J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
- Location
- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
'KentT said:JJ,
First of all, it is a variable displace tram pump, not a fixed displacement pump.
Second, it isn't "something for nothing" -- it is trading off speed for torque, a common calculation and "balancing act" done in hydraulic systems, whether it be motor speed or reaction time of a hydraulic cylinder.
Third, the White wheel motors are rated for 3000 PSI, twice what they appear to be running now...
I'm not sure what the tram pump is rated for... nor am I sure how well the wheel motors will stand up at that pressure AND the wheels reversed.
But, as long as I don't damage the tram pump, I have little to lose -- because the only alternative I see for making the PT-425 useful for me is to replace those wheel motors with higher torque ones anyway...
I also find it interesting that you weren't a naysayer when Stray was originally discussing his mod:
http://www.tractorbynet.com/forums/power-trac/69056-two-speed-modification-pt-422-a.html
You know that I know that the tram pump is a variable displacement pump. The other pump was an example. You keep talking about pressure, that is a non issue. The pressure is what it is, whether it is in series or parallel. I have looked at variable displacement hyd pumps, and some of them run in the 3000 to 3500 psi range. I see no reason why you would damage your tram pump, unless pieces of o-rings, or pieces of metal, or just dirt from opening up the hydraulic lines. You know that the tram pump is the only pump that gets filtered before the fluid gets to the pump. The rest of the pumps draw fluid from the tank. If you want more torque, you increase displacement, which in turn will lower rpm, and therefore overall speed. As for Stray's project, he did not mention anything about changing pressure. You do have another option, and that is two speed motors. I don't feel that I have mis-stated anything that I have said. I have 33 years of being wrong 50% of the time, but that also means that I have 33 years of being right 50%of the time. I hope you figure out, if that project is feasible. I am wiling to help, just ask.