Wind turbine main shafts and gearbox cooling vertical fans are core supporting equipment for onshore and offshore wind power. Bearing support positions operate under harsh conditions: alternating wind impact loads, continuous vibration caused by blade rotation, deflection of long main shafts, coaxial deviation during installation, wide temperature variation throughout four seasons in the wild, salt spray erosion in coastal areas, persistent intrusion of wind sand and dust, and long-term intermittent operation all year round. Most wind farms are located in remote mountainous areas and coastal tidal flats. The hoisting and maintenance cost of wind turbines is extremely high. Once the bearings of main shafts or cooling fans fail, the unit must be shut down for maintenance with a long downtime period, directly leading to massive power generation losses. Ordinary spherical roller bearings cannot adapt to the composite environment of wind power equipment featuring continuous vibration, drastic temperature difference and coastal salt spray. They are prone to edge stress concentration of rollers, grease solidification at low temperature and deterioration at high temperature, as well as seal aging causing water and dust ingress, which has become a key challenge for wind turbine manufacturers and wind farm operation teams.

Focusing on transmission supporting field for wind power equipment, Japan NMT specially develops spherical roller bearings dedicated for wind turbine main shafts and gearbox cooling vertical fans to solve industry pain points including continuous alternating vibration of wind power equipment, eccentric load caused by shaft deflection, alternating high-low temperature cycles, erosion by coastal salt mist and dust, and high requirements on service life under long-term maintenance-free operation. Taking advantage of optimized double-row spherical roller self-aligning structure, combined with five core upgrades including high-purity bearing steel for wind power, low-vibration profiled rollers, reinforced brass cages, optional salt-spray resistant composite seals and clearance & lubrication matching suitable for wide temperature range, the bearings fully compensate main shaft deflection and assembly misalignment and restrain vibration fatigue damage. Adaptable to inland wind-sand and coastal salt-mist wind farms, they fundamentally relieve stress concentration under misalignment, lubrication failure induced by temperature variation and corrosion from dust and salt mist, stabilize rotation precision of main shafts and cooling fans and extend fault-free operation duration of wind turbines.

Core Product Advantages

1. Efficient self-aligning performance to adapt to long shaft deflection and assembly deviation: Spherical raceways matched with double-row spherical rollers with optimized profiles allow reasonable angular offset, absorb deflection deformation of main shafts under wind loads, avoid unilateral loading of rollers and greatly reduce edge stress concentration, effectively improving eccentric load operation of long shaft systems for wind turbines.

2. Resistance to alternating vibration loads to withstand intermittent impact of wind energy: Symmetric double-row bearing structure provides sufficient contact area to continuously bear alternating radial and axial impact loads generated by unstable wind force. Precisely profiled roller surfaces weaken vibration amplification effect and delay contact fatigue spalling caused by long-term vibration.

3. Thermally stable substrate for wide temperature range to adapt to drastic seasonal temperature change in wild areas: Selected high-purity bearing alloy steel specially for wind power undergoes stabilized heat treatment with excellent dimensional stability. It resists seizure due to shrinkage at low temperature and restrains creep deformation under high temperature, suitable for long-term operation within -40℃ ~ 120℃.

4. Low-vibration precision machining reduces frictional temperature rise inside bearings: Micron-level super-finishing on raceways and optimized profile at roller ends improve contact stress distribution, lower operating vibration and frictional heat generation and slow grease aging, meeting the demand of long-time intermittent start-stop operation of fans.

5. Multiple sealing options against dust and coastal salt spray corrosion: Open type, contact sealed type and salt-spray resistant composite sealed type are available. C3/C4 clearances are preferred. Dust-proof seals can be configured for inland wind-sand sites, while multi-layer salt-spray resistant sealing structures are optional for offshore wind power units to block ingress of water vapor, salt mist and sand into bearings.

Application Scenarios

Low-speed main shaft support bearings for onshore and offshore wind turbines; spindle bearings for gearbox cooling vertical fans and cabin ventilation fans; transmission supports for cooling towers and dust removal fans matched with wind power; heavy-duty supporting positions of transmission auxiliary equipment for wind turbines of 2MW, 3MW, 5MW and above.

Precision Quality Assurance

NMT spherical roller bearings for wind power series are manufactured strictly in accordance with Japanese manufacturing standards for wind power equipment components. Raw materials are screened by ultrasonic flaw detection. Tests including alternating vibration durability test, high-low temperature cycle dimensional stability test, neutral salt spray corrosion test, dust sealing durability test and long-term fluctuating load fatigue test are carried out. Featuring reliable self-aligning capacity, outstanding vibration fatigue resistance and stable dimensional performance under wide temperature conditions, the bearings fully satisfy long-term intermittent operation conditions of inland mountain and coastal offshore wind farms.

Product Range

Standard open-type spherical roller bearings for wind power, salt-spray resistant sealed spherical roller bearings, low-vibration heavy-duty spherical roller bearings with brass cages, customized large-bore spherical roller bearings for wind power equipment. Both cylindrical bore and tapered bore mounting specifications are available.

Brand Strength

Japan NMT focuses on R&D and manufacturing of transmission bearings for wind power equipment, specializing in core technologies including alternating vibration fatigue control, wide-temperature dimensional stabilization technology, long-life salt-spray resistant sealing and simulation optimization of self-aligning profiles. Supported by refined heat treatment production lines and complete wind power condition simulation testing platforms, NMT solves common industry pain points of wind turbine bearings such as vibration-induced fatigue spalling, operation failure under temperature alternation, corrosion by salt mist and dust and short maintenance intervals, supplying highly reliable long-service-life spherical roller bearing solutions for global wind power equipment manufacturers.