Convert Rear PTO Snowblower to Front Hydraulic

[J_J]

Presently, is your PTO driving your snow blower directly or through a gear box?

 

[rswyan]

Presently, is your PTO driving your snow blower directly or through a gear box?

Presently my snowblower isn' being driven at all ... it's laying over in the woods ...

No, seriously ... it's a designed to be driven directly off the rear PTO (540 rpm) as a rear-mounted blower.

I believe it does have an open gear set up on it (not a gearbox per se) - but I think that's just to transfer (and gear down) the motion 90 degrees to power the auger ... I think the blower impeller itself is driven direct - same speed as whatever the PTO is spinning.

 

[rswyan]

Just looked through my old invoices from Surplus Center and the hydraulic reservoir I have is indeed a 10 gallon unit. I know that's a bit on the small side ... but after pricing reservoirs @ Surplus Center (man ... have they gone up in price ) it just might have to do until I can fab up a larger one designed specifically for the space constraints I'm dealing with.

 

[rswyan]

Looks like the coupling on the mower end of the MMM shaft is 1" 10T ... think that might also be the size on the mid-PTO shaft itself ...

The shaft on the Eaton pump is 7/8" keyed and has a standard 1 3/8" female PTO coupler on it.

Seems like a stub insert could be made, with a section of 1" 10T shaft welded onto a piece of 1 3/8 6T shaft to couple them together. Or something else to couple directly to 7/8" keyed shaft on the pump itself.

 

[robstaples]

I'm curious why the mmm pto and not the rear PTO. I've never seen a HP rating on the mid. Only on the rear. Like 85_90% of total.

 

[bigdeano]

Hydraulics are terribly wasteful of horsepower using a pump - motor drive. At best you're going to have about 15 horsepower at your blower, probably closer to 12. If the pump and motor are each 80% efficient you've lost 1/3 of your horsepower without the losses in hose and fittings. I doubt if you'll get 80%, probably less.

I went through the same thought process putting a hydraulic tiller on my garden tractor. I have 20+ pto horsepower which should be plenty for a 40" tiller, but so much is lost in the hydraulic drive that it's pretty easy to stall it. I wish I'd used a mechanical drive every time I use it.

Good luck with your project.

 

[rswyan]

I'm curious why the mmm pto and not the rear PTO.

Not really sure what you're curious about ... I have rear-mount PTO blower and I wish to repurpose it to the front so that I don't have to blow snow in reverse, sitting halfway turned around in the seat and straining my neck.

Various ways to achieve that ... all of which have upsides and downsides. Doing it hydraulically seems to have some advantages, given my particular circumstances and the resources available.

The mid-PTO runs at 2500 rpm @ 2578 rpm engine speed.

The Eaton hydraulic pump I have will not produce anywhere near the flow I need at 540 rpm (rear PTO speed) ... in fact, the literature doesn't even show any flow in the flow charts (graphs) for less than 750 rpm operating speed - that's where they begin - 750 rpm. (750 rpm is listed as "Minimum Speed at Continuous Pressure")

At 750 rpm, the graph shows a flow rate on the order of 6 to 8 gpm (8 gpm @ 1000 psi and 6 gpm @ 3000 psi)

I've never seen a HP rating on the mid. Only on the rear. Like 85_90% of total.

I suspect the overall HP rating would be similar ... however the amount of torque might be considerably different, given the difference in the gearing.

 

[rswyan]

Hydraulics are terribly wasteful of horsepower using a pump - motor drive. At best you're going to have about 15 horsepower at your blower, probably closer to 12. If the pump and motor are each 80% efficient you've lost 1/3 of your horsepower without the losses in hose and fittings. I doubt if you'll get 80%, probably less.

Dean,

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

I went through the same thought process putting a hydraulic tiller on my garden tractor. I have 20+ pto horsepower which should be plenty for a 40" tiller, but so much is lost in the hydraulic drive that it's pretty easy to stall it. I wish I'd used a mechanical drive every time I use it.

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.

Good luck with your project.

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.

 

[rswyan]

The thread below, which I linked earlier in this thread, is worth having a look at, in terms of the practicality of doing this. The tractor seems to be of a similar size (hp) as mine ... although my blower is 16" wider (60" vs 44")

Last picture in the thread shows the unit blowing snow ... but the snow isn't all that deep:

Hydraulic Snow Blower for FEL

 

[jenkinsph]

I think Deano has it right, with the hp losses you will have it will be slow going in heavy snow. A 60" blower is about all your tractor wants on the rear pto I would think so moving to the front using the hydraulic drive is going to be tough.

Other than the power to operate this well I don't see anything wrong with your proposed hydraulic set up.