| 摘要 |
The objective is to provide a high-efficiency, low-noise propeller fan with which turbulent inflow at the front edge of primary blades can be suppressed while achieving suction from downstream by means of a boss. This propeller fan (4) is equipped with a first boss (9), a second boss (10), auxiliary blades (11), and primary blades (12), and an air passage (13) through which air passes in the axial direction of the rotational axis O is provided between the first boss (9) and the second boss (10). When rotating around the rotational axis O, the blowing direction of the primary blades (12) is in the direction opposite the blowing direction of the auxiliary blades (11), and when an upstream side and a downstream side are defined with the blowing direction of the primary blades (12) as the reference, the second boss (10) includes at least one location, that is, an inner diameter narrowing part (18), where the inner diameter at the upstream end is less than the inner diameter at the downstream end. |
