摘要 |
A first minute gap ( 18 ) is formed between the front end of a ventilation fan ( 16 ) and a first bracket ( 8 ) and a second minute gap ( 21 ) is formed between the front end of a partition member ( 19 ) and a second bracket ( 11 ); a first aperture ( 9 a) is provided in a location at the inner periphery further inward than the vanes ( 16 b) on the bearing bracket ( 9 ); a current of cooling air is formed by introduction of external air by the ventilation fan from this aperture; this current of cooling air is again discharged to the outside through a ventilation passage ( 8 a) of the first bracket and a ventilation passage ( 1 a) on the outer peripheral side of the stator core ( 1 ); in addition, a second aperture ( 11 b) is provided in the second bracket ( 11 ), a current of cooling air is formed by introduction of external air by the ventilation fan from the second aperture ( 11 b); and this current of cooling air is again discharged to the outside through the ventilation passage ( 3 a) of the rotor core ( 3 ), the ventilation passage of the first bracket and the ventilation passage on the outer peripheral side of the stator core.
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