hydraulic motor driven little giant Hammer

[Krush]

I am designing a little giant style hammer similar to the DP hammers that move up and down the mast. i plan on building mine on a mast that is mounted in a box with gibs to raise and lower the height of the entire mast on the fly using a hydraulic 2 stage pump with a 5 horse electric motor with a cylinder connected to the mast and main frame. i can use the pump system to lift and lower the ram assembly and will run a smallish hydraulic press of the back of the unit with everything built into one animal. i want to setup the hammers flywheel drive using a hydraulic gear motor. Ive seen it done on another site where the fellow used a 6 cubic inch motor running an eccentric shaft for an appalachian style hammer and ran the pump at 500 psi getting 300 bpm with an 85 pound hammer head. 

now that ive thoroughly confused all of you does anyone know if a 2 stage pump could do this? if its staying in the high volume (13gpm) stage which runs from 0 - 600 psi (the ones ive been looking at) and kick into high pressure stage anything over 600psi? Another question because i am not as proficient with hydraulic engineering as id like does anyone know what rpm, pressure or flow a 6 cubic inch gear pump motor would need to be for this application? theres alot of selection out there and i want to make sure i go with the right one. ive tried registering on the other site to contact the fellow who created the appalachian style unit but unfortunately to no avail.

Please enlighten me if you know anything on the hydraulic motor and 2 stage pump.

 

thanks!

[BeaverNZ]

I would think it should work as long as you keep below the kick down pressure, Some of the cheaper pumps have trouble with wearing out the seat of the kick down valve after a bit of use so be mindful of that as far as working out the speed goes find a conversion chart to convert gpm into cu/in per min then divide by 6 and that will give rpm. It would probably more energy efficent to use another motor dedicated to the hammer but i can under stand trying to maximise your equipment Also be mindful of hose sizes and use large radius fittings if there are any angled fitiings any restrictions is lost power and heat generated and 500 psi is a very low pressure to start with Cheers Beaver

[BeaverNZ]

Actually I was thinking about this and the low presure another way of doing this with your pump is use a smaller displacement motor that will require a higher presure to run so it uses the pump in its lower output/higher presure but im not sure how efficent this setup would be have you already got the pump, I could ask the local hydrulic company for advice that I deal with what horse power electric motor have you got or do you have a good grunty electric supply do you have to have a dual stage pump?. Another thought has just ocurred if you use the hyd motor you can do away way with the clutch and use a spool valve or flow control and direct couple to the drive.

[Krush]

thanks for the replies, it is taking time to be thorough and get it right the first time, gotta make sure i dont run to close to the kickout pressure for highstage psi on the pump or may have to explore the option of running the high psi unit with low volume, getting the right hydraulic motor for moving the mass will be key in this and i think the starting point. i want to make the powerhammer a 100lber ram with LG style linkages so if they run off a 3hp electric motor i have to figure out what will be an equivalent in hyd. motor roughly and then i will go even a little larger just for good measure. Plan is to have a 5hp electric motor running the 2 stage pump and run the hydraulic press along the spine of the hammer mast and a telescoping mast with adjustable gibs and a hydraulic cylinder for lifting and adjusting throw height of hammer. 

this way i will have an infinitely adjustable hammer similar to the DP hammers without a bottle jack or bolts to tighten and untighten and no treadle adjustments.  just turn on main hammer walk to back of hammer and use valves to operate the press and walk to front use treadle valve to operate hammer and a valve on the side for simple raising the mast up and down via the cylinder.

 

this is the goal anyway, i wont be happy with anything else if i dont achieve that. I want it to be a truly utilitarian tool lot of farmgineering going into it before i start.

for sure appreciate the response, looking at it from different angles will give me the best perspective on how to solve the problem

[arftist]

Sounds like you are creating way more problems and expenses for zero gain.

[basher]

I have thought about this , make sure that your motor controle valve allows for the continuation of the flow of oil  around the motor circuit as the motor tries to stop but the inertia of the large weights involved keep pumping oil, very easy to have a situation where huge pressures are generated.

[Krush]

thank you basher, im working with a local hydraulic supply guy. he has built compactors and other hydraulic equipment and has been great as a resource in helping me figure out how to do what i want.