Previous in Forum: Little Help to Remember - Propeller that Thrusts Water Out of Blades   Next in Forum: Latch Solenoid Actuator
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
15 comments
Rate this Comments: Nested
carun
Member

Join Date: Jul 2013
Location: Kuala Lumpur, Malaysia
Posts: 5

Pump Choice for Hydraulic Cylinders

07/14/2013 9:45 PM

Would Gear or Axial Piston pump be more suitable choice in a mobile application which has multiple hydraulic cylinders such as for actuating a Loading Arm and tilting a Feeder Conveyor ?

__________________
 Palm to Pulp in 120 seconds
Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
lyn
Guru

Join Date: Oct 2008
Posts: 42376
Good Answers: 1692
#1

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 10:30 PM

Don't know. Have you looked at pumps that meet your requirements for pressure/flow/duty cycle and all the other things that a pump specification might contain?

Have you talked to any pump vendors?

What have you done so far??? Anything?

Give us a clue, please!!!!!!!!!!
Register to Reply
carun
Member

Join Date: Jul 2013
Location: Kuala Lumpur, Malaysia
Posts: 5
#6
In reply to #1

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 11:20 PM

The estimated total flow needed is 30 gpm or 114 litres per minute at 210 bar. This has been calculated based on the maximum flow possible in all cylinders simultaneously, which in practice will never happen. The loading arm has 3 cylinders for manipulating the boom, with one cylinder for the grabber and a small rotator motor.

Both gear and axial piston pumps are readily available to meet this requirement. In machines such as excavators, axial piston pumps are commonly spec'd for the hydrostatic drives and the benefits are well known. Gear pumps tend to get spec'd for auxiliary functions (besides pilot pumps) and I am wondering if this is simply a decision based on economics.

__________________
 Palm to Pulp in 120 seconds
Register to Reply
3
tcmtech
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8376
Good Answers: 775
#8
In reply to #6

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 11:57 PM

At higher flow rates and pressures piston type pumps are far more efficient than gear pumps plus they can be set up as fixed pressure variable flow as well.

Down side is they are more complex and cost more.

That said 30 GPM at ~3000 PSI is still well within the range of common gear pumps and the efficiency losses in the pump itself are not much.

Really in the end it's all a matter of what you want to spend your money on. Given this flow rate range and pressure it's a near equal slit on which one to use. The displacement piston pump will give you a higher overall system efficiency but if cost is an issue and you have themechaincalpaoer to spare and a way to dissipate a little more system heat the gear pump will do just fine as well.

FWIW I have a tractor type backhoe built around a old Farmall W450 farm tractor that runs on a 16 GPM 2500 PSI system with four circuits and it does just fine with a standard PTO driven gear pump as its power source with nothing more than the 12 or so gallons of transmission oil as the reservoir and cooling system. It runs warm when worked hard but nowhere near dangerously hot.

Register to Reply Good Answer (Score 3)
Go to Next Good Answer
Oliver Dunthorne
Power-User

Join Date: Nov 2008
Posts: 116
Good Answers: 4
#12
In reply to #8

Re: Pump Choice for Hydraulic Cylinders

07/16/2013 3:54 AM

Hi

The decision is one best made knowing all the facts. i.e. duty cycle, ambient temperature etc etc. Either pump will do the job but you need to consider what type of control valve(s) you are going to use (presumably LS ?). Is this a manual duty or fully automated. What type of cooling, power source etc. You need advice from someone who (a) understands you application and (b) knows his hydraulic equipment. Go to the source of your hydraulics and ask them for advice. Pass the responsibility over to them for specifying the kit then if it does not work you have a come back.

Regards

Oliver Dunthorne - Hydraulic Engineer Retired
Register to Reply
jesw55
Power-User

Join Date: Aug 2010
Location: Wales, UK
Posts: 389
Good Answers: 18
#10
In reply to #6

Re: Pump Choice for Hydraulic Cylinders

07/15/2013 5:00 AM

Hi carun,

If the 30 g/m will in practice never happen, don't use it to size your pump. try and get a realistic figure, the pump will be smaller (cheaper), and you will not have to "spill" the excess flow you will have that will cause all sorts of problems.

Best regards,

John

__________________
 Best advice I can give as you get older "Never miss an opportunity to relieve yourself"
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21022
Good Answers: 795
#2

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 10:38 PM

Maybe a vane pump.

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
lyn
Guru

Join Date: Oct 2008
Posts: 42376
Good Answers: 1692
#3
In reply to #2

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 10:42 PM

Are you "positive" about that?

Register to Reply Off Topic (Score 5)
SolarEagle
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33316
Good Answers: 1810
#4
In reply to #3

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 10:46 PM

Use impellers....

__________________
 All living things seek to control their own destiny....this is the purpose of life
Register to Reply
SolarEagle
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33316
Good Answers: 1810
#5
In reply to #4

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 11:08 PM

These people probably know.....

http://www.team-twg.com/documents/gear-products/sales-literature/hydraulic-pump-drives-catalog.pdf

__________________
 All living things seek to control their own destiny....this is the purpose of life
Register to Reply
Tornado
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21022
Good Answers: 795
#9
In reply to #3

Re: Pump Choice for Hydraulic Cylinders

07/15/2013 12:33 AM

Up until 2000 psi or so, but I'm not sure about the higher pressure that we've since learned.

__________________
 In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
K_Fry
Guru

Join Date: Feb 2011
Location: Atlanta, GA
Posts: 1053
Good Answers: 110
#7

Re: Pump Choice for Hydraulic Cylinders

07/14/2013 11:51 PM

Both types are used on mobile equipment. Axial piston pumps are made in variable displacement versions which are more efficient (allowing a smaller reservoir or less cooling equipment) than throttling flow from a gear pump. Gear pumps are cheaper, however, and can tolerate more filth.

If you are not too concerned about moving the cylinders at a wide range of speeds, then gear pumps are probably the more cost effective solution.

__________________
 Think big. Drive small.
Register to Reply Score 1 for Good Answer
Go to Next "Almost" Good Answer
2
sawmilleng
Power-User
Popular Science - Weaponology - New Member Canada - Member -

Join Date: Dec 2006
Location: In the sticks of the Central Kootenays, BC, Canada
Posts: 266
Good Answers: 20
#11

Re: Pump Choice for Hydraulic Cylinders

07/15/2013 10:58 PM

Hi, Carun,

It sounds like you are in a similar business to me....turning natural fiber into something useful at staggering rates of speed! My tagline could be something like "turning logs into lumber at 30 per minute!" You must be chipping up palm trees for pulp use?

As long as you are operating only cylinders with this pump setup, a fixed displacement pump should be fine, as long as you don't need to move multiple cylinders at the same time. Also, if you have other uses for the hydraulic power, like driving a conveyor belt, then, the problem becomes a little more complicated. You also need to be aware of the difference between open and closed center hydraulic valves because the different pumps need different valves to operate properly.

The simplest way to get this designed would be to contact your favorite hydraulics supplier. They usually have someone who can come to your site, evaluate the requirements, and give you a proposal (and usually will help you work out the bugs when you are ready to start up the new equipment.)

Hope this helps,

Jon.
Register to Reply Good Answer (Score 2)
No more Good Answers. Go to first "Almost" Good Answer
carun
Member

Join Date: Jul 2013
Location: Kuala Lumpur, Malaysia
Posts: 5
#14
In reply to #11

Re: Pump Choice for Hydraulic Cylinders

07/16/2013 7:20 AM

Hi Jon,

May I message you directly ?

Arun

__________________
 Palm to Pulp in 120 seconds
Register to Reply
sawmilleng
Power-User
Popular Science - Weaponology - New Member Canada - Member -

Join Date: Dec 2006
Location: In the sticks of the Central Kootenays, BC, Canada
Posts: 266
Good Answers: 20
#15
In reply to #14

Re: Pump Choice for Hydraulic Cylinders

07/16/2013 10:46 AM

Sure. Use the private message function of this forum.

Jon.
Register to Reply Off Topic (Score 5)
VAIBHAVSUREKHA
Participant

Join Date: May 2013
Posts: 2
#13

Re: Pump Choice for Hydraulic Cylinders

07/16/2013 6:05 AM

Hi, IO thought in mobile application as space is very less and yo have to run one application at a time then gear pump is suitable.

VAIBHAV ( ASST.PROF)
Register to Reply
Register to Reply 15 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

carun (2); jesw55 (1); K_Fry (1); lyn (2); Oliver Dunthorne (1); sawmilleng (2); SolarEagle (2); tcmtech (1); Tornado (2); VAIBHAVSUREKHA (1)

Previous in Forum: Little Help to Remember - Propeller that Thrusts Water Out of Blades   Next in Forum: Latch Solenoid Actuator

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
Mechanical Engineering:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (43 right now)
Show Members
Advertisement