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Question for Engineers here
I have a engine that needs to run @ 48oo RPM
I need it to drive a shaft at 90 deg to engine at about 530 RPM A rear end ( car ) would work except I dont know of anyone that makes a ring and pinion close to that ratio . It would be too large for the housings i know of. So. Maybe a planetary set up? your thoughts are appreciated . PS - I do not want use a jack shaft arrangement, as thats what i am trying to get away from. thanx in advance ! |
How much hp and torque is required and is it a constant load?
This isn't a sawmill by any chance is it? |
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Is that ft, or in?
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I hate to say it, but that appears to have been the reason for the belts and/or jackshafts. All a planetary is is a jackshaft.
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150 pounds TQ
The belts a and chains and shafts are prone to breaking. With a planetary or way to reduce RPM all this crap could be done away with. It would make a simple clean set up. Engine powr in a 90 deg shaft power out. It would get rid of over 13 belts ! 6 off the engine to the jack shaft alone ! And the maintenance , H.S. ! |
If this has anything to do with aviation, I'm not qualified to comment.
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Its all experimental so there is no liability, just conversation here.
just need to locate a planetary of sorts. |
Being a Porsche forum... I'd suggest a 901 or 915 transaxle with a 8:31 3.875 diff and (edit) 2.33 second (or a 7:31 4.43 diff and 2.0 2nd). Weld the diff, gut any unused parts.
edit: I transposed the ratio numbers |
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Why are you starting another thread on this? Was there something wrong with this one?
http://forums.pelicanparts.com/off-topic-discussions/790710-belt-pulley-engineers.html How about this one? http://forums.pelicanparts.com/off-topic-discussions/790389-calling-all-helicopter-engineers.html |
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Is there a vendor for such a thing , or do i build it from scratch? |
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Or you could go with the other suggestion and use 915 and take all but one gear out and replace the diff with a spool.
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Just remember that the reason you are removing so many belts and pulleys is redundancy, and your system will have none. Nothing in aviation does a job on its own with no backup.
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I suggest you make friends with your local reps from Applied industrial technologies or Kaman industrial technologies.
My local reps are Jim Sullivan and Dave Lester, known em both for 20 years or longer. They're more than happy to do the leg work for me. Applied.com Industrial Supply, Industrial Bearings, Material Handling, Power Transmission, Fluid Power Products | Applied Industrial Technologies | Applied.com | Applied.com https://ec.kamandirect.com/us/index.jsp There have been times when I have tried to "invent" a solution that already existed. Not very cost effective. If your local reps are worth their salt they'll show you what's available, connect you with the factory reps, offer up several options so you just need to crunch some numbers and decide which one best suits your needs. Time is money. |
please don't kill yourself after you make a helicopter. im being genuine and serious.
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Geesh guys......Are we all so scared as to NOT do anything anymore.?
The crap that is installed is just that , crap, it works, but there is so much a better way.! I do NOT want a secondary (Jack shaft) breaking on me, and thats what they are famous for.!!!!!!!!'if i get rid of this and install a real Power delivery devise, it will not break, will require no belts and chains, just a chip detector and oil sight guage. Its the right thing to do. This I do know |
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I spent three years at the Sikorsky Factory as the Chief Government Test Lead. I learned more about shear, Rockwell C numbers, lubrication, cooling and failure modes than I ever really wanted to know. Transmissions are the heart of a helicopter and generally the failure point: In an H-60 there are five "transmissions" that redirect energy to the main and tail rotors. Do not think any gearing systems designed for one application will work in yours: In aviation they call it the "wheel of misfortune": my recommendation to you is to stay off of it. |
I do appreciate everyone's concern and input..
However if you knew what i was dealing with you would readily see its a NO brainier. The way its all designed,..It is designed to fail. (and MANY have) serious. The factory to solve it went from a 30 MM shaft way up to a 35 MM .... BIg DEAL The shear loads from jack shaft to Main shaft break them at the bearing from the stress A straight in design would be ideal like R22. I am NOT the only one that has done this... just i want to do it a little cleaner to solve the problem There are people that have converted these to turbine Pwr with no problems, BUT the did get rid of the crap ( Kiss Aviation ) Its hard to post over on their " Board" as "we" that want to change from the caveman to something better is regarded as outlaws of sorts. Its a catch 22 not a R22 LOL Anyway thanx for the help..... |
Listen to Seahawk, he is a very wise man with more time around birds than the rest of us combined. If he says it won't work, I'm inclined to believe him. ;)
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YOO Ok......
It has all ready worked for other people. OMG you guys .If you were around the wright Bro would have never got off the ground......! Its kind of interesting you will poo poo what you do not even know what you are being negitive about. All most too funny |
found it
SUBARU REDRIVE I think something like this then a 90 deg gear box (ring and pinion) to gear down rest of the way . |
There is room for innovation and improvement in almost any design...
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Yup
Hence the "freeze" Plus, when there are other agendas aboard......leaves lots a room ! |
I wouldn't expect a planetary gear to be any more reliable than a (well designed) intermediate shaft.
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The shafts break!!,
Has 6 belts to it, a 20 pound chain on top, plus HUGE sprockets to gear it dwn some more. Bearing temp stickers on each bearing because they run too HOT . (and BREAK ) ( to monitor after the fact (cause you can not see them in use ) More belts to accessories ..... plus more stuff. Maybe a "well" designed one would work, but they all are under worrisome watch full eyes . The key word would be a well -"designed one."- With as much effort to replace ( and EXPENSE ) it might as well be tossed. A new one is 3500 bucks , and now back to Sq one to repeat all the above *(if you live through it)* So, why repeat the same mistakes over and over. I think thats the definition of stupid ?... or crazy ! ? I would think a well designed planetary would mean check the oil once in awhile and be done. |
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A planetary gear set has 3 or so shafts inside it which the planets rotate on. These shafts are smaller and you can't easily inspect them and I am not sure what kind of bearing they might have on them, if any. You hold those shafts stationary and turn the sun and you get a big reduction between the sun and ring gear. |
I know you want to steer me in the right direction and i do appreciate that.
The shaft is solid, mounted vertical, a 2 bearing affair with the drive sprocket above top bearing. It drives a 5 row chain with a master link inserted FROM the BOTTOM so as to keep a eye on the clip be fore use..LOL....the chain i think weighs 20 some odd pounds bathed in oil...above the exhaust Needless to say......the shaft breaks right there above the loaded bearing . Right about then you know if you passed autorotation class or not...and even of you do...hope there was a pretty good place to put it dwn. |
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Helicopters are vibration nightmares and many design compromises are made to dampen vibs, which substantially impact the airframe structure in terms of fatigue and stress cracks. The drive train in a helo must be in harmony with respect to vibration...there are instances where low frequencies harmonics in different flight regimes (harmonics in helicopter change depending of hover, forward flight, etc.) can quickly damage the airframe and drive components. I can refer to any number of airframe and drive component "improvements" to the H-60 that ended up causing unintended stress on the airframe. You can also cause what is referred to as "ground resonance" by changing drive components: <iframe width="560" height="315" src="//www.youtube.com/embed/Cf1N70szHLg" frameborder="0" allowfullscreen></iframe> The OP can do whatever he wants, not my issues, just don't fly over my house |
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Wonder what came off, or broke? |
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[QUOTE=Seahawk;7855830
Helicopters are vibration nightmares and many design compromises are made to dampen vibs, which substantially impact the airframe structure in terms of fatigue and stress cracks. The drive train in a helo must be in harmony with respect to vibration...there are instances where low frequencies harmonics in different flight regimes (harmonics in helicopter change depending of hover, forward flight, etc.) can quickly damage the airframe and drive components. I can refer to any number of airframe and drive component "improvements" to the H-60 that ended up causing unintended stress on the airframe. You can also cause what is referred to as "ground resonance" by changing drive components: [/QUOTE] I have scratch built and flown my own airplanes... That said, helis scare the crap out of me. As a mechanical guy, I can't get past the small fittings/ linkages/bearings that are involved keeping the whirring blades under control. While I have ridden in quite a few over the years, I view it as playing Russian roulette. :) |
After Hueys in nam ...I cant get anymore scared so it dont matter
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H-60's? Not a care in the world, really...I was going to do something stupid before the 60 would, guaranteed. To the OP: Your earlier posts on the kits available is really the only alternative in my mind, although this bothered me, from the link: Note that the airframe-attachment points are not shown in these pictures. They are awaiting final design, and will be completed after we finish the accurate 3D-CAD model of the airframe. PROJECT STATUS STATUS: The design of this product is essentially complete, with 3D-CAD components and assemblies, complete analysis calculations, engineering drawings, and some components already manufactured. This product (and the Mark-17 as well) has been acquired by a client company to provide the powerplant basis for a new helicopter product currently in development. Get the ground run test data and flight test data before you pull the trigger. I have to ask, do you own a Rotorway? |
who is the question directed to?
I have owned a couple R.W. this one is going to be like Monty Python, now for something completely different *************************( Or as it SHOULD have been )************************* I am not doing it their way anymore.! Is stupid. |
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