| 摘要 |
PURPOSE:To eliminate 2n z sound generated at brush sections and to obtain noise reduction, by covering the brush sections with a shielding plate in a commutator motor directly connected with a centrifugal fan. CONSTITUTION:A centrifugal fan is directly connected to a commutator motor 1 and housed in a fan casing 3 and a motor frame 6. And a shielding plate 8 is provided for a pair of brushes 2 of the motor 1 to prevent air flow discharged to an air outlet 7 from colliding with the brushes 2. In this way, the sound (2n z sound) having frequency twice the number of rotation of blades multiplied by the number of blades generated at brush sections can be eliminated. |
