Anyone know of a 2 spd shift on fly gearbox?

[xfeejayx]

hello all.
I don't even know where this would fit, but here it is.
I'm the team leader of team that makes a one man-off road race car at the University of Illinois in Urbana-Champaign. For this years car we want to put a 2-spd hi-low (reverse not necessary at all, but could be nice...maybe) mated to our normal CVT. Does anyone know of a (small) 2spd gearbox that can shift on the fly. Powershift (no clutch) would be great, but hand clutch could work. The only 2spd I know of is one made by Polaris and it is not shift on fly, you have to stop to shift (nor workable on a race car). I've been researching for about a month, with no luck. It is going to be mated to a 10HP motor, so it doesn't have to be beefy at all (smaller is better).

Thanks for any help, though I'm not holding my breath since this probably isn't the right place for this.

[GreyGoose006]

best thing would be a transfer case with a inertia clutch.
we are doing a similar setup at my college.

you could order a transfer case and modify the gears inside to your liking.
usually those are shift on the fly.

[xfeejayx]

Originally Posted by GreyGoose006

best thing would be a transfer case with a inertia clutch.

I'm not too familiar with transfer cases, or inertia clutches for that matter. Care to enlighten me?

[Moppie]

An over drive off the back of an old Triumph, MG or Rover gearbox.
Operated by a 12 volt solonoid and about the same size and weight as a starter motor.

[curtis73]

Two companies that I know of sell two-speed planetary gearboxes over the counter; US gear, and Gear Vendors. Both are variations on the European OD, and like Moppie said operated with a 12v switch. I have one and its geared 1:1 with no 12v and 0.78:1 activated.

www.gearvendors.com
www.usgear.com

[Moppie]

xfeejayx are these little off road buggies run in an inter-university challange, similar to Formula SAE?

[GreyGoose006]

i think so. SAE has two divisions. mini baja, and formula racer.
i just joined the formula racer division at my college.

[xfeejayx]

Originally Posted by Moppie

xfeejayx are these little off road buggies run in an inter-university challange, similar to Formula SAE?

yes. it is very much like formula SAE. SAE Mini-Baja is just the off-road version of an SAE sponsored, international collegiate event.

[Blue Bowtie]

What ratios are you seeking? Does one of them have to be 1:1? I understand you need something for "10HP", but power transmission components are typically rated by maximum torque, not horsepower, so what is the peak torque the drive would have to transmit? There are several options.

[xfeejayx]

Originally Posted by Blue Bowtie

What ratios are you seeking? Does one of them have to be 1:1? I understand you need something for "10HP", but power transmission components are typically rated by maximum torque, not horsepower, so what is the peak torque the drive would have to transmit? There are several options.

sorry, thought i specified tourque. it gets about 8 hp at 3800 rpm, so thats about 14 ftlbs. I would want a 2.5:1 and a 1.5:1, but anything that has about the ratios of 2.5, and 1.5 would work. i.e. a 5:1 and a 3:1>>5:3, we can put another reduction on it, or make our final drive reduction smaller. i would even be happy with a 2:1 and 1:1. I'm getting lots of ideas with stuff that really isn't a gearbox (transfer cases/overdrives), is there just a regular gearbox with those ratios out there?

Need input and output shafts on opposite sides(inline or not, preferably not), and prefferably .75" diameter input/output, but now i think i'm just asking too much.

[jveik]

stick a powerglide from an old chevy in there lol!!!!

[GreyGoose006]

i'm sticking with the transfer case idea. you would essentially be using it as a high and low before the CVT.
kinda like (well, exactly like) a transfer case on a rock crawler 4x4.

how are you transferring the power. do you have a clutch, or does the CVT have a built in torque convertor?
if the CVT doesnt have a torque convertor (ie. the wheels spin when the motor is running) and you havent put in a clutch yet, i'd go with an inertia clutch for simplicity. you could start in the low gear and go until you needed to shift. let off the gas for a split second, and the inertia clutch disengages, you shift gears, and give it gas, and the inertia clutch engages again.

[jveik]

what the crap is a CVT? is that one of them newer continuously variable trannies or something? scratch the powerglide idea lol im an idiot...

[GreyGoose006]

yeah. CVT is Continuously variable Transmission. think two cones with a belt running between them
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