Is it possible to increase flow of Sundstrand?

[Bolens]

Hello
Is it possible to increase the flow of a Sundstrand 15 hydrostatic transmission from 2.5-3 GPM to 4 GPM?

I have a Bolens HT20 and was wondering if I can increase the on board hydraulics to accomodate a loader.

 

[J_J]

I believe the only way to get more volume is to increase displacement, or increase pump rpm.

 

[wdchyd]

IIRC the series 15 hydrostat on bolens uses the charge pump for aux......this makes for pi$$ poor pressure out of the geroler section of that pump.....(I'm thinking max 850 to 1000 psi)......not very usefull for high pressure, but you'd need to increase the size of the cyls to do any work

Plus doesn't the Bolens use the transaxle housing for the reservoir??.......Yes/No??....it may limit how many cyls you need to power

 

[Bolens]

Thanks J.J.

Wdcyhd yes my Bolens uses the transaxle as a reservoir, it's capacity is 2.5 gallons.
I thought with the lower pressure I would require a smaller bore on the cylindars.

 

[wdchyd]

Actually you'd need larger bore to do the same equivalent amount of work (taking up more space too)

 

[J_J]

As far as bore size, it is not the bore size that determines the pressure. It is the resistance to pressure that determines the pressure and the pumps ability to accomplish the task.

On my Power-Trac, I have a loader that uses a fan belt driven 3 GPM pump at 3000 psi, and does very well as a loader.

The size of the cyl's will affect the speed of operation. The larger cyl will be slower, but will produce more power.

If you have a PTO, you can power a PTO pump based on the available HP. They run about $500

I tried to delete this post 5 times and as you can see, it is still here.

 

[J_J]

As far as bore size, it is not the bore size that determines the pressure. It is the resistance to pressure that determines the pressure and the pumps ability to accomplish the task.

On my Power-Trac, I have a loader that uses a fan belt driven 3 GPM pump at 3000 psi, and does very well as a loader.

The size of the cyl's will affect the speed of operation. The larger cyl will be slower, but will produce more power.

If you have a PTO, you can power a PTO pump based on the available HP. They run about $500

If the 20 in the HT20 model number is the HP, then you have the capability to run a hyd pump that will pump 9.5 GPM's at 3000 psi.

 

[Bolens]

As far as bore size, it is not the bore size that determines the pressure. It is the resistance to pressure that determines the pressure and the pumps ability to accomplish the task.

On my Power-Trac, I have a loader that uses a fan belt driven 3 GPM pump at 3000 psi, and does very well as a loader.

The size of the cyl's will affect the speed of operation. The larger cyl will be slower, but will produce more power.

If you have a PTO, you can power a PTO pump based on the available HP. They run about $500

If the 20 in the HT20 model number is the HP, then you have the capability to run a hyd pump that will pump 9.5 GPM's at 3000 psi.

Yes the 20 is HP. I would like to use 2" bore cylinders x 4. I've read that 1500psi is sufficient so a 4.5-5 GPM pump?
How many gallons in a separate reservoir would be necessary?

 

[J_J]

Once all the cyl are full, you will need tank capacity equal to pump flow.

It depends on what you think is sufficient. More pressure equal more power, more load.

The PTO pumps are rated 2000 to 2250 psi, and the cyl are probably rated to 2500 to 3000 psi.

This pump will pump 7.1 GPM at 2000 psi, using 11.9 HP.

Surplus Center - 3.6 CU IN PRINCE HC-PTO-7A PTO PUMP 540 RPM