Over Running Couplers

[rich_ncal]

Any suggestions on over running clutches?

Agri-supply has two types. The over running clutch costs about twice as much as the over running coupler.

Any experience with these two? Do both last as long? Except for the time to remove and install do both perform the same?

http://www.agri-supply.com/pdfs/ASC238C20-25.pdf

 

[Inspector507]

They perform the same, but I had the 31949.........quick release /forums/images/graemlins/grin.gif
Easy on, easy off

 

[AlanB]

I am not positive reading your post, but I believe you mean,

Slip Clutch and over running clutch.

There are also two types of mounts (there may actually be more) for the over running clutches that I am familiar with, one mounts with a roll pin and one mounts with a spring type quick release pin.

A slip clutch prevents damage to equipment and driveline, when the unstoppable force, (your bushhog) meets the immovable object, (Uhhh, lets say a 1" steel pin buried in the ground) it is the piece that gives. It acts in place of a shear bolt, but does not have to be replaced when it gets used.

The over running clutch prevents a bushhog or other heavy flywheel type device from back driving your tractor through the driveline if your tractor does not have this built in.

A note of caution that I never heard when buying the over running clutch is that they can only handle limited torque loads. They will not operate items that are high torque, such as a post hole digger, of course I found this out after mounting with a roll pin and had to change back!

So, my 2 cents is to buy the quick release one if you are looking at the over running clutch.

 

[DavidJ]

From the file you posted I saw the Slip Clutch and the over running coupler.

The slip clutch is as the name suggests. If you put too much torque on it, it slips. It's adjustable as to the amount of torque it takes to slip. It has no provisions for overrunning.

The overrunning coupler provides no provision for slip at high torque but prevents the implement from driving the PTO (as well as the tractor on single clutch non independent PTO's) when clutching the tractor.

The best of both worlds is an overrunning slip clutch. It takes care of both situations.

 

[AlanB]

The overrunning coupler provides no provision for slip at high torque but prevents the implement from driving the PTO (as well as the tractor on single clutch non independent PTO's) when clutching the tractor.

Hi David, I will kindly disagree, and this is the same information that I was told prior to my purchase of the overrunning clutch.


You will find that if you disassemble the common over running couplers available at TSC, Rural king, my local tractor place, and I bet the ones from Agri Supply shown, that there are ramps in both directions for the teeth on the over running coupler. It will not provide a positive, 100% lock in, in the forward direction. Those over running couplers will then "slip" if too much torque is applied to them.

Pull the outer snap ring and cover and you will see what I am referring too.

The signifigance of this, is that if you use a tractor as we do, that an over running coupler is reccomended on (New Holland 1925 HST) and you go between bush hogging and post hole digging often, you will need to remove the over running coupler to utilize the post hole digger.

If you chose to use the "pin on" type instead of the quick disconnect, you will then need to roll around under the tractor and drive out the roll pin to remove the coupler, and for me this was a task.

 

[Soundguy]

</font><font color="blue" class="small">( You will find that if you disassemble the common over running couplers available )</font>

Not disagreeing with you.. but My guess is that the different ORC's made by different manufacturers may not all function that way you describe.

I emailed a few of my buddies at ytmag where I hang out on the olf foord N board, and got this reply... certaintly didn't sound like any 'give' in his ORC if it twisted the spline off..

Soundguy

Here is my friends reply:

</font><font color="blue" class="small">( I don't know about that BUT,I bought a new Speeco 1 3/8" for my IH424 about a month ago,hit a small (maybe 3") stump while hoggin,and it sure DIDN'T slip, it put about 1/2 a spline twist in the ORC before my grade 2 shear bolt broke..I was not impressed,dang near $60 )</font>

 

[Soundguy]

I'm getting more replies with the same info.... no slippage.

I wonder. Could the units be machined to ratched either direction.. but be selected depending on how it was assembled? Like for a machine with a reverse pto?

Just wondering out loud...

Soundguy

 

[Soundguy]

Alan.. here's a question for you.. If these ORC's are built to slip in forward drive as you claim.. then how come we ORC users still shear bolts when we hit solid objects.. or blockages like sand mounds... doesn't seem to ring true here.

And if they do 'slip'.. like you claim.. then they are useless.. as they 'slip' at a point heavier than a shear pin... Therefore.. if the mower is designed to be protected by that force where that shear pin breaks.. then relying on the ORC to protect the mower is letting a higher than planned fore get thru to the gearbox ( and your tractor pto! ).

We need to get some manufacturers specs here... something doesn't sound correct. Come to think of it.. I've seen ORC's on round hay bailers... now if that isn't a load.. nothing is..

Soundguy

 

[rich_ncal]

Great information in the responses on overrunning couplers.

I was interested in the benefit of the pin install type or the quickly release type. Everyone favors the quick release type?

Would the pin through the PTO shaft in the pin install type coupler act as a shear pin?

I use a Howse 400 48" rotary cutter, with two blades spin freely on bolts connected to large spinning disk in the center. If I hit a rock or stump don't the blades just bounce back and spin around on the pivot points?

Any other responses to how well the units from Agri-supply hold up over time?

 

[Soundguy]

</font><font color="blue" class="small">( Would the pin through the PTO shaft in the pin install type coupler act as a shear pin?
)</font>

No.. a 'roll pin or dowell' is what pins the OR-coupler to the tractors pto shaft. A shear pin there would be useless as the splines are present.. all the splines would have to shear off.. and the shear pin too... wouldn't work too well.
Quick release is nice as you can slid it on and off with thumb pressure on the release button.. no need to remove grease zerks and plugs.. then use a drift and mallet to drive the roll pin out.

</font><font color="blue" class="small">( I use a Howse 400 48" rotary cutter, with two blades spin freely on bolts connected to large spinning disk in the center. If I hit a rock or stump don't the blades just bounce back and spin around on the pivot points? )</font>

Well.. yes.. the blades do pivot on the stump jumper.. that just helps 'clear' a obstruction.. the shock load when the blades hit is still present even if the blades can pivot...And you still need either shear or slip protection in the driveline though.

Soundguy