What gearbox? Turboshaft engine

[richardm]

I dont get it ". Why would tou use it in reverse ? Do you mean connecting tour turbine to the slow side to increase the output rpm ?
Anyways by looking at the size of the gears I doubt greatly about those being able to handle 16 HP..
You ll just grind those teeth away ..

[racket]

I've had a bit more of a look at the GY6 150 cc engine gearbox and they look pretty good , nice chunky gear teeth and lotsa ball bearings .

LOL...............cheap enough to buy the complete unit and cut the engine off ...................plenty of spares available at reasonable prices

[turbinenjoe]

Apr 1, 2024 16:19:53 GMT -5 richardm said:

I dont get it ". Why would tou use it in reverse ? Do you mean connecting tour turbine to the slow side to increase the output rpm ?
Anyways by looking at the size of the gears I doubt greatly about those being able to handle 16 HP..
You ll just grind those teeth away ..

Sorry, I see that my last post was confusing and that i mixed things up.

Of course my plan was to attach the power turbine shaft to the shaft of the sun wheel. I understand your doubts about the capability of the gear box. Probably I have to figure out a way to test the gearbox beforehand.

Greetings

Matthias

[turbinenjoe]

Hello,

I found something that might be interesting.

There is a company that sells centrifugal supercharger kits with a 3“ impeller that are driven directly by a cogged belt:

hydemotorworks.com/shop/de/produkt/harbinger/

They offer two different pulley setups. They say that the smaller pulley arrangement can turn the supercharger with around 30 k rpm and with the larger pulley arrangement the supercharger should be able to reach 50 k rpm.
The power that is needed to turn a compressor wheel of this size at 50 k rpm should be more than 20 kW. Therefore I think a similar cogged beld setup could be interesting for reducing the rpm of small turboshaft engines.

Best regards

Matthias

[richardm]

Might work provided that the turbo charger output shaft and pulley are mounted on a beefy bearing capable of sustaining the radial loading of a tensioned belt. To find such a bearing also capable of let say 50 K , is a challenge in itsel in my opinion

[racket]

Some interesting numbers .............that kit is for www.speedmaster79.com/P-2-Centrifugal-Supercharger-Without-Gearbox

1150 CFM = 88 lbs/min =1.46 lbs/sec

22psi max boost = 2.5PR at 78% effic = 110 C deg rise

110 C = 67.5 HP/lb

67.5 X 1.46 lbs/sec = 98 HP

Using a skinny belt at 52,000 rpm ............. I need to find out who makes such fabulous transmission products .

98 HP at 52,000 rpm = a tad under 10 ft/lbs of torque , but a freepower can produce twice its max rpm torque at stall , so ~5 ft/lbs max for the freepower , so say 50 HP for a freepower ..........with good heat protection for the belt , no heat soakback from the redhot turbine wheel , which could also make bearing cooling an issue as well .

BUT , toothed belts are good , I used one back in the 1970's to run the supercharger on my bike , but it kept on breaking :-(

Cheers
John

[enginewhisperer]

There are some fancy high power capacity belts available these days, but I've still had issues with those at much lower power and rpm than this thing!
Some motorbikes use a belt instead of a chain, but the belt manufacturer recommendations specify much larger belts needed even at those loads.

Speedmaster is a pretty dodgy company. Most of their stuff appears to be knockoffs of other peoples products, made cheap in China.
I actually bought one of their dry sump oil pumps that was on special, and it was junk. I sent it back.

So I wouldn't trust their specs at all!

[noshell]

Very interesting stuff. Modern components are just amasing.
98hp to drive that supercharger is bloody mental aswell.

[wannabebuilderuk]

A Torque multiplier might work, usually have anywhere from 1:5 to 1:70 ratio planetary gear set.