hydrostat vs gear hp loss

/ hydrostat vs gear hp loss #81  
Ok.. could be...an air/pump issue.. been so long I couldn't remember... whoever... it begs looking at another neat fact... Had that been a gear tractor.. it would (may.. traction dependent.. )have crawled out.. even if the gears weren't running in oil.

Soundguy
 
/ hydrostat vs gear hp loss #82  
Well, what I got from the thread was; he hooked up a new log splitter, didn't make sure the fluid was back to full, and backed down a steep hill. In his post where he said the tractor was out, he said the dipstick read "a hair" above. After putting in all that fluid, is sounds like he went down the hill quite low on fluid.
 
/ hydrostat vs gear hp loss #83  
A friend of mine discoved what he now considers to be a very important advantage of hydro over gear. Last week he was clearing some land down near the river. He was using a Kuboto with a fel. I haven't had a chance to speak with him directly, and what I have heard has been heersay, and what was published in the local paper. It seems he managed to flip the tractor on its back and then rolled it on its side. He was trapped underneath the rear wheel. He said the tractor ran for a loooong time, it finally cut off when the oil flooded the engine. It smoked and snorted and just kept running for what seemed like an eternity. His arm and shoulder were pinned underneath the rear wheel. He was able to get his pocket knife and dig out enough space under his body to enable himself to scratch and claw with his finders to dig enough of a hole to make clearance to slid himself out from under the wheel. It took him almost four hours to get out from under the tractor. He then walked to a nearby house about a mile away. He was very lucky. His worst injury was a broken collar bone. He said that if he had been using a gear drive tractor, the wheel would have just chewed him up and spit him out. He was very grateful that since it was a hydro, the wheels stopped turing when he fell off. He learned several lessons that day, many of which he had forgotten in his 40+ years of driving tractors.
 
/ hydrostat vs gear hp loss #84  
What we do know for sure:
Kubota L4610
Hydrostat transmission
In a big hole
Engine ran fine
Tractor would sit and look at the hill and not do anything.
The problem was transmission related.

He apparently did NOT hit a pop off or relief. Do we know that? If he tested for that I don't remember.

_RaT_ said:
He apparently did NOT hit a pop off or relief. The only thing that was deduced was that the tractor was on a steep enough hill that the pickup tube pulled air (now that would be a very steep hill). The final conclusion was never 100% other then the tractor would not move but then, the engine would not load up either. Bad linkage as John Miller III sugests, maybe, we may never know. I know I have been in similar circumstances with my front end buried down hill to where it took all my bucket force and spinning tires to get me out. No popoff popping. Heres the thread for folks to browse.

http://www.tractorbynet.com/forums/showthread.php?t=20041&highlight=L4610
 
/ hydrostat vs gear hp loss #85  
JerryG said:
What we do know for sure:
Kubota L4610
Hydrostat transmission
In a big hole
Engine ran fine
Tractor would sit and look at the hill and not do anything.
The problem was transmission related.

He apparently did NOT hit a pop off or relief. Do we know that? If he tested for that I don't remember.


It was some time ago and as I recall, he said the odd thing was the engine did not load up as you would expect leading up to a relief situation and thus the many thoughts and opinions as to what could be the problem such as sucking air or as John Miller III said, a mechanical linkage issue. I could be wrong. As the owner of both a gear and hydrostatic drive, I say it was a mechanical problem not inherent to HST. I say this because neither my L48 or my current L3830 can produce the issue that the "Whats ailing my Bota" thread had nor have I seen a plethora of posts addressing the same thing. Its not from a lack of terrain out here to have such a test executed since the foothills where many of us TBN folks reside will produce similar scenarios on a daily basis. It may be hard to explain just how steep a hill I have put my Kubota on, but I would venture to say, 95% of the folks would simply not do it. I have had to use my loader with the tooth bar to help push myself out all the while my front wheel(s) and both rear wheels were spinning. I have on occasion had to have my wife help drag me out with the truck. That was also the case with my old NH 2120 too, a gear drive. This seems to contrast with the post that Soundguy made about gears drives on a normal functioning HST. Of course his experience with HST may well differ from mine as I am only familiar enough with Kubota's to comment. I must also offer that my experience with HST is only about 1100 hours to date and that with gears would be several thousand. RaT...
 
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/ hydrostat vs gear hp loss #86  
While I agree that if it had been a gear tranny.. it may have chewed him up.. but.. I think he needs to sell that tractor and get one with a ROPS and SEATBELT.. reguardless of the tranny...

Soundguy

qstott said:
A friend of mine discoved what he now considers to be a very important advantage of hydro over gear. Last week he was clearing some land down near the river. He was using a Kuboto with a fel. I haven't had a chance to speak with him directly, and what I have heard has been heersay, and what was published in the local paper. It seems he managed to flip the tractor on its back and then rolled it on its side. He was trapped underneath the rear wheel. He said the tractor ran for a loooong time, it finally cut off when the oil flooded the engine. It smoked and snorted and just kept running for what seemed like an eternity. His arm and shoulder were pinned underneath the rear wheel. He was able to get his pocket knife and dig out enough space under his body to enable himself to scratch and claw with his finders to dig enough of a hole to make clearance to slid himself out from under the wheel. It took him almost four hours to get out from under the tractor. He then walked to a nearby house about a mile away. He was very lucky. His worst injury was a broken collar bone. He said that if he had been using a gear drive tractor, the wheel would have just chewed him up and spit him out. He was very grateful that since it was a hydro, the wheels stopped turing when he fell off. He learned several lessons that day, many of which he had forgotten in his 40+ years of driving tractors.
 
/ hydrostat vs gear hp loss #87  
The single largest "cause" of inefficiency would probably be a tractor that ISN'T compatable to an operators skills or abilities. If that operator prefers Hydro, than I'd venture a guess he's more efficient WITH hydro. In the hands of a qualified, experienced operator, a gear tractor may well be just as smooth, just as fast cycling as a hydro.

The somwhat difficult (on to IMPOSSIBLE) to measure difference in efficiency would be negated by operator skills in most cases IMHO.

It's all what you're used to and what you LIKE.

By the way, give me GEAR drive any day for what I do. I'm used to it, like it, and feel more comfortable with gear drive. That in no way says it's better or worse.
 
/ hydrostat vs gear hp loss #88  
SPYDERLK said:
This does not fit with my experience. Deducing from the ones I have driven

I believe it's written down in the operator's manuel..
 
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/ hydrostat vs gear hp loss #89  
Soundguy said:
get one with a ROPS and SEATBELT.. Soundguy

Believe it was equiped with ROPS and belt but the operator acknowledged he was not wearing the belt as the story was told to me. Understand he plans to wear his belt from now on.

This was just a couple miles from where I live. My neighbor happened to be passing by the next day and saw an excavator carrying the wounded Kobota across the field in a sling to a waiting dealer's trailer.

Lucky man. There have been 4 tractor related accidents resulting in 2 deaths in about a 20 mile radius in the past week or so.
 
/ hydrostat vs gear hp loss #90  
dieselsmoke1 said:
Believe it was equiped with ROPS and belt but the operator acknowledged he was not wearing the belt as the story was told to me. Understand he plans to wear his belt from now on.

This was just a couple miles from where I live. My neighbor happened to be passing by the next day and saw an excavator carrying the wounded Kobota across the field in a sling to a waiting dealer's trailer.

Lucky man. There have been 4 tractor related accidents resulting in 2 deaths in about a 20 mile radius in the past week or so.

Must be an East coast thing, it just doesn't happen out here. :eek:
 
/ hydrostat vs gear hp loss #91  
New Holland lists the PTO HP for the TC-40D (hydro guys) at 33.2 They list the gear drive at 35.0

You couldn't tell the difference in PTO HP with the seat of your pants between the two, it's minimal.
 
/ hydrostat vs gear hp loss #92  
dieselsmoke1 said:
My neighbor happened to be passing by the next day and saw an excavator carrying the wounded Kobota across the field in a sling to a waiting dealer's trailer.

Just sittin here thinking about this and realized why it was being carried. They couldn't pull it out to the trailer.

Don't know if others do but I have not seen a release mechanism on mine to bypass flow and allow towing if the engine cannot be started, such as on a hydro mower. Is there such a function on some?

When I ripped the tranny line elbow off on a snag and lost all the fluid, I released the brake and let it roll down the hill a few feet so I could make the repair without lying in a puddle of oil. I guess that's one way, but probably not a real smart one..
 
/ hydrostat vs gear hp loss #93  
The variable displacement pump is a cool mechanism. When I was at NNPS we had a cutaway of one - it was the first time I had heard of the mechanism and I thought it was really ingenius. The drive shaft rotates a cylindrical pump body that has about 8 cylinder bores arranged in a circle. A piston in each cylinder bore is connected to a raceway that circles the swashplate. When the swashplate is vertical, the pistons stay in the mid stroke position and do not move in or out. When the top of the swashplate is tilted toward the pump body it acts like a cam. The pistons go in at the top and come out at the bottom. At the fluid end of the piston, a crescent shaped slot acts as an intake as a piston rotates from top to bottom. A second crescent shaped slot acts as an exhaust as the piston rotates from bottom to top. The angle of the swashplate dictates the displacement of the pump. It tales a lot of force to hold the swashplate at an angle and that is accomplished by a hydraulic cylinder fed by the charge pump. I am attaching a graphic I found that shows the mechanism but inverted - they are rotating the swashplate (I have no idea how they control the tilt that way)
 

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/ hydrostat vs gear hp loss #94  
Here is the way I look at drawbar horsepower.
Lets say it takes 10 hp to pull a single plow bottom at 2mph (ideal conditions). Lets say you have 2 tractors that have equal traction force and each can pull up to 4 plow bottoms. One tractor has 40 drawbar hp and one has 50 drawbar hp. The 40 hp tractor can pull 4 bottoms at 2mph or 2 bottoms at 4mph or 1 bottom at 8mph. The 50 hp tractor can pull 4 bottoms at 2.5mph or 2 bottoms at 5mph or 1 bottom at 10mph. In both cases the tillage rate is constant regardless of implement size or traction force utilized. Power is defined as the rate of doing work. High traction force buys you the option of working at a comfortable speed and still tilling at a good rate by using the larger implement.

Brad
 
/ hydrostat vs gear hp loss #95  
dieselsmoke1 said:
Just sittin here thinking about this and realized why it was being carried. They couldn't pull it out to the trailer.

Don't know if others do but I have not seen a release mechanism on mine to bypass flow and allow towing if the engine cannot be started, such as on a hydro mower. Is there such a function on some?

When I ripped the tranny line elbow off on a snag and lost all the fluid, I released the brake and let it roll down the hill a few feet so I could make the repair without lying in a puddle of oil. I guess that's one way, but probably not a real smart one..

You put the range selector in neutral.
 
/ hydrostat vs gear hp loss #96  
dieselsmoke1 said:
Believe it was equiped with ROPS and belt but the operator acknowledged he was not wearing the belt as the story was told to me. Understand he plans to wear his belt from now on.

This was just a couple miles from where I live. My neighbor happened to be passing by the next day and saw an excavator carrying the wounded Kobota across the field in a sling to a waiting dealer's trailer.

Lucky man. There have been 4 tractor related accidents resulting in 2 deaths in about a 20 mile radius in the past week or so.

Man... had a rops and seatbelt.. and the op nearly got crushed due to not using them. Kinda like a skydiver jumping out of an airplane and -NOT- using his parachute...

Soundguy
 
/ hydrostat vs gear hp loss #97  
Ford SOS had a traction disconnect.

Soundguy

dieselsmoke1 said:
Just sittin here thinking about this and realized why it was being carried. They couldn't pull it out to the trailer.

Don't know if others do but I have not seen a release mechanism on mine to bypass flow and allow towing if the engine cannot be started, such as on a hydro mower. Is there such a function on some?

When I ripped the tranny line elbow off on a snag and lost all the fluid, I released the brake and let it roll down the hill a few feet so I could make the repair without lying in a puddle of oil. I guess that's one way, but probably not a real smart one..
 
/ hydrostat vs gear hp loss #98  
BillyP said:
You put the range selector in neutral.

That's what I thought. I'm pretty sure mine will roll easily that way.
 
/ hydrostat vs gear hp loss #100  
That brings me back the instigator of my earlier brainfart. Granted they had to have the excavator or something similar to right the machine because in the newspaper photos it was not on it's side, more like 30 degrees from bottoms up. It was a small excavator that had to quickly lower the load to regain balance at least once on downhill section. Wonder why would they would strap a sling on and carry it across a field rather than pull it?
 

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