| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that a conventional multi-blade blower requires another component having a large loss coefficient such as rubber ring to suppress resonance of an impeller with respect to excitation from an electric motor, which results in complication of a structure to increase the cost and that vibrations from the electric motor are transmitted to the impeller to excite a resonance phenomena which results in the production of noise when deterioration of rubber through a long-term use lowers an effect of insulating vibrations. SOLUTION: An outer peripheral ring 11 is arranged keeping a certain distance from an intake side opening end 12 to make a natural vibration mode frequency of an impeller 5 different with respect to the frequency of excitation force of an electric motor and the section modulus of the impeller 9 is maximized on the main plate 8 side and minimized toward the intake side opening end 12 as shown in Fig.8, which leads to the suppression of the excitation of a resonance phenomena. As a result, the production of noise can be stably prevented for the long term while simplifying the structure and reducing the cost. COPYRIGHT: (C)2013,JPO&INPIT |
