Convert Rear PTO Snowblower to Front Hydraulic

[rswyan]

One thing I've been pondering on was attachment and removal of the snowblower on the loader ... particularly how making hydraulic connections would figure into that. The pump will be located roughly under the operators station and will be installed on the tractor for the snowblower only in winter. I'd like to be able to disconnect the hydraulic lines at the pump (ideal) or at the blower (ok I suppose, but less than ideal)

I realize that the ideal situation is to keep the fluid flowing as freely as possible ... and that hydraulic quick couplers can impose some restriction, with ISO 16028 Skid Steer quick couplers probably being the least restrictive ...

Seems like the suction line/supply/feed to the pump would be the place where the least restriction would be desired. With that in mind, does anyone know if "wet line" quick couplers like the ones at the link below are less restrictive than the ISO 16028 Skid Steer type ?

Wet line Coupler, Dry Break Couping, Hydraulic Quick Disconnects

I was thinking either an ISO 16028 Skid Steer coupler on the pressure side (3/4) and wet line on the suction/supply side (1 1/2) ... or maybe wet line for both ...

 

[bigdeano]

I'm pumping about 18 gpm on my tiller drive. I have a 1" hose 18" long on the suction with a regular 1" quick coupler at the reservoir. The reservoir is above the pump. It hasn't ever cavitated that I know of. Seems to me your 1.5" suction is overkill unless you're pulling the oil a long ways. Just my .02 worth.

 

[rswyan]

Deano,

Thanks for your continued input.

Here's my thoughts:

I'm pumping about 18 gpm on my tiller drive. I have a 1" hose 18" long on the suction with a regular 1" quick coupler at the reservoir. The reservoir is above the pump. It hasn't ever cavitated that I know of.

Right ...

I dunno ... since I'm not really all that familiar with hydraulics (just enough to be dangerous ... ) but it might be that you could have cavitation and it may not be easily discernible by eye ...

There is a phenomena that can occur on diesel engines (from incorrect coolant IIRC) where coolant (water) gets super-heated at the cylinder liner wall, turns into steam, and essentially "explodes" and then collapses ... which can pit and erode the liner ... to the point of perforation even:

diesel cylinder liner cavitation - Google Search

I don't know that if one opened the radiator cap on an engine where this was occurring that you'd see foam in radiator.

IOW: it's happening ... but you may not be able to (easily) observe it while it is.

But the eventual result may be easily observable.

Seems to me your 1.5" suction is overkill unless you're pulling the oil a long ways. Just my .02 worth.

Proper hose sizing is something that has been researched and for which standards have been developed. These are created with longevity in mind, as well as proper function.

This is not something that I'm really well versed in, but as I understand it, much of it has to do with the velocity of the fluid and the turbulence that can be created as a consequence of restrictions and excessive velocity.

 

[bigdeano]

I was just thinking that 1.5" hose is super stiff and hard to work with. Seems like 1-1/4 would be plenty big and stiff.

One thing to consider is that on many hydraulic transmission setups the entire flow doesn't go back to the tank. The pump and motor are hooked in a loop and the pump sends part of return flow to the reservoir and pulls the same amount from reservoir. The Vickers hydro pump on my garden tractor works like this.

The same could be done by splitting the return from motor, sending part to pump inlet and part to tank. The pump inlet would also be hooked to tank outlet. Your hoses from and to tank could be smaller.

 

[SPYDERLK]

Dean,

Your numbers look correct ... and it makes me wonder.


I can imagine ... although I'd bet that there is a good bit of difference between tilling dirt and blowing freshly fallen snow.

I can probably fab up a mechanical drive/speed reducer, using gears and roller chain running in an oil bath in a housing ... but pump/motor hydraulics seemed less involved ... more quick and dirty. Easier.


Thanks ... I'm not fully committed to going the hydraulic route just yet ... but I am committed to getting the blower moved to the front before the snow flies.

Where will you put the 2500rpm pump. Would there be room to augment its drive with an auxillary engine?

 

[rswyan]

I was just thinking that 1.5" hose is super stiff and hard to work with.

If we're talking about a hydraulic pressure hose with crimped-on JIC fittings I'd say that you're right - especially if it's a two-wire hose ... dunno ... they may all be two-wire (or more) at that size.

But I've got a piece of hydraulic suction hose (1") for my logsplitter project that has the consistency of automotive heater hose ... it's big ... but really, really easy to bend ... to the point of kinking ...

Seems like 1-1/4 would be plenty big and stiff.

The fluid in a 1 inch I.D. hose flowing 22 gpm is moving at nearly 9 feet per second ... or 539 feet per minute ...

Upsize the hose to 1.5 inch I.D. at the same flow rate and the velocity drops to about 4 feet per second ... or 240 feet per minute.

Recommended flow velocity for a suction line feeding a hydraulic pump ?

... 4 feet per second ...

One thing to consider is that on many hydraulic transmission setups the entire flow doesn't go back to the tank. The pump and motor are hooked in a loop and the pump sends part of return flow to the reservoir and pulls the same amount from reservoir. The Vickers hydro pump on my garden tractor works like this.

The same could be done by splitting the return from motor, sending part to pump inlet and part to tank. The pump inlet would also be hooked to tank outlet. Your hoses from and to tank could be smaller.

True ... but I don't see that that gets me much of anything ... other than increased complexity, a greater chance for leakage, and possibly less cooling ...

 

[rswyan]

Where will you put the 2500rpm pump.

Directly underneath the tractor (roughly mid ... maybe a little forward), probably about 1 1/2 to 2 feet forward of my feet. There's a pair of brackets with (approx) 5/8" holes which are used to pin up the MMM deck when it's not being used that are just crying to be used as mounting points for the pump ...

Would there be room to augment its drive with an auxillary engine?

Not using the mounting location above.

The mounting location above has several advantages:

1. Done properly, I won't lose much ground clearance.

2. It will be close enough to the mid-PTO shaft that I can use the driveshaft from my MMM (saves money) by having a small/short stub adapter (1" 10T ---> 1 3/8" 6T) made up at a local driveline shop. I could probably cobble something myself on the adapter, but I'd rather just spend a little to have someone do it professionally to ensure both pieces are centered on each other.

3. The driveline angles at this mounting location would be pretty mild ... which is easier on the equipment, safer, etc.

4. Should be fairly easy to mount and remove.

 

[SPYDERLK]

SS,


There was a thread on TBN awhile back about several members that were running hydraulically-powered snowblowers on larger tractors ... one fella was actually concerned about the fluid being too cool ... seems that he could only get it up to around 70 or 80 degrees.

One question I had was what kind of pressures one would see in the return to the tank line, coming off the motor ... seems like that (or the suction line to the pump) would be the place to plumb in a cooler.

you could make a killer cooler by running the oil thru a pipe that is welded to a plate dragging in the snow.
larry

 

[rswyan]

you could make a killer cooler by running the oil thru a pipe that is welded to a plate dragging in the snow.
larry

LOL ... good one :thumbsup:

Yeah ... that sure would keep things chilly ... :laughing: