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Hydraulic powered drive-wheel

Started by Revival Sawmill, November 25, 2016, 02:20:20 PM

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Revival Sawmill

Ok, I'm hoping someone on here knows their way around hydraulic pumps and motors, and can give me some guidance.  I've gotten two diesel railroad power units which have very large hydraulic pumps on them.  This is the tag off one:

I *think* I've matched it to the one in the attached pdf.  I'm hoping the combination of the diesel engine and this pump is powerful enough to drive the bandwheel and a couple parasitic loads (carriage traverse and headrig elevation).  My current problem is that I know NOTHING about hydraulics and can't seem to figure out what sort of hydraulic motor would match this pump and be capable of powering the bandwheel effectively.  It's a 30" wheel, 2" blade, and there will be 3' between the wheels (not planning to cut that wide all the time, but it would be slick to be able to!).  If anybody has some guidance or can even tell me where to start researching, you'd make my day!
Thanks,


Kbeitz

One thing you do have to watch is when you run your controls to the hydraulic motor that you need one that will let your wheels freewheel when you tell it to stop.  If not you just might get to see what happens when everything slams to a stop.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

bandmiller2

Dusty, I'am no authority on hydraulics but I have worked with them for years. My feeling is you have enough engine and pump to run a band mill. There are two common hyd. motor types the piston wobble plate type and the gear type. The wobble plate type tend to be low speed, probably the gear type would work the best. Some gear type pumps can be used as motors they have seals designed for pressures involved. We had an Arial ladder truck that had what they called a hydraulic PTO. It used three similar Hydreco gear pumps one driven from the trans. piped to one used as a motor under the turntable up to another used as a pump on the turntable.  If you can figure the gallons per Minuit of the pump ( its variable depending on engine speed) match it to  a hyd. pump that is motor rated. The best way is to buy it from someone local that will help you with the engineering. You will need to know the RPM of the bandwheel. Frank C.
A man armed with common sense is packing a big piece

Revival Sawmill

Quote from: Kbeitz on November 25, 2016, 02:45:26 PM
One thing you do have to watch is when you run your controls to the hydraulic motor that you need one that will let your wheels freewheel when you tell it to stop.  If not you just might get to see what happens when everything slams to a stop.
That is an excellent thought, which had not occurred to me at all! Thank you!
Quote from: bandmiller2 on November 25, 2016, 03:31:01 PM
Dusty, I'am no authority on hydraulics but I have worked with them for years. My feeling is you have enough engine and pump to run a band mill. There are two common hyd. motor types the piston wobble plate type and the gear type. The wobble plate type tend to be low speed, probably the gear type would work the best. Some gear type pumps can be used as motors they have seals designed for pressures involved. We had an Arial ladder truck that had what they called a hydraulic PTO. It used three similar Hydreco gear pumps one driven from the trans. piped to one used as a motor under the turntable up to another used as a pump on the turntable.  If you can figure the gallons per Minuit of the pump ( its variable depending on engine speed) match it to  a hyd. pump that is motor rated. The best way is to buy it from someone local that will help you with the engineering. You will need to know the RPM of the bandwheel. Frank C.
I wonder if I could just use the second one of these pumps as a hydraulic motor on the bandwheel? I think you're right and I'll have to find someone around here that deals with this type of thing...  My math says that I want the wheels spinning between 600 and 700 rpm... sound right?

Thanks,


Kbeitz

Quote from: bandmiller2 on November 25, 2016, 03:31:01 PM
Dusty, I'am no authority on hydraulics but I have worked with them for years. My feeling is you have enough engine and pump to run a band mill. There are two common hyd. motor types the piston wobble plate type and the gear type. The wobble plate type tend to be low speed, probably the gear type would work the best. Some gear type pumps can be used as motors they have seals designed for pressures involved. We had an Arial ladder truck that had what they called a hydraulic PTO. It used three similar Hydreco gear pumps one driven from the trans. piped to one used as a motor under the turntable up to another used as a pump on the turntable.  If you can figure the gallons per Minuit of the pump ( its variable depending on engine speed) match it to  a hyd. pump that is motor rated. The best way is to buy it from someone local that will help you with the engineering. You will need to know the RPM of the bandwheel. Frank C.

In my area there is another very common type.  A vane pump.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

Ljohnsaw

Quote from: wooddust on November 25, 2016, 03:36:26 PM
I wonder if I could just use the second one of these pumps as a hydraulic motor on the bandwheel? I think you're right and I'll have to find someone around here that deals with this type of thing...  My math says that I want the wheels spinning between 600 and 700 rpm... sound right?

Thanks,
If you used the matching pump as a motor (assuming the seals are the right type), you would need some sort of flow control/bypass or the "motor" will be the same speed as the pump rpm (2-3,000 rpm?)  Way to fast.

600-700 rpm will give you 4,700 - 5,400 FPM.  For the 2" blade (and if you have the HP) you want to be at the upper end, maybe faster?  I thought I read somewhere that the 2" blades run in the 6-6,500 range.

This could be a pretty high production machine!  I'll be watching...
John Sawicky

Just North-East of Sacramento...

SkyTrak 9038, Ford 545D FEL, Davis Little Monster backhoe, Case 16+4 Trencher, Home Built 42" capacity/36" cut Bandmill up to 54' long - using it all to build a timber frame cabin.

Den-Den

You need to know the flow rate of the pump when engine is running full speed and compare to the volume per revolution of the hydraulic motor so you can calculate the output speed.  I think you will need a hydraulic oil cooler also.
You may think that you can or may think you can't; either way, you are right.

york

Bad idea.too complex for a new build-transmit power by belts at first,later can be removed if your sawing ok,then get into your HYD. idea...
Albert

Revival Sawmill

Thanks!  I've started a build thread, but I'm sticking these design questions out there on their own.
https://forestryforum.com/board/index.php/topic,93309.0.html

Revival Sawmill

Yep!  It is starting to sound pretty complicated!! 
I sort of 'fell into' the two diesel motors and hydraulic pumps, and at this point it would greatly simplify my life if I could mount either one of the diesels or the 50 hp electric in a fixed position down on one of the lower carriage rails and just route the hydraulic hoses up to the headrig and driveshaft... I might even end up hanging the hydraulic motor on the front of the headrig and saving myself the clearance between the back of the headrig and the front vertical of the carriage... I'm not even sure how I'd accomplish that otherwise.
Thanks for the input!! Let me know if you think of a way around it!

york

There is a mill built in Germany,that does what you want,but big bucks,i have there info,will look for it tomorrow....
Albert

Revival Sawmill

Thanks York!  I'd love to see how someone else handled it! 
I guess the first thing I really need to know is how many Āæinch-pounds? of torque I need to apply to the driveshaft?  What the heck is an inch-pound?  It can't just be 12x a foot-pound, surely?
Thanks,

Kbeitz

One foot lbs = 12.000000427771214 inch lbs.
Collector and builder of many things.
Love machine shop work
and Wood work shop work
And now a saw mill work

ozarkgem

Direct motor belt drive will be a simpler and cheaper way to go. You will want 50 HP to run the 2" bands. I am sure there is a formula for band HP but I would think 50 would be min to really saw. If you go to the trouble to build I would want the most production I could get out of it. You will need some kind of an oil cooler or a very large tank. 50 gal of hyd oil is around 700.00 bucks here. Not sure how much engine HP you would need to produce 50 hp at the wheel. There is a reason the big mill mfg,s don't use this system. Even a gen set and electric motor would be better. Wire is cheaper than hoses.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Gearbox

My concern would be volume of oil needed  and the weight on the carriage . also how are you going to keep the oil below 150 degrees . I am fighting heat on my home built wood processer all the time and I am only running  16 GPM .
A bunch of chainsaws a BT6870 processer , TC 5 International track skidder and not near enough time

Revival Sawmill

I guess I could put the electric motor up on the headrig beam, but it's bound to be heavy, and I'm back to the clearance and belt tensioning issues... And I'll have to track down a cheap 3phase generator that I could drag around to power it. 
The only formula for hp I could find came back with 35 hp for the numbers I had/guessed, but even then I'm thinking it meant actual hp delivered to the drive-side bandwheel.
Thanks for the help/feedback!

ozarkgem

Quote from: wooddust on November 25, 2016, 08:00:50 PM
I guess I could put the electric motor up on the headrig beam, but it's bound to be heavy, and I'm back to the clearance and belt tensioning issues... And I'll have to track down a cheap 3phase generator that I could drag around to power it. 
The only formula for hp I could find came back with 35 hp for the numbers I had/guessed, but even then I'm thinking it meant actual hp delivered to the drive-side bandwheel.
Thanks for the help/feedback!
50 hp diesel motors are routinely used on mills. Some have over 100 hp motors.
I have an 20 hp electric motor and an electric clutch on mine and run it off a 20KW gen set. Works very well. 35 hp  will saw pretty slow on a 2" band. You have to design your mill around the power plant then clearance and weight are not a problem. Look at how WM, TK, Cooks, Baker and others build their mills and get some ideas there. Don't reinvent the wheel. Keep it simple.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Don_Papenburg

 Check out Surplus Center.   they have books on fluid power for sale under $30.oo.
call the tech line and they will help you with the book you need for your job.
Frick saw mill  '58   820 John Deere power. Diamond T trucks

bandmiller2

Dusty, are you planning to mount the diesel and pump on the saw head carriage or festoon hoses to the motor with the engine stationary on the ground.??
A man armed with common sense is packing a big piece

Revival Sawmill

The plan was to mount the engine on the lower fixed rail of the carriage so it goes back and forth over the deck with the carriage and would only need festooning😜 of hydraulic hoses to allow the headrig to go up and down. Still trying to sort this out in my mind.  Sounds like the 50 hp electric coupled to the drive bandwheel with a belt might be a more powerful/efficient option. And I've figured out how to modify my design to free up the needed clearance.  But that brings up other issues, like how many v-belts does it take to transmit 50 hp? How do you idle/slow the band between cuts with an electric motor that big? Would I have to protect the shaft/bearings in the motor from the side-load of tensioning all those v-belts somehow?  As complicated as the hydraulic system sounds, it might actually end up being simpler.
Thanks,

Revival Sawmill

And how do you change band speed for different conditions with an electric motor- change belt pulleys every time?

york

Albert

Revival Sawmill

Cool mill! Looks like they are hanging the power unit and hydraulic reservoir on the back of the headrig instead of down on the carriage? I wonder why they chose hydraulic final drive? Also looks like a 31.5" wheel that's getting pushed by a 30kw/44hp diesel, so 50 hp electric may well be over the line into overkill?
Thanks!

ozarkgem

Quote from: wooddust on November 26, 2016, 08:02:11 AM
And how do you change band speed for different conditions with an electric motor- change belt pulleys every time?
You don't change the band speed. They are designed to run at a certain FPM depending on what Hp motor you are running. You slow down or speed up the feed rate for different conditions. Different logs take different hook angles also.
Mighty Mite Band Mill, Case Backhoe, 763 Bobcat, Ford 3400 w/FEL , 1962 Ford 4000, Int dump truck, Clark forklift, lots of trailers. Stihl 046 Magnum, 029 Stihl. complete machine shop to keep everything going.

Revival Sawmill

Really? I've read/seen on the cooks videos about using different fpm for frozen logs/different types of wood?  I guess it makes more design sense to have one permanent set of pulleys on an electric motor and varying feedrate.

So, how many belts would it take to transmit 50 hp from the electric motor to the drive-side bandwheel? I know our chipper has some strange 4-in-1 belt to transmit about 85 hp, but that's shock loaded often and is powering a tremendously large flywheel. Even then it slips occasionally. I'm hoping that bandmills don't need that many?
Thanks,

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