hey, any of you builders know the apx. rpm of the 1990's J.D. hyd. pumps input shaft at full throttle? I am considering a special project and wanting to see if I could get decent hoe operation and bucket breakout pressure running the pump at 1000 rpm. Thanks for sharing your knowlege.
Which pump off of which application? Generally they run at engine speed which is up to 2,600 RPM, at least on backhoes. Running a backhoe at 1,000 RPM is fine for an amateur. A pro will miss the extra speed. Force shouldn't be any different unless the pump is worn out.
Thanks Delmer. The pump AT164404 would be from a Deere 310D hoe. Since the hyd. pump would be running the same rpm as the engine, I am with you-that the speed would be too slow....looks like I would be searching for a gear box or gear head with a 1 to 2.5 ratio to keep respectable hoe capacity. Any ideas on what type of equipment that I could find this gear box, would also be of help....I am thinking perhaps a 8 foot wide snow blower gear box would have a fairly significant increase in the output shaft speed. Thanks.
Is this for a PTO pump? powering a backhoe attachment converted to three point? And what kind of use do you expect to get out of it? In any case it's a fairly simple problem to find the appropriate sized gear box, gets a little more complicated when you want to do it cheap with what's available at your local junkyard. I'd find a hydraulic HP calculator and try to find something close to double the theoretical HP of the hydraulic output of the pump. 2 to 1 would get you plenty of speed for most backhoe uses, if this is a tractor PTO then any tractor big enough to carry it around would have enough power to run it at a slower engine speed and 3 to 1 would work fine too. As far as what type of equipment to look for, sometimes the easiest way is to do some walking, I'm not sure about snowblowers, at least around here they don't get worn out and scrapped at the rate of something like a chopper or combine. What are you thinking and what do you need to know? I don't know if I'm talking to somebody with lots of relevant experience or what.
Thanks Delmer, yes you hit it right on the head. Am looking into mounting an industrial hoe onto my 115 HP IH 1256 farm tractor, and would like the hoe to have as close to possible the same capacity as the factory ones. However I would not be using a 3pt "factory" ineffecient 540 hoe pump to power my hydraulics. Unfortunatly from what I was told years ago, I am not able to use the tractor hydraulics for continued not stop use since the earlier IH tractors used the open system hyd, and the hyd oil would get overheated. I was not able to use a hyd. driven centrifical sprayer pump on my open system either because of overheating issues. Any idea how Case or Deere gets by with using the open system? Is it with the large or combined pump capacity of 25 to 38 gpm @ 2700 to 3800 capabilities or is it in their configuration? My pump capacity is only 8 gpm @2250. With their open system, they would not be using a variable on demand pump in theirs-correct? My biggest obstacle use to be coming up with the right pump to use off my pto, to keep full hoe power...great advise Delmer-I was not aware a hyd pump hp caculator existed and I found a good one that should provide the needed info. An area I need of expertise on now is-my previous 3pt hoe had its own SMALL oil reservoiur, not sure on gallons and cant find specs on line, and it had no oil cooler. Since its not very likely that I am able to effectivelly reconfigure how I would hook in this industrial hoe to my tractor hydraulics, what refrence or caculations would I use to determine the seperate hyd oil reservoiur gallons needed to prevent overheating with a 30 gpm or so pump, driven off of pto, to be used by just the hoe?...Maybe there is an engineerng caculator online for this too? Will have to check. And no, I dont have past experience of converting over a project like this, but I have never let lack of experience stop me from carrying out my desires. Hopefully you Delmer or someone else can explain above questions about Case and Deere open system. Thanks. Good day.
Lots of questions. One answer for now, big oil coolers, as big as the radiator and in front of the radiator. None of the open center hydraulic systems that I know about have variable on demand. I could be wrong?
I would think that using a cogged belt with correctly sized sheaves would produce the RPM you're looking for without excessive shaft load. It would also eliminates some of the alignment issues with coupling a pump shaft to a gear box output shaft.
A typical backhoe has about a 20 gallon reservoir and about 15 gallons in the plumbing and cylinders, including the loader. That's not the cooling capacity though, the oil cooler is much more important to be able to run all day without overheating. The reservoir is just there to store the extra fluid when the cylinders are all retracted. Closed center systems only return leakage to the reservoir typically so the reservoir does very little cooling. A small three point backhoe is probably not designed to be able to run all day without overheating, why would anybody use one like that? I don't think that even with a similar sized tractor, pto pump and more power, that the performance will be close to a real backhoe. Even if you get he hydraulic power, the three point linkage won't be as stable as the backhoe being part of the tractor frame. It might work fine for what you want to do, but it won't be as easy to use or as fast. I wouldn't hesitate to use a tractor system to power the backhoe IF there is enough fluid reserve to function the cylinders without overflowing when they're retracted. For typical backhoe use the load isn't going to be constant enough to overheat under most conditions. Besides the fluid capacity, the other big problem is that it would be slow even with that big engine at full speed.