Hey Doctorturbo. You have some interesting points. However, we must remember that a typical shaft driven quad losses over 35% of its power to heat due to all the right angle gears and the transmission. Now it is not unusual to lose 10-15% in a hydraulic pump and 10-15% in the hydraulic motor. The hydraulics gets rid of all the shafts and gears. Seems to me that these numbers are not too far off from the typical shaft driven quad!! I think it has more to do with cost than technology or efficiency. However, by adding on a number of benifits, maybe even the costs can be justified.
Bryce

 

I think as far as cooling, use oil/air to cool the engine like a number of quads do and just bump up the capacity slightly to add the additional cooling for the hydraulics. As far as noise.. Honda makes their hydrostatic drive act like a normal transmission so the ATV drives pretty much like any other ATV. I think these are two non-issues. Weight again I think is a non-issue because all those heavy shafts and CV joints are replaced with a few hydraulic hoses. I say its a good idea.
Bryce

 

I think you guys are missing the point of the system . All we need is to put a couple of horse to each wheel . No need for something that can give all for traction. And the drive pump is run off the tranny output sprocket. Actual motors need wiegh but a pound or 2 . The whole system could come in under 15 to 20 pounds. Just think what you could do in a holeshot if the fronts were clawing while everyone else is spinning. Or even on a muddy track. Just like the bike it will give the advantage in certain situations . We discussed this back when the bike came out but never went any further than specing out the pump and motors.

 

Thats a good point WISTECH. Quads; however, have two extra wheels and all the extras that goes along with 4 wheels. It is not uncommon for a quad to have to transfer full torque to a single wheel: front or rear. Imagine having to back up a hill. This requires most torque to be transfered to the front tires. LOL, I don't think we'll see our two wheel drive cousin doing that.
Bryce

 

BryceGTX you have some good ideas but your figures are off.
According to your figures a juice drive is 5 to 15% more efficient than a mechanical drive. That's impossable. If it were, I would have one in the drag car I drive. Take out all of the tranny and rear end BS and bolt up a pump and a few wheel motors and few valves and wa- la, a 5 to 15% faster car. Or I would have one in my commute car. I could use the extra gas left over!!!! [img]i/expressions/face-icon-small-wink.gif[/img] The most efficient system is plain old gears and chain that have been around for hundreds if not thousands of years. A Gilmer belt will beat chain but not by much. The V belt system is bad news for efficiency. The power goes up in heat. That is why they get hot and chains don't.
There are a few cross over quads on the market right now. They don't sell very well because of the extra weight. I'm in no way dissing on the cross overs. They do everything well but nothing the best. They look very fun.
Everybody wants the smokin fast Shee or Rappy or 450 take your pick. It's almost like if people want a sport quad; they buy it. If they want a ute; they buy it. Now too many people buy the cross overs.
Also, in no way am I thinking your ideas are bad. If you want one of these quads and they make it, I say go for it. I'm just stating the facts of power transfer. Just like my V, they will hog power and won't be the drag quad some think they will be.

 

Actually Doctorturbo.. My numbers are right on!!

You need to read carefully what I wrote: I wrote a shaft drive ATV. Remember each gear set is good for a 5% loss. Count the gears, 1: right angle drive to rear axle, 2: right angle from prop shaft to transmission output: 3&4: At least two gear sets in the transmission. 5: gear set between the engine and clutch. That adds up to 25%. Then add all additional losses in CV joints, bearings... You will end up with best 25% and typically 35%.

Now as far as your drag car: You have a single gear set in the rear axle and worst cast 2 gear sets in the trans and best no gear sets in 1:1 transmission. The car is must more efficient.

The quad.. now thats a different story.

Gears are not all that great at 5%. if you don't believe me.. Take your rear wheel drive car/truck and drive it up an 8% grade for a few miles. Then get out and put your hand on the rear diff. Careful.. you may burn your hand. Not sure what you are comparing about v-belts. But if you compare a CVT drive with a manual transmission (IN AN ATV), you might be in for a shock.

The reason a sports quad has a manual trans and a chain is that this combination represents the most effeicient method to transmit power (unlike the shaft) It only has 2-3 gears in the trans and the chain.

The facts of power transfer is that each gear set throws away 5%, so you have to count gear sets. Once you do that, hydraulics is looking much more comparable. Now if you want a drag quad.. get a banshee.. If you want a AWD quad, hydraulics seems to be a good way to go.
Bryce

 

The BEST of course would be direct drive.............just thought'd I'd add that in there....

 

LOL.. How about we connect the connecting rod directly to the rear wheel!! Two cylinders.. One for each wheel. They did it with steam driven trains.. Hey, but watch out for the boiler!!
Bryce

 

lol.....yeah no kidding.....I was just stating the obvious.....I think someone above said the best setup is gears/chains.

 

BryceGTX your missing my point here. The point is, a juice system is not more efficient than a gear system. If you still believe it, then you can sell your juice system to every auto maker in the world that uses a 4X4 system. Why not just bolt some hydro motors to each wheel and you would get 5 to 15% better mileage. Any time you you switch to one energy system to another energy system you loose efficiency.

Ha, ha, ha, ha, try and put 500 ft lbs of torque through a juice system at 55mph it will make a gear set feel like an ice cube.

V belts are what is used on quads. You can call them anything you want. They are just wide V belts. Why would I be in for a shock? I already stated that gears and chain are more efficient than a V belt. Gears and a Gilmer belt are more efficient than the former.

I can tell that you don't believe that a juice system is less efficient than a shaft and gear set-up. That's fine. Some people think that a four stroke size for size will out power a two stroke also.