Independent Pto and use of external ORC

[JC-jetro]

Howdy and a good morning to all,

I'd like to bounce a question off of you guys. Please indulge me with your opinions.

Here a situation, consider having a tractor with independent PTO along with a wet clutch pack ,PTO brake and a switch operated electro-hydtaulic pto clutch activation mechanism

Has anyone ever considered to use an external ORC to minimize the the shock load to the brakes when suddenly pto in turned off and the PTO brake automatically applies. In general solenoid is a quick acting valve and quick closing can cause a shock load on hyd( not too worried about it because of relief mechanism built in) but the brake might get a good whip lash if you're running a heavy rotary cutter. It looks too me adding an external orc might minimize the wear on the PTO brake.


Any opinions?


Thanks,
JC,

 

[jinman]

JC, I'd have plenty of spare shearpins available until you find the sweet spot for engaging the PTO. You may find that a low rpm just above idle is best. It's a balance between lugging your engine and shocking the driveline. Any electro-hydraulic actuation should be metered so that there is not a sudden engagement, but rather a ramp of pressure that allows slippage. Some of the early electric PTOs had big shock loads, but I think tractors like Kubotas have that down to a decent level if the engine is not at high rpm.

When you disengage the PTO, just lower the engine rpm to idle first and let the clutch/brake take care of the rest.

On my New Holland, I have a lever that actuates the hydraulic valve for pressure to the clutch/brake. I feather the lever at low engine rpm so that the engagement is smooth. I also lower the rpm so that the cutter does not have a lot of momentum and is easy for the brake to stop. I have seen no deterioration in the clutch/brake operation on my tractor since new. It still seems to work perfectly.

 

[JC-jetro]

Thanks Jim,

I was thinking about the same as how to engage and disengage at a bit above the idle. The engagement switch for some of Kubotas are designed where you twist the pto switch against an internal spring to turn it on and then you can just hit it on top and switch will turn off by the action of spring. There is no physical shield to keep the pto from disengaging if some object fall on the switch. The pto switch is a mushroom switch, on the right of the operator next to lift control arm. I have to study the diagram to see if there is a ****** chamber, metering orifice or something to more slowly remove or add pressure to clutch cylinder.

I have to also look to see if there are any safeties to keep the clutch destroying itself if the solenoid is leaking oil by squeezing the clutch disks together while the brake is on.

Thanks,
JC,


Edit: I suppose rather see the rotary cutter continuing turning and dissipate the momentum rather than a shear pin and consequent torque transferred to PTO brake.

 

[TripleR]

We use an external ORC on our old Fords out of necessity and I prefer how quickly we can stop the blades on our tractors with independent PTOs with brakes.

 

[Jerry/MT]

I use an external ORC on our Ford 4610 to save the pto brake from excessive wear when I use our rotary cutter. I also always start the pto from low idle and shut the mower off from low idle.

 

[Soundguy]

I use an external ORC on our Ford 4610 to save the pto brake from excessive wear when I use our rotary cutter. I also always start the pto from low idle and shut the mower off from low idle.

exactly what I do. i have on eon my 5000 as well. it has a 10' mower and that's alot of force on a small band brake. orc solves that.

 

[JC-jetro]

Guys,

Thanks for the replies. I just can't see any negative impact if ORC is used where it can only help with the life of the PTO brakes.$60 for TSC ORC seems to be a cheap insurance. Again, I'm not talking about intentional shock loading and more of the accidental occurrence like you're running tractor at PTO rpm and running a heavy 7 ft brush hog and all of the sudden something falls on the switch, gets bumped and turns the pto off. Momentum of the blade got to go someplace, may be it shears the pin but why expose the brake to that force first.

JC,

 

[JC-jetro]

We use an external ORC on our old Fords out of necessity and I prefer how quickly we can stop the blades on our tractors with independent PTOs with brakes.

Is the PTO on your old ford transmission driven? do you have live (double clutch) pto? I suppose you do not have an internal ORC on the ford. My Ford 1700 does have internal ORC and transmission driven PTO.

 

[TripleR]

Is the PTO on your old ford transmission driven? do you have live (double clutch) pto? I suppose you do not have an internal ORC on the ford. My Ford 1700 does have internal ORC and transmission driven PTO.

It's transmission driven and if you don't put one on, the tractor will keep going until the implement stops, so a rotary cutter will drive you into trees, ditches etc.

Here are a couple of interesting threads:

http://www.tractorbynet.com/forums/owning-operating/22763-power-take-off-types.html

http://www.tractorbynet.com/forums/.../177989-disengage-pto-before-idling-down.html

 

[JC-jetro]

It's transmission driven and if you don't put one on, the tractor will keep going until the implement stops, so a rotary cutter will drive you into trees, ditches etc.

Thanks,

I do realize what happens with the momentum if you don't have ORC on transmission driven pto . There you have to do it as a necessity. My questions here is " what is a better practice? " to use or not to use external ORC in an independent pto system just for a brush hog. I suppose if you did not have ORC The torque can be directly go all the way to flywheel should one of the safeties such as Operator presence activate and kill the engine and the pto did not have a brake.

JC,


Second link was pretty good.

Just FYI, PTO switch on some kubota model, you turn the knob and it turns on, you hit it on top and by spring action it goes to it's normal off position. A plastic cover over the switch would keep the accidental pressing and Turing the pto off while mowing with a heavy brush hog.