As some of you may recall I have a Ramseys 20K winch I want to install midship (rear cable) on my U1200. I would like to run it off the stock hydraulics but they are not large enough (11 gpm on a 30 gpm winch). Adding a second PTO drive hydraulic system is a big job with lots of extra parts (pump, tank, valves, filter.....). Since the winch will not be use on a daily basis I would like to run it direct off the PTO, the problem is the PTO spins the wrong way for the winch.
Do any one know of a 1:1 (or close to 1:1) reversing transmission of gear box for a PTO or similar? I am looking into a reduction box (portal) off of an early VW van, to see if I can get it to work. But in the world of farming and PTO's is there such a unit (off the shelf) available.
I know Atckison Vos has a PTO revers box but they want way too much $$$ for me.
My internet conections been down for a few weeks, so I've not been able toview the list for a while... For your question, I've considered adapting a divorce mount domestic (probably np 205) transfer case to use as a centralizer. If you found the right case maybe you could use it to reverse the rotation?! The vw box is an interesting idea, though I wonder about the hp rating. When running high hp through a vw trans there are a lot of weaker links than the reduction boxes, so something always lets go before them...
The winch will run both ways but for cable routing I need it to spin cable under. As for the HP rating of the VW box, I don't think the winch will need full PTO HP. The bonus of a VW box is I might be able to find one for free.
I also thought of using a 3 or 4 sp truck tranny mounted inline with the PTO shaft. It would give me 3 outfeed gears and 1 infeed, BUT most truck trannys have a 3 or 4 or more to 1 reverse gear. So the already slow PTO speed would be even slower. I could run the PTO into the truck tranny backwards (feed into output shaft, winch on input shaft) and have a 3 or 4 to 1 overdrive.
The ultimate would be a small tranny that has 1:1 forward and reverse to put inline with the PTO, giving me cable in and cable out with 2 speeds (540 and 1000 rpm PTO) But I think thats just a dream, unless I have the tranny custom made.
They're designed as differential gearboxes and right angle drives but some of them give you a rotation reversal, too. Single speed and one direction, though.
Could you not mount the winch with the input shaft facing to the rear of the vehicle then use some pillow block bearings to take the pto shaft under or to the one side of the winch then use some simple sprockets and a length of chain to reverse the shaft rotation as it goes into the winch.
Don’t forget you MUST HAVE an overload clutch or shear pin system built into the PTO system or you WILL overload the winch and brake cable etc very quickly, if you tell me the gear ratio and drum diameter I will tell you the max input toque in lbf, remember the 1000rpm pto is a ~2.2:1 and the 540rpm pto is ~4:1 vs. flywheel torque rating, so you have between 640lbf and 1280lbf at the pto output and about 105hp
Could you not mount the winch with the input shaft facing to the rear of the vehicle then use some pillow block bearings to take the pto shaft under or to the one side of the winch then use some simple sprockets and a length of chain to reverse the shaft rotation as it goes into the winch.
Don’t forget you MUST HAVE an overload clutch or shear pin system built into the PTO system or you WILL overload the winch and brake cable etc very quickly, if you tell me the gear ratio and drum diameter I will tell you the max input toque in lbf, remember the 1000rpm pto is a ~2.2:1 and the 540rpm pto is ~4:1 vs. flywheel torque rating, so you have between 640lbf and 1280lbf at the pto output and about 105hp
b101uk
No due to the braking system on the winch and the lack of mounting space behind the tranny I have to have the gear trane on the drivers side.
So the input torque for the winch must be ~131.041LBF
However non of the above account for efficiency of the gear train in the winch, being a worm drive it is more efficient than normal gears but there will be some loss from the PTO input value to the winch output in pull lb, I would guess this to be 1% to 5% loss, but by calculating without the loss it gives you that margin on the correct side of 20000lb witch can them be fine tuned using some form of load gauge for the final setting, but a 5% loss is only an additional 6.55lbf on ~131.041LBF or 5.95lbf on 118.541lbf input torque.
If you want to make a load gauge, find an old working hydraulic ram with a known piston surface area and a structural capability of obviously grater than 20000LB, for a 20K lb winch I would recommend a ram with >10in2 surface area on the stanchion side of the piston, get a good quality finely graduated calibrated pressure gauge capable of ~3000psig and a suitable single length of hydraulic hose to permit the reading of the gauge from a safe distance like 10ft, hand prime the ram with the hose attached with oil so there is very little air left in the ram and hose then once primed screw the gauge to the hose making shore there is no + or – pressure introduced, once complete you now have a load gauge that will accurately tell you the pull you winch generating by connecting the winch hook to 1 end of the ram and the load object you are pulling agenced to the other end of the ram, as the load increases the pressure in the ram builds in relation to line pull vs. surface area vs. pressure reading e.g. a ram with 10in2 surface area stanchion side of the piston will give a pressure reading of 2000psig when 20000lb of pull is put into the stanchion side of the ram.
Just so you understand the need for either a clutch or shear pin to protect the winch and the Unimog as well as people the calculation for an unprotected winch driven of the 540rpm pto and assuming an engine torque output of 320lbf is:
~1274.074 * 40 = 50962.96lbf (the affect of 40:1 gear ration in the winch at 1ft to the drum centre)
50962.96lbf * 3.8155802861685214626391096979332 (16mm rope) = 194453.2lb pull or in metric that is ~88227.405kg or 88.227 tons (97.0497 tons US – short tons)
witch can them be fine tuned using some form of load gauge for the final setting, but a 5% loss is only an additional 6.55lbf on ~131.041LBF or 5.95lbf on 118.541lbf input torque.
Linear Mode
