm, ensuring long-term stable operation.

LTZC wind turbine bearings feature an optimized structural design, increasing load capacity by 15%–30%, with a design life exceeding 175,000 hours. They are adaptable to extreme environments ranging from -40℃ to +85℃ and have passed a 720-hour salt spray test.

LTZC not only provides wind turbine bearings but also covers precision bearings, slewing ring bearings, and bearing gear, supporting customized bearings. This helps customers reduce failure rates, extend maintenance cycles, improve power generation efficiency, and continuously reduce total lifecycle maintenance costs.

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