Page 1 of 2 12 LastLast
Results 1 to 10 of 15
  1. #1
    New Member
    Join Date
    Feb 2013
    Posts
    6
    Location
    Maricopa Arizona
    Tractor
    trailer

    Default pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    I have a pair of 2500psi cylinders going on a dump trailer that will carry no more than 2,000 lbs. The cylinders are 48" long, 5" diameter with a 2" rod, 36" stroke, power up/power down . They are overkill but I got them cheap! I need help deciding what size of motor/pump/ and reservoir to get to power these cylinders. Thanks

  2. #2
    J_J
    J_J is online now
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    15,794
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    This unit will power and down, pumping 1.3 GPM, @2500 psi

    Surplus Center - 12 VDC 1.3 GPM 2500 PSI SPX DA POWER PACK

    That 36 in stroke, and 5 in cyl bore, will push 49,000 lbs at .3 in per sec. = 120 sec or 2 min.

    With that kind of power, you could rip the bed off the trailer. There will be less power at smaller angles.

    At 45 degrees, you are still pushing at 37,000 lbs/16 ton.

    Extended, each cyl will hold about 3.12 gal x 2 = 6.24 gal

    Retracted, the cyl will hold about 2.63 gal. Difference of .489 gal x 2 = .978 gal

    Larger tank.

    http://www.surpluscenter.com/item.as...name=hydraulic
    Last edited by J_J; 02-21-2013 at 08:50 AM.
    J.J.

    When I works, I works hard. When I sits and thinks, I goes to sleep.

    Git er done.

  3. #3
    Gold Member
    Join Date
    Apr 2011
    Posts
    373
    Tractor
    none

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Seeing how it won't be used like a log splitter I would get a pump and reservoir just big enough to fill them. Your not going to heat the oil up in that short period.
    That being said, you will have to do some math to figure gallons required including all hoses.
    I know my 30" stroke 4" with 1.75" rod will hold over a gallon, closer to two.
    I'm not the best at the math but I think this is how to do it,
    piRsquared times length of stroke minus piR squared times length of shaft
    R for cyl would be 2.5" and R for shaft would be 1". Then convert that to gallons. About 231 cubic inches to the gallon.

  4. #4
    Platinum Member
    Join Date
    Dec 2006
    Posts
    692
    Location
    Columbus, Georgia
    Tractor
    Kuborta B2400, L2900, L4330; Caterpillar D3B, John Deere 455D

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Each 36" x 4" x2" cylinder requires almost exactly 1 1/2 gallons for a full stroke. So two cylinders is 3 gallons. If you use the full stroke your pump will have to discharge 3 gallons into the cylinders, plus a bit for the pump body, lines, etc. Seems to me you need a 3 1/2 or 4 gallon reservoir. I am sure there are some 12V DC pump/reservoir sets that hold that much, but I don't think they are very common. One that size may be expensive.

  5. #5
    J_J
    J_J is online now
    Super Star Member J_J's Avatar
    Join Date
    Sep 2003
    Posts
    15,794
    Location
    JACKSONVILLE, FL
    Tractor
    Power-Trac 1445, KUBOTA B-9200HST

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Cylinder volume capacity (Gal.) = Pi x radius2 (inches) x stroke (inches) / 231

    I would say those 5 in , 2 in shaft cyl are a waste of potential power.

    Save them for another project.
    J.J.

    When I works, I works hard. When I sits and thinks, I goes to sleep.

    Git er done.

  6. #6
    Gold Member
    Join Date
    Apr 2011
    Posts
    373
    Tractor
    none

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Monarch hydraulic DC pumps

    You may have to buy one with a smaller reservoir and modify it.

  7. #7
    Platinum Member
    Join Date
    Dec 2006
    Posts
    692
    Location
    Columbus, Georgia
    Tractor
    Kuborta B2400, L2900, L4330; Caterpillar D3B, John Deere 455D

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    OOOPS! I made a math error. Each cylinder requires nearly two gallons for a full stroke.

  8. #8
    New Member
    Join Date
    Feb 2013
    Posts
    6
    Location
    Maricopa Arizona
    Tractor
    trailer

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Quote Originally Posted by davedj1 View Post
    Seeing how it won't be used like a log splitter I would get a pump and reservoir just big enough to fill them. Your not going to heat the oil up in that short period.
    That being said, you will have to do some math to figure gallons required including all hoses.
    I know my 30" stroke 4" with 1.75" rod will hold over a gallon, closer to two.
    I'm not the best at the math but I think this is how to do it,
    piRsquared times length of stroke minus piR squared times length of shaft
    R for cyl would be 2.5" and R for shaft would be 1". Then convert that to gallons. About 231 cubic inches to the gallon.
    Thanks for the input guys. I appreciate the link JJ I will look into that powerpack. Davej the reason I want to leave them power up/down is due to the fluid volume, it will take around 3 gallons per cylinder im guessing to fill each cylinder, which means id need around a 7 gallon tank...

  9. #9
    Veteran Member
    Join Date
    Sep 2007
    Posts
    1,771
    Location
    Doniphan, Mo.
    Tractor
    Kubota L4240, B7800 & BX2660

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    You might not need any bigger tank then what comes with that pump. Just pull the cyls all the way out and leave the hoses off the base end. Fill the tank and start pumping into the rod end, don't let the tank run out of oil. After they are full just run the pump in the other direction long enough to fill the lines. now hook up the base end lines and it should be full of oil and has no air in the system. Then pump well use the returning oil to keep oil in the tank. If you pump into the base end first the tank well overflow a little, but after 1 or 2 times going all the way in and out it well level off.

  10. #10
    New Member
    Join Date
    Feb 2013
    Posts
    6
    Location
    Maricopa Arizona
    Tractor
    trailer

    Default Re: pump/motor/reservoir size help for two 36" stroke cylinders-first timer

    Quote Originally Posted by Leejohn View Post
    You might not need any bigger tank then what comes with that pump. Just pull the cyls all the way out and leave the hoses off the base end. Fill the tank and start pumping into the rod end, don't let the tank run out of oil. After they are full just run the pump in the other direction long enough to fill the lines. now hook up the base end lines and it should be full of oil and has no air in the system. Then pump well use the returning oil to keep oil in the tank. If you pump into the base end first the tank well overflow a little, but after 1 or 2 times going all the way in and out it well level off.
    Useful info thanks leejohn. Another question, how do I split the power up/down lines to go to each cylinder? (2 up lines and 2I down lines, one for each cylinder) just a coupler the splits off?

Page 1 of 2 12 LastLast

Similar Threads

  1. PUMP and Motor size
    By horseman 120247 in forum Hydraulics
    Replies: 7
    Last Post: 10-22-2010, 04:17 PM
  2. pump and motor size ?
    By captjack in forum Hydraulics
    Replies: 26
    Last Post: 10-22-2010, 01:11 AM
  3. Determining motor/pump size
    By dodge85rc in forum Hydraulics
    Replies: 43
    Last Post: 01-08-2010, 12:22 AM
  4. Motor size for 72" deck
    By farmboy12 in forum Build-It Yourself
    Replies: 5
    Last Post: 05-16-2009, 10:03 PM
  5. Two-stroke pump: Worn out?
    By rmorgan in forum General Lawn & Garden
    Replies: 8
    Last Post: 07-26-2002, 10:54 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© 2013 TractorByNet.com. TractorByNet is a registered trademark of IMC Digital Universe, Inc. Other trademarks on this page are the property of their respective owners.