hydrostat vs gear hp loss

PineRidge · Aug 14, 2006

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.

dieselsmoke1 · Aug 14, 2006

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..

Brad_Blazer · Aug 15, 2006

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)

Brad_Blazer · Aug 15, 2006

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

BillyP · Aug 15, 2006

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.

Soundguy · Aug 15, 2006

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

Soundguy · Aug 15, 2006

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..

shvl73 · Aug 15, 2006

BillyP said:
You put the range selector in neutral.

That's what I thought. I'm pretty sure mine will roll easily that way.

dieselsmoke1 · Aug 15, 2006

BillyP said:
You put the range selector in neutral.

Duh.......

Put brain in gear (or push hydro pedal) before engaging fingers

Thanks

dieselsmoke1 · Aug 15, 2006

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?