Rubber cushioned drive chain

[XLerate]

Hi guys! Just thinking about my near-future build. Tranny at this point is expected to be my Suzi GS550 engine cut down, it's already apart. These engines are rated at 54 hp/31 ft lbs torque, or 40.3Kw/42Nm. I may try to use a VW 1.6 engine or other diesel with more torque than the Suzi engine.

Wondering if a guy could use something like the rear sprocket rubber cushioning adapted to either the engine output shaft or gearbox input, to help a tranny withstand high shock loads from more power? Seems like it might make a somewhat weak trans survive a little better?

[alexanderfoti]

It does seem like a good idea, but adds complexity. Its the Torque that kills the gearboxes in the end

[XLerate]

YEP! The torque monster shows no mercy on weaklings. Many, many stories about the bad boy Dodge Cummins 6 cylinder shredding very stout transmissions if not carefully driven. Lots of guys tried to drive them like a weak sister gasser, only to discover the sledge hammer factor, oh my!

I'm most concerned with the little gear on crank that's the input to trans. Just not much there. I can change the shaft to a strong solid piece in place of pressed crank but the little gear is what it is. Not convinced the rubber cushion would help much there.

If I try this trans it looks like I'd better plan for change in the future, just in case. Some suggested a Harley Davidson trans at minimum, most likely wise advice. If they made them separate and if I could afford a 5 speed HD trans I'd prefer that but MAN, Harley stuff ain't cheap!! Not real interested in a 4 speed unless I could come up with a Hi-Lo splitter for a total of 8 speeds. A splitter wouldn't be too difficult to engineer.

The secret of a happy diesel build is gears, Gears, GEARS! There's a darned good reason the big trucks run 10-24 speed gearbox setups: to stay in the narrow power band under all conditions. Fortunately I'm doing a trike layout [no choice] so I can stretch the chassis all I want for virtually any gearbox/drivetrain.

Thanks for the input!

[alexanderfoti]

Hmm

Its another argument towards the CVT, properly engineerd, you are in the power band the whole time.

Whilst im not a fan, I see where they are applicable.

I do like the idea of a hi-lo splitter!

Can you up the gearing of the crank to allow you to increase the size of the gear on the input to the trans?

[XLerate]

Hmm

Its another argument towards the CVT, properly engineerd, you are in the power band the whole time.

Whilst im not a fan, I see where they are applicable.

I do like the idea of a hi-lo splitter!

Can you up the gearing of the crank to allow you to increase the size of the gear on the input to the trans?

Gear science exceeds my brains ha! I have no idea how to increase actual size & still have it mesh with the next gear it meshes wth, or if it's even physically possible.

A splitter would make for some seriously dangerous torque into gearbox in Low range so extreme care would be needed while running there. High geared split would be lots less strain on stuff. Still thinking the rubber cushioned sprocket on input might help, but only one potentially expensive way to find out. If the cash flow ever catches up to the imagination I'll be looking deeper into options.

[Jocalopse]

There are rubber coupelers used in industrial applications between electric motors and pumps. It usually consists of two half shells with rubber pucks between to dampen shock loading, much like the cush drive in a motorcycle rear hub. They are usually available in many shaft sizes, with associated keyways and grub screws. Google is your friend here.

[coachgeo]

There are rubber coupelers used in industrial applications .... They are usually available in many shaft sizes, with associated keyways and grub screws. Google is your friend here.

Got any suggestions on search terms; such as a common name for this thingamagig your speaking of.

[XLerate]

Yes I worked with those a lot in industrial machinery. That's where I got the idea, but had seen it also used on almost all motorcycles. Figured more guys here would know about the cycle use than about industrial couplings.

Lovejoy is one, probably the most common in the USA, there's several others.

Thanks for the tip!

[DieselFly]

Be careful when putting rubber couplers in drivetrains that have pulsing torque output. If you get the wrong durometer cushion you can actually amplify the vibration. Load does not kill gears anywhere near as fast as torsional vibration can. True story of a microlight in the UK. The rubbers in the gearbox coupler were changer in attempt to smooth out the vibrations. On the first runup they hit the magic spot for the durometer of the cushion and it vibrated so badly they tore the engine of its mount. Rotax is not as dumb as some people wish the were. A little read for openers http://en.wikipedia.org/wiki/Torsional_vibration.

[pietenpol2002]

Had to be the 277 single.

[XLerate]

Thanks for the tips there!

[DieselFly]

old 477

Had to be the 277 single.