wdchyd
Elite Member
That's the right way to do it as the pump doesn't have a relief
Old two spool control valve (very slow)
- Thread starter nsmithnd
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J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
- Location
- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
Can't see the engine, but my hyd pump for the loader is run off the fan belt on my engine.
If you are running a pump off the shaft of the engine, that would be hard to do, but if your pump is belt driven, then maybe a double belt could drive a separate pump for all the hyd except the hydrostatic transmission.
My 3 gal pump only takes about 6 HP to pump 3 GPM at 3000 psi, and with that, you can do a lot.
That pump only cost about $120
If you are running a pump off the shaft of the engine, that would be hard to do, but if your pump is belt driven, then maybe a double belt could drive a separate pump for all the hyd except the hydrostatic transmission.
My 3 gal pump only takes about 6 HP to pump 3 GPM at 3000 psi, and with that, you can do a lot.
That pump only cost about $120
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wdchyd
Elite Member
That's a great modification JJ
the only thing to watch with some smaller pumps is they don't like the side load when pulley/gear/sprocket driven......it all depends on what they use for bearings in the front of the pump....
IIRC the haldex uses needle roller bearings
the only thing to watch with some smaller pumps is they don't like the side load when pulley/gear/sprocket driven......it all depends on what they use for bearings in the front of the pump....
IIRC the haldex uses needle roller bearings
OP
nsmithnd
Silver Member
Finally got back to the Bolens. Used the calculator on the web-site below to verify approximately 2 GPM (full throttle) by timing the stock 2" bore x 6" stroke x 1" shaft dual-acting cylinders through the stock control valves (approx 2.4 seconds to extend the dual-acting cylinders).
Hydraulic Cylinder Speed Calculator
Then I re-configured the hoses so I could operate the single-acting cylinders through one of the stock control valves. Speed was the same as it was through the dual spool control valve (5.5 seconds to extend) so I'm assuming the dual spool is fine.
Plugged the 2.25" bore x 5-11/16" stroke x 1.5" shaft into the calculator and it shows that the single-acting cylinder speed should be 3 seconds to extend. When I time it, I'm getting 5.5 seconds to extend the cylinders.
Now I have to ask if the plumbing might be causing the 2.5 second discrepancy. The entire system is 3/8" steel tube and hoses, except for the 1/4" quick disconnects (and the two hoses from the QD's to the single-acting cylinders). Would this be my problem?
Thanks
-Neil
Hydraulic Cylinder Speed Calculator
Then I re-configured the hoses so I could operate the single-acting cylinders through one of the stock control valves. Speed was the same as it was through the dual spool control valve (5.5 seconds to extend) so I'm assuming the dual spool is fine.
Plugged the 2.25" bore x 5-11/16" stroke x 1.5" shaft into the calculator and it shows that the single-acting cylinder speed should be 3 seconds to extend. When I time it, I'm getting 5.5 seconds to extend the cylinders.
Now I have to ask if the plumbing might be causing the 2.5 second discrepancy. The entire system is 3/8" steel tube and hoses, except for the 1/4" quick disconnects (and the two hoses from the QD's to the single-acting cylinders). Would this be my problem?
Thanks
-Neil
