The core purpose of self-aligning roller bearings for fans is to support the main shaft or gearbox rotor of the fan, compensate for installation errors and operational deviations, withstand complex loads, and ensure long-term stable operation of the fan under high-speed, heavy load, and variable working conditions. Its specific functions can be expanded from the following aspects:
1. Support and rotation function.
High load-bearing capacity: Its double row roller structure (with each row of rollers arranged at a certain angle) can simultaneously withstand radial loads (such as impeller weight, airflow reaction force) and axial loads (such as gear meshing force, thrust generated by changes in wind direction), making it suitable for heavy-duty wind turbine conditions.
.2. Automatic centering compensation installation error
Coping with eccentricity and tilt: During the installation of the fan, the main shaft may be offset or tilted due to foundation settlement, component processing errors, or thermal expansion.
. The spherical raceway design of self-aligning roller bearings (with the outer raceway being spherical) allows for automatic adjustment of the angle between the inner ring and the roller in the radial plane (usually the self-aligning angle is 1 °~2.5 °), compensating for installation errors and avoiding stress concentration at the edge of the bearing. Reduce vibration and noise: Through the automatic centering function, the bearing can maintain a uniform load distribution, reduce vibration and noise caused by eccentricity, and extend the overall life of the bearing and fan.3. Adaptability to complex working conditions and variable loads
High speed operation stability: The main shaft speed of the wind turbine is usually several hundred to several thousand revolutions per minute (such as the wind turbine main shaft speed of about 10-20 rpm, but the gearbox can reach several thousand rpm after increasing speed). The self-aligning roller bearing reduces centrifugal force and friction at high speeds by optimizing the roller shape (such as logarithmic convexity) and cage structure (such as copper alloy or polyamide cage), ensuring smooth operation.
. Variable load adaptability: The load of the wind turbine fluctuates with changes in wind speed and direction during operation (such as alternating loads generated by turbulence on wind turbine blades). The elastic contact design of the self-aligning roller bearing can absorb some of the impact and avoid fatigue damage.4. Environmental Corrosion Resistance and Long Life Design
Sealing and Lubrication: Fans are often exposed to outdoor or harsh environments (such as wind and sand, salt spray in wind farms), and self-aligning roller bearings are usually equipped with dust-proof seals (such as double lip seals) and long-lasting lubricants (such as lithium based or polyurea based lubricants) to prevent impurities from entering and reduce lubricant loss, extending maintenance cycles.
.Materials and Heat Treatment: The bearing rings and rollers are made of high carbon chromium bearing steel (such as GCr15) or carburizing steel (such as 20CrMnTi), which is quenched and tempered to achieve a surface hardness of HRC60-65 and good core toughness, which can resist failure modes such as pitting and peeling.
.5. Typical application scenarios
Wind power field: used for the main shaft bearings (single or double row self-aligning roller bearings) and gearbox bearings of wind turbines, supporting the rotation of the impeller and transmitting power to the generator.
.Industrial ventilation: in large fans and blowers, self-aligning roller bearings support the main shaft to ensure the continuity of air flow transmission.
Air conditioning compressors: Some centrifugal air conditioning compressors use self-aligning roller bearings to adapt to high-speed rotation and variable load conditions.
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