On 2/6/12 6:04 AM, dave pierson wrote:
I haven't had to think critically about this for years, so i grabbed a (oldish....) book. Three phase synchronous motors have 'three phase' (6, etc) rotors. From this i infer that modifying an 3 phase induction rotor would follow thee same geometry. This would want testing...
Depends on the number of poles. A LOT of synchronous 3 phase motors (esp in big sizes) are things like 8,10,12 poles so they run slowly (requiring less gearing to get down to the speed of whatever it is they are running..e.g. a rolling mill)
We had a 60/50 hz motor generator to do frequency conversion at a place I used to work.. Sync 60 Hz motor driving a 50 Generator by toothed belt (ratio of teeth on pulleys was 6:5 of course). The toothed belt created quite the whine ("Satan's siren") but they were both 4 pole machines (i.e. The 60 Hz machine ran at 1800 RPM, the 50 Hz at 1500 RPM)
I think that the "machining flats" thing would have to have a flat for each pole, not each phase. So an 1800 rpm 60Hz machine would need 4 flats, whether single or 3 phase.
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