PTO & hydraulic pump spline adapter

I'm working ahead a bit so I can figure this all out before it becomes a problem stopping progress.

First off, this is a one-off issue, not production.

So I need to drive a hydraulic pump off a Kubota Mid-PTO. This is going to require a 6-7' long drive shaft to get the power from the PTO to the front of the tractor where I need the pump to sit. The first 2 problems I have to deal with are the splines on both ends.

The Mid PTO is listed as being "USA No. 5 (Kubota 10-tooth) involute spline" but I can find nothing matching that description. I need to grab my machinery's handbook from work to look into this further, but that is not handy right now. I also have not yet been able to put a caliper to the shaft as I don't have it yet (I will be installing it in a couple months). My searching shows it is approx 1" dia, or slightly less (perhaps .980) 10 tooth. This appears to be a bit of an oddball. Question 1: Does anyone know what this thing is?

Opposite end will need to mate to a hydraulic pump. A couple options I am looking at include an SAE 13T-16/32DPx30P spline (SAE B pump spline) or an SAE 9-tooth spline on a 0.6" dia shaft (SAE A pump spline ... much less detail on that one in the drawing I have). I think these two are more common, but I know very little about splined shafts. I need to match up to this on the other end of the driveshaft.

So what I am trying to figure out is how to spec out a driveshaft that mates the PTO to one of those pumps (I need to pin down which one first, obv). I'm not sure that the pump spline is normal for PTO yokes, so I may well need an adapter. Are there ANY stock sources for these? My searching has not been fruitful but I figure you guys see this stuff much more often and may have sources.

So looking for info on the PTO spline and anything on an adapter for the pump spline(s). Any help appreciated. I have a machinist friend that I think can make what I need if I can't find an adapter but that is more complicated than something stock, if it is out there.

Thanks,
Dave

There is a good chance that the pump shaft is not well enough supported for connection to a drive shaft. You will need an overhung load adapter for it. Specifically, if those style of SAE flange mount gear pumps are driven by anything other than an squishy inline direct coupling they can fail.

They make pumps with PTO splines on them, but they are more expensive because they have the bearings to accommodate the service.

Thank you. Though I did not note it above, I was planning to support the driveshaft near the pump end with a bearing in a pillow block. How to do that is TBD as I am still sorting through all my options and figuring out what is viable. I am also not yet sure if I need a mid-span bearing for this shaft or not. If you have more details on the overhung load adapter, I am all ears.

From what I have seen, PTO pumps all want the standard rear PTO at 540 RPM, where the Mid PTO runs 2000 rpm with a totally different spline. With other equipment already on the rear 3-point hitch, I have decided the Mid PTO is the only decent option for driving this.

I think you are overlooking some key parameters such as the maximum shaft speed and the torque required to drive the pump.

A problem I see with your approach is that the 7ft. long drive shaft is relatively long if you make it one piece. You will have to deal with shaft whip which can be addressed with the proper sizing of the shaft element dia. There is also the issue of critical shaft speed and the likelyhood that a 7ft. shaft will have multiple critical shaft speeds.

You will also need to have equal U-joint angles on each end to minimize harmonic vibrations. To add to this problem, the drive shaft will also cause a radial load to the driven ends. You will need to have a good fit on the spline shafts. Any looseness will add to shaft runout and increase the radial loads on the spline shafts.

I suspect that you will ultimately need to use use an intermediate straight shaft in the middle and use appropriately short end shafts with a u-joint at each end. The intermediate shaft will need to be mounted to the tractor with a bearing at each end.

This approach will keep most of the loads reasonable and allow for a smaller shaft dia.

dstig said:

Thank you. Though I did not note it above, I was planning to support the driveshaft near the pump end with a bearing in a pillow block. How to do that is TBD as I am still sorting through all my options and figuring out what is viable. I am also not yet sure if I need a mid-span bearing for this shaft or not. If you have more details on the overhung load adapter, I am all ears.

From what I have seen, PTO pumps all want the standard rear PTO at 540 RPM, where the Mid PTO runs 2000 rpm with a totally different spline. With other equipment already on the rear 3-point hitch, I have decided the Mid PTO is the only decent option for driving this.

Click to expand...

The 2000 rpm mid-shaft is a show stopper.

Balance and runout at that speed will be difficult to control with PTO components. You also want to avoid using a bearing in the middle of a shaft.

Ziggy, please expand. Kubota drives snowblowers off this same set up with 2 intermediate bearings. Similar shaft length, though not one piece. The shaft is almost 100% straight shot, with the only angle being the slight misalignment that is inevitable. I am not wedded to a one-piece drive shaft and have expected it to require additional supports and components to be successful. I 100% know it can be done, but the devil is in the details, as they say... If Kubota can drive a 6' snowblower, I can drive a pump requiring 20-30 hp from a 45 hp PTO.

Wait, why use a long driveshaft to a pump in the first place? Mount the pump directly to the PTO spline and let the hoses handle the run and flex.

dstig said:

Ziggy, please expand. Kubota drives snowblowers off this same set up with 2 intermediate bearings. Similar shaft length, though not one piece. The shaft is almost 100% straight shot, with the only angle being the slight misalignment that is inevitable. I am not wedded to a one-piece drive shaft and have expected it to require additional supports and components to be successful. I 100% know it can be done, but the devil is in the details, as they say... If Kubota can drive a 6' snowblower, I can drive a pump requiring 20-30 hp from a 45 hp PTO.

Click to expand...

You need to do exactly what Kubota does then. They have already done what you are asking us to help solve.

Kubota is also likely using V-belts for transmitting power and speed reduction from the drive shaft to the snowblower. The V-belts do add a significant amount of load shock absorption.

You will either need to use V-belts for a speed reduction to the hydraulic pump if you use a pto version or else directly couple the pump to the driveshaft.

Not sure what you are trying to accomplish with mounting the hydraulic pump at the end of a 7ft. shaft that turns 2000rpm.

Mounting a pump designed for 2000rpm directly to the mid pto shaft seems a lot simpler and better.

Exactly, that’s how I run my limb ninja.

Depending on the age of your tractor there are two different yokes.

For some reason I can't post any links... but look up Messick's (Kubota 70060-01250) or Weasler #: 105-0610 as sources for the yokes.


In the early 1980’s I put a pump on my 1942 Farmall A (< 20HP) that had no hydraulics what so ever.

This involved welding a Lovejoy coupling to a spline shaft and building a small tubular support housing for the pump which was mounted to the pto seal flange (this is no where near the size/HP you are dealing with)

Still runs fine today… I'll be snow plowing with it within the hour...

Just built a simular setup for a neighbor to front mount a snowblower on the front of his case- Ih farmall compact tractor. Found a drive shaft quick attach yolk for the tractor at the dealer odball 15 spine 16/32 spline ( probably din) on a shaft they warranted for vibration. Go figure. Built a gearbox oil bath chain, mounted the gear reduction box to the front of the tractor with two quick pins. Back to the shaft , i used the slip spline from the old shaft and made a new one with a little more ridged seamless tubing.
A little on the long side for driveline rules but after welding and keeping runout with in a couple thousands overall it spins at 1500 at pto speed 1800-1900 with engine wide open. No vibration or whipping at all has worked flawlessly for couple years now.
Check out surplus center for pumps, overhung pump adapters and pto parts.
Surpluscenter.com


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Why re-invent the wheel? There are hydraulic pumps readily available that mount on the rear shaft. Not that expensive and come in different sizes.

Twraska said:

Why re-invent the wheel? There are hydraulic pumps readily available that mount on the rear shaft. Not that expensive and come in different sizes.

Click to expand...

As a fella with a fair few bastard size pieces of equipment around, I can understand why. It allows you to run an implement with a couple hundred dollars or lots less worth of hardware, instead of the many hundreds they charge for a PTO mount pump. And with less hassle than mounting an engine driven pump.

Personally, I'd be looking at the places like the Surplus Center, or ebay, (search Snow Blower Drive shaft Kubota Mid Mount PTO, as an eg) for a direct fit coupling for the mid mount PTO. If there are implements out there that run it, then there will be someone supplying spares. The A&I website is a good place to look.

Once you have a coupling, you can build up a PTO shaft as you see fit, matching cross bearing dimensions as you follow along the line.

trevj said:

As a fella with a fair few bastard size pieces of equipment around, I can understand why. It allows you to run an implement with a couple hundred dollars or lots less worth of hardware, instead of the many hundreds they charge for a PTO mount pump. And with less hassle than mounting an engine driven pump.

Personally, I'd be looking at the places like the Surplus Center, or ebay, (search Snow Blower Drive shaft Kubota Mid Mount PTO, as an eg) for a direct fit coupling for the mid mount PTO. If there are implements out there that run it, then there will be someone supplying spares. The A&I website is a good place to look.

Once you have a coupling, you can build up a PTO shaft as you see fit, matching cross bearing dimensions as you follow along the line.

Click to expand...

So the op is going to build a 6-7’ long driveshaft, which will require 3-4 u-joints, 1-2 carrier bearings, plus balancing, for a couple hundred bucks? Lots of commonly available PTO pumps could be had for the same amount of money that he will have in it and a lot less time.

Ziggy2 said:

I suspect that you will ultimately need to use use an intermediate straight shaft in the middle and use appropriately short end shafts with a u-joint at each end. The intermediate shaft will need to be mounted to the tractor with a bearing at each end.

This approach will keep most of the loads reasonable and allow for a smaller shaft dia.

Click to expand...

Ziggy2 said:

You need to do exactly what Kubota does then. They have already done what you are asking us to help solve.

Kubota is also likely using V-belts for transmitting power and speed reduction from the drive shaft to the snowblower. The V-belts do add a significant amount of load shock absorption.

You will either need to use V-belts for a speed reduction to the hydraulic pump if you use a pto version or else directly couple the pump to the driveshaft.

Not sure what you are trying to accomplish with mounting the hydraulic pump at the end of a 7ft. shaft that turns 2000rpm.

Mounting a pump designed for 2000rpm directly to the mid pto shaft seems a lot simpler and better.

Click to expand...

The pumps I am looking at are all 2000 rpm. The main reason for mounting at the front is accessibility. This way the pump and the equipment it is driving are all together and can be mounted or removed with a couple bolts and the quick attach on the loader. The pump would be exposed underneath during other tasks in the woods if left there, or it would be a PITA to remove and install. Essentially I want to extend the Mid PTO to the front.

Here is a look at how Kubota does it on their subframe for driving a snowblower:

View attachment 308532

The left end of #4 fits the PTO. The right end of #1 drives the snowblower The bearings #2 are attached to the subframe. I was thinking about making a mid support that would be attached to the tractor to mount the bearings, and based on your comments, having that intermediate shaft sounds like a very good idea, so I will retain that. This is direct drive on the snowblower and will be direct drive for my pump which is rated at 2000 rpm, matching the PTO.

Here is the subframe assy. Different call out numbers in this diagram from above but same parts.

View attachment 308533

So that gives me a solid idea (and the reasoning why) on how to support and make the drive shaft assembly. Thanks!

Joe21 said:

Depending on the age of your tractor there are two different yokes.

For some reason I can't post any links... but look up Messick's (Kubota 70060-01250) or Weasler #: 105-0610 as sources for the yokes.

Click to expand...

Thank you for that! I talked with a guy at PaulBParts regarding that Weasler part # but he could not tell me if it matched this PTO or not. Now that I have confirmation on that, the PTO end is covered. I have talked to Messicks as well and may end up getting some parts from them if it makes more sense, but that shaft assembly only really helps on the PTO end, and I still need the pump end. They sent me the diagrams above.

Twraska said:

Why re-invent the wheel? There are hydraulic pumps readily available that mount on the rear shaft. Not that expensive and come in different sizes.

Click to expand...

Yes it would be easier in many cases. Now where's the fun in that? But seriously, as I noted above, I have other equipment on the 3 point hitch that would be in the way, so it is not a viable option in this case.

trevj Personally, I'd be looking at the places like the Surplus Center, or ebay, (search Snow Blower Drive shaft Kubota Mid Mount PTO, as an eg) for a direct fit coupling for the mid mount PTO. If there are implements out there that run it, then there will be someone supplying spares. The A&I website is a good place to look.

Once you have a coupling, you can build up a PTO shaft as you see fit, matching cross bearing dimensions as you follow along the line.

Click to expand...

You are describing what I am trying to do. Surplus Center is where I am sourcing the pump, but I am not finding PTO parts in their site that work.

So now it looks like all I need is a source for something (an adapter?) to mate to the spline on the pump. Where can I find Spline shaft components/adapters that will work? My internet searching has not been very fruitful on this, but I am guessing someone here knows a source or sources.

Thank you for all your help, and I hope everyone has a Merry Christmas and happy new year!
-Dave

Ok, interference issues does change the way to fix it up. Question,,,,, would a crankshaft driven pump work? The reason I’m so against the mid PTO is,,,, I foresee grass wrapped around the ujoints and/or the driveline damaged from a hidden obstacle.

"Where can I find Spline shaft components/adapters that will work?"

G&G Manufacturing Company - Adaptors

Twraska said:

Ok, interference issues does change the way to fix it up. Question,,,,, would a crankshaft driven pump work? The reason I’m so against the mid PTO is,,,, I foresee grass wrapped around the ujoints and/or the driveline damaged from a hidden obstacle.

Click to expand...

The radiator, AC condenser and hydraulic cooler plus the battery are all in the way in front of the engine. I think that would be even harder to do than using the mid PTO. I have been thinking about shielding the drive shaft in some manner for safety and to prevent grass and weeds getting all wrapped up as you say, but that will have to come later once I get the bulk of the engineering sorted out on this. Maybe plastic pipe or sheet metal. Dunno yet.

Twraska said:

So the op is going to build a 6-7’ long driveshaft, which will require 3-4 u-joints, 1-2 carrier bearings, plus balancing, for a couple hundred bucks? Lots of commonly available PTO pumps could be had for the same amount of money that he will have in it and a lot less time.

Click to expand...

That depends pretty much entirely what the OP has on hand, as far as a farm collection of 'maybe useful' stuff!

If he lives near a U-pick auto wrecker yard, even easier and cheaper, as I figure a drive line off a small rear drive pickup truck would likely do him very well.

I have run across websites while searching for oddball PTO shaft components, that had pretty easy to follow lists and catalog pages, showing the different styles and HP rated sizes of PTO ends, bearings, and the like. Can I tell you what they were? Not off the top of my head, but I can tell you that some digging around is pretty liable to find them.
hydraulic pump drive yoke ends - Google Search

1000 SERIES - 1 1/4" X 5/16"kw PTO PUMP AND ACCESSORY DRIVE SHAFT ASSEMBLY - 1.25" X 5/16"kw ROUND SHAFT 1000 SERIES PTO PUMP SHAFT - COMPLETE 2pc 1000 SERIES PTO SHAFT WITH CENTER SUPPORT PILLOW BLOCK - PN# st1000-2PC/1.25" - Fort Wayne Clutch & Driveline

These two are from a real quickie search. Learn to use the correct names for the parts you are after, it gets easier to make the search engine work for ya!

Type (1 X 10 spline pto adapter" into your search engine, and look around.

That configuration is pretty much Kubota exclusive. I bought a pto yolk when I built a front mount blower drive.

The front pto assemblies (post #15) show up on the used market from time to time, as the blowers get torn up, or separated from the tractor during resale. If you can get one at a good price (used market prices can be all over the place, from a couple a hundred to near $2k) Get one! The are the best way to go.