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Very odd 4x4 concept.

2K views 24 replies 15 participants last post by  mtnbikeboy 
#1 ·
Let me warn you. This concept is very out to lunch, I thought it might work. I have no $$$ or time to even think about trying it but wanted some input to see if all you rock-gods thought it even feasible.

One summer of my life I worked at a Case-IH dealership in my area. Specifically in the combine shop. At one point we added a kit to a combine to make it 4wd. I was thinking about this the other day and a strange idea popped into my head. All wheels on a combine are driven by hydraulic motors all run off of one pump run by a Cummins Turbo diesel that is pretty much the same as in the Dodge trucks. The rear motors are heavy but are also heavy duty. It seems to me that it would be feasible to obtain 4 of these motors & the engine & pump and bolt them onto a custom frame. I was thinking some sort of high travel, tube chassis frame, with fully independent suspension. The hydraulic lines could be run right next to the frame for protection, and since the frame is custom built you could place the seat and engine just about anywhere for the perfect weight balance. There are no axles, driveshafts, ujoints, t-cases or anything mechanical except the engine, suspension and steering that could break.

I know this is waaaaaaaay out in left field, but just wanted some honest input. If you flame me and say I was :smokin: then so be it. BTW I don't :smokin: and was completely sober and caught up on sleep when I thought of this. Have fun.

Tim
 
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#3 ·
I was thinking the axact same thing about a week ago. Would be a neat idea, but I don't think it would go very fast if youw anted to take it on road. Off road though, would probably be fine. The only real design *challenge* would be how to make the steering work. With no solid front axle, and front wheels that could move through large ranges of motion completely independant of each other, bump steep would be an issue.
 
#5 · (Edited)
Jared Rude said:
I was thinking the axact same thing about a week ago. Would be a neat idea, but I don't think it would go very fast if youw anted to take it on road. Off road though, would probably be fine. The only real design *challenge* would be how to make the steering work. With no solid front axle, and front wheels that could move through large ranges of motion completely independant of each other, bump steep would be an issue.
One hydro ram on each side of the suspension. I'm not sure the point of useing IFS, even a super longarm design would have limits.
 
#6 ·
I've often thought about getting two of those hydro motors and attach insuch a way that they would be above the diffand have some sort of gear drive that connected the pinion to the Hydro motor.

you could even throw in a quick gear adjustment at this point and you would get rid of the driveline issues :D

You could keep 4.10 gears in the diff and then have different gear sets that that connected the hydro units to the pinion.
This could be the lightweight breakthrough for the crawling world.
No transmission no tcase just a motor driving a hydro unit.
 
#7 ·
Some college SAE teams are already experimenting with this concept in their mini-baja cars. I know MSOE is one of them.

It's a good idea ... someone just has to step up to the plate and try it ... much like "someone" and their IFS/IRS "rock racer."

cm "jury's out on that one" k
 
#8 ·
That wouldent be too hard with a top loading 2.5, you could just mount the hydro motor right on the end of the pinion. Would you realy need gearing between the hydromotor & axle? Seems like extra stuff to break; just match the motor to the axle gearing.
 
#9 ·
I imagine that lowering the gear ration would take more pressure off of the pump and motors. This would probably give you more controlable power through the hydro system.
Less chance of blowing the lines as well.

I'm just guessing I am not a hydro expert
 
#11 ·
this is not a new idea by any means, but like cmk said, somone needs to step up and build it, its not difficult but needs money and one off machine work. i would go electric rather than hydraulic, mostly cause of the fluid and heat. but i think you are all thinkin too simply here, i would make a beam suspension type system, with one arm for each wheel, comming from a central point of the frame extending out toward each wheel, with steering on all fours. this design has been built on a small scale by toyota, dont have a link i read about it a while ago in a technology rag. around the same time i read about honda's humanlike walking robot.
i would build it,,, if i had a financial backer and a complete machine shop.
 
#12 ·
cmk said:
Some college SAE teams are already experimenting with this concept in their mini-baja cars. I know MSOE is one of them.

It's a good idea ... someone just has to step up to the plate and try it ... much like "someone" and their IFS/IRS "rock racer."
Well according to the "someone" with the "rock racer", everyone is going to be running these.

Currie, Shannon Cambell, Pat Grimillion, and Walker Evens either have/ are working on buggies similar to Randy's.

I think ti would be too heavy for mini baja though. Hydro fliud weight alot.
 
#14 ·
I had a post the other day about rocker bogie suspensions ( so far all very small scale) these all use independently powered and steered wheels. Also no real suspension travel.

I think what may slow this type of tech down, is that the vehicle is unconventional in all aspects. and yes top speed is very slow. one of the benifits of the hydro would be weight transfer ability. instead of dead weight sloshing about in one location, you could build you tank into the chasis and use valve's and pressure to move it around. Like for climbing move the fluid up front. side hills etc.

lots of options just lots of money too.
 
#15 ·
There's always ways around the $ issue if you have time, skills, and conections. Hopefully this picture will attach ok. If you look at the rear axle you can see the tires are both turned at 90 degrees. They are hydraulically driven and hella strong. Best of all my dad has worked for the company that sells them for 30+ years and is on the look out for two rear axles for cheap. I think the only hard part would be sorting out all the hydraulics into an easy to operate system. If the picture didn't attach go check out the material handlers at www.gradall.com
Travis
 

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#16 ·
I too have looked at this idea while working with gradalls. They don't seem to be that difficult. The only problem I have is the motors are really big. If you look at the knuckles on those, they are really tall. You would have to have a large wheel and have a odd backspacing. A friend of mine has looked into this and had even had someone offer a pump and motor system to him. I don't know if he took it or not, but would be really cool.

Here is another off the wall idea. Using a quickchange centersection out of a sprint car and making it a ifs,irs rig. You could choose the gear ratio you want depending on the condition. You could even have one for driving to the trail and one for trail riding. They are simple to change, and come in a wide variaty of ratios. The only problem we are having is getting some way to flange the to ends. Both at the wheel and at the center. I just need to sit down and think about this some more. Need more :beer: .

Erin
 
#17 · (Edited)
willymutt said:
Here is another off the wall idea. Using a quickchange centersection out of a sprint car and making it a ifs,irs rig. You could choose the gear ratio you want depending on the condition. You could even have one for driving to the trail and one for trail riding. They are simple to change, and come in a wide variaty of ratios. The only problem we are having is getting some way to flange the to ends. Both at the wheel and at the center. I just need to sit down and think about this some more. Need more :beer: .

Erin
The nice thing about that is you can pick...lets say a 3.30 gear ratio for driving, and once you hit the trail, pop off the 10-12 bolts, swap the top gear for the bottom, and you would get something like a 6.80 ratio. Another plus is the gears are so small you can carry 15 gear sets in one small case:beer:
 
#18 ·
This has been beat to sh!t a couple of times already. The one thing that I have a concerm about is leaks. They are going to happen, don't even think about denying it. Now, you have 15 to 50 gallons of oil spilling on the ground. what do you think the enviro's are gonna do? Next, you're outta fluid, 10 miles into the trail. How ya gonna get out?
Tiing the motors will be the next thing I see. I work w/ heavy equip and have seen dual hyd motor equip. WHen you try and go straight, you have to have a vavle for each motor and getting them timed correctly is a bear.
If I was to do the hyd motor thing, I would get the rear axle from two Cat backhoes (4WD & 4 wheel steer version) and connect a motor to that. They have final drives so the r & p doesn't have to be to radical.
 
#20 ·
willymutt said:
I too have looked at this idea while working with gradalls. They don't seem to be that difficult. The only problem I have is the motors are really big. If you look at the knuckles on those, they are really tall. You would have to have a large wheel and have a odd backspacing.
Sounds like a good excuse for 20" wheels and huge military tires to me:D. Hopefully pops will score a axles for cheap and we can find out how it works. That 90 degree turning sounds good to me.
Travis
 
#21 ·
Please protect the driver from the pressure lines. My friend’s dad almost lost his finger because of a pinhole in the line. It blew up like a balloon. NOT good.

We thought of doing this on our mini baja in 1994. I think there is a hunting ATV that uses this type of drive. We were thinking of maybe using water to beat the environmental issues.

And it may be an old topic, but things get bumped so fast. This is the first time I’ve seen it and I like it. :D
 
#22 ·
water won't work, as a drive fluid. boiling point is to low.

I have to agree leaks would be huge issue.

You can get vegitable based oils, however they are contaminated by the metals as soon as you put it in the system.




Our snow cats at work use a splitter box off the (cat Diesel) engine that drives two pumps these then drive the main drive motors. ours run left and right for the tracks. You could run front axle and rear axle that way too.
 
#24 ·
I agree the oil factor is a problem but I don't think it is so big the concept must be scrapped. Everyday we drive vehichles with high pressure hydraulic lines and incidents are rare. Power steering lines, brake lines, and tranny cooler lines do rupture on occasion but by using quality lines and routing them carefully 99% of all accidents could be avoided. If a spill did occur it would be a bigger mess then your usual trail accident but it could still be cleaned up. I would imagine a hydraulic trail rig would be mainly used in competition where there would be plenty of resourses to completely clean up any spills. Logging companies and others routinely use hydraulic equiptment in the back country and I've never seen or heard of a spill. There's got to be a braided steel double hydraulic line, line within a line, or a green fluid that could used to work around the problem. Trail rigs are already on the scene with full hydraulic suspension and steering this just seems like a next step. If someone want to give some $$$$$ I'll be glad to work out the kinks:D.
Travis
 
#25 ·
This is going great. Thanks for all the input guys. As far as mini-baja goes I agree with the person that said it wouldn't have a high enough top speed. I think for now higher speed applications have to be traditional. I was definitely thinking big wheels (like rear combine tires). You guys are mentioning front and rear beams. I was thinking if IFS/IRS wasn't feasible it would be easy to do it the same way combines & gradalls do it. One beam front and rear mounted in the middle. That gives you somewhere easy to mount everything. I do like the sound of electric too. For anyone who has heard of LeTourneau Inc. mining & earth moving equipment that is how they are run. One big generator with a motor for each wheel.

As far as leaks, out of all the combines our company performed service on it was very rare to get a leak, and those lines weren't even steel braided I don't think.

Tim
 
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