Hydraulic motor speed "identification"

[sako243]

Short version not after an identification but more what it's likely to be capable of speed wise.

Longer version - it's the slew motor off a Gardner Denver 14.5m cherry picker (possibly VM145 but I'd need to double check the data plate). The cherry picker is down for the count current undergoing some significant repairs but in the meantime I'm wondering if I can repurpose the motor for another project "temporarily". Ideally I'd like somewhere close to 3000rpm if possible.

It appears to drive a worm gear and then a further reduction gear to the actual slew ring so it's pretty geared down.

If there's no chance of it being reasonably fast I won't bother trying to remove it as that looks like it requires dismantling or at least removing the worm box.

One for @8ob or @Rannsachair?

 

[Kram]

My understanding is hyd motors are positive displacement, so the speed is directly linked to the flow through it, so it might depend more on the pump?

If you can get the motor off and spin by hand with the hoses unpressured but primed with fluid, say 20 revolutions and measure how much fluid squirts out, should give a rough idea of the CC?

 

[sako243]

Well the options for power are all around the 80lpm mark I think. The JCB definitely chucks out that, then both the 6x6 and the Defender have PTO driven hydraulic pumps.

 

[Rannsachair]

Difficult to tell from the picture what the name plate says. It looks like a gerotor motor, by its side shape I would guess its a low speed motor, though ideally want to look up a data sheet for speed, pressure, Torque. Can you get a close up of the label?

 

[sako243]

Can you get a close up of the label?

I'll try tomorrow but it's been painted over in thick yellow paint and when I scraped that off it's taken some of the paint for the manufacturer name off. I think it was A&S hydraulics. The data plate is pretty illegible but I'll see what I can do.

 

[sako243]

Is the block on the back a check valve of sorts?

Whilst hunting I came across this which offers no more info

Rotation Motor - Cherrypicker Parts | Fast Reliable Service

Cherrypicker Parts make finding and buying Gardner Denver Rotation Motor - CSP00946 parts easy. If you are not sure which is the correct component for your Gardner Denver Rotation Motor - CSP00946 machine our cherry picker parts experts are happy to help – just give us a call. We are one of the...

cherrypickerparts.co.uk

 

[Pete.]

Commonly, hydraulic motors are specced in volume of oil displaced per rotation so if you have 80LPM delivery available that's 80,000cc/min and if you want 3000rpm you need a motor of 80/3 = 26.7cc displacement.

 

[sako243]

Isn't there an "upper" limit though? For example on flow fits website I've not seen anything that's "rated" for above about 2950rpm.

Basically I'm thinking of powering a chainsaw bar with it, gearing is an option.

 

[Rannsachair]

I used to design radial piston motors for harvesting heads, the chainsaw motors were chunky high speed axial piston motors like: https://www.parker.com/content/dam/...gs/Fixed_Motors/F11_F12_Saw/MSG30-8245-UK.pdf They are not cheap.
Depending if that's the sort of application I would definitely not be using a slew motor, it will not have a long life.

 

[minimutly]

Slew is slow, so this motor surely will not be suitable?

 

[sako243]

It's not going to be anything particularly powerful, just home use so doesn't matter if it needs to be a bit gentler on the cut.

I've got the option of a cheap 40tish cylinder from someone up the road. So the idea is a firewood processor that can split something like an 18" or 2ft round straight off. Our fireplace is relatively small so the stroke on this ram isn't that important but given it's 40tish (roughly 6" diameter) then it can split everything in one hit.

I agree that it's probably not the best suited but it's "free" currently so allows me to make something before having to spent any moneys.

The reasoning for hydraulic over say electric is because we can then easily take the processor to the wood rather than having to haul the wood up.

Slew is slow, so this motor surely will not be suitable?

It's feeding a worm drive then a further reduction stage after that by the looks of it so I'm not saying it's not slow but it's not not inconceivable that it's higher than I think.

 

[Bornfree]

The fastest hydraulic motor I use is a 12cc/rev fitted to the jcb loadall engine cooling fan.

 

[sako243]

The fastest hydraulic motor I use is a 12cc/rev fitted to the jcb loadall engine cooling fan.

Oo that's a thought. Those are spendy but I know some 1UZ engines were fitted with hydraulic fans so perhaps hydraulic fans are a possible source of a cheap fast motor.

 

[sako243]

Had another look and the data plate appeared to say MM S 32 C which turned up the motor. Looks like it's 630rpm continuous so not particularly suitable without a lot of gearing.

 

[Pete.]

Its a shame coz I had a tired 50cc high speed motor off one of our machines it was working but slipping a lot of oil. Went in the bin at work. It would probably have been much improved with a bit of hand lapping.

 

[8ob]

Had another look and the data plate appeared to say MM S 32 C which turned up the motor. Looks like it's 630rpm continuous so not particularly suitable without a lot of gearing.

You need to look at chain speed Ed, slapping a sprocket on the end of a hydraulic motor and hoping for the best may not work. You need to be looking at about 30mts a second chain speed and some kind of bar oiling system. If you want to suck it and see come here and grab some motors off the shelf .

Bob

 

[sako243]

@8ob I appreciate all of that. Basically I'm seeing what's possible with what I have (if at all). There would of course be oiling.

Doing a bit of research for a non commercial setup 3000rpm(ish) on a standard 7 tooth drive sprocket appears to be fine. You can go up to harvester chains etc., to get larger drive sprockets but if I can I'd rather keep the chains consistent with the 562XP then it's only one batch of sharpening I have to do.

Plenty of gaztube videos showing that. The idea is to minimise double handling, hence chunky shear grab ram so that I don't have to do double handing for splitting, just make a 6 (or maybe up to 12 way) splitter and be done with it.

Part of it is also bucking up the smaller stuff (say up to a few inches), I've got a big diesel table saw but it's a pain pushing things through, pulling back, sliding sideways and repeat. I prefer using one of the chop saws as I can just move it sideways but they're limited on capacity. Hence using a 20/24" bar as a chop saw in effect.

 

[sako243]

Long term, if it's powered off the 6x6 it can be mounted on the back, chop and split stuff straight into the bed. Then we just have to dump the load straight from the field into the log shed(s).

The 6x6, 110 and JCB aren't short on hydraulic power hence using those. Initially use the JCB since it can provide power straight off without having to faff with tanks etc. Then slowly as things are made it can be made more adaptable.

Initially probably just slap a pair of hooks onto it so it can be picked up by the front quick hitch.

 

[Kram]

The reasoning for hydraulic over say electric is because we can then easily take the processor to the wood rather than having to haul the wood up.

The answer to that is petrol

Small electric start motorbike engine

 

[sako243]

There's already diesel in the JCB and petrol in the 6x6, diesel and eventually petrol in the 110.