| 摘要 |
PURPOSE: An impeller attached with a ventilation groove is provided to obtain a strong rotational force by maximizing the difference in drag forces of impellers at both sides of the center of a rotating shaft. CONSTITUTION: Impellers(11,12) are attached to a rotating shaft(15) vertical to the ground. Other impellers(13,14) orthogonal to the upper impellers are combined to the rotating shaft. Impellers are attached to the rotating shaft in multiple layers. A drag force applied to the first upper impeller(11) is stronger than a drag force applied to the second upper impeller(12) when wind force is applied to the impellers in a specific direction. Due to the difference in drag forces, torque is generated. The impellers rotated clockwise by the torque. Ventilation grooves(41) inclined tangential to a rotational circle of the rotating shaft are formed in the centers of the impellers. A wind flowing in along the inner face of one impeller returns along the inclined face in both directions. Due to the curtain effect of the air layer, wind is blocked up. Thus, the drag force is maintained. Otherwise, the drag force of the other side impeller is reduced for the wind easily passes through the ventilation groove. Thus, the difference in drag forces is increased proportionally. With speed increase of the impellers, instantaneous vacuum phenomenon is removed. Therefore, a windmill adopting the impellers obtains high rotational efficiency. |
