| 摘要 |
PURPOSE: To reduce noise by decreasing the frequency by diminishing the number of vanes of an outer fan without increasing the noise due to the vortex of cooling fluid or without introducing the decrease in air supply performance, and to reduce the noise due to flow with the vortex of the fluid as well. CONSTITUTION: The totally-enclosed fan-cooled rotary electric machine body comprises a main plate 23, and an outer fan 21 having a plurality of circular- arc-like vanes 24 protruding from the plate 23 and a side plate 25. When the air volume of the fan 21 is Q0, a pressure head is H0, the number of revolutions is N0, the inner diameter of the vane 24 is D1, the bore width is b1, an outer diameter is D2, the peripheral width is b2, the number of the vanes is Z, and an outlet angle isβ2, the specific speed defined by N0.Q0<1/2> /H0<3/4> is set to 900 to 1100 [m/min<2> ]<3/4> , D1.b1=D2.b2, Q0/(π<2> .D2<2> .b2.N0)=0.25 to 0.32 and D1/D2 is about 0.8, the outlet angleβ2 of the vane 24 is set to 30 to 35 deg., and the number Z of the vanes 24 is decided to the integer number obtained by Z=β2/β3.
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