Locking Blades - Turbine Engines: A Closer Look
ฝัง
- เผยแพร่เมื่อ 9 ก.ค. 2024
- Installation of the turbine blade lock pins in the GE J47 turbojet engine.
To see the removal procedure for the pins...check out Jet Questions 48
For even more detail, check out "removing turbine blades from a J47" here:
• Removing blades - J47 ... - ยานยนต์และพาหนะ
Yours are amongst the MOST interesting and informative videos on all of TH-cam. Succinct and to the point with no unnecessary content. Many thanks.
Another awesome video! You have no idea how much I look forward to each of these.
What I would give for just a few hours of a macro shot of you working on installing blades. Boy. The most relaxing thing while working on projects late at night
I think you need to take the gearhead test...
that is so cool ... imagine the heat and forces applied to those materials during operation ... thanks for the up close look at how this stuff goes together !
Iv been searching for design details on jet engine for over a month now and the videos from your channel saved me a lot of time, "SUBSCRIBED"😊😊👍👍
Excellent! you mean business. No extra music, nothing. I appreciate.
"actually the mop bucket wouldn't be there in operation" lol... good one
Amazing! Technical explanations while demonstrating practical application. I envy you in your vocation!
Keep up the good work and please dont stop bringing us these awesome videos!
@343jonny Those are struts in the tail pipe, used for positioning the rear cone. The rear cone reduces turbulence in the exhaust stream by eliminating the step change from the annular shape of the turbine exit to the tubular shape of the jet pipe. The struts are airfoil shaped to reduce turbulence as the gases flow past them. They are replaceable, but not adjustable. Thrust-vectoring is a relatively new technology of flight engines, and we never see it in our business.
Letting you do these vids is good advertising, and it's working. If I had an engine that needed servicing, I'd want you guys to do it!
You're Teaching ME Something I Did Not Know Sir!!!
I want to say "fantastic". You've got a great coping mechanism
Nice vid! Can't wait to see it run!
You need dedicated roll pin holders and punches, as used in gun-making.
Excellent work
amazing...keep making such videos
I would never have thought of that trick. thanks for the responce
that is just amazing! you have a cool job. Thanks!
Excellent video!
This guy makes super explained videos for the layman 🇬🇧
Great videos and I expecting more from you.
Wow... these videos are great, thanks for sharing them!!! I hope one day it could be possible to make stage compliant commercial SST's...
You are the purveyor of North American turbine goodness to humanity!
@MiG29MOVT The pins are destroyed in shear upon blade removal. The pins are then driven out of the hole in the disk... towards the hub.
The blades are indeed ceramic thermal barrier coated. This can increase the temperature tolerance of these parts for increased performance or longer life, or both.
The blades themselves are made of hi-temp alloys, like the blades in all jet engines.
Excellent professor!! :)
We apply Pt-al coating for the t56/501k stage 2 vane segments down here in Texas for Rolls Royce. That was really interesting to see the size difference between that j series and t56
I'm watching your videos and You are the best.
thank you sir your videos are great :)
@TalksWithDirt .. I'm just a machine geek who is allowed to film the toys.
Most turbine overhaul companies won't let employees take pictures of the work they do.
I'm lucky, so feel it's my obligation to share with the curious.
great work, post more.
Spins 4 times with a single push, those bearings are so perfect
Whether the slots face front or back, they still are arranged from inner diameter to outer diameter, so balance-wise it makes no difference.
Axial position is of such a small consequence that it is disregarded.
AgentJayZ
I have to correct you, sir. I worked on C-130's for about 6 years. We used the T-56-A-15 engines which put out around 4,000 horsepower. If you do the math, 19,600 in/lbs at 13,820 rpm = 4297 horsepower. If you subtract frictional losses from the gearbox (13.54:1) , I wouldn't be surprised to see that you lose 100-200 hp at least!
That being said, I really do enjoy your videos. I just so happen to be a specialist for one engine. You seem to know quite a bit about turbine engines in general!
Older than I am and I am 60 . I worked APU s one was used to start the F4. The other ran Radar we would get some that had 40,000 hours on them, we would put new bearing and seals in them, ship them back
This videos are great
@AgentJayZ I enjoy your vids and all the extreme detailed close-ups of the jets. There's always something new to learn about every time.
Oh, maybe a "female hand-model" pointing to jet-parts on an episode (as you narrate) would be a fun twist. ;)
All the best to you and continued... jet-success!
That's pure art..
It's a little hard to get size perspective when we're looking at just the core of one engine and the entire housing of the other. But it likely is a big size difference. I think looking at the turbine disc was where the extreme size difference was more obvious. I am curious how much the sheer mass of that spool not only slows the acceleration but adds significant weight to the aircraft.
I have answered this question so many times, I'm afraid I am unable to continue. Perhaps you may want to read below...
Wow just a standard rollpin retaining those blades incredible
The blade locks, whether pins or small metal strips have a very specific function, discussed in detail in other videos. It would not be correct to say that the locking devices "retain" the blades during operation of the engine, but in only a very small range of rotor speeds which are between being completely stopped, and turning just enough so centripetal force begins acting on the blades.
Centripetal forces lock the blades into their mounts in the disk long before any aerodynamic forces are created which would tend to slide the blades axially in their mounts.
The locking devices only need to be as strong as a paperclip, whereas the forces on the blade roots in their mounting slots during engine operation is equal to the weight of several full size pickup trucks for each blade.
Ok got it. With the molds, tools & machines I design and build for a living I'm used to the hardened dowel and roll pins that are used. One would have to beat pretty hard to get them to shear & in the process destroy the blade and possibly the disk. The pins you're using, being a roll pin and probably a little softer allows it to fold over and shear with minimal persuasion. Trust me until being able to have you walk use through these engines, most things about these was a big mystery.
Those lock pins are spring roll pins, which I've used as an auto and bus mechanic for decades. They look to be SS or better, very hard, strong, tough, doesn't like to deform. I am going to see if I can find a video that shows how you remove those pins. They are installed into blind holes, you can hear them clang as they bottom out in their holes. I'll bet it isn't easy. And these are the hollow types. There are pins that look like a lunch wrap, a tight spiral of SS or spring steel. I remember the pain of trying to remove those monsters. Cryo, perhaps? I'm keen to find out, if I dan.
@AgentJayZ lol, I had kinda wondered if the blades simply sheared them off! Otherwise there would be evidence of removal, just shear it, tap out remaining piece! Pretty ingenious system they thought up back then! Neat stuff! If i remember correctly, there was 1 afterburning Sabre, the very last one, The "Dog" the F-86D. I dont see it as an F-86 myself, looks way differant, not much in common with the other variants. Much uglier too! Forgot we have a Westinghouse J30 at school too...
The answer is in the comments to this video. I never did show it in any video, because it really isn't a big mystery.
Your videos are sharp and closeups are clear. What camcorder do you use?
fantastic!, facinating
Jayz those lock pins you have (we call them roll pins here in NZ) are what I used to rebuild the power-valves in my Suzuki RGV-250 N....and when done right they last forever and dont flog out a horrible hole...usually due to the difference in characteristics
+psycronizer A long way back, I rode a friend's RG500 Gamma. It was quite impressive,
I like this work
Correct me regarding what?
This video is about a different engine that the one you mention.
I was hoping you would say what the compressor rotor in the background was, I have a C-130 squadron right across the street from my shop. I wonder how much thrust a T-56 engine without the extra turbine stages would produce? I like the size of the T-56 not to big, but not to small. Perfect size to do some experimenting with :)
@AgentJayZ all this is true, and you have helped me greatly in understanding that, but I was speaking more of a jet powered go cart, or something ive always wanted, a small jet powered glider, with a system that restarts the engine while air born so one could get to altitude under its own power, shut the engine off, glide back down, then get back up to altitude again. Or in my own crazy case, just having an engine to run and work on for the hell of it : )
@JetAce08 A go kart or a display engine? Well, a 501, which is a T56 without the gearbox or prop, weighs 1200 lbs, and at 3 to 5 thousand Hp,burns many hundreds of gallons of fuel per hour.
You need to look at one of those start carts. They come up for sale often on Ebay. Keep in mind they are about 75 to 100 Hp. They`d make good engines for a kart project.
An insane kart project...
Oh, well I will not argue with anything you say, because you have much more experience with that engine than me.
I was just rying to point out how much better the T56 was at making power than the older engines.
When you say gearbox, that is a different thing on a turboprop: The J47 gearbox uses one percent or so of engine power to drive accessories.
The T56 gearbox drives the prop with about 99% of engine power, so it would likely have the losses you mention.
@gushhnet Is that what that was? It gave me a little chill, like it was a ghost or something.
@mytmousemalibu Yes, I'm not as up on my old time fighters as I should be, but i know some J47s were fitted with afterburners. The roll pins are hi temp, and bit softer than regular ones. At least they shear off easily when the blade roots are tapped forward to remove the baldes.... Uhhhhh never mind that! I never said that.
@mytmousemalibu You're right that the F-86D Sabre "Dog" was an afterburning Sabre, but it was far from the last Sabre. Rather, it was an offshoot of the main Sabre line that was specialized as an all-weather air-defense interceptor, a bomber killer. It had an afterburner for faster climb. The ordinary Sabre was a general-purpose fighter not suited as an interceptor.
@Fierobsessed I was going to ask the same. My best guess is that since it is a blind hole, a self tapping bolt and a slide hammer is used. Would be a good subject for another vid.
JayZ, shoulden't the slots in the pins all be oriented the same (facing enine inlet)? I can imagine 96 tiny slits could add up to close to an ounce of weight?
Thank you very much oh you are very nice man. I like a person like you ,you are very kind to share these for the people. i wish God bless you. Hey AgentJayZ please let me see how to take out the locking Blades. Very thanks again and that will make every one be happy and you too. May God bless you.
As always im greatful for your interesting videos! You showed us how the turbine disk got cooled by air coming in through a center hole in the rear(?) cone. As I've understood it, it enters there, but where does the hot air, after it has cooled the disk leave, or exit? Is it through same pipe?
Cooling air for the back of the turbine disk in this engine leaks out into the gas stream where the outside edge of the rear cone forms a small gap to the base of the blades mount to the disks.
Question: It looked to me like the airfoils on the tail cone are adjustable since they have those little circles under them. I watched your videos on the engines with adjustable vanes. Do the tail cone vanes use the same piston-linkage system if they are adjustable?
thank you mate.....
@Dhillipboy Turbines, wherever they are, have only one function.
and what do you mean "the" turbine ? Typical bypass turbofans have two, and sometimes three turbines. They all do the same thing.
They convert the energy contained in a stream of moving fluid into mechanical torque.
@mykhaledi F86-F sabre, flown in California Airshows.
How do you get out the sheared part of the pin that's still stuck in the blade? Is there a small hole in the blade to drive them out from the other side or is there some kind of "extractor" for them?
Are those eight or ten smaller cylinders the combustion chambers?
That would be a really fantastic career! And yes, I'm heavily biased haha. We were brainwashed to hate "straight jets" (turbofan/jet) In the USAF, there were two engine mechanics: turboshaft/prop and straight jets. It kinda biased us a bit, but we got to work on some really cool aircraft! (The slow aircraft tend to have the most guns). But I'd much rather have the deep knowledge of different types of turbine engines. Impulse, reaction, impulse/reaction, dual spool, Variable IGV's, etc etc
These videos are great. Sound, lighting, content, all first rate. Thanks!
A couple of questions, first do you make any of your own tools? And, you deal with a lot of little parts, how do you know for sure that all the pins are in, that you didn't somehow loose a pin and skip a hole?
Yes, if needed. You need to be organized, and check, check , and check again.
I thought so, you can't afford to make even a small mistake.
JayZ you do a pretty awesome job with your video's. Like many Canucks I've known and follow on youtube, you are entertaining and have a gift of teaching. I have one little complaint, What video is it because I haven't found it. Don't beat me for asking, Please! Go easy, I'm a new follower.
Have you ever worked on a j58 out of the sr71? I'm an A&P mechanic as well, but I never used my license much just a little sheet metal work. I went to an Aviation school in San Antonio. The name of the school was Hallmark Aviation school of Aeronautics, but it is now called Hallmark Aviation College. I would love to work on turbines like yourself. As a young teenager I was fascinated with jet aircraft.
The T-56-A-7 engines put out even less horsepower, since the TIT was reduced from 1050 to 960 *C (If I remember correctly; I used the tech data that dealt with -7 engines, but never dealt with them in reality. They used solid turbine blades vs. the -15 hollow, cooled turbine blades that could handle the higher temps). I believe that would put the horsepower somewhere around 3500+. Again, all of this is on a nice, cold day. A warm day would make you hit TIT before max torque and limit your power
Hey +AgentJayZ love the videos, they've been very helpful with my personal project! Quick question: How much clearance is there between the tailcone inner portion and the rotating disc? Is there anything that contacts the disc to seal the area where the cooling air travels or is the cooling air higher pressure so no inward leakage occurs?
+Ignition Aero Tech On the older engines I work on, which are from fighter jets of the 1950s, there's about 1/4 to 1/8 inch between the back of the turbine disc and the tail cone front face. That gap between these two is often supplied with compressor bleed air to help in cooling the turbine disc.
Hi!! Agt J very nicely explained. I suggest you to start tutorial classes ,step to step ,every minute details inside of latest
fighter and pax jet engines. Either you be live or video post. You see at currently all your previous videos are not in order.
Just uploaded the 54th video chronicling the overhaul of a turbojet engine on Patreon.
So it looks like the roll pins fit into blind holes. How do you get the old pins out?
Is that SSR on the shelf for sale?
how did you take the pin out originally?
that turbine wheel looks spiffy.....hahaha...awesome!!!!!
Silly but obvious question. How in the world do you get the roll pins back out?
@JetAce08 Take away the power turbine, gearbox and prop of a T56, and you would have a screaming little turbojet, but you would need at least 8 of them to get a C-130 off the ground.
Those pieces take the energy in a low mass, hi velocity jet of exhaust, and turn it into a high mass, low velocity prop wash. Much more push.
It turns a speedboat into a tugboat. Perfect for a cargo plane.... or a monstrous gunship.
Considering the direction of motion of the turbine blade, those locking C type slotted coiled spring pins should be inserted in position with their slot pointing outwards. The first one was fine , but that shown at 1:33 should be rotated a little. When inserted as I suggested the load that can be taken by the locking pin is much higher.
In one of my industrial investigations , I once found one of these C slotted coiled spring pins was being used as a cotter pin to lock a very large boiler fan on to a shaft for an Electric power station. The slot was positioned parallel with the shaft and the double shear action caused it to spring each time the fan started and stopped. Eventually metal fatigue crept in and the other side of the slot broke all along its length. If the locking pin was installed through a rotation of 90 degrees, The shearing action would not have resulted in the locking pin being subjected to such metal fatigue through continuously springing it.
In this particular case it I do not know how important it is but the point how to insert these type of locking pin needs consideration when the load is "pulsating". In this case the ,considering that the turbine blade is taking the slipstream of the guide vanes before it, the blade is being pulsated and forced back.
+Carmel Pule'
Well you sure have a pedant's taste for minutiae. Unfortunately, you are lacking in understanding on the function of turbine blade locking devices.
I've made videos discussing this subject, but a guy that knows as much as you about so much prob shouldn't bother...
Thanks for the criticism, tho.
Cheers.
AgentJayZ, Sir, no criticism was ever meant and as a consultant engineer, I just related my own experience with such locking C slotted pins inserted in the wrong orientation.
I thought the pins would be somthing special, not just a simple roll pin! I'd be a bit nervous putting the tail cone on there with an overhung turbine! Also intresting a big castle nut holds it on! Now the F-86 wasn't afterburning if I remember right? Cool stuff Jay! I may be one of you soon! There's a chance ill be at GE here soon. If allowed ill film some at school, we have a JT8D, some APU turbines, looks like what's in your huffer cart!
Could you plan to start balancing that first section of rotor blades by matching lighter pins with heavier blades?
No. The weighing and sorting only gets you to the starting point. The balancing runs are where the balancing takes place...
Also, all the pins are of identical weight, within the resolution of our scale.
@AgentJayZ lol, well ok a drag cart then. But I was speaking more of using the thrust to push it, not shaft Hp though. Plus I think i have more fun building my own stuff then getting a actual jet engine. I learn more from building it, not to mention its hard enough building the little projects I do since I have no real area to build in. Im technically not suppost to have any of this crap in my barracks room, or work on it at the cryo shop, so im kinda stuck with hoping a shop mate will let
Thank you for teaching........ SAT SAHEB =)
I do not work in the industry but I am fascinated by jet engines. Your videos are fantastic. One question, why are the turbine blades locked in with set pins rather than screw based fasteners? is it a heat consideration... or vibration etc.. thanks if you get a chance to answer and keep up the great work, both on the clear and understandable videos and the building and maintenance of awesome engines.
I don't really know, but I think it's the simplest, most reliable way to get it done. If the pins were to work loose, they would be driven towards the bottom of their slot by centrifugal force. They are already there, so they would not move.
Thanks makes sense. Thanks for taking the time to reply. Your vids are the best imo for understanding how a jet engine works, short of being an engine mechanic. You really make the components come together for me. Thanks and again keep up the great work, just got done watching your vid of testing on the jet "dynometer" and I loved that... the sound was awesome!!!
Interesting that you use anti seize on the pins. Do they see a lot of corrosion?
+Kenneth Cohagen I'm just trying to make the removal job easier for whoever does it 50 years from now.
It's interesting that the pins don't modify the balance. Or does balancing happen after this point?
I've wondered about that too. I weighed a few dozen pins individually. They are all the same weight, within 0.1 gm. Actually they all register exactly the same on our scale with a resolution of 0.1 gm is a better way to say it.
The pins are added after the final balance, but during test runs, the engines are far under maximum vibe limits.
A lot of you have asked that... so many that I gave the answer over a year ago...
@AgentJayZ When do I begin my training Master Yoda?
Is the ceramic coating a update,I work,on J 79 net engines Its been 50 years But I don't remember the ceramic coating on the hot section turbine blades ,but it's been a long time ?
We apply modern technologies to old engines, and they become immortal.
@CNCAddict Yes, of course you are correct. BUT I choose to use the common ( and wrong ) description of the effect as centrifugal, just because I sound like a pedantic geek when I insist on using the absolute correct terminology... plus, it's like holding back the tide with a spoon... so I go with the flow. Meh.
Plus, your referring to a comment in another video, aren't you?
how heavy is one piece of the ceramic turbine and will break if knocked?
How much wood could a woodchuck chuck...
@Fierobsessed I would imagine you tap them similarly to how you remove headless / broken bolts from an engine head, etc. There are reverse bits you can use, but we're talking lawn mower vs jet engine here, potentially having quite a few differences in finesse and tools required :)
Hi
I cant good speak english i am michanic turbin sgt 100 t0 400 you are vere nice man and frandli tanki you for every think
how do you remove those pins to replace a blade?
I've shown the procedure in a video. Please use the index for the playlist "Your Questions Answered"
That’s all that holds the blades in?
That's what maintains their position at rest. When operating, the engine spins quickly and forces a great deal of heated gas through the turbine. So the blades are "held in" by both centrifugal loading, and by the locking nature of the fir tree joint when subject to bending loads. This is demonstrated in a recent video about turbine buildup for the Orenda 14.
You must have a serious amount of patience to install that many pins.
How do you get the pins out when servicing? Aren't they in blind holes?
Info section...
Wen the leaf requres replacement how will u pull out that small pin.i racked my brains no way i can guess. Can u pliz pliz pliz replay. Iam so much intrested in this videos.i will not have a restful sleep without ur replay. Some of the greatest videos and explanation is outstanding
+Sharif Abdul
A later video shows the process.
th-cam.com/video/aNoS_If4K9g/w-d-xo.html