Why Aren't PTO's Hydraulic?

glennmac · Sep 29, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Art raises another potential benefit of hydraulic PTO's: you should be able to reverse the flow to make your implement spin the other way. This must have a use other than for augers.

If hydraulics are difficult to diagnose and fix, why has Case/Ingersoll always given a lifetime warranty on their all hydraulic tractors. In my experience manufacturers only give or sell extended warranties when they are convinced that they will not have much reason to honor them. That is also the reason why it is foolish to buy them.

Glenn

art · Sep 29, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Glenn the Case system isn't that fool proof. You have the chance of over speed which could destroy some equipment. In the area where I'm from they never sold many because on hills you had to use the brakes heavy to slow down. Those that did get sold here we often see after 20 years of lawn duty to staighten out drive problems that people have been unable to fix. To me I'm glad as a dealer I don't have that option to sell. There are people that could use this system but I know it would take more time for some simple explanations as to why the mower can't spin backwards and still cut grass. We hit probably 5 to 10 calls a year alone on blades put on upside down and the mower deck would just be one of the problems.

W5FL · Oct 6, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Glenn,

A Power Take Off is just exactly what it says. It allows any other device the same access to the engine directly geared as if it were part of the tractor. Many PTO devices depend on being driven at a fairly constant speed. There is absolutely nothing that a hydraulic system could do that the direct drive cannot do better. I would certainly hate to pay for the hydraulic motor (and the hydraulic pump) to run it to get the 62 HP that I get out of that 540 rpm PTO shaft now.

Hydraulic motors are nice, but very expensive. A good hydraulic auger that I would love to have is $2500. A $1000 gear driven unit is more powerful as most tractor hydraulic systems are not up to running them.

The auger that I need is $4500 and it will only use a straight PTO take off as it needs more power than you can conveniently obtain from a hydraulic motor.

Even a hydro transmission has enough slip in it that you cannot obtain constant ground speed that are required for some agricultural applications (spraying) etc.

Sorry, but I will keep the hydraulics for what they do best and use the mechanical pto for what it does best.

gordon · Oct 6, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Wen I have to ask what kind of auger are you looking at for $4500? Must be a monster! What can it do that my Danuser can't?
Gordon

Anonymous Poster · Oct 6, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

So far, ALL above points but pro and con about hydraulics are lucid and valid. But,,,,,,,,,,,,,

Hydraulics are far more flexible. It is easier to buy and run a hose than it is to find and align mechanical components. Even a simple mower deck drive belt must be an exact replacement, where a broken hose can be replaced by one twice as long if necessary.

True, the initial expense of hydraulics is usually greater than mechanical. But, hydraulics are cheaper to maintain (a readily available hose or seal as opposed to a hard to find, obsolete, and expensive mechanical part).

Adequate power (engine, pump, cylinder, motor) is part of the design. Speed vs. Power? Consider a 2 stage pump. Closed vs. Open system? It depends on the application.

Surely, if you already have a PTO and a mechanical attachment, a shaft is the logical way to go. But, if your buying a log splitter, would you really consider a reversing gearbox/transmission, shaft, and worm screw? Do you think that might be more expensive and less efficient than hydraulic?

Just imagine an all mechanical road grader. I don't have to, I've got one, crank start and all. It's an all mechanical Caterpillar. It works! It's a marvel of mechanical engineering! It belongs in a museum along with the steam shovels, NOT on a job site!

W5FL · Oct 7, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Gordon, The Danuser is the best available for drilling in soil. This one locks the 3 point and has two hydraulic cylinders that put over 4000# of down force on the auger when it drills. Makes quick holes in chunk rock and drills holes in solid rock.

gordon · Oct 7, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

I'd say that monster would make some quick holes with that much down force. I'd hate to price out the auger bit for that one ---ouch---. One thing goes without saying if you need it you need it. I'm not sure if threre is a downforce kit available for mine or not. Food for thought I guess.

On that Danuser I bought I would have sold it to you Wen but turns out I really like it and I'll never come across another deal like that on a F-8 in my lifetime.
Gordon

W5FL · Oct 9, 2000

Re: Why Aren\'t PTO\'s Hydraulic?

Yeah for about $450 a downforce kit is available, but it is not in the same ballpark for downforce. It helps when using a pry bar would help, but still will not drill rocks. The augers are about $1000. I see several of them in use in this area, so they must do the job for the fence companies and farmers with a lot of rocks.