sprocket and chains

[Baloo]

hi chaps
thanks for the suggestions keep em coming

only 2 things seem to be an option at this time, well in my mind anyway

hydraulic drive l like this as it would allow me to drive one side forwards and the other side backwards allowing me to turn on the spot something l cant do using solid axles as l propose, down side is the amount of fabrication it will create removing the solid axle casings from the equation they are doing many jobs as it is from supporting the common shaft locating the wheel bearings and forming part of the chassis/assembly mucho more to make but maybe ???

the other option l might consider is using front axles instead of rear to allow some normal steering as well, l cant nick em of a vitara as they are independent suspension on the front but that may still work as l could use that as well and at have working suspension something the supacat dosent have l would have to forget about it being amphib though as l doubt l could seal around a suspension that moves

 

[dan.taylor.1]

Sealing an independent sus setup isn't as difficult as it seems, just all the arms and springs need to be outside the sealed bit with just the inner uj/cv joint to seal where it exits the tub, steering makes this difficult as you've got to seal the steering ram/arm, but if you only need a small amount a short ram could be used outside the tub.

The hubs from skidsteers are easily available which already has the setup for hyd drive via a chain, most skiddies have two motors with a chain linking the left wheels to give 4wd. I can tale some pics of ours if you need them.

Dan

 

[dan.taylor.1]

Just had a brainwave, keep your solid axles and fit a motor to each diff input flange, you can then have one, two or three drive axles, no shafts to worry about, and if you fit lockers to each diff you can have fixed 6wd, or with no lock in you have the ability to skid steer so no need to fit steering axles, plus you'll have little drag if you put the front two into a hydraulic float position and drive the rear axle using breaks to steer.

Dan

 

[Baloo]

Hi Dan

yes please any pics you have l would love to see, no point in trying to re invent the wheel if its been done already l best have a look lol

hydraulics are complicated if you had a motor on the nose of each diff how would you connect them in series or parallel ? both has its issues in parallel if one wheel looses grip they will all stop as the fluid will take the path of least resistance in series it more difficult to drop one motor out of the drive train as the fluid needs to by pass that motor for the others to operate and the undriven axle will need to free wheel so the fluid must go round somewhere

locking diffs would be nice but the cost of 3 arb's is a lot more than 3 times the budget for the whole project so they are out lol

anyway the vitara diff does have a nice flat mounting point on top for the common shaft to mount off, simples

 

[normspanners]

A sliding muff coupling would do that.

Do they have to be well lubricated before the rigid shaft is inserted??

 

[normspanners]

how about turning the axle tubes upwards through 90deg so that the flanges and the first part of the diff are through the bottom of the tub which could be sealed, you could then link the flanges and a hydraulic motor simply with a chain that is inside the tub you could have a hydraulic motor to the front axle direct to the flange the two motors could be powered by a tandem pump so you would get a slight diff effect between the two because they are seperate but would maintain maintain drive a little similar to farm slurry tanker trailers that have hydraulic drive to the trailer wheels for field use just to maintain the drive and assist the tractor so it becomes six wheel drive assuming using a4X4 tractor?

 

[Baloo]

how about turning the axle tubes upwards through 90deg so that the flanges and the first part of the diff are through the bottom of the tub which could be sealed, you could then link the flanges and a hydraulic motor simply with a chain that is inside the tub you could have a hydraulic motor to the front axle direct to the flange the two motors could be powered by a tandem pump so you would get a slight diff effect between the two because they are seperate but would maintain maintain drive a little similar to farm slurry tanker trailers that have hydraulic drive to the trailer wheels for field use just to maintain the drive and assist the tractor so it becomes six wheel drive assuming using a4X4 tractor?

nice thinking Norm
turning the axles through 90 deg would mean l dont need a common shaft or bearing blocks, just 3 sprockets and a long chain,
not sure how l would get my pug engine to hook up to it but the night is young yet
and the pinion bearings may get a little dry pointing skywards but it has merrit

 

[normspanners]

just grease em up, as said just go tandem hyd pump. no clutch to wear out gears to change and virtually immediate forward- rev change when in sticky situations just by having a foot control twin shuttle valve. the steering could be done simply by separate brake master cyls to the left/right sides on levers. then if it was amphibious it would be simply to have a prop powered by a hyd motor on a change over valve with a simple rudder to do the main steering.

 

[dan.taylor.1]

Hi mate, you'd control each axle via a spool block, a big enough one won't limit flow, could be operated via solenoids that a flick of a switch changes from one live axle to two to three.

As for flipping the axle up 90* you could but I'm sure you'd have oil starvation issues but could maybe get round it by overfilling? I see your point re cost of arb's they aren't cheap. Would you need them with 6wd??

I'll get pics asap, it's basically a big pump driving two motors, then a sprocket on the driver stub axle links via a chain to the driven stub axle in an oil bath for lubrication.

The pump (along with tandem for the lift rams and other hyd services) run off a 4cyl Kubota engine that's maybe 30?bhp, so a 90/100 horse derv should handle it no bother. If you can't find a big enough pump several could be linked to add flow maintaining pressure.

Dan

 

[normspanners]

One way to test if there was enough oil throw from the crown wheel up to the pinion bearing would be to remove the pinion put the diff back in the axle then pull the axle along and see how much oil was thrown up to the pinion and at what speed.