[mmendozabn]

I thought I knew how a brushless AC motor worked in that you spin a
magnetic armature inside a surrounding coiled-wire stator.

But I just took apart my 1.65 HP pool pump AO Smith QC1102 220V motor and
all I see are the two bearings holding up the armature in the center.
There are no brushes and the armature is a very heavy cylindrical chuck
of 'something'.

But, that something is not a magnet.
Nor does it appear to be a coil of wire (even if it were, there are no
brushes to get electricity to the 'field' if that is what it is).

So how does the darn thing work?

Googling for that motor I only see the same exploded diagrams that I see
physically when I take it apart.

What is the armature made up of?

[[email protected][_2_]]

On Nov 3, 5:27*pm, mmendozabn wrote:
I thought I knew how a brushless AC motor worked in that you spin a
magnetic armature inside a surrounding coiled-wire stator.

But I just took apart my 1.65 HP pool pump AO Smith QC1102 220V motor and
all I see are the two bearings holding up the armature in the center.
There are no brushes and the armature is a very heavy cylindrical chuck
of 'something'.

But, that something is not a magnet.
Nor does it appear to be a coil of wire (even if it were, there are no
brushes to get electricity to the 'field' if that is what it is).

So how does the darn thing work?

Googling for that motor I only see the same exploded diagrams that I see
physically when I take it apart.

What is the armature made up of?

What you apparently have is an induction motor. There
are no brushes. The armature is a mteal core with
conductors embedded in it. The conductors are heavy
and may not look like wound wire, if that is what you're
expecting.

[U vigilance]

On Thu, 03 Nov 2011 15:00:51 -0700, wrote:

What you apparently have is an induction motor. There are no brushes.
The armature is a metal core with conductors embedded in it.

Ah, that's what it must be.

From Wikipedia, apparently the stator surrounding the rotating armature
contains coils of wire to induce current in the armature. Apparently
single phase 220V motors can't START the magnetic field, so, that
explains why there is a big capacitor (to kick the thing into spinning).

I never knew induction motors even existed!

[deadgoose[_2_]]

Thank Nikola Tesla. For polyphase induction motors, they can start
themselves. For single phase motors, there is a starting winding that
"fakes" rotating field until the rotor is up to speed, then cuts out.

They are pretty non-obvious in their operation.

/paul W3FIS