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| | | | Joined: Apr 2014 Posts: 28 Wrench Fetcher | | Wrench Fetcher Joined: Apr 2014 Posts: 28 | anyone know what HP is required to turn the hydraulic pump under full load on a 2ton rock bed? was planning on getting a stand alone small engine to power this. before i trial and error this, wanted to know if anyone knew how much i needed.
49chev6400.webs.com
| | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | It's really all in the gearing.
I did a 12V motor drive for the 48 2 ton flatbed.
It was the type used for lift gates on freight trucks.
The old PTO driven pumps pumped high volumes at low speeds because of the high torque and low shaft speeds. The modern electrics drive much smaller pumps at very high speeds.
I built 3 step reduction gearing from off the shelf parts and it lifts just fine with a farm tractor on it.
You could probably lift it just fine with a 5 HP gas engine with a big reduction gear. (except you'd need a manual clutch and all that)
Last edited by Jim Sears; 04/20/2017 5:11 AM.
| | | | | Joined: Apr 2014 Posts: 28 Wrench Fetcher | | Wrench Fetcher Joined: Apr 2014 Posts: 28 | do you have any project pics? i fully understand what you said, would just like some visual idea for concept purposes. i was trying to use a 3 hp gas motor with a centri clutch, but it was burnig up the clutch. so, gear reduction....how many rpm does the shaft need to turn at to get the pump going?
49chev6400.webs.com
| | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 |
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jan 2013 Posts: 1,384 Shop Shark | | Shop Shark Joined: Jan 2013 Posts: 1,384 | I don't remember without finding some notes, But I believe I calculated that if the truck engine was running at 800rpms the PTO shaft would be turning 120.
I'm sure that someone with PTO experience will jump in and correct me.
That would mean your gas engine governed for 2500 would need a 20:1 reduction. | | |
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