Convert/Redo hydraulic snow pump

[fitterski]

You still need a res.... CJ

Looks like maybe a 10 cu-in pump will be my upper limit & maybe 150 gpm max. That 'small' reservoir would then still need around 30 gallons i.e. almost a full size drum! Do you mean radial piston units or axial? I would run them only a fraction of the time so those durability specs would be more than adequate.

The more I get into it the more problematic it becomes. 300 lbs each pump & motor & reservoir is 900 lbs. An Allison 6-speed automatic can do all of that and more at 350 lbs. The mechanical solution does open other issues of course

 

[CJONE]

Looks like maybe a 10 cu-in pump will be my upper limit & maybe 150 gpm max. That 'small' reservoir would then still need around 30 gallons i.e. almost a full size drum! Do you mean radial piston units or axial? I would run them only a fraction of the time so those durability specs would be more than adequate.

The more I get into it the more problematic it becomes. 300 lbs each pump & motor & reservoir is 900 lbs. An Allison 6-speed automatic can do all of that and more at 350 lbs. The mechanical solution does open other issues of course

All piston units, just like a bent axis. If they are closed or open loop is what matters. A open system returns the full pump output back to tank. A closed system just returns the charge pump volume to tank. Piston units are more efficient so less cooling needed but it comes at greater expense. You are always better to mechanically drive something if possible so if you can do that, I would go that direction. Hydrostats work great for forward and reverse applications and speed control, you need neither so direct drive or a open loop system would fit you better. 50gpm at 5000psi is almost 170hp and that is electric brake so that would be in the 225+ range for diesel.CJ

 

[fitterski]

CJONE;

I spent my life thinking that 6000 psi was a lethal weapon. Just talked with a mechanic friend who 'updated' me i.e. that today it is commonplace. I will recalc to maybe a nominal 5000 psi and that should save weight all around. I would just instinctively prefer a closed system as it may become the speed control as well, it would keep the fan at x/y of the engine speed.

 

[fitterski]

There, i added up the beans for a nominal 5000 psi setup and the pump volumes (weights) look much better now. I hope I didn't screw up the calc anywhere

 

[CJONE]

CJONE;

I spent my life thinking that 6000 psi was a lethal weapon. Just talked with a mechanic friend who 'updated' me i.e. that today it is commonplace. I will recalc to maybe a nominal 5000 psi and that should save weight all around. I would just instinctively prefer a closed system as it may become the speed control as well, it would keep the fan at x/y of the engine speed.

Ya, it is! 3500 will pierce you without feeling it. But to get the HP and force modern equipment needs, the higher pressures are common now. Higher pressures = more done with less weight. With hydrostats 6k is actually common now. A lot of the snow cats are running close to this for their drive systems. I have pumps rated to just under 7k. If you build a hydrostat system you CANNOT have a overrunning situation with your blower. You must install a bypass line at the motor with a checkvalve facing the pressure side, we will say this is line A. Line A is pressurized for forward motion, If when you shutdown fast either from running out of fuel or by accident, the motor will pressurize line B from a overrun and the check will open allowing oil to enter line A and still feed the motor so it does not destroy itself. Most of the time this is not a issue but with large fans in a single direction application it does happen. I don't know if this would happen with a snow blower but it is food for thought. CJ

 

[CJONE]

oh and remember that large displacement piston motors are not common and are expensive. Normally you would run lower CC or CI motors through a planetary reduction system for the rpms you are looking for. When you are talking 20+ cuin motors gerollers are used but 3000-3500 is max on them and they usually don't like higher rpms like 600 and up. Just another fly in the soup for you! CJ

 

[fitterski]

those motor torques are in error, i made 2 separate goofs, should approximate 1500 & 1000 ft-lbs

 

[fitterski]

Thanks 4 the pointers CJONE, all those 'system design' issues will have to be addressed in time. For now I'm shooting for ballpark figures that let me have some basic ideas. Many manufacturers do use a reduction gear on higher powered fans but those also add weight and cost. I suspect they have other reasons for doing so since they reduce to 540 which happens to be the standard PTO speed. IF all else is equal I'd go for the simpler method with motor only. This is also something to explore, I'm also tending to downsice as my formulas get more precise so hopefully the final motor volume might be only around 15 cuin.

 

[CJONE]

Alright, did a little looking and a 26 series Sundstrand motor is efficient into the 400 rpm range. It is 13.87 Cuin and is a E pad mount, sooo this is a large motor FYI. I can get these rebuilt fairly reasonable. It would fit what you want to do. 55 gpm would get you 900rpm and over 900 ft lb of torque at 5000psi and 157 hp at the shaft. Soooo I hope the blower is stout!! Most don't want to spend the $$$ to do this right so I usually don't get in this deep on the net. A 23 series Hydrostat will supply enough oil to power this unit. You will need to somehow control your RPMs on that engine from load to no load, these pumps like constant smooth rpms. CJ

 

[fitterski]

I cooked up some more #'s, they are definitive of nothing but do give me a much needed "sense" of the thing. The fan is strong enough but it sits on the original JD throughshaft auger gearbox, not sure but it's only about 1-1/4" shaft. That gearbox comes off if i go hydraulics and using the existing platform. In all cases a smaller motor will turn just the auger as is mostly done on skid-steer blowers for example. The original JD blower had been designed for about 50hp ))

I can make a fan but this one might be based on drawings made by experts or bought as-is, they put a lot more into the design than i could and it does make a difference. The target spot is still in the left top box but "A" it's much too soon & "B" i will stray from it if i have to.

 

[CJONE]

If you look at that chart, the center box is almost exactly the figures I have in post 29. If you only have a 1-1/4 shaft you don't want to play with the figures you are looking at. The hydraulic set up that was laid out will destroy that shaft the first time it is fully loaded at speed with a chunk of ice, dirt ect. Let alone a gearbox only rated for 50hp. CJ

 

[fitterski]

If you look at that chart, the center box is almost exactly the figures I have in post 29. If you only have a 1-1/4 shaft you don't want to play with the figures you are looking at. The hydraulic set up that was laid out will destroy that shaft the first time it is fully loaded at speed with a chunk of ice, dirt ect. Let alone a gearbox only rated for 50hp. CJ

That means I was poking around dead-center :laughing:

I haven't found those 26 & 23 series units you cited, can you give links? I need all the data including weight & maybe approx street price. As for the gearbox I'm aware of its flimsiness (1-1/2" btw, just measured it) and it's coming off except if I continue with a mechanical solution on the existing platform and with a 150hp or so engine (this combo being unlikely but they say never say never).

I'm working on the next edit of my doodle-page but I have just now run into a new issue. In any hydraulic solution except maybe the most powerful one where I might HAVE to use a big gearbox, I intend to use no gearbox but have the motor hold up the fan. This also means a separate motor for the auger and that's the current homework. I think around 100rpm would be OK and anything like 500-2000 ft-lbs. The new toothed augers with teeth are what I need to gouge up any ice and not just broom snow into the fan like some feather duster. Sooo, this will take a low-rpm high torque motor that I can bury into a pipe at the end of the auger axle, or both ends. AND the extra demand has to be covered at the pump level.

Meanwhile the guy I had a deal with on th Duramax looks like he's wavering so that my hearts desire, the 6bt, may be back in the running:cool2:

 

[CJONE]

I am not a computer geek so no links. The simplest way for you would be to go to Metaris usa website and look at the pv and mf series pumps and motors. They are a knockoff company and have import replacements for these units. we rep them and can rebuild replace anything in the Sauer series pumps 20-27. Most of the new stuff is a throwaway unit. That is why I stay away from it. 2000 ft lbs of torque??? Wow I think you need to get a few things worked out before looking for drive components that will deliver numbers like you are asking for. You are getting in the lower range of some of the topdrives and swivels that I build power units to drive, CJ

 

[bigdeano]

Search for Sundstrand 26 on Ebay. Yikes, hope you have a fat bank account.

 

[fitterski]

Search for Sundstrand 26 on Ebay. Yikes, hope you have a fat bank account.

The stuff can be very pricey, I'm going to study the setup and keep different options open for as long as I can. I'll call it probably in late spring or summer. Everything is expensive, as an example the current reduction at the fan involves a gearbox, 2 machinery pulleys, and even the belt cost aroud $500 for a total of around $2300 so that amount really has to offset the price of any hydraulic pump/motor replacing them. If I go for an alternative mechanical transmission like the Allison 6-speed auto and a 3-driveshaft horror under the frame that also adds up to well over a grand used. Finally it costs me $1500/season to farm out the snow removal and that is open to increase (it has doubled in 10 years).

 

[fitterski]

I am not a computer geek so no links. The simplest way for you would be to go to Metaris usa website and look at the pv and mf series pumps and motors. They are a knockoff company and have import replacements for these units. we rep them and can rebuild replace anything in the Sauer series pumps 20-27. Most of the new stuff is a throwaway unit. That is why I stay away from it. 2000 ft lbs of torque??? Wow I think you need to get a few things worked out before looking for drive components that will deliver numbers like you are asking for. You are getting in the lower range of some of the topdrives and swivels that I build power units to drive, CJ

my first response to this just vanushed somewhere, so here goes shorter version #2

About the auger torque: the present setup delivers a maximum of about 370 ft-lbs to the impeller gearbox the sideshaft of which I think is not geared down any further as some others are. On the other hand the chain drive gears it down another 3.5 so we have 1300 ft-lbs. The torque I do have is, like the power all-around, inadequate but I had forgotten that pointed nose-down the auger actually cuts (planes) ice and frozen ground so re-evaluating it I think that even 3000 ft-lbs and more would not be out of place. But I don't know if the skid-steer blowers that use a hydraulic auger motor also use further gearing.

 

[bigdeano]

The Char Lynn 10,000 series motors can develop over 2000 lb ft torque. I've seen them go cheap on ebay in the past.

 

[CJONE]

The Char Lynn 10,000 series motors can develop over 2000 lb ft torque. I've seen them go cheap on ebay in the past.

Ya the 57 cuin one will BUT I am really curious to see what the o/p plans on driving with this. Also it would require a double pump system. What we are talking about here is a lot of $$$. There is a reason these units are geared down for the augers and driven off of the main drive. So the torque is developed from gearing and slower speed is needed. I guess I should have asked how much the o/p was planning on spending to start with. That usually tells me how serious they are to start. CJ

 

[bigdeano]

Yes, I think hydraulic is too expensive. I think mechanical drive with the Allison transmission is the way to go. There's a utube video of a walk behind blower with a big block chevy for power. The snow really moves.

 

[fitterski]

Yes, I think hydraulic is too expensive. I think mechanical drive with the Allison transmission is the way to go. There's a utube video of a walk behind blower with a big block chevy for power. The snow really moves.

Agree, but never say never. I've seen that v8 walk-behind, now THAT's starting to get warm except I want it bigger and 30 times the forward speed with a 7 foot mouth. I have 2200' driveway, needs 2-4 passes, not interested in spending half a day on it each time.