| 摘要 |
The electrical machine has a fan wheel (5) at one end (4) of the rotor shaft (2), with a second fan wheel (8), for auxiliary cooling, selectively switched into operation in dependence on the machine revs. Pref. the fan wheels are coupled together by a rev-dependent coupling element (19,20), e.g. a centrifugal coupling, the first fan wheel rotating with the rotor shaft and the second fan wheel free to rotate relative to the rotor shaft. The fan wheels may be concentric with the first fan wheel lying on the inside and secured to the rotor shaft, the second fan wheel enclosing it. |
