Jeff Major,
I think you are just getting fouled up in termnology. Hp stays the same
4 large poles or 8 1/2 size poles. the same pole area, same power in
same power out. But for a given total pole area it can be configured in
multiple torque/rpm configurations.
Now either I configure the motor for less torque and higher rpm and gear
it down more or I configure for twice that torque at 1/2 the rpm @ the
same frequency.
There is a range of frequency that is reasonable for the materials and
the cost. frequency costs. On the other end, torque costs. So each
manufacturer achieves their own tripple point of best freq range,
gearing, and pole count.
think of it like the siamese 8 setup the poles run their current in
series so for a given amperage output you get twice the torque that the
same size inverter could otherwise give. You could switch from 8 pole to
4 pole on the fly just like the siamese 8 with a zilla does.
There is also slow rpm smoothness to consider. Skewing the rotor bars
helps but you will find low rpm "torque " motors like wheel motors are
usually about 12 pole.
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I think you are just getting fouled up in termnology. Hp stays the same
4 large poles or 8 1/2 size poles. the same pole area, same power in
same power out. But for a given total pole area it can be configured in
multiple torque/rpm configurations.
Now either I configure the motor for less torque and higher rpm and gear
it down more or I configure for twice that torque at 1/2 the rpm @ the
same frequency.
There is a range of frequency that is reasonable for the materials and
the cost. frequency costs. On the other end, torque costs. So each
manufacturer achieves their own tripple point of best freq range,
gearing, and pole count.
think of it like the siamese 8 setup the poles run their current in
series so for a given amperage output you get twice the torque that the
same size inverter could otherwise give. You could switch from 8 pole to
4 pole on the fly just like the siamese 8 with a zilla does.
There is also slow rpm smoothness to consider. Skewing the rotor bars
helps but you will find low rpm "torque " motors like wheel motors are
usually about 12 pole.
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev