| 摘要 |
PURPOSE: To disperse a noise level of the whole body, and reduce the noise level by making at least a single phase difference different from the other phase difference in a cross flow fan in which impellers are arranged in a plural ity in the rotary shaft direction and which have a fan rotor having a phase difference between the impellers. CONSTITUTION: A cross flow fan has a impeller 2 having circular arc blades 1 in large numbers (for example, 35 sheets), and the circular arc blades 1 are arranged at random pitch angles α1, α2... in the circumferential direction. The impellers 2 having the same shape are arranged in a plurality (for example, 10 pieces) in the rotary shaft direction, and rotary shafts of these impellers 2 are coaxially arranged with each other, and a fan rotor 11 is constituted. In this case, the mutually adjacent impellers 2 are positionally dislocated in the circumferential direction, and a phase difference (a skew angle)θ is arranged between both impellers 2. This phase difference θ is set in two angles (θ1 =θ3 =θ5 =θ7 =θ9 =3.6 deg., and θ2 =θ4 =θ6 =θ8 =2.6 deg.). That is, the two angles are alternately changed in the rotary shaft direction. |
