Hydraulic motor and pump help

[Metalburner]

I'll take that into consideration. But would higher pressure and smaller work a lot harder than a smaller lower pressure?

 

[aczlan]

I'll take that into consideration. But would higher pressure and smaller work a lot harder than a smaller lower pressure?

If the torque/rpm output from the motors is the same, they would work the same, just less fluid to move around, so a smaller tank and smaller hoses.

However, the pumps will probably be a lot more expensive, so keep that in mind.

Aaron Z

 

[Metalburner]

Thanks for the clarification.

 

[Metalburner]

Found one pump from Parker that goes upwards of 3000psi max Nichols™ 11A Medium Duty Motor is a very short motor with thru-shaft capabilities (up to 1-1/4" shaft) | Parker NA

 

[MossRoad]

Here's another good source for hydraulic equipment.... Motors, pumps, coolers, filters, hoses, etc...

Shopping

I've ordered from them in the past.

 

[oldnslo]

Metal burner,
I did some calculations today for sizing the drive components.

machine weight of 1000 lbs

Drive sprocket diameter 10 inches.

T = F x r
T= torque in inch lbs
F = lbs. of draw bar pull ( 1000 lbs per track to turn)
r = radius of drive sprocket (5")

T = 1000 x 5 = 5000 in - lbs. torque required per track or 5000/12 = 417 ft. lbs.

Hydraulic motor torque @ 2,000 PSI differential pressure
T = (CIR x PSI x mechanical eff) / (24 pi or (417 x 24 pi) / (2000 x .9) = 17. 5 CIR motor

T = torque ft lbs.
CIR = displacement cubic inches revolution
PSI = pressure differential across the motor
Mechanical off = typical 85% - 90%
pi = 3.14

Travel speed RPM = 336 x MPH / d 336 x 3 MPH / 10 = 101 RPM for 3 MPH
d = drive diameter

Required flow = RPM x CIR / 231 or (101 x 17.5) / 231 = 7.65 GPM @ 100% volumetric efficiency

Figure theoretical pump size

CIR = (GPM x 231) / RPM or 7.65 x 231 / 3300 RPM = .54 CIR pump required for each track .54 / .06102 = 8.8 cc/rev I would look for around a .6 CIR (10cc) pump to achieve close to the 3 MPH.

You will have to refigure size of components based on machine weight, pump and motor operating pressure, etc.

hope this info helps

 

[Metalburner]

It's above my limited knowledge but it makes sense to me. Is 5mph a better speed or would 3mph be good? I mean as long as everything holds up on the track without premature failure, a bit more speed would be nice. Even if I can adjust easily between speeds up to maybe 5mph it might be worth it.

 

[aczlan]

It's above my limited knowledge but it makes sense to me. Is 5mph a better speed or would 3mph be good? I mean as long as everything holds up on the track without premature failure, a bit more speed would be nice. Even if I can adjust easily between speeds up to maybe 5mph it might be worth it.

If your property is bigger than an acre or two, I would go for more speed. I don't think you will regret it.

Aaron Z

 

[Metalburner]

I'm at just under half an acre. But eventually mat want to buy a place with a few acres.

 

[aczlan]

I would say go with the setup I linked to if you can make space for a big enough tank/cooler. Otherwise, see what you can find for a higher pressure pump/motor, but expect to pay 2-3x the prices of the ones on Surplus Center (unless you can find something like a skidsteer with a bad motor).

Aaron Z