| 摘要 |
PROBLEM TO BE SOLVED: To provide an impeller that suppresses the dimension of a height direction, and can suppress decease in air flow without increasing its size and further without increasing a rotation frequency.SOLUTION: In an impeller 1, when the outer diameter of a blade part 10 of a multiblade is defined as A, the outer diameter of a projection part 12 formed inside the blade part 10 is defined as B, and the inner diameter of the blade part 10 is defined as C, a ratio B/A of the outer diameter A of the blade part 10 and the outer diameter B of the projection part 12 is 0.68-0.83, a ratio C/A of the outer diameter A of the blade part 10 and the inner diameter C of the blade part 10 is 0.83-0.89, and the ratio B/A of the outer diameter A of the blade part 10 and the outer diameter B of the projection part 12 and the ratio C/A of the outer diameter A of the blade part 10 and the inner diameter C of the blade part 10 are different from each other. |
