一风冷发动机风扇的型式风冷发动机中所用的鼓风机有轴流式式和离心式两种。鼓风机按照风扇动轮叶片的变曲方向不同又可分为两种:一种是叶片相应于旋转方向向前的,另一种是向后的。这两种风扇的比较,后者的效率比前老高,因为向前变曲的结果使风从工作输出来的速度高,这意味着气流从速头转为压头时所损失的能量就大,但是却有一个优点,那就是在相同的压力的条件 An air-cooled engine fan type air-cooled engine blower used in both axial and centrifugal blowers. Blower fan blades in accordance with the direction of the different turns and can be divided into two kinds: one is the blade corresponding to the direction of rotation forward, the other is backward. The comparison of these two fans, the latter being more efficient than before, as the result of the forward curl results in a high rate of wind output from the work which means that the energy lost when the air flow is changed from head to head is large , But there is an advantage that is the same pressure conditions