Curious AC Motors
Dragon64, Tue Jun 09 2015, 03:48AMRecently, I purchased two "AC motors" locally and found out that the motors had some strange attachments to it that I cannot figure out what they are.
On one of the motors, the marking on the top of a aluminum ring read "120mm APDS SX139GE-RLB 1/67 82B". When I checked online for possible clues, this marking is supposed to be for a 120mm sabot tank shell
There is also an metallic aperture inside that I have no clue what it's function is. Were these sabots spun by an AC motor before firing and what is that iris for?The second motor doesn't have any markings but the blue/green grid grip seems to be the same as the first motor. The only other thing that I can pick out is the four fuses on one side.
If anyone knows what these are, it'd be greatly appreciated.
Here are some pictures: (First 4 pictures = first motor, last 3 pictures = last motor)
Re: Curious AC Motors
klugesmith, Tue Jun 09 2015, 10:19PM
Nice find.
Are you sure the four "fuses" aren't actually lamps to illuminate something? That would be consistent with the iris diaphragm as part of an optical system. The lamp (bulb) style is sometimes called Festoon.
The motor itself in last picture appears to be just what the nameplate says. A hysteresis motor, much like one in my collection of synchronous AC motors. The rotor is a plain cylinder of magnetically hard material. It turns at synchronous speed without slippage, but can start (or be forced to slip to) any shaft angle.
Maybe the whole instrument is something for inspecting or testing gun barrels.
I thought tank guns are (were?) all smoothbore, so they can shoot HEAT rounds without spinning them.
In this video, a fin-stabilized projectile appears to "slowly" spin up _after_ discarding its sabot. Is that desirable, or just a side effect of fin tolerances?
klugesmith, Tue Jun 09 2015, 10:19PM
Nice find.
Are you sure the four "fuses" aren't actually lamps to illuminate something? That would be consistent with the iris diaphragm as part of an optical system. The lamp (bulb) style is sometimes called Festoon.
The motor itself in last picture appears to be just what the nameplate says. A hysteresis motor, much like one in my collection of synchronous AC motors. The rotor is a plain cylinder of magnetically hard material. It turns at synchronous speed without slippage, but can start (or be forced to slip to) any shaft angle.
Maybe the whole instrument is something for inspecting or testing gun barrels.
I thought tank guns are (were?) all smoothbore, so they can shoot HEAT rounds without spinning them.
In this video, a fin-stabilized projectile appears to "slowly" spin up _after_ discarding its sabot. Is that desirable, or just a side effect of fin tolerances?
Re: Curious AC Motors
hen918, Wed Jun 10 2015, 11:37AM
The sabot in the link has rifling marks on it from the rifling on on the barrel
hen918, Wed Jun 10 2015, 11:37AM
klugesmith wrote ...
...
I thought tank guns are (were?) all smoothbore, so they can shoot HEAT rounds without spinning...
No,...
I thought tank guns are (were?) all smoothbore, so they can shoot HEAT rounds without spinning...
The sabot in the link has rifling marks on it from the rifling on on the barrel
Re: Curious AC Motors
Dragon64, Wed Jun 10 2015, 06:06PM
Hmm, you may be right. Those don't seem to be fuses as they seem to light up like a lamp. Though those "Festoon type bulbs are on the motor without the iris diaphragm.
I was able to pull the top off the festoon cap and saw a hollow metal square piece attached to the shaft. (See picture)
Dragon64, Wed Jun 10 2015, 06:06PM
klugesmith wrote ...
Are you sure the four "fuses" aren't actually lamps to illuminate something? That would be consistent with the iris diaphragm as part of an optical system. The lamp (bulb) style is sometimes called Festoon.
Are you sure the four "fuses" aren't actually lamps to illuminate something? That would be consistent with the iris diaphragm as part of an optical system. The lamp (bulb) style is sometimes called Festoon.
Hmm, you may be right. Those don't seem to be fuses as they seem to light up like a lamp. Though those "Festoon type bulbs are on the motor without the iris diaphragm.
I was able to pull the top off the festoon cap and saw a hollow metal square piece attached to the shaft. (See picture)
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