hydraulic motors

[STLfirewood]

Ok I have a couple questions. I have an old corn conveyor that I want to turn with a hydraulic motor. It's about 20ft long. How do know what size motor I need? Also how do I know what size pump I need to push that motor. I don't know anything about sizing hydraulics. Thanks Scott

 

[kevin j]

Defining the load is the hardest part. If you can determine the torque or hp, its easy to size a motor and pump.
Otherwise, it's a guess, 5 hp, 10 hp, 20 hp??? Speed you can pick by watching another conveyor.
In theory, moving xx pounds of wood up vertically yy distance in tt seconds is the hp, but the friction and losses are high.

Do you have any buddies with similar conveyors, what t do they use.
if not, pick a speed and a sprocket diameter and we can make a stab.

kcj

 

[Tree Student]

Check out this thread.

http://www.arboristsite.com/showthread.php?t=61535

 

[cmetalbend]

Ok I have a couple questions. I have an old corn conveyor that I want to turn with a hydraulic motor. It's about 20ft long. How do know what size motor I need? Also how do I know what size pump I need to push that motor. I don't know anything about sizing hydraulics. Thanks Scott

Single chain or double?

 

[cabinman]

conveyor speed

Defining the load is the hardest part. If you can determine the torque or hp, its easy to size a motor and pump.
Otherwise, it's a guess, 5 hp, 10 hp, 20 hp??? Speed you can pick by watching another conveyor.
In theory, moving xx pounds of wood up vertically yy distance in tt seconds is the hp, but the friction and losses are high.

Do you have any buddies with similar conveyors, what t do they use.
if not, pick a speed and a sprocket diameter and we can make a stab.

kcj

The most important thing in conveyor speed is no faster than needed, time your splitter speed and set your conveyor about 25% faster, If conveyor speed isnt a little faster than the cylinder, the wood will damage the conveyor when its forced off the splitter, too much conveyor speed is like spinning your wheels and wearing things out, T,C, E,J,

 

[cmetalbend]

The most important thing in conveyor speed is no faster than needed, time your splitter speed and set your conveyor about 25% faster, If conveyor speed isnt a little faster than the cylinder, the wood will damage the conveyor when its forced off the splitter, too much conveyor speed is like spinning your wheels and wearing things out, T,C, E,J,

really this would depend on if the splitter pushes into or onto the conveyor, I agree why have speed if you don't need it. Just use a flow valve and the hydralic fluid can be adjusted. In my case the wood is split and tossed onto the conveyor.

 

[cabinman]

Got it

really this would depend on if the splitter pushes into or onto the conveyor, I agree why have speed if you don't need it. Just use a flow valve and the hydralic fluid can be adjusted. In my case the wood is split and tossed onto the conveyor.

The speed factor I gave was a rule to follow so you dont n F*#k up other equipment slash conveyor dosent matter weather you are throwing it on the conveyor, or feeding it threw the wedge, output is output The Idea here is dont spin your wheels and dont dammage the conveyor, supply and demand If you will,...T,C E,J,

 

[cmetalbend]

Defining the load is the hardest part. If you can determine the torque or hp, its easy to size a motor and pump.
Otherwise, it's a guess, 5 hp, 10 hp, 20 hp??? Speed you can pick by watching another conveyor.
In theory, moving xx pounds of wood up vertically yy distance in tt seconds is the hp, but the friction and losses are high.

Do you have any buddies with similar conveyors, what t do they use.
if not, pick a speed and a sprocket diameter and we can make a stab.

kcj

Try this method once you have your elevator set up (no motor(. Load it, let's just say half. Affix a torque wrench and test the actual mearsurement. convert to inch pounds.(most hyd. motor's are rated in inch pounds) That will give you the basic torque required to turn the unit. Try to find a motor with the needed torque at slower speeds, it will generate less heat. That way you can also mount it direct to the drive shaft, again less parts, less expence. Again this might get you started. the speed is a very difficult one to caculate due to alot of variables. I gaurentee you will not get it as close as you'd like, until you've gotton your feet wet. You can do caculation's all day and night. Just rememder you need torque more than anything else.

 

[cabinman]

C metal

Try this method once you have your elevator set up (no motor(. Load it, let's just say half. Affix a torque wrench and test the actual mearsurement. convert to inch pounds.(most hyd. motor's are rated in inch pounds) That will give you the basic torque required to turn the unit. Try to find a motor with the needed torque at slower speeds, it will generate less heat. That way you can also mount it direct to the drive shaft, again less parts, less expence. Again this might get you started. the speed is a very difficult one to caculate due to alot of variables. I gaurentee you will not get it as close as you'd like, until you've gotton your feet wet. You can do caculation's all day and night. Just rememder you need torque more than anything else.

Its, really not that hard, Ive set up farm elevators with hyd motors, and never had a problem with the torque issue, I dont think they even make a low speed hyd motor that dosent have a high torque rating, If you think about it its not possoble to have a low speed motor without a high torque rating,.. its really not that complecated, maybe you should look at the larger conveyors that the fire wood people make, the most common is a 5,5 hp honda engine, there you go, they have figured it all out for you,..check out hondas tourque ratings, but dont bet your life on it,..Ill tell you this much, you can run it with less torque, the main thing is rpm,..and the torque thing will follow, Its really not so hard once you try it, no worries mate,...T,C, E,J,

 

[cmetalbend]

Its, really not that hard, Ive set up farm elevators with hyd motors, and never had a problem with the torque issue, I dont think they even make a low speed hyd motor that dosent have a high torque rating, If you think about it its not possoble to have a low speed motor without a high torque rating,.. its really not that complecated, maybe you should look at the larger conveyors that the fire wood people make, the most common is a 5,5 hp honda engine, there you go, they have figured it all out for you,..check out hondas tourque ratings, but dont bet your life on it,..Ill tell you this much, you can run it with less torque, the main thing is rpm,..and the torque thing will follow, Its really not so hard once you try it, no worries mate,...T,C, E,J,

I'm sorry but your missing several variables to your caculations. Your Banking on the rated ouput of the pump being available to the motor at all times. It's not going to happen unless you run more then one pump, a priority valve or diverter. And now your comparing a gas engine to hydralic motor. They function totaly different. You can't base your caculations on rpm Due to the fact you may not have the avaliable flow to achieve it. If you don't have the torque to turn the unit what good is RPM gonna due. I've seen firsthand the mistake in the message your sending. Which would you rather have? A)a motor without enough torque, which would stop or B) a motor with torque(which wouldn't stop) and less rpm. Most hydralic motors won't even turn a thousand rpm, heck they're all slow speed. Again if you don't have the flow you won't achieve the rpm and thus it is better to error toward the torque then rpm. In comparison Your stating to figure the speed he needs, and the torque will be enough, I'm saying figure how much torque you need, then look for one with enough torque to actually factor in other losses such as flow. Here' an example my elevator is a single chain 11' long. and I want the chain to move at 3' per second. By your caculations I needed a motor that turned (500)RPM. just for the sake of argument. OK now I have a 20' elevator double chain that I want the chain to move at 3' per second. By your caculation they should take the same motor. In reality you'd need a motor with more torque. Your tellin everyone to drive a nascar to a truck pull. (Ya got the RPM you SHOULD have enough torque). I don't need to figure anything out, I already went down this road with my own stuff. You can look at it on another thread, and read all about it. I just want people to make best decision in regards to hydralics, cause they're expensive. In short I guess we'll just have to agree to disagree.:bang:

 

[Mike Van]

Scott, just my 2 cents here - Cmetal's on the right track, if you don't know the load, you're really just hoping what you buy will work. No hyd. parts [motors, pumps, etc] are cheap. Torque wrench is the way to go, set your elevator up, several pieces of wood on it, and see what it takes to turn it. If you only need 500 in. lbs, you don't buy a motor that has 2000. On the other side, if you need 500, you don't want a motor that only does 450. Once you know the load & motor, you can see what gpm & pressure it takes to run it [continuous, not intermittant] You can then size the pump, tank & engine to run it all. You can sign up here http://www.machinebuilders.net/ if you want, there's people there that do this stuff all the time. Unless you have $$$$$ to burn, hydraulic's are best done right the first time. I've done the guessing route before, big pain in the butt to have to re-do it all.

 

[cabinman]

conveyor speed

I'm sorry but your missing several variables to your caculations. Your Banking on the rated ouput of the pump being available to the motor at all times. It's not going to happen unless you run more then one pump, a priority valve or diverter. And now your comparing a gas engine to hydralic motor. They function totaly different. You can't base your caculations on rpm Due to the fact you may not have the avaliable flow to achieve it. If you don't have the torque to turn the unit what good is RPM gonna due. I've seen firsthand the mistake in the message your sending. Which would you rather have? A)a motor without enough torque, which would stop or B) a motor with torque(which wouldn't stop) and less rpm. Most hydralic motors won't even turn a thousand rpm, heck they're all slow speed. Again if you don't have the flow you won't achieve the rpm and thus it is better to error toward the torque then rpm. In comparison Your stating to figure the speed he needs, and the torque will be enough, I'm saying figure how much torque you need, then look for one with enough torque to actually factor in other losses such as flow. Here' an example my elevator is a single chain 11' long. and I want the chain to move at 3' per second. By your caculations I needed a motor that turned (500)RPM. just for the sake of argument. OK now I have a 20' elevator double chain that I want the chain to move at 3' per second. By your caculation they should take the same motor. In reality you'd need a motor with more torque. Your tellin everyone to drive a nascar to a truck pull. (Ya got the RPM you SHOULD have enough torque). I don't need to figure anything out, I already went down this road with my own stuff. You can look at it on another thread, and read all about it. I just want people to make best decision in regards to hydralics, cause they're expensive. In short I guess we'll just have to agree to disagree.:bang:

well my friend, Ill have to disagree , The first thing is were not on the same page with the speed, your doing your calculations @ 3 feet per second, holly crap, If your splitting wood @ that speed Its going to be on FIRE, Iam figuring the speed at one foot per second, and thats faster than the fastest splitters Ive seen, and like I said in other posts you dont want to run the conveyor any faster than neccessary, my experince has been using the popular char lynn h series, 101 -1001 and the 101-1003, either one, @ 2 gpm, and 2000 psi, the 101-1001 moter is 2.8 cu in, turns 165 rpm, with 891 in pounds of torque or 75 foot pounds, the 101-1003 moter is 5.9 cu in, turns 78 rpm, with 1878 in pounds or 156 foot pounds, , these figures are off the chart posted a few weeks ago on the AS, All I know it worked fine for me and the hay bailes weigh more than wood , I dont under stand what you meant by not having a constant supply to run the motor, If you use a flow divider,.. you only need 2 gallons to run your conveyor, @ one foot per second, Of course this was the one I set up, direct drive, 4 in sprocket, And it dosent mean it will work for you, good luck, E,J,

 

[cabinman]

Baileys

Baileys have the char-lynn moters for 200.00, T,C, E,J,

 

[tanker]

just remember that if it was originaly made to run off the pto of a tractor,540 rpm is max and you really don't need probably more than 300 rpm to do what you want to do. I have cribbed a lot of corn over the years (10-15000 bushels a year and 4-5000 bales of hay and straw all at about 1/4 throttle on the tractor and about 3/4 throttle is pto speed (540)

 

[kevin j]

we're sort of going in circles here. Engine and pump and motor sizes have nothing at all to do with anything UNTIL the goal is defined:

What torque and how many rpm do you want to turn the shaft? It depends on load lifted, sprocket sze, etc but ultimately the torque wrench idea is great.

Then, torque is motor displacement x pressure (with some converson factors)
bigger cubic inch or higher pressure = more torque.

Usually, pick an operating maximum pressure, then pick, a motor.

When torque is satisfied, then the motor size and rpm defines the gpm required.

gpm times psi = horsepower required.

It all starts with defining the goal to be accomplished.

Are you taking some flow off the main pump with t pirority divider or ratio flow divider? If so, it might have some talk with the two stage as it shifts up and down may chatter or be unstable.
If single stage pump, divider works great. However, if the conveyor is working without the spliiter working, a spool divider works by throttling the entire unused flow to the splitter (say 20 gpm) up to the pressure demanded to send 2 or 3 gpm to the conveyor. Thus, very inefficinet and maybe a serious heater.

If you need to do that, I'd look at a gear type flow divider. Hard to find in a big ratio like 5:1 or higher, they are usually 1:1, etc. Or a two section pump, just a small 2 gpm pump running conveyor only.

kcj

 

[cabinman]

elevator science

Kevin,.. going around in circles is a waist of time,..First the Goals are pretty simple, The elevator/reciving vehicle needs to be capable of no less then 25% faster than the producing vehicle/log splitter,. Given these facts you can do the math with a few more stats, In most cases Ill be using a 10/20 % buffer, So feel free to post (your) findings here,.. log splitters normally take at least 6 seconds to cycle a 24 " block,.. or 10 " per sec, keep in mind that the return stroke is about 50 % faster than the push stroke, on High preformance splitters, Iam doing the math in my head, you can run the numbers your self,.Its all relative,. The weight of the wood is lets say a 16 in block every 8 seconds, not really realistic, even the fastest wood processors arent that fast, but go with that figure,.Ok thats about 6.6 blocks per 20 foot of elevator, NOT going to happen but use those figures,. elevation is about 45 %, thats more than enough, Now plug in your torque wrench,....And tell me how much torgue it takes to turn the shaft,?......The problem I see with your torque wrench therory is How are you going to read the dial at 60 to 75 rpm,???, I dont see the resemblence of a torque reading as if you are torquing a bolt, compaired to spining a shaft at 75 rpm, maybe you have a formula that you can use to get an accurate figure, Id like to see it, and specific data, How are you going to determine, specific drags, what bearings are you pluging in to your calulations, More important what kind of trac is your load bearing chain draging on,? I think you know where iam heading, Your torque wrench therory, aint gona sell NASA ,. OK , this isnt rocket science, Thats the point Ive been trying to make, Its really not that hard,..spec the motor bigger better and bader, than you think you need, as long as you have the gpm to run it, according to the charts posted here on AS, 2 gpm is enough to do the job, thats @ 2000 psi, Prove me wrong and you wont hurt my feelings, I know what has worked for me and I didnt have the charts that I have now, All I know is,. it worked for me T,C, E,J,