Motor Coil Design

Hey Can somebody tell me, how Poles are formed inside the motor with the windings?

Reply to
scant
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Hey Can somebody tell me, how Poles are formed inside the motor with the windings?

Reply to
scant

Czechs are written to pay for the copper.

Reply to
contrex

Physically they are groups of coils connected together. Imagine a set of "O's" decreasing in size stacked inside the bigger one. That is how they would look, with each "O" being a coil of wire around the laminations of the stator.

Reply to
Rheilly Phoull

Finnish cracking all of these puns already!

Reply to
Paul Hovnanian P.E.

On Thu, 22 Mar 2007 19:49:08 -0700 Paul Hovnanian P.E. wrote: | contrex wrote: |> |> On 21 Mar, 12:00, "scant" wrote: |> > Hey |> > Can somebody tell me, how Poles are formed inside the motor with the |> > windings? |> |> Czechs are written to pay for the copper. | | Finnish cracking all of these puns already!

Oh, now you're making me Hungary for some Chile but my only bowl is China.

Reply to
phil-news-nospam

"...wants to be taught all the knowledge of the world while standing on one foot."

AC or DC motor?

In typical polyphase machine, a small number of coils are connected to form a pole-phase-group. These are used to create a 'pole'. But things get tricky when you try and count them. Take for example a typical four-pole three-phase induction motor. It has a synchronous speed of 1800 RPM (on

60Hz). We say it has 'four poles', but that really means that the A phase winding has four poles, the B phase winding has four poles, and the C phase winding has four poles. So it has 12 pole-phase-groups. Each one of these may have six individual coils connected in series, for a total of 72 coils in the machine (and probably 72 slots to put them in).

So in that example, six coils, in six adjacent slots are connected in series. As current enters the first coil, passes around it, then the next coil passing around in the same direction and so on, finally exiting the sixth coil. The current flowing in the large number of turns creates a magnetic pole of one polarity. When the current reverses, the magnetic pole reverses polarity.

In small single phase machines, the windings might be different sizes mounted concentricly as 'Phoull' suggested. Then each 'set' of windings forms a magnetic pole of its own, and the magnetic polarity alternates with the applied AC.

In a DC machine, the coils are mounted around a piece of iron to form a large electromagnet. The current doesn't reverse, so the polarity is fixed. For a 'four pole' DC machine there are simply four identical pieces of iron situated evenly around the inside of the stator. Every other one is wired up backwards from the others so the magnetic polarity alternates as you move from one pole piece to the next.

daestrom

Reply to
daestrom

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