Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Crawlers, Dozers, Loaders & Backhoes Discussion Forum

Hydraulic motors

Welcome Guest, Log in or Register
Author 
greywynd

01-31-2005 00:19:33




Report to Moderator

A post on one of the other boards got me to thinking about my post hole auger. I have a Ford post hole auger (built by Danuser, I believe) that I'd love to set up with a hydraulic motor, and make some brackets so I can use it on my mini excavator. (The tractor is just too big for a lot of residential work). I know that hydraulic supply from my machine won't be a problem, it has a high flow auxillary circuit. I just don't know how to go about 'sizing' the hydraulic motor so the auger will run roughly the same speed it would if it were PTO driven. I know I want to get a motor that will run close to 540 RPM, of course, I can adjust the flow to the hydraulics through the valves and throttle. (One major advantage to this is the addition of 'reverse'.)


This is as far as I can easily get, it's the sizing of the motor calculations that leave me in the dark. I don't know the flow(GPM) or the exact pressure in my hydraulic system. I just don't know how to figure out something close enough to get me in the right size range. I know that the lines are 1/2", can anyone tell me what sort of flow 1/2" lines might handle?

Thanks,
Mark

[Log in to Reply]   [No Email]
Heat Houser

02-01-2005 19:17:05




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
To determine the size of motor, you will need to know GPM output and max pressure of your excavator.

To calculate motor shaft speed, take your GPM and multiply it by 231. This converts gallons per minute into cubic inches per minute. Motors are rated in cubic inches per revolution (called displacement) so divide the excavator's cubic inches per minute by the motor's cubic inches per revolution to get motor shaft RPM. This is assuming 100% efficency.

Inversely, to select the motor that will turn at 540, divide cubic inches per minute by 540 revolutions per minute and this will determine the displacement of the motor you need to find.

Example; 22 GPM flow. 22 X 231 = 5082 cubic inches per minute. 5082 divided by 540 RPM = 9.41 cubic inches per revolution motor that you need.

Select a motor that is rated for your max pressure.

Confused yet? Torque requirements is another story.

[Log in to Reply]  [No Email]
J. Schwiebert

02-01-2005 19:58:51




Report to Moderator
 Re: Hydraulic motors in reply to Heat Houser, 02-01-2005 19:17:05  
That is the best advice that has been posted on this discussion yet. The only thing I would add since we are dealing with a used unit(tractor) and no measurments have been taken pump output is given at rated engine speed. If you do not want to run the engne that fast deduct displacement accordling.Then if the tractor has a gear pump, pump effeciency really falls off below say 1000 to 1200 RPM. Also I would not calculate an effecinecy rating of over 85% to allow for some wear. Also the motor as mentioned will be only be in the 85 to maybe 90% effeciency range. Heat houser, I would like to talk to you sometime.

[Log in to Reply]  [No Email]
greywynd

02-01-2005 23:23:58




Report to Moderator
 Re: Hydraulic motors in reply to J. Schwiebert, 02-01-2005 19:58:51  
I will be running this off the auxillary circuit of a mini-excavator. It has a dedicated (piston, I believe) pump for this circuit only. The only thing I currently run off this is my woodsplitter from time to time, at a fast idle. If I figure out the time it takes to extend the cylinder a given distance, I should be able to calculate GPM of my supply. (Knowing the bore and stroke of the cylinder.)I will also take a look, I think I have a hydraulic pressure gauge, hopefully I have the fittings to tee it in and get a pressure reading. Thanks guys, all of you, I hope to get out and do some checking in the next few days, unfortunately, I have a funeral to attend and some other unexpected 'problems' as well, so I'm not sure when I will squeeze in the time to do it. When I do though, I will report back with my findings and calculations.

Thanks again,
Mark

[Log in to Reply]  [No Email]
AJK

02-01-2005 11:32:54




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
You say you want to mount your auger on your mini digger and you need a hydraulic motor to drive it,the ideal hydraulic motor would be a motor the same as the track or swing motor fitted to your mini,that would be compatible with the pump,flow,pressure and valves,a track motor would be the best bet,I would be looking for one in a salvage yard.
AJ



[Log in to Reply]  [No Email]
fixerupper

02-01-2005 06:25:02




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
I think we are getting way too technical here. Beg, borrow or steal an orbit motor, any orbit motor, and put it on, tie a chain to it so it can't rotate, and try it. Then you will have something to compare to. They aren't that hard to work with. I'll bet you two bucks that is what the factory would do.



[Log in to Reply]  [No Email]
greywynd

02-01-2005 08:34:19




Report to Moderator
 Re: Hydraulic motors in reply to fixerupper, 02-01-2005 06:25:02  
I've been watching for a motor for a year or so, just haven't found anything. If I had access to something, even to borrow, that's what I likely would have done. I haven't been really looking very hard though, so, maybe I will make a few calls and see if I can dig one up. I seem to have access to all sorts of cylinders, valves and the like, just not the motors. Part of the reason I was trying to figure out the calculations was just for the learning, never know when I might have an application that I really need to figure this out for.

Mark

[Log in to Reply]  [No Email]
fixerupper

02-01-2005 08:55:06




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 02-01-2005 08:34:19  
I know the feeling, when you want one it won't fall in your lap. A lot of the older farm machinery dealers would probably have one laying around. The reel on combine grain heads is driven hydraulically. Feed truck augers are driven by orbit motors. I don't know where you are located, but maybe the local fertilizer dealer might have one on a back shelf. Good Luck.



[Log in to Reply]  [No Email]
770jdman

02-01-2005 05:25:27




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
My advice would be to call Precision Hydraulics, out of oklahoma city. Makes life easy. they can tell you eveything you need and they also sell and/or rebuild all types of pumps and motors.just email me and i"ll find the number.



[Log in to Reply]  [No Email]
fixerupper

01-31-2005 18:50:57




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
I bolted an old Danuser with A ten inch auger to the loader bucket on a 630 J.D. and ran it with a regular old mid sized orbit motor plugged in to the grapple claw outlets on the front of the loader. I haven't used it much but it does work fairly well. The 630 doesn't put out a lot of pressure or flow like a more modern tractor but it has enough for this job and it sure beats digging by hand.



[Log in to Reply]  [No Email]
DMont

01-31-2005 15:40:06




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
You can find all the Hyd. formulas you want under Basic Hydraulic Formula on the web. Do you have a closed or open center system? Most JD have closed center systems. YOu are on the right track by measuring the speed of the wood spliter. An easier method would be to check the service manual of the machine and they normally give the GPM of the pump. A quick call to the dealer service dept. will also do the trick.

[Log in to Reply]  [No Email]
thurlow

01-31-2005 13:44:20




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
Don't think you need the 540 rpm; do you run your (pto) digger at that speed? When I had a pto digger, always ran the engine just above idle; probably not over 200-250 pto rpm. Can't answer your other questions; have a hydraulic Danuser(sp) digger; a search for their web site might turn up needed information about flow-rates, ect.



[Log in to Reply]  [No Email]
greywynd

01-31-2005 08:33:54




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
May not have been clear on my full intentions, the plan is to use the existing gearbox from my 3 point auger, take the PTO shaft off, and put the hydraulic motor in it's place. This way I have an auger that I can put back to farm use when I need to, I just often wish I could use it off the excavator for backyard work in the city.



[Log in to Reply]  [No Email]
J. Schwiebert

01-31-2005 03:08:27




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 00:19:33  
I can send you a flow chart for lines. It does not scan well and right now I can not scan. You need a low speed high torque motor. You do need pump out put, either actual measured with a flow meter or pump rating which is actually theoretical displacement for everyone. No doubt you have an open center hydraulic system. Hydraulic motors are rated in inch pounds of torque. Questions?



[Log in to Reply]  [No Email]
greywynd

01-31-2005 08:30:23




Report to Moderator
 Re: Hydraulic motors in reply to J. Schwiebert, 01-31-2005 03:08:27  
I just thought of something....I use this thing to run my wood splitter. If I were to time the stroke on the wood splitter, and then figure out the volume of the cylinder, I should be able to number crunch and get a rough idea of the flow. Will have to see if I can find a semi-accurate watch or stop watch and try to do that today.

Your flow chart for lines, I'm guessing it gives a flow for different pressures? If I can find a gauge and measure the pressure, can you tell me roughly what flow a 1/2" line would handle?

Mark

[Log in to Reply]  [No Email]
J. Schwiebert

01-31-2005 11:43:32




Report to Moderator
 Re: Hydraulic motors in reply to greywynd, 01-31-2005 08:30:23  
Length has more effrect than pressure. Send me a phone number.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy