| 摘要 |
PROBLEM TO BE SOLVED: To provide a fully-closed external-fan cooling electric motor that suppresses heat generation of a rotor bar inside an electric motor body so as to inhibit heat transfer to a bearing part, prevents a service lifetime of a bearing and that of grease from being reduced, and is ideal as an electric motor for driving a railway vehicle. SOLUTION: A ventilation fan 9 of the fully-closed external-fan cooling electric motor has radially extending blades 109a on a bracket 2 side, or radially extending blades 109b on a core side. Outside air is taken into a ventilation passage as cooling air from an opening part opened in the bracket 2. The cooling air is guided to a cooling hole formed in the outer peripheral part of a stator core 10 and then discharged to the outside. Air to be discharged inside an electric motor body is returned again to the inside of the electric motor body through an external heat exchanger 23. COPYRIGHT: (C)2009,JPO&INPIT
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