lightweight rock crawler and Hydraulic drive options

[Baloo]

I don't think the shafts on those are rated for any kind of radial load. It would be better to build a bearing housing/hub assembly that the motors could be bolted too.

 hi
 when you say radial loads do you mean like when a wheel hits a tree and tries to push the motor shaft sideways and wrecks the seals ?

l was thinking about looking at some light car front hubs such as sidekick or mini and seeing if l can modify it to carry the hyd motor on the back where the drive shaft went in,  that way l could use the pivot points for the steering and the discs and clipers if l wanted brakes ,  the disadvantage l see with this is that l am placing the motor further in board from the wheel where as l wanted to tuck it up in the wheel   to protect it from getting bashed on rocks,  not that we have much in the way of rocks over here 

[Boostinjdm]

You will have to look up the specs or call the manufacturer to see what kind of radial load they can handle.  Lots of those motors are used to drive chains and things with the sprocket mounted right to the shaft.  they also can be used as wheel motors, but those may have a little extra support for that.  A farmer I help out has a big z-turn mower that weighs like 1500lbs and he put duals on the drive wheels.  has held up fine so far, even pulling his 1200lb lawn roller while mowing.

[Engineer]

yes l agree there,  l dident think the steering was going to work well with 2 wheels on each side, looks like normal buggy type steering is heading my way

l havent seen a drain port on the motors but will look again,  the idea of using little rams for the steering instead of linkages sounds good, l will have a hunt on ebay and see whats about,  1" dia  piston 5" stroke sound a good starting point ?

Andy

I am having a little trouble looking up the specs for your motor.  The Sauer Danfoss website is a little weak, but I downloaded the 20 meg PDF, and I can't find the exact matching part number.  I am reading it as OMR 160  #151-0486.  They don't give a breakdown of how to interperet the part number, however they show the series.

I GTG now but I think that the case drain is under the sticker acording to the diagrams.  Push on the middle a bit and see if it is hollow underneath.

Your steering size sounds like a good starting point, but I would look into the orbital deal that connects to the steering wheel first.

[Baloo]

[Engineer]

I like the drawing.  Here are my thoughts.

It is good that the steering pickup points are right on the pivot axis of the leading/trailing arms.  That will work out well.  The arms at the wheels are going to cause a problem, because when the wheels are pointed forward, the link is not close to 90 degrees to the tie rod.  Anyway I realize the the drawing is more of a sketch than a blueprint, and it is very thought provoking.

I don't know of the Citroen cars , but I have seen the hydraulic jumping cars. 

I always thought that it would be cool to be able to adjust the ride attitude hydraulically.  The accumulators would allow the suspension to work, but you could have a valve that allowed you to bring the front/back or left/right up or down to accomodate the slope that you were on.

I have seen the air car deal on the discovery channel, and some of it is real, but they are liars about the efficiency IMO.  The special I saw they made some outrageous claims.  However, It would work....  You would just need to bring your air compressor with you....

On the drawing, is that a small motor to the right of the driver, and the pump and reservoir to the left?

[lee1969GB]

Baloo you could run the steering links above the suspension arms for better ground clearance with a quadrant link mounted above the arm pivot to avoid bump steer, do this on all 4 corners then 2 more quadrant links linking the left and right and to the single ram.

[lee1969GB]

A rough sketch, P is pivot to chassis S is to be in line with suspension pivot piont. The ram might be best mounted at an angle and keep all of the links the same length or mount the ram solid and run links to the quadrants. Baloo I think I have ram and orbital steering set up to do this.

[Baloo]

I don't know of the Citroen cars , but I have seen the hydraulic jumping cars. 

I always thought that it would be cool to be able to adjust the ride attitude hydraulically.  The accumulators would allow the suspension to work, but you could have a valve that allowed you to bring the front/back or left/right up or down to accomodate the slope that you were on.


On the drawing, is that a small motor to the right of the driver, and the pump and reservoir to the left?

 hi,  yes the motor is to the right of the driver v, twin would be good,  battery is also along side the driver on the right,  drive shaft under the drivers knees to the pump and tanks on the left side,


heres a couple of links to citroen suspension, bit of a read but it looks like the bits off a citroen would be usfull on a buggy


http://www.citroenet.org.uk/miscellaneous/hydraulics/hydraulics-1.html

http://www.autozine.org/technical_school/suspension/tech_suspension3.htm

hi lee,  l think mark intends to pass the steering rods through the trailing/leading arms rather than under

the sketch you have done looks good, thats how l imagine the linkages might work, will give you a ring about the orbital valve and ram

Andy

[Engineer]

The tough part about the Citroen cars, is everything it does, the computer controls.  That will be the tough part, is the control.  I had thought about it for a rock crawler years ago, use a gyroscope and have the computer try to keep it level.  It could get pretty involved and expensive.  I don't know if you could use the controls out of the Citroen car, or if it would do what you need.

I made a sketch that might simplify Lee's steering.

[Baloo]

[Engineer]

I would be honored if you could use the idea.  The important part is what Mark already had in his drawing, the tie rods meeting at the intersection of the leading/trailing arm pivots.

You could have manual controls on the hydraulic suspension, but with my luck, at the critical point I would run the lever the wrong way and roll down the hill.

[Baloo]

[Boostinjdm]

I'm starting to think you got too much time on your hands.   What do you do for a living?

[Engineer]

[Islander]

For your steering controls, IMHO, having separate control over the front and rear steering would be a must.  Maybe having the fronts operated by the steering wheel / orbital valve, and the rear on a lever / switch the same as they do on the monster trucks.   
Anyone remember a show that was on a few years back where the contestants were given a small budget to build a off road machine to compete in a bunch crazy obstacle courses?  There was a hydraulic powered machine on there, but it was run the same as the zero turn mowers with two large caster style fronts, and it was kinda quick if I remember right.  Quite different then the machine proposed here, but it shows that it is a viable offroad powertrain at least!