Convert Rear PTO Snowblower to Front Hydraulic

[rswyan]

I've forgotten what your tractor PTO HP was, but it takes 25 HP to produce 22 GPM @ 2000 PSI.

Mine is 22 HP ......

But using Surplus Center's calculator, I get 30 HP required to produce 22 GPM @ 2000 psi (for electric motors ? )

It is good to have the relief valve there to protect from spikes whether you can produce that pressure constantly or not.

Right.

If your mower coasts to a stop you should be good with the motor circuit.

Yeah, I hope so ..... I need to check it again and see exactly how long it takes to spin down when clutched.

If it's too fast, I can always plumb in a check valve like Farmerford did on his hydraulically-powered RC .... although I'd have to figure exactly how he did it (some thinking required)

Sounds like you have a plan.

I do indeed ... now it's mostly a matter of time and money ...

 

[KWentling]

I use: GPMxPSI required/1714=HP There are differences between electric motor, gas motor, hydraulic motor, ect HP, but I don't have it handy.

Kim

 

[mmurphy]

Max the snow beast is finished - TractorByNet.com

This guy may have some of interest for you.

 

[rswyan]

I use: GPMxPSI required/1714=HP

Right - that oughta work ....

Figuring it backwards, looks like 1700 psi continuous would be about all I'd be able to develop in light of the HP available .... hafta play around with the relief once I get it together ...

There are differences between electric motor, gas motor, hydraulic motor, ect HP, but I don't have it handy.

No worries .... again thanks for all the help :thumbsup:

 

[rswyan]

This guy may have some of interest for you.

Murph,

Thanks .... yeah I scoped out that thread .... nice set up .... and a real "snow beast" to be sure :thumbsup:

Using an idler sprocket to create a reverser doesn't look like it would be all that hard to construct/fab up .... but maybe somewhat more involved than what I'm looking at .... dunno ...

I was going down the hydraulic path because of several reasons:

1. Seemed to be the quickest/easiest route to go, in terms of fabricating something up - I've been off work for several months and I now need to go back to work to pay the bills and keep the wolves away. My available time over the next several months will be pretty limited - and just fabbing up the front 3PH will be involved enough.

2. I only needed the hydraulic motor (plus hoses and fittings of course) - since I already had the hydraulic pump, filter mount & filter, strainer, and the tank/reservoir ... although it appears that a larger reservoir would be in order, which would be an additional cost - both in the tank and in the hydraulic fluid to fill it.

The easiest cheapest route for me to go on the tank/reservoir would be to just pick up another identical 10 gallon tank ($120) from Surplus Center and couple the two together (20 gallon total capacity) ... could probably mount them in saddle configuration, each on opposite sides of the tractor, and use that mounting frame as a mount for the pump as well.

3. I was looking at "borrowing" the driveshaft off my MMM to power the pump .... so that's one less thing I have to purchase ....

4. Using hydraulics avoids having to deal with multiple driveshaft supports & mountings and u-joint angles ..... hydraulic hoses from the pump to the motor are flexible of course, and should easily accommodate the up/down movement of raising and lowering the blower, as well as any side to side to movement.

Surplus Center has a pair of short Cat 1 3PH lower arms for fairly cheap ($18):

CATEGORY 1 PAIR KUBOTA SHORT LOWER LIFT ARMS

And I have a 2" x 8" cylinder I can swipe off my landscape rake to use for the lift mechanism for the front 3PH for the blower.

Using my loader valve I'll be able to raise/lower the blower and rotate the chute - I don't have the cylinder for the deflector on the blower yet, but if I get that I'll need to add a front remote (diverter) for the loader valve so I can use it .... which is fine, since I planned to do that anyways for a grapple. Or just go with an electric linear actuator.

Need to get up to the shed today and see exactly what I have in inventory as far as lines and fittings go, so I can some kind of idea about I'd need and what the cost might be.

 

[rswyan]

Checked the spin down from PTO speed on the MMM this afternoon .... was about 10 seconds .... seems like a check valve for the hydraulic motor might be a good idea.

 

[IceStationZebra]

hydraulic motor coast down circuit. In normal use the check valve is closed, but if the oil flow stops suddenly the hydraulic motor can coast down at it's own speed and not self destruct. It also will not allow reverse rotation of the motor, which can be nice when you want to prevent someone from hooking the hoses up backwards.

Also, don't forget to allow for drivetrain power requirements in your calculations. If you use all of your power for the snow blower you won't have any left to drive up the hill.

ISZ

supply -------------------------------------|
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^ check hyd
O valve motor
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return---------------------------------------

 

[wdchyd]

RSWYAN,

Sorry been w/o puter for a while......reading up on this, the only input I have is a system I've seen fabricated similar to what you want...

They had a Prince PTO mounted pump on back running a Commercial Gear Motor on the front snow blower.....the gear motor displacement was 10-15% larger than the pump as to take up for efficiency loss....giving them basically a 1 to 1 ratio for RPM's.....

They tee'd in a PRV and a normally open solenoid (12 VDC power to close valve) at the inlet of the motor for stall control and on/off operation.....the exhaust from the PRV & SCV was tee'd back in to the line coming out of the motor......The unit worked pretty good but concerns about heat had them alter the hoses larger to reduce pressure drop to run cooler.....

I don't think they needed the SCV as the PTO control on/off on the tractor was sufficient......the PRV was needed in case of stall to protect the tractor.....

Didn't know if this would help but this unit I've seen is basically where you want to be........

 

[rswyan]

Thanks ISZ & wdchyd .....

I'm back out on the road myself - picked up a load this afternoon and am waiting for cons to open right now so I can drop it.

If I don't get loaded again immediately I'll reply further in a bit.

Thanks again !

 

[Reg]

I think the 47 HP for (...whatever those displacement, RPM and pressure numbers were),
assumes a maximum LOAD, i.e. 47 HP is what you COULD put through it IF you were trying to do that much work.
With no snow... maybe a horse power or two just to turn the egg beater and overcome internal friction and losses.
Start feeding it some powdered snow and it loads down, hopefully your tractor's governor keeps up.
Load it with a LOT of snow, or heavy slush, say to 20 HP and your tractor would have a hard time, but that is just a limitation of the power going IN.
If you go slow enough you can probably cut into deep drifts and throw them a good long way with 20 HP.

This is a bit like the generator question, it might have a CAPACITY of say 15 Kw, but that doesn't mean it will blow up a 15 watt light bulb.
Sure the light bulb can't take all the power of the generator, it will only draw 15 watts.
The fact that the generator COULD put out 15 Kw is irrelevant to a 15 watt load.