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 Post subject: Pyle National Generators
PostPosted: Sat Feb 03, 2001 4:29 am 

(Note: I am posting the following excerpt for Neal from an e-mail he sent me - Hume)

The Turbo generator which we have is form a small 2 foot gauge locomotive that was used to haul sugar cane in Natal, South Africa. We (that is four of us) are currently slowly rebuilding this locomotive at the Spoornet Nursery at Inchanga, Kwazulu-Natal in South Africa. The locomotive was built by Avonside in the UK in the early 1930's and has been plinthed for about the last 30 years. I suspect that the turbo Generator was not original equipment as it would seem rather unusual to have a American built turbo generator on a British built locomotive.

The generator casing has stamped on it K2AC-3-742. There is also a small plate which gives details of the generator. "742" is the serial no., K2-3 is the model and it is an AC machine. I understand that Pyle National mostly made DC turbo generators. The only data I have on this is a small cross section drawing of the DC version of the K2 model taken from the 1919 (5th edition) of the "Locomotive Dictionary and Cyclopedia".

We have to open up our generator to clean it because the covers for the oil wells are missing and insects (probably wasps) have made mud nests inside the end bearing and when we tipped the generator upside down, we were rewarded with a hand full of sand coming out of the chimney. So far we have only taken the end bearing cover off and taken the governor out. The cover which the governor is mounted in can only be lifted about 10mm and the it refuses to move any further. SAR steam locomotives have Stones turbo Generator which are completely different to Pyle National turbo generators, thus any information we can obtain about maintaining or overhauling a Pyle National turbo generator would be appreciated.

(I have checked the link for e-mail notification, so Neal will be notified of any responses to this post.)

 Post subject: Re: Pyle National Generators
PostPosted: Sat Feb 03, 2001 8:25 am 

AC gennies are rare in US steam locomotive practice. Bernie Watts of Backshop Enterprises has lots of spare parts if the mechanical end is like the DC units. Pleased to help with specific mechanical questions by private email.


 Post subject: Re: Pyle National Generators
PostPosted: Sat Feb 03, 2001 3:10 pm 

I forget how the governor comes out, but it's valving should have absolutely no end play. Also have the turbine rotor/armature assembly dynamically balanced for for 3,000 rpm.

 Post subject: Re: Pyle National Generators
PostPosted: Sat Feb 03, 2001 7:00 pm 

The governor is comprised of flyweights acting against a sprung yoke on the shaft which act through a thrust bearing on a lever which works the valve which is screwed into a ground in seat, and topped by a cap. Rough adjustment is made on the screws which tension the spring yoke assembly with the valve spool flush with the top of the valve body with the screen removed. This is done by experience and feel on the screwdriver. Fine adjustment is made in the valve stem.

I think it is 3200 RPM.


 Post subject: Balancing
PostPosted: Sat Feb 03, 2001 10:24 pm 

There are three speed ranges that a rotating mass should be balanced at and not for just one speed. Take the parts that spin to a shop that balances hotrod engines, they will do a great job for you.

 Post subject: Re: Pyle National Generators
PostPosted: Sun Feb 04, 2001 1:12 pm 

The steam driven generator business of Pyle-National was sold to Wegner Manufacturing Co. in the 1960's (Wegener also owned the Nathan Maufacturing Co). In the early 1990's Wegner moved to South Windham, Connecticut and currently does business as Windham Machine Co. phone: 860-423-4575. Jack Swendsen is the best guy to talk to, he has been with the company since the 1950s'. They still sell a lot of parts for the K-2 and other dynamos, mostly smaller, consumable parts, no turbine wheels or cases. They can supply an assembly drawing.
In answer to your question regarding dissassembly, the shaft is a press fit onto the bearings and must be gently pulled off being careful not to break the end of the dynamo housing. I would counsel against dissassembling the fly-weights unless absolutly necessary, they are difficult to get adjusted properly. The governors sometimes are difficult to remove from the generator. We made a little puller that screws on in place of the screen cap, soak the governor for a long time in Kroil or such and even then sometimes have to heat the generator casting to get the governor out for the first time after sitting for decades. Good luck!

 Post subject: Re: Balancing
PostPosted: Mon Feb 05, 2001 2:25 am 

Balance the armature for the speed it will be running (3,000 or 3,200). Have a motor shop which is set up to do dymanic balancing do the job, not an automotive racing car place.

The most compelling reason to balance things like this is that when they are out of balance, the vibrations shake the windings loose, in both the fields and the armatures. When electrical apparatus sits for prolonged periods of time (a year or two) the windings in the slots of the armatures move through the insulation slightly, putting things out of balance. As the [unbalanced] machine rotates, the windings move back an forth, work hardening the copper which eventually breaks. Or the insulation itself crumbles, allowing a coil to go to ground.

 Post subject: Re: Balancing
PostPosted: Mon Feb 05, 2001 8:18 am 

More I think about it, an AC unit if at 60 CPS is more likely to run at 1800 or 3600 rpm.

Not sure I like the idea of AC grounding to the frame of my locomotive when the insulation wears through on a wire someplace.


 Post subject: Re: Balancing
PostPosted: Mon Feb 05, 2001 11:58 am 

> More I think about it, an AC unit if at 60
> CPS is more likely to run at 1800 or 3600
> rpm.

> Not sure I like the idea of AC grounding to
> the frame of my locomotive when the
> insulation wears through on a wire
> someplace.

> Dave

Thank you to everyone who has responded thus far.

I have a few more technical details about our generator which I should have included up front. These details have been taken from a plate on the generator which is barely readable, but I think I have most of the important stuff.

Volts AC-32
Amps 16
?? 3800 (this must be the RPM)
Press Max 300 (presumably all pressures are in PSI)
Press Min 75
Exh Press 0

also kV 0.3 (this I am sure should be kW 0.5 which would make more sense but it is partially obscured)

South African Railways loco's and probably most industrial steam in SA have 32 Volt AC systems, which I imagine would just earth through the track and would be non-lethal?


 Post subject: Re: Balancing
PostPosted: Mon Feb 05, 2001 4:02 pm 

You cannot balance the armature for only the the speed that it is running at. The problem is that at 3200 rpm the armature is spinning at the upper range of the harmonics. Or resonance factor. The harmonics are usually found between 1400 to 2800 rpm. Generally balancing or "flattening out" at the first harmonic will take care of the rest (other 2) This is how any item that spins is dynamically balanced, automotive, aircraft and even steam turbine generators.By not taking care of balancing through the harmonic ranges then the turbine as it spins will come in and out of balance as it it spins at this upper end. you can hear one that is improperly balanced do this. Any balancing shop will tell you the same story on balancing. As far as hotrod balancing versus industrial parts, what ever they may be, any shop with the proper equipment can do this. I mentioned hotrod engines as they are precision balanced for RPMs upward to 8-10,000. When a part is placed into a fixture for balancing it is run up to the first harmonic, approximately 1400rpms, however this will very slightly. The operator will change the rpms back and forth till he is right on the first harmonic than do a balance. Then the part is spun up through the next two ranges. If the first harmonic is flattened out then the other two are genenerally taken care of and the part then can be spun up to its normal operating range. No Balancing would then be required at 3200 as it was taken care of through the harmonic ranges. Sometimes the part may need balancing through the other two ranges. There are also harmonic ranges as parts are spun up to higher ranges like 8,000 rpm. This is standard practice in dynamic balancing.

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