B-29 Generator or Motor in tail part

[M. Tanaka]

Hi, does anyone recognize this, held by a local museum?
A part from downed B-29 42-65212 T-square 42, on April 7th, 1945, Chofu, Tokyo.
Looks like 'Putt-putt' generator, or, Central Firing System gun motor.
Any input would be appreciated.
Regards,
M. Tanaka

 

[FLYBOYJ]

I believe it is an electrical component, probably part of the fire control system. This is what the B-29 APU (Putt-putt) looked like

 

[M. Tanaka]

Many thanks. A motor that moves the gun vertically or horizontally like this you mean.
Thanks again. mt

 

[M. Tanaka]

Sorry, pictures from below link seems slightly different in its shape. No other possibility... mt
B-29 Tail Azimuth and Elevation Motors

United States Boeing B-29A Super Fortress 44-62208 Miss Liberty Belle

United States Boeing B-29 Super Fortress Bomber Aircraft A.A.F. Serial Number B-29A-65-BN 44-62208 History of B-29A-65-BN 44-62208 Miss Liberty Belle Body, Installation - Tail ASSY 3-14335-13 UNIT 998.During World War Two the B-29 Super Fortress bombers were built by three different companies...

www.questmasters.us

 

[M. Tanaka]

One more possibility; one of CFS amplidynes at the bank of firing commander seat?

 

[EAIAnalog]

The B-29 was a mostly electric aircraft with a dollop of hydraulics. So there were a lot of motors, generators, and dc-ac converters. This isn't from an amplidyne because that was a special motor-generator on a single shaft. For the same reason, dc-ac converters can be ruled out. So we're left with motors and generators. The only stand-alone generators I know about are on the engines or on the putt-putt. This item looks too small to be any of those. So we're left with one of the many motors. On the left end is probably the brush assembly which clamps the brushes to the motor's commutator. It doesn't look like the brush assembly on the gun turret motors, so they are ruled out. Unfortunately I don't have any information on the autopilot servo motors, so this might be one of them. And there is a compressor motor on each gun turret. However, on all of the motors, the end cap and brush assembly is the same diameter as the motor casing. Here it is much smaller. I'm attaching an exploded view of the compressor motor from a maintenance document, just to illustrate what I mean.

It would be helpful if a good picture of the part were available, possibly from more than one angle. There are two protuberances from the middle of the part that are puzzling, and a better picture would help.

 

[MiTasol]

I do not think it is a Cornelius compressor part but I would not rule it out as it is purely a gut feeling.

To me it looks like an electric motor that is missing the whole end containing the bearing and brushes. See below and consider that all the parts inside the red line are missing.

As others have said - better photos would help - as would any part numbers and stamps on the unit.

 

[M. Tanaka]

Many thanks; yes, additional pictures are on the way as the local museum accepted my request; please give me a few more days.
Meanwhile, it that is the case, where the motor is located on the B-29? Or, is it too common one that cannot be decided which one?

 

[MiTasol]

We can guess better when the additional photos arrive but from memory the B-29 used electric turrets so there will be two or more per turret. Flaps and landing gear are electric and probably the bomb doors as well. It is not an aircraft I have worked on much and not one I have any great interest in.

Boeing B-29 Erection and Maintenance Manual is a link to at least one manual.

 

[Shinpachi]

Sorry but I happened to find these images at 8:03 in a Youtube video.
My instant impression as a former engineer, the motor/generator case would have been removed by an engineer to check inside structure.

Source: //www.youtube.com/watch?v=koKN5mqGMgk&t=482s

 

[M. Tanaka]

Shinpachi-san,.
Thank you for reminding me of the video ! The part is exactly what I am trying to identify.
I have heard that the part was picked up from underground 1 meter below by the owner of the field, so not sure an engineer could examine it at that time. Let me check if there is any additional information.

Dear all,
The Museum of Flight, Seattle, has kindly come back with their view to the same question of mine; it is likely be the generator part of APU.
Anyway, some more pictures follow shortly; so let us see if it becomes clear.

With many thanks, mt

 

[Shinpachi]

Thanks Tanaka-san.
As you may know well, there was a facility of IJA Special Intelligence Division (陸軍特別情報部) in Chofu as well as in Tanashi, Tokyo. I think that such a motor/generator would have been a good material for them to research.

 

[M. Tanaka]

Taking time more than expected, but please wait for a while until the local museum responses with new pics.

 

[MiTasol]

No panic.

Those of us who are most likely to respond will automatically get notification when you reply.

I for one would rather a long wait for quality photos than a quick and nasty photo or two

 

[M. Tanaka]

Hi all,
Please find three pictures from the local museum with size information, though not clear enough, unfortunately.
Your further inputs would be highly appreciated.

(a bit earlier but deleted attached file due to the arrangement with the local museum.)

Regards,
M. Tanaka

 

[MiTasol]

Please thank the person who provided the photos for those dimensions - they are very detailed and quite readable. I have saved then and adjusted the lighting to show more detail so I can do more research.

 

[M. Tanaka]

Hi all,
As a possible conclusion.
1) Dotted part of the left pic from FLYBOY above;
2) Red-circled part of the center pic from Museum of Flight in Seattle, but type maybe different;
3) Not-circled parts of the right pic from MiTasol above, probably except No.18 etc.;

All indicate to me 'generator of the put-put APU'.
Is it acceptable for you all?

Your inputs would be appreciated.

Regards, mt

 

[MiTasol]

That is most likely to be correct.
Congratulations on your research.

 

[Shinpachi]

I think it is too early to conclude, Tanaka-san, because the motor/generator relic has no permanent magnets but coils on both armature and stator, which means the relic is not a generator but a motor. Wasn't it from either rudder servo or elevator servo of a B-29 as no one pointed it out yet?
This is just my guess at the moment.

 

[M. Tanaka]

Shimpachi-san,
Thank you as always.

For Autopilot Servo motors, it was actually mentioned by EAIAnalog above; so please let me ask if you have any further information on the shape or size, etc., as I have not reached that far. Happy to check this possibility going forward.

And, sorry to make such an ABC type question, but 'no permanent magnets but coils on both armature and stator means the relic is not a generator but a motor'. Isn't there 'no permanent magnetic' type generator'? If so, does it make difference? Please allow me to ask, lacking basic knowledge.

Any help would be highly appreciated.

Regards, mt