Sea King Power Turbine to Gearbox Connection

[Cracker Box]

Hi, I am trying to find some info and images of the power transfer connection between the Gnome H.1400 power turbine and Sea King rotor gearbox. I need to replicate this connection, or engineer a similar alternative, to connect a H.1400 to a bespoke gearbox for a ground based application.

I have the engine and power turbine and a Sea King shaft which runs to the rotor gearbox.

(Sorry, due to lack of posts so far, I'm not allowed to post images yet).

The shaft has a Thomas flexible coupling which attaches to the power turbine output flange. Strangely, the bore of the Thomas coupling is an interference fit onto the PT's coupling which must make its fitting and removal difficult, does anyone have any experience of fitting this shaft?

I don't have a rotor gearbox but from web images I can see where and how the shafts connect. I can't, however, find any images or info on the torque tubes which run between the PT casing and the gimbal rings which are around the gearbox input shafts, I can see these must attach to the gimbal at the 3 & 9 o'clock points but if anyone can shed any light on what the tubes look like, or any other information, I'd be very grateful.

Thanks in advance,

Dave

[sycamore]

Dave, it probably depends on which engine/PT/COUPLING you have ,as the Port drive to the main gear box has an electrically driven unit in it ,called the `MAIN DRIVE`..,or it maybe in the gearbox...can`t remember...it allows the port engine to drive the PT and the electrics, hydraulics ancillaries,and rotorblade unfolding, before starting the stbd engine ,which is then used to spin-up the blades....The port engine is then set to ground-idle,it`s free-turbine is now slower than the stbd one ,and the `speed-select levers`are now positioned ,stbd forward,port SSL back,the `main-drive` can now be selected` in`(it is protected by microswitches).This now allows both turbines to share the `power`..Same system on Wessex 2 and 5.Procedure is reversed on shut down....Enjoy deciphering electrical and transmission diagrams,,,!!!!

Failing all else ,go down and find the guys who have got the SeaKing flying between Chard and Crewkerne.....

[wrench1]

engineer a similar alternative, to connect a H.1400 to a bespoke gearbox for a ground based application.... or any other information,

FWIW: The Gnome/T58 turbine is used in a number of high performance racing boats. I believe you would be better served to contact that side of the market instead of the aviation side. Most boat turbine applications require custom-built input shafts, engine controls and in some cases a separate reduction gearbox. This would be similar to what you are doing. The aircraft input shafts, etc. were specifically designed for more dynamic operating situations (e.g., Thomas couplings) than a fixed ground based application and may not work as you planned. Plus any "aircraft" part could be more expensive which you do not require with your install. I've never personally seen a Gnome/T58 boat install, but have been around and assisted with some other boat turbine installs like a T55, C28, PT6. There are a number of turbine boat builders out there if you search online. Here's one below. Good luck.

https://www.turbinefun.com/index.asp

[NutLoose]

Cracker, same engine on the Wessex so look at that, but your best bet is to contact one of the numerous American tractor sled pulling competitors as that is where most of the Ex RAF Gnomes ended up..

engines on the Wessex ran through a reduction combining gearbox then via a shaft to the main rotor gear box

https://www.everettaero.com/gnomebox.html

This guy may have your answer


https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/640x425/image_b211167b1f25d5a2f32c88b93c8ebe1048f6cc5b.png



check out the squirt

https://nyethermodynamics.com/index.html

or

http://www.schumi978.addr.com/turbineboat2_firstpage.htm

[NutLoose]

Also

Welcome to S & C Thermofluids Ltd Gnome Engine Test Laboratory (http://www.thermofluids.co.uk/getl.php#)

[Cracker Box]

Thanks sycamore. Fortunately I don't need to delve into black magic of the electrics, I just need to transfer the mechanical drive into a bespoke gearbox.

Yes, I'd forgotten about Historic Helicopters and their Sea King I will give them a try :ok:

[Cracker Box]

Thanks wrench1. I believe a lot of the boat builders tend to use the aircraft gearbox which on some Gnome (e.g. Whirlwind) and T-58 (SH-2?) installations had a compact reduction gearbox which fed into the rotor gearbox. These gearboxes give a much more boat friendly output speed than direct feed off the PT. The gearboxes connect directly to the PT without the need for a separate drive shaft and torque tube like on Sea King and Wessex. The resulting power plant is very compact and ideal for boat use.

In my application I need to drive at full PT speed into a bespoke gearbox. I will almost certainly have to use custom drive shaft and I agree, I may be able to dispense with a flexi coupling. I just want to get a better understanding of the Sea King installation.

[Cracker Box]

Hi NutLoose, I work at S&C Thermofluids! :)

[NutLoose]

K, Wessex is a H1200 and 1300 if I remember correctly..

Out of interest, its a long time ago since I worked on them, The Puma used a splined shaft with a Thomas Coupling flextor pack, it was six from memory (but I could be wrong) plates that clamped to the shaft in three places and also to the engine in three placed between to shaft points if that makes sense, this is a puma Turmo engine shaft.. the shaft would then slide into the gearbox and the gearbox was bolted to the engine with three long 10 mm bolts.

https://www.ebay.co.uk/itm/Puma-helicopter-shaft-pen-Pot-Westland-Aviation-aircraft-Storage-Pot-man-cave/353036865314?hash=item5232a30f22:g:WF8AAOSwL7leiaWB

..


..

[Cracker Box]

Thanks NutLoose. The basic engine is the same as in Wessex, with uprated power, but the coupling to the gearbox is very different. Our company operates several Wessex H.1200 engines driving them into the Wessex aircraft gearbox and bespoke gearboxes. The Wessex coupling is a beautiful and complex design but we have pretty much exhausted most commercially available examples of these!

In starting from scratch with the Sea King 1400s we need a simpler bespoke shaft and coupling solution than Wessex which at the same time can take the higher power. The aircraft installation does appear fairly simple and easy(ish) to replicate, especially when compared to Wessex, but I would just like to see an image of the Sea King torque tube to confirm my theory!

Nye and the other guy do great things with those boats but they use an aircraft reduction gearbox, close coupled to the power turbine, to give a relatively low speed output shaft which drive the boat or jet pump. Such a box doesn't exist for the Gnome 1400 and I need full power turbine speed into my gearbox anyway.

[NutLoose]

It might be worth having a word with these people as they are putting one back in the air

https://www.historichelicopters.com/Pages/35/Sea-King.html

[Cracker Box]

Cheers, NutLoose, I'll see if I can find any images of the Puma installation.

Nice pen pot BTW :ok:

[Cracker Box]

Yes, absolutely, they sound like handy people to get to know!

[NutLoose]

https://www.bidspotter.co.uk/en-gb/auction-catalogues/witham/catalogue-id-witham10042/lot-41a82960-d57d-4735-9775-a7ac00965151

thats the box from past sale

[Cracker Box]

Yes, I've been looking at similar images to those. From them you can see where the input shafts connect and there is a gimbal ring around them which the torque tube from the power turbine connects to. It's this torque tube which is my primary interest at the moment but I can't find an image/drawing for love nor money. I have messaged Historic Helicopters to see if they can help.

Finally up to my 10 posts :8

[Cracker Box]

Sea King rotor gearbox, port input shaft and torque tube gimbal ring circled:

https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/2000x1500/gbox02b_e66f32c2ee89aaa307180d239be3af9825b81f20.jpg

Torque tube attaches at the 3 & 9 o'clock gimbal points.

[wrench1]

It's this torque tube which is my primary interest at the moment but I can't find an image/drawing for love nor money. :8
PM John Dixson. He posts in the Rotorheads forum and is a retired Sikorsky Chief Test Pilot. He should be able to help your inquiries.
https://www.pprune.org/members/168874-johndixson

[NutLoose]

Ok this is the coupling the Puma used for the engine to gearbox, the shaft I put the pic of above was connected to the engine via a coupling similar to this

http://heliwrench.********.com/2008/10/inspection-of-bell-thomas-couplings.html

missing word is b logspot No gaps

also

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840022225.pdf

..

[Cracker Box]

PM John Dixson. He posts in the Rotorheads forum and is a retired Sikorsky Chief Test Pilot. He should be able to help your inquiries.
https://www.pprune.org/members/168874-johndixson

Thank you for such a potentially useful contact wrench1. I have a video call later today with Historic Helicopters who are about to fit an engine to their Sea King, this may answer all of my questions, but failing that, I will definitely contact John Dixson :)

[Cracker Box]

Ok this is the coupling the Puma used for the engine to gearbox, the shaft I put the pic of above was connected to the engine via a coupling similar to this

http://heliwrench.********.com/2008/10/inspection-of-bell-thomas-couplings.html

missing word is b logspot No gaps

also

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840022225.pdf

..

Thanks for this NutLoose. The Thomas coupling is such an elegant solution to a flex drive, although I may be biased, sharing my surname with it as I do (Thomas, not Coupling, that would be weird! :))

Interesting NASA paper too, it all adds to the knowledge base :ok:

[sycamore]

Cracker,as a point of interest ,how do you control your Gnomes;do you use the `computer Mk1/1A/2,or do you run in `manual...?
Do you have `electrically operated HP cocks`; flight-idle stops, HPT overspeed-trip`and how do you do the `surge-margin checks`...?
Have you had a `surge` on a Gnome...as unless you have an `instant HP COCK` you`ll have a very pretty decorated jet-pipe....?

[Cracker Box]

Cracker,as a point of interest ,how do you control your Gnomes;do you use the `computer Mk1/1A/2,or do you run in `manual...?
Do you have `electrically operated HP cocks`; flight-idle stops, HPT overspeed-trip`and how do you do the `surge-margin checks`...?
Have you had a `surge` on a Gnome...as unless you have an `instant HP COCK` you`ll have a very pretty decorated jet-pipe....?

sycamore, we don't use the computers at all, we have manual throttles, with idle stops which operate a small servo motor at the fuel valve. We have larger servo, also manual, on the HP cock. We have our own build electronic monitoring system for GG & PT speed and turbine temp. Any over speed (or PT under speed, indicating a broken PT tacho drive quill shaft) or over temp condition triggers the opening of a high pressure solenoid valve in the HP fuel line to the combustor, this dumps HP fuel pressure from the rail very rapidly causing an instant flame out and run down (hopefully!). This acts well well as an instant HP cock and is, I believe, the system they used to have on the SRN6 hovercraft. At the same time as the fuel dump, the HP cock servo automatically closes although this takes half a second or so.

Yes we have had (many :eek:) surges but only ever lost a compressor once, which if IIRC was cause rather than effect, and fortunately we haven't lost any turbines in 20+ years of operation <touch wood emoji>.

[Cracker Box]

I have a result! The good people at Historic Helicopters have sorted me out with photos of the missing pieces to complete the jigsaw and have also offered some of their spares stock should we go choose!

Complete H.1400 engine and coupling assembly ready for installation into aircraft:
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1125/dsc_0012_3c7579bf8cec187f67963a2bf111edd9cc34b5be.jpg

Drive shaft, with Thomas coupling, as it fits to PT output shaft:
https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/2000x1125/dsc_0010_6007d39eb79c11ab9045eb59f08f29ba494c37a5.jpg

Torque tube (actual term Support Tube!) with yoke to connect to the gearbox gimbal ring:
https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1209x2000/dsc_0018_c13339fc89cc53c63a4a6fb207a8b63e66da15c7.jpg

Thanks to everyone who has helped in my search, it is much appreciated :).

[sycamore]

C-B, AAHHHaaa,nothing like the whine of an early morning start on a Gnome,followed by a `WHOOOOSSH`,THEN SILENCE,as there is a realisation the intake blank had not been removed...….!!

[NutLoose]

Or the hiss as you Comp wash it to find stores had ordered the wrong grade of walnut shell and all those little pieces blowing out of the exhaust are parts of the compressor blades as well as shell... oops.. :)


Brilliant, so glad the links paid off so handsomely. Interesting to finally see how it installs having worked on Wessex and Puma's, almost a mixture of both.

.

[Cracker Box]

C-B, AAHHHaaa,nothing like the whine of an early morning start on a Gnome,followed by a `WHOOOOSSH`,THEN SILENCE,as there is a realisation the intake blank had not been removed...….!!

:O oops. Didn't the Vuclan to the Sky team destroy an engine that way too :sad:?

Or the hiss as you Comp wash it to find stores had ordered the wrong grade of walnut shell and all those little pieces blowing out of the exhaust are parts of the compressor blades as well as shell... oops.. :)


:eek:

[sycamore]

Swinging a lamp a little.....b4 walnuts in a land and time Far away,we did comp washes using a mixture of avtur and `distilled` water,which as any `fuel` knows does not mix well,even using a big wooden spoon,so ,trying to keep a steady crpm and PTIT,IN MANUAL THROTTLE was a 3-handed job,one on HP cock,one on throttle,and one waving to the stirrer...didn`t make a lot of difference as the compressor was worn out in about 25 hours,and the later sand-filter mod. didn`t help if it got wet in the tropics........
Not nearly as much fun as starting a Belvedere,cartridge-avpin to turbine starter,....

[NutLoose]

https://www.pprune.org/images/smilies/embarass.gif oops. Didn't the Vuclan to the Sky team destroy an engine that way too https://www.pprune.org/images/smilies/puppy_dog_eyes.gif?

Silica Gel bags put into the intake of all the stupid places as an anti det measure to try and ensure a low moisture content, why the heck they never put them in the jetpipe where they would have blown out if forgotten is beyond me..

Looked at the range of engines you have BTW
Gnome Wessex... Worked on..
T55 Chinook....... Worked on
Adour Jaguar...... Worked on
MicroTurbo Jaguar...Worked on

You only need a Turmo ( Puma ) and a Conway ( VC10 ) and you have my complete RAF engine technician career sorted.

[Cracker Box]

Looked at the range of engines you have BTW
Gnome Wessex... Worked on..
T55 Chinook....... Worked on
Adour Jaguar...... Worked on
MicroTurbo Jaguar...Worked on

You only need a Turmo ( Puma ) and a Conway ( VC10 ) and you have my complete RAF engine technician career sorted.

I'll add them to the shopping list! Do you need a job? ;)

[JohnDixson]

Dave,I sent a note to a retired friend who might assist, but even there,his experience ( he and I joined SA about the same time) might begin after the T-58/S-61 engine/airframe interface issues were designed and tested. I’d suggest you get in touch with both Westland Engr Dept and Rolls and see if they can connect you with some of their retirees who may recall the details you are looking for. I dimly remember conversations about early T-58 high speed shaft issues,but that’s about it.

[Cracker Box]

Dave,I sent a note to a retired friend who might assist, but even there,his experience ( he and I joined SA about the same time) might begin after the T-58/S-61 engine/airframe interface issues were designed and tested. I’d suggest you get in touch with both Westland Engr Dept and Rolls and see if they can connect you with some of their retirees who may recall the details you are looking for. I dimly remember conversations about early T-58 high speed shaft issues,but that’s about it.

John, thank you very much for taking the time to help.

[Cracker Box]

Dave,I sent a note to a retired friend who might assist, but even there,his experience ( he and I joined SA about the same time) might begin after the T-58/S-61 engine/airframe interface issues were designed and tested. I’d suggest you get in touch with both Westland Engr Dept and Rolls and see if they can connect you with some of their retirees who may recall the details you are looking for. I dimly remember conversations about early T-58 high speed shaft issues,but that’s about it.

John, I approached a company in Canada, Rotor Maxx, who overhaul of Sikorsky S61/H-3 drive train components and engines. They kindly marked up the diagram as follows:
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1184x613/coupling_assembly_2_185810012bdd301bdb9985b63a2a46c72fa3c070 .png
They confirmed the compliance at the gearbox input coupling (coloured red) to compliment the gimbal movement. The driven gear, inside this coupling and connected to the input shaft (coloured blue), is crowned to achieve this, much like the Wessex coupling in reverse.