Hydraulic Motor question

[mmurphy]

I was thinking hydraulic motor too much H.P...No use in over sizing. Dfkrug may be right on "so what if compressor stops a few seconds", but I would do a little more research on that. If compressor stops and starts on full pressure all the time is what I would be concerned about. Just my thoughts.

 

[Regal]

I was thinking hydraulic motor too much H.P... If compressor stops and starts on full pressure all the time is what I would be concerned about. Just my thoughts.

Ok I don't think that a few stops and starts with head pressure should be a big factor. As often as A/C units cycle on cars I doubt that pressure ever has much time to bleed off.

dfkrug
Thanks for the links. Hoses were exactly what I was thinking about on the way home from work. I was planning on cutting that line that wraps around the rear and welding fittings for hose attachment, but after seeing photos of how you did it, I may not sacrifice that hard line just in case I am forced to abandon my idea. I also had planned on soft connections with hard lines up into rooftop, but I think now I might do it all with hoses.
Several ones here have stated that the 3pt will be the last served in this scenario. I thought that hard line was coming from the pump to the loader valve, but in your photos it appears as that it is coming from the valve. Correct? I guess it doesn't really matter so long as fluid is moving constantly. (With minor interruptions that is)
Thanks for help and advise.
Rick

 

[SPYDERLK]

I think you touched on the main problem with his idea...The motor will always be robbing power from the hydraulic system. The limited flow of the pump will be fully realized I think trying to raise the loader, curling the bucket AND running the motor.

The Power Beyond line that is at the rear of the tractor (runs over top the PTO-under the seat) is after the FEL valve and before the 3PH.

If the motor isnt loaded it will take very little pressure to spin it.
larry

 

[wdchyd]

The ONLY way I can even believe this would work is with a Priority Valve plumbed in just after the pump that would "dedicate" a portion of the flow to the motor with the rest going to the stock system. Plumbing that in would require cutting into the steel lines under the tractor.

Just not as good option IMHO.

That being said, the other requirement with a hyd motor with down stream pressure needs to have an external case drain port plumbed unrestricted back to tank to relieve back pressure on shaft seal (This is used typically on several motors running in series)....also a priority valve will solve a dilema of too many rpms (can be tuned at max rpms)

wdchyd

 

[dfkrug]

I don't think that a few stops and starts with head pressure should be a big factor. As often as A/C units cycle on cars I doubt that pressure ever has much time to bleed off.

Exactly. A car's A/C uses an electric clutch, and it goes on and off
often and suddenly. I assume you will use such a compressor, too, as
you don't want to waste power running the compressor when not
needed.

The 3-pt cyl is always last in the series (or bypassed entirely) because
it's valve has no power beyond. The hoses you saw are between the
PB of the aux valve and the IN of the 3-pt cyl.

As for case drains in hyd motors, it is true that if your back pressure
on the OUT port is greater than 500psi, a case drain is called for. But
you will likely operate your 3-pt cyl for only a second or so, so you are
probably OK without one, IMO.

 

[Regal]

I'm really grateful for all the responses here.

dfkrug
I was just looking things over again and I notice 2 ports on the left side under the rocker shaft just above the aluminum axle housings. Are these pressure ports? Did this just become a no brainer, that I can pull off one of these ports and dump back into the large return plug on the right side of the top link mount??????? If so,this would give me a dedicated source and I could incorporate a ball valve to shut it down during off season. Pleeeese tell me it's so!!!!!
I'll understand if you have to bust my bubble. It couldn't be that simple I suppose.
I am really getting excited to test this whole thing out. I just need to find some $$$$.
Yes, my whole A/C unit will operate exactly like any other auto A/C unit with pressure switches, e.t.c. cycling the system.

 

[mmurphy]

Yes, my whole A/C unit will operate exactly like any other auto A/C unit with pressure switches, e.t.c. cycling the system.[/QUOTE]

I hope it works for you.

 

[kennyd]

I'm really grateful for all the responses here.

dfkrug
I was just looking things over again and I notice 2 ports on the left side under the rocker shaft just above the aluminum axle housings. Are these pressure ports? Did this just become a no brainer, that I can pull off one of these ports and dump back into the large return plug on the right side of the top link mount??????? If so,this would give me a dedicated source and I could incorporate a ball valve to shut it down during off season. Pleeeese tell me it's so!!!!!

No, they are not pressure ports.

 

[Regal]

Well that's not what I wanted to hear first thing this morning. Thanks Kenny

 

[dfkrug]

I was just looking things over again and I notice 2 ports on the left side under the rocker shaft just above the aluminum axle housings.

These are two of the three low pressure hyd return ports on the tractor.
As I said earlier, there are only 2 places to access pressure from the hyd
pump: the hardline from the pump to the AUX valves (triple SCV) that
runs under the left floorboard, and the one from the SCV to the 3-pt
valve.