| 摘要 |
<p>A fan apparatus employs such structure that a setting angle of the blade is kept to be a predetermined angle at a first area from a bottom portion of the blade to an intermediate portion of the blade and the setting angle is increased at a second area from the intermediate portion of the blade to a top portion of the blade. A chord length of the blade of the present invention gradually increases from the bottom portion to the top portion. A first wing axis ( l 1) of the blade at the first area from the bottom portion to the intermediate portion and a second wing axis ( l 2) of the blade at the second area from the intermediate portion to the top portion are not parallel from each other but the second wing axis is inclined toward the rotational direction of the fan apparatus. Furthermore, the profile of the is formed in such a manner that the profile at the first area is perpendicular to the first wing axis and the profile at the second area is perpendicular to the second wing axis. The fan apparatus of the present invention employs such structures that a pressure distribution along with the wing chord is substantially the same at the first area from the bottom portion to the intermediate portion and a pressure distribution along with the wing chord at the second area is gradually increased in such a manner that the shape of the pressure distribution is the similar figures to that of the first area. The chord length of the blade is gradually increased from the bottom portion to the top portion. Since the fan apparatus of the present invention employs the structures described above, the fan apparatus well prevent the occurrence of the burbling at the outer surface of the blade even the resistance of the air flow introduced into the fan apparatus is high and the air flow passing the blade is incline to the wing chord.</p> |
