| 摘要 |
PURPOSE:To improve the performance of an electric blower by closing a recess corresponding to the impeller of a diffuser by means of a closing member and eliminating a space for generating eddy current. CONSTITUTION:The air sent from an impeller 11 flows into a return passage 20 through an involute chamber 18, and the direction of said flow is smoothly changed in said return passage 20, and the flow reaches the cooling-air inflow port 23 of an electric motor 13. Since each sectional area of the involute chamber 18 and the return passage 20 is incread gradually towards the downstream side, dynamic pressure is converted to static pressure. Since the recess 21 of a diffuser 16 which corresponds to the undersurface of the impeller 11 is closed by a closing member 22, the air sent from the impeller 11 does not flow into said recess 21, and generation of eddy current can be prevented. |
