摘要 |
A counter-rotating axial-flow fan device, which requires low power consumption and has an improved flow rate-static pressure characteristic, is provided at low cost. The counter-rotating axial-flow fan device includes a first axial-flow fan unit with first blades and a second axial-flow fan unit with second blades, which are connected in series. The first axial-flow fan unit includes a three-phase motor for rotating the first blades. The second axial-flow fan unit includes a single-phase motor for rotating the second blades. The first blades and the second blades rotate in a direction opposite to each other. In addition, the three-phase motor is driven by controlling the rotation speed thereof. |