The role of variable rotor bearing is to rotate the blade installed on the hub, the outer ring is connected with the hub through bolts, and the inner ring is connected with the blade. When the wind speed is too high or too low, the Angle of attack of the airflow on the blade is changed by adjusting the pitch of the blade, so as to change the aerodynamic torque obtained by the wind turbine, so that the power output remains stable At the same time, the starting process of the fan also needs to obtain enough starting pitch by changing the pitch. The application environment of the bearing is bad, the diameter is small, the anti-overturning moment is large, the maintenance cost is high, and the high processing precision, zero clearance assembly and surface anti-corrosion treatment are usually adopted to ensure the high reliability and high life of the product.