Design Possibility, can or CANT be doneà 2

[DDame]

I’m kicking around an idea and want to get some comments as to its possibilities and maybe even its practicality.

Ok, I spent the weekend watching rock climbers, no not people climbing mountains but modified trucks, Jeeps and moon buggies (Purpose built 4x4’s). I seen more broken parts (drive line of course) then I see in my 15 years of being a mechanic (12 years ago). The other observation was the current mechanical drive line creates more limitations then I could count. This includes traction, clearance, power and the list goes on and on. Ok, Ok… Here’s my question.

It seems like the power of fluid could solve so many of these problems I have to investigate. Is it possible with the current technologies in fluid power (Motors, Pumps, Valves and Controls) to build the ultimate 4x4 or even rock crawler using 100% fluid power? Now I said “Possible”, let’s assume for the monument that money is no object (wouldn’t that be nice). Could one take say a Ford truck and replace the axels with Hydraulic motors (all 4 wheels), replace the transmission with a pump and the steering wheel with say joy sticks. Now I KNOW it’s much more complicated than that but for the monument think simple, what do you experts think is this something that could be done?

I’m not looking for any designs or direction at this point, just your thoughts!!

 

[tad1299]

keep in mind this will be for use only off road and on he rocks for rock crawling. Wheel slippage is going to be the name of the game. If I drive the front and rear set of wheels with a set of pumps, steering could be difficult in high angle situations if the left or right side of the wheels are driven this significantly reduces this problem. Also remember depending on the throtle position and configuration, it could act like a skid steer, or act like a front/rear drive vehicle with lockers. Also depending on the situation one could utilize flow deviders and an orifaced bypass circuit around the inside drive wheel depending on which one you wanted to slip. It does get a little complex for control and actuation, but for this application I think it will work. Another setup, could be to look at steering angle and drive the wheels front to back or side to side depending on angle of the steering mechanism.
I have started collecting tubing, hoses, minor valves, flow controls solenoids, needle valves, I have a few actuators for suspension and steering. I still have to get the wheel motors and pumps. I think I will drive the pumps off a standard piston engine/funk gearbox until I can afford/justify a turbine. I also have the bladder (reservoir) and heat exchanger that are going to be used. I am going to put the bladder inside of a tank, and pressurize the tank with shop air for positive system return/suction pressure. I may be able to get away with a bootstrap reservoir arrangment.
Another arrangment would be to utilize one pump per wheel motor.
This is obviously still in work, slowly collecting pieces and parts as I go. I have the frame designed in Cad, but can't finalize the design until I have all the parts I am going to use. Thanks for all the feedback and contructive critisicism.
This is a really great site.

Tad

 

[maytag]

tad 1299,
You haven't mentioned a budget or where you are located-during the mid 1970's International Harvester made several models of combines that used a D414 diesel motor and most were hydrostatic drive with a C-faced mounted Eaton or Sundstrand pump(this was contrary to the popular design of belt drive pumps at this time). The DT414 was rated at 175 hp but was capable of a lot more-some tractors used this same basic motor and it was used a lot for hotrod pulling tractors. There are some of these combines still floating around -some with the RWA-Mud Hog. As these models are 30 plus years old they are not worth a lot to todays farmers and might furnish you with a power plant,pumps and wheel motors along with a lot of other parts you might need. Good luck ,Maytag

 

[kcj]

Combines: good idea. A neighbor bought one to make into a sprayer package, and paid less than $1000 in running condition. They are not productive for todays farms, so have bascially only scrap value.

I ride Observed Trials motorcycles, and last weekend rode an event in Northern MN at a state off-highway vehicle park made from an abandoned open pit iron mine. Two square miles of blast and haul rock, from tailings to rocks the size of a car, in piles up to 300 ft tall. There are endless trails for motorcycles, ATV, Jeeps, etc. The ATV people blasting through mud doesn't interest me at all, but the rock crawlers are fascinating to watch. Trials riders have a lot in common with the crawlers: precision technique, control, traction, etc. vs. just throttle and blast through.

There was plenty of hp present, but generally they are well engineered and technical machines. Looks like a ball, but expensive!

keep us posted

kcj