What would be the issue if you were to drive a motor directly off a hydraulic PTO pump and not use a control valve in the circuit? Would simply turning the PTO on and off be sufficient? Of course there would be relief valves, filters, and such just not a control valve.
Hydraulic motor without using control valve
- Thread starter dgarrett
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muddstopper
Veteran Member
Yes you can do it that way, I know of several situations where hydraulic motors are plumbed that way. Usually, the motors are low flow and pressure for cooling fans on oil coolers. I guess my next question is, why do you want to plumb your motor that way? I think just using a control valve with a relief already built in might be easier, and maybe just as cheap as buying a separate relief and plumbing it into the system. Not to even mention that every time you want to engage or disengage the pto to stop the motor, your not reaching down below the seat, or reaching over and around the fender, or having to walk to the other side of the tractor to reach the pto lever. Or swapping hoses in the event you need to reverse the direction of the motor.
J_J
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With a load on the motor, the engine might not start or run.
Another reason is safety. You would not want something running and you not be there to observe.
You can control the speed of the motor by varying the engine rpm.
If you overload the motor, you might blow the pump if no relief.
12 VDC 10 GPM OC MOTOR SPOOL SOLENOID VALVE
12 VDC 10 GPM OC MOTOR SPOOL SOLENOID VALVE
or
3/8 NPT HYD FLOW CONTROL VALVE W/RELIEF RDRS137-08
SPYDERLK
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Lower flow losses in transmitting the hyd power -- a good thing. ... The motor and its inertial load would try to drive the pto pump as it coasted down, which would in turn drive the pto stub. Usually no issue, but a cross over relief would allow you to incorporate safe limits if they are not inherent.
,,,, It could be an ideal solution for you.
larry
bigdeano
Platinum Member
That's the way my hydraulic tiller works on my garden tractor. It works fine. There are enough power losses without putting an unnecessary valve in the circuit.