| 摘要 |
<p>PURPOSE:To enable each windmill blade to cope with abrupt change in wind pressure without making its structure complex by providing each spring so that the pitch angle of each blade is changed in response to change in wind pressure applied to each blade. CONSTITUTION:Each blade 1 is rotatably supported by a boss 2. When the blade 1 is tried to be rotated by wind pressure F, a link 3 is pulled out, so that a spring 5 is thereby held down via a crosshead 4. The spring 5 is deformed in response to wind pressure F, and subsequently the pitch angle of the blade 1 is changed in accordance with the aforesaid deformation. The change of the pitch angle of each blade 1 permits not only the efficiency of the windmill to be improved but also air resistance to which each blade is subjected at the time of a sudden gust of wind, to be lowered while its projected area is made small, so that the windmill can thereby keep rotating without being damaged.</p> |
