Hydraulic power hammer possibility?

[Ben Potter]

First I have no experience with neither hydraulics nor pneumatics so this is all based on internet research.

 

 I have been crunching numbers for a new hydraulic press primarily looking at speeding up my air over hydraulic 20ton (a lost cause I think) and had the thought: Could you make a combination hydraulic press/hammer?

Using a 2hp 120v two stage pump producing 1.37gpm @ 2500 psi and 5.27gpm @650.

It would have 2 cylinders.

A 4" one that would generate ~16 tons @2500psi and 1.6in/sec @650psi and .4in/sec @2500 psi for the press (think Coal Iron Works 16ton press)

and a 1" one generating ~1 ton @2500psi and 6in/sec and 1/4 ton (500lbs) @650psi and 26in/sec.

Adding a geared flow devider / combiner to the small cylinder should ad 90% to the speed producing ~ 49in/sec @250 lbs.

For a 10in stroke that equals roughly 2.6 bps(less reversing time) straight or 4.9bps with the flow combiner.

 

For comparison the early De Lisle Power hammer De Lisle Power Hammer on Youtube uses a 2 1/2" bore  10" stroke  pneumatic cylinder running ~100psi producing 490lbs force at about 2bps. (the cnc version in the video is twice or more as fast)

 

I know the pneumatic cylinder will hit faster and harder but it seems that it might be possible to get a passable hammer with the small hydraulic cylinder.

 

Thoughts?

[Latticino]

For power hammers think greater force, lower BPM, lower force, greater BPM.  Take a look at the Anyang USA site for details.  I have a "34 lb" that hits at 250 BPM when all is running properly; their "178 lb" is only rated for 205 BPM.

What I've seen work well is a combination hydraulic press and rolling mill using a hydraulic motor to produce low RPM and high torque...

[Bob Brandl]

There are pneumatic over hydraulic hammers in steel mills all over the world, but they're massive. Hydraulic power is used to lift the ram/head, then get driven down with compressed air or nitrogen. I've seen them on Modern Marvels and other shows like that. I don't know why anyone would want one in a small shop.

[Frosty]

I can think of a couple concept type experiments but you'd have to know hydraulics and or pneumatics to evaluate your chances before experimenting even. The pump and motor you have are non-starters for a pure hydraulic forging hammer.

As suggested a forge roll would be my choice but forge presses work a treat too. I'd consider trying to combine those two but I'd use the same pump to drive the two  individually, NOT try and make one device do both jobs. 

You have a useful piece of equipment but you'll need to come up with something else to make a useful power hammer.

Frosty The Lucky.

[Ben Potter]

Thanks for all the good input.

I think that the pure hydraulic hammer is a nonstarter for a small shop. Just for giggles and grins what would happen if you took a double acting cylinder and attached your pump to the ram side and a precharged accumulator to the other port. Sort of like a breaker on an excavator. The hydraulic pump lifts the ram/hammer and when the valve is opened to tank the pressure in the accumulator acts as a spring and slams the hammer down?

[Randy Griffin]

In theory, yes, it would work. But, your cylinder ports would need to be oversized and your up stroke is still slow. If you force too much fluid through standard sized ports you’re in danger of over pressuring the rod end of the cylinder.

[Frosty]

If you've ever heard hydraulics squeal it's usually cavitation behind the valves, sometimes leakage around them. Even 1/2" ports, lines and fittings would make a slow hammer accumulators and all. Forcing fluid fast tends to eat components and hydraulic components that large are expensive. 

Still it's a fun subject and you just never know when someone somewhere in the world has worked out a workable device.

At one point years ago I was going to plumb the shop for hydraulic power. That way I could tap into the lines in different locations with various tools, mostly rams for bending, lifting, pressing, cutting, etc. I was thinking of a putting hydraulic motor on a mechanical power hammer and all kinds of neatO things.

I used to work with a soil sample type drill rig with probably a mile of hydraulic lines, more than a dozen control valves, regenerative circuits, accumulators and tools. The drill rarely got downtime I didn't spend working on the hydraulics, made lots of field repairs too. 

Hydraulics are WICKED COOL, I love them but for some things not so.

How about this idea, you have a highly useful and desirable piece of equipment so make an upsetting press. a hydraulic vise and upsetting ram. If you made the vise 2 individual parts you could adjust the distance between and make longer upsets. Say open basket twists. 

Frosty The Lucky.

[poleframer]

I have a hydraulic power hammer. No working camera atm tho. Might find an old pic or two somewhere.

It is basically a "rusty" style hammer on steroids. Has about a 75-80 lb 2x4 solid steel bar with bolt on top dies for the head, and 2 dump truck springs.

The "cam" plate that connects with a long drag link to the rear of the spring is mounted to a hydraulic motor. The motor is controlled by a flow control valve, which is activate by the foot pedal, giving varying speed control, I can even one hit quite well with a tap of the pedal.

Now the center pivot of the leaf springs is mounted on a hydraulic cylinder that has a control valve next to the ram head for easy adjustment of striking height. I can go from slapping the dies to about 7-8 inches up.

Oh, an since it is so long, about 6' overall (5' long leaf springs) I ha room to put a 7" bore cylinder for a push-up forging press, an a 5" bore top own press next to it, all under an in line with the leaf springs.

That machine, my lathe, a big bandsaw (30" parks), a couple belt sanders and a iron twister are powered hydraulic with a 2 stage pump on a 15 hp diesel engine outside that I usually run just above idle for good speed, unless I feel spicy and crank it up :)

I'll see if I can fin some stored pics if anyone is interested, I think my old photobucket is still there.

 

[ThomasPowers]

How many beats per minute does it run?

[poleframer]

250-300, if I rev the engine, but with 65 lb, 3/4" thick (at the center) leaf springs it's about to take off. I never run it as fast as it can go. If I do the top die will start hitting the head.

But then I have the pin in the cam wheel at the furthest out hole for maximum whappage, if I moved the pin closer to the hydraulic motor shaft I get shorter stroke, and could go faster.

I havnt done the test there was a thread about years ago, but it will easily take a hot 1" bar down to 1/2" or less in a few hard hits.

I sort of play around with how I want it to hit, and how fast by elevating the spring pack, to have it hitting at the speed I like, if I want to hit harder I just go a little faster with the treadle, or go slower for lighter blows.

I'd suppose at 100-120 bpm the head is going about 8 inches up and down, and I have about 16" between the dies if the top die was to the head.

[Frosty]

I misunderstood you earlier, you're replacing the electric motor, line shaft, etc. with a hydraulic motor. Oh YEAH BABY! If I had my shop plumbed for hydraulics the way I planned before the accident my 50lb. Little Giant would be driven with a hydraulic motor, along with a bunch of other things. You can't be a driller as long as I was without developing a serious love/hate relationship with hydraulics.

Frosty The Lucky.

[poleframer]

YES! After messing around, (hate puters) I got my old camera to transfer pics. Lemme see if I can load them here. Looks like my old photobucket is gone.