Remote Hydraulic PTO - MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information
Hydraulics From tractors to wood splitters, fluid power lives here.

 
LinkBack Thread Tools Display Modes
post #1 of 10 Old 09-11-2019, 04:58 PM Thread Starter
B2620
 
Join Date: Dec 2013
Location: MT
Posts: 10
Remote Hydraulic PTO

I have a situation where I need to operate PTO powered equipment that is detached from the back of the tractor. A very flexible work-a-round would be to have a PTO driven pump, a reservoir, two 20' hydraulic hoses, and a hydraulic motor with PTO spline.

Has anyone experimented with such an arrangement? If so, what components did you use and what kind of power/efficiency loss did you encounter?

2013 Kubota B2620 MMM FEL Snowblower Rototiller
Rfisher0049 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 Old 09-11-2019, 07:47 PM
Proud Member of the 1K Club
 
Join Date: Mar 2015
Location: Missouri
Posts: 1,325
What you planing doing about heat dissipation? Going to need a resevior some where with enough capacity to protect the pump.
Ariens93GT20 is offline  
post #3 of 10 Old 09-11-2019, 08:37 PM
2000 Posts and climbing!!!
 
Join Date: Oct 2009
Location: ON
Posts: 2,255
Re: Remote Hydraulic PTO

Yeah, its doable. What's yer budget? What do you want to drive? An auger? I just supplied a friend with a Prince PTO pump; has a spline that slides right on the 540 PTO shaft. He hasn't finished project.

Girls with large lawns like a guy with a really big deck!
Hydronerd is offline  
Sponsored Links
Advertisement
 
post #4 of 10 Old 09-13-2019, 12:17 PM Thread Starter
B2620
 
Join Date: Dec 2013
Location: MT
Posts: 10
Re: Remote Hydraulic PTO

Quote:
Originally Posted by Ariens93GT20 View Post
What you planing doing about heat dissipation? Going to need a resevior some where with enough capacity to protect the pump.
Yes. Definitely a reservoir - above and on the suction side of the pump. Return would go to the tank to ensure circulation.

2013 Kubota B2620 MMM FEL Snowblower Rototiller
Rfisher0049 is offline  
post #5 of 10 Old 09-13-2019, 12:38 PM Thread Starter
B2620
 
Join Date: Dec 2013
Location: MT
Posts: 10
Re: Remote Hydraulic PTO

Quote:
Originally Posted by Hydronerd View Post
Yeah, its doable. What's yer budget? What do you want to drive? An auger? I just supplied a friend with a Prince PTO pump; has a spline that slides right on the 540 PTO shaft. He hasn't finished project.
It would have to be universal. For instance, a stationary PTO driven generator, sawmill, and ultimately, to power front mounted PTO equipment without a front PTO. My prime target is a three point snowblower that would be mounted on the front; either with a fabricated front three point or on the loader. For only a single purpose, it would be costly. But for a remote PTO, with proper reactionary framework, it could be quite useful. A secondary purpose would be a portable hydraulic supply. Well, as portable as the SCUT. With a set of quick couplers, any hydraulic equipment could be powered by the pump and reservoir portion. A log splitter or processor with its own control valves would only require the connection of the two quick connectors. You would not have to mess with a temperamental small engine. You could run a back hoe on a tractor with either no hydraulics or with hydraulics with to small a volume. Any higher volume equipment, within the horsepower range available, could be run. The pump and reservoir could be mounted on a three point frame for versatility. I don't want to oversell the idea, because it has a large number of drawbacks.

2013 Kubota B2620 MMM FEL Snowblower Rototiller
Rfisher0049 is offline  
post #6 of 10 Old 09-14-2019, 03:23 AM
20,000 Posts & Climbing
 
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 21,217
Re: Remote Hydraulic PTO

Auxiliary Hydraulic system parameters:

- Horsepower available.

- Horsepower requirements of the various appliances to be driven.

- Available pump rpm. On a SCUT, direct driven by the engine (up to 2700 rpm), driven by the mid PTO (2000 rpm nominal), driven by the rear PTO (540 rpm nominal).

- Relief pressure requirement to match flow rate to horsepower production of the engine and/or need of the appliance.

- Flow rate to suit requirements of the various appliances. eg. A SCUT back hoe with its relatively small cylinders requires approximately 4.5 gpm while a large cylinder suitable for a log splitter will be very slow at the same flow rate.

- Fixed displacement pumps require engine speed adjustment to change the flow rate.

- Appliances that require reversing capability will require a spool valve in conjunction with a fixed displacement pump. eg. Post hole digger, bi-rotational tiller.

- Appliances cannot be simply plugged into a fixed displacement auxiliary hydraulic system that is operating. Such a system that is open center must, at all times when operating, have a clear passage for the fluid from the reservoir to the pump and back to the reservoir. Shutting off the engine or PTO may not always be a desirable option when connecting an appliance. It also requires an open center spool valve for the appliance and a method of breaking the continuous flow path of the system that is necessary when no appliance is connected.

- Reservoir size should be at least 1/4 the maximum pump flow rate, and a cooler may be required for high performance, continuous duty applications. eg. Snow blower, tiller.

Rather than a fixed displacement PTO pump, I suggest investigating a variable displacement piston pump similar to what used for the hydro in some GTs. They cost more than even a 540 rpm PTO pump, but the need for spool valves is decreased since flow rate and direction can be controlled at the pump without adjusting the engine speed. That makes for a much more flexible system more in line with your suggested uses than can be achieved with a fixed displacement pump. Remember the comment about the back hoe and log splitter above? Engine speed for the splitter would be max and for the hoe, about 900 rpm. A variable displacement pump can do both at a fuel efficient engine speed with only a little speed reduction for the splitter cylinder and without lugging the engine when used with a hoe.

The splitter cylinder would require a suitable spool valve, the hoe has its own valves, the snow blower, tiller, and post hole digger hydraulic motors do not. Speed and direction of those appliances is controlled by the variable pump delivery.

Bob

Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.

Last edited by TUDOR; 09-14-2019 at 03:35 AM.
TUDOR is online now  
post #7 of 10 Old 09-15-2019, 06:01 PM Thread Starter
B2620
 
Join Date: Dec 2013
Location: MT
Posts: 10
Re: Remote Hydraulic PTO

Quote:
Originally Posted by TUDOR View Post
Auxiliary Hydraulic system parameters:

- Horsepower available.

- Horsepower requirements of the various appliances to be driven.

- Available pump rpm. On a SCUT, direct driven by the engine (up to 2700 rpm), driven by the mid PTO (2000 rpm nominal), driven by the rear PTO (540 rpm nominal).

- Relief pressure requirement to match flow rate to horsepower production of the engine and/or need of the appliance.

- Flow rate to suit requirements of the various appliances. eg. A SCUT back hoe with its relatively small cylinders requires approximately 4.5 gpm while a large cylinder suitable for a log splitter will be very slow at the same flow rate.

- Fixed displacement pumps require engine speed adjustment to change the flow rate.

- Appliances that require reversing capability will require a spool valve in conjunction with a fixed displacement pump. eg. Post hole digger, bi-rotational tiller.

- Appliances cannot be simply plugged into a fixed displacement auxiliary hydraulic system that is operating. Such a system that is open center must, at all times when operating, have a clear passage for the fluid from the reservoir to the pump and back to the reservoir. Shutting off the engine or PTO may not always be a desirable option when connecting an appliance. It also requires an open center spool valve for the appliance and a method of breaking the continuous flow path of the system that is necessary when no appliance is connected.

- Reservoir size should be at least 1/4 the maximum pump flow rate, and a cooler may be required for high performance, continuous duty applications. eg. Snow blower, tiller.

Rather than a fixed displacement PTO pump, I suggest investigating a variable displacement piston pump similar to what used for the hydro in some GTs. They cost more than even a 540 rpm PTO pump, but the need for spool valves is decreased since flow rate and direction can be controlled at the pump without adjusting the engine speed. That makes for a much more flexible system more in line with your suggested uses than can be achieved with a fixed displacement pump. Remember the comment about the back hoe and log splitter above? Engine speed for the splitter would be max and for the hoe, about 900 rpm. A variable displacement pump can do both at a fuel efficient engine speed with only a little speed reduction for the splitter cylinder and without lugging the engine when used with a hoe.

The splitter cylinder would require a suitable spool valve, the hoe has its own valves, the snow blower, tiller, and post hole digger hydraulic motors do not. Speed and direction of those appliances is controlled by the variable pump delivery.
Thank you for your reply. You list a number of important considerations. However, a number of them are beyond the scope of this project. Ideally, this system would include a PTO driven pump which supplies hydraulic fluid to an appropriately sized hydraulic motor with the same size PTO spline. The return line would go into a hydraulic oil reservoir through a filter.

There will be no variable displacement pumps or motors. The output speed would be controlled exclusively by the RPM of the tractor PTO. 540 in = 540 out. 300 in + 300 out. Assuming an efficiency of 100%. There will be no control valves. There are not many PTOs that are reversible. This one would not be reversible. SCUTs typically range in horsepower from 15 to 30.

If the pump was in fact sized to work with an additional "appliance" that would be a plus. And yes, the appliance would have to include its own control valve unless it was a continuous run device. For instance, a vibratory shoe or hydraulic driver. In that case, the operation of the tractor PTO would control the speed and operation of the device.

The original design of this is to be nothing more than a remote PTO. Anything beyond that would be a bonus.

2013 Kubota B2620 MMM FEL Snowblower Rototiller
Rfisher0049 is offline  
post #8 of 10 Old 09-15-2019, 09:29 PM
20,000 Posts & Climbing
 
Join Date: Jun 2009
Location: Sault Ste Marie, Ontario
Posts: 21,217
Re: Remote Hydraulic PTO

Quote:
I have a situation where I need to operate PTO powered equipment that is detached from the back of the tractor. A very flexible work-a-round would be to have a PTO driven pump, a reservoir, two 20' hydraulic hoses, and a hydraulic motor with PTO spline.
Quote:
It would have to be universal. For instance, a stationary PTO driven generator, sawmill, and ultimately, to power front mounted PTO equipment without a front PTO. My prime target is a three point snowblower that would be mounted on the front; either with a fabricated front three point or on the loader. For only a single purpose, it would be costly. But for a remote PTO, with proper reactionary framework, it could be quite useful. A secondary purpose would be a portable hydraulic supply. Well, as portable as the SCUT. With a set of quick couplers, any hydraulic equipment could be powered by the pump and reservoir portion. A log splitter or processor with its own control valves would only require the connection of the two quick connectors. ... You could run a back hoe on a tractor with either no hydraulics or with hydraulics with to small a volume.
The use of hydraulics allows flexibility for end purposes, but with an accompanying loss of power for the pump and motor efficiencies that can combine from as little as 20% to over 40%. That power loss is due to the loss of fluid under pressure through the clearances between individual parts that are necessary to allow them to move in relation to each other and to supply lubrication to those same parts.

The power loss manifests itself as heat generation, even under no load conditions, and increases in lock step with an increase in load. It also manifests as noise from almost silent under no load to a quite load whine when under high load. I worked in maintenance in a steel mill where even 3 or 4 10 hp pumps would generate enough heat to warm a 12'x20' concrete room to 100+į, and which was also a hearing protection zone.

For some of your stated applications, a drive shaft would be simpler and less costly. For others, my concern was for efficiency. A piston pump (90%) is more efficient than a gear pump (75-80%) and variable displacement allows adjustment to flow rates independent of throttle position for some of the other stated applications.

Your idea is good. I have a small auxiliary system on my GT for the loader and log splitter. But it can get to be quite expensive in both cost and efficiency if care isn't used for the selection of components that can handle all of the appliances that you mentioned.

BTW, you can drive a 3PH snow blower on the front of the tractor with the rear PTO. You just need a reverser to change the direction of the drive shaft rotation.

Bob

Click for The Hydraulics Forum!

Sometimes you get on a roll, sometimes the roll gets on you.

In Service
MF GC2310, Husqvarna YTH20B42T

Down for Repairs
MF1655 w/ FEL, MF1655, MF12H, MF8H, MF7H
Spending too much time on MTF to work on my toys.

Last edited by TUDOR; 09-15-2019 at 09:42 PM.
TUDOR is online now  
post #9 of 10 Old 09-15-2019, 10:21 PM
2000 Posts and climbing!!!
 
Join Date: Oct 2009
Location: ON
Posts: 2,255
Re: Remote Hydraulic PTO

It will work, but you will need to anticipate a little loss in HP. At 550 rpm, G-roto type motors are well suited, they have good bearings and heavy shafts; but, unfortunately, poor efficiency. Still, they are likely the most popular motor, and therefore easiest to find at a good price. If you go this route, find a pump 125% larger than the motor. If you use a high speed gear motor directly coupled to the blower shaft, then you need a pump 110-115% bigger.

I wouldn't recommend a PTO pump, though, I don't know the efficiency of that style gear pump. Industrial hydraulics is moving towards variable speed electric motors. I have seen servo drive gear pumps working at near zero rpm. These pumps are high precision gear pumps and cost more than some variable piston pumps at the same displacement.

You likely have a high speed PTO or a gear to shift from 550 to high speed (2000rpm), I suggest using that with either a gear or a piston pump. There are often pintle control piston pumps on e-bay. Using the higher speed, improves efficiency and reduces the size/cost of the pump.

Girls with large lawns like a guy with a really big deck!
Hydronerd is offline  
post #10 of 10 Old 09-16-2019, 09:39 AM
2000 Posts and climbing!!!
 
Join Date: Oct 2009
Location: ON
Posts: 2,255
Re: Remote Hydraulic PTO

Some simple math;

30HP=15gpm * 3000psi
With pump connected to 2100pto, 15gpm=(15gpm*231cu-in)cu-in/min / 2100pto-rpm=1.65cu-in per rev pump
Typical blower speed 2100 rpm, therefore gear Motor =1.65 x 0.91=1.5 cu-in
If you use g-rotor motor for 550 rpm, Motor=(2100/550)*1.65cu-in x 0.8=5.04cu-in
However, instead of getting a smaller motor, increase engine speed from 2100 to 2310 or 2520 would provide desired output speed.

Girls with large lawns like a guy with a really big deck!
Hydronerd is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the MyTractorForum.com - The Friendliest Tractor Forum and Best Place for Tractor Information forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome