Wish we had a clutch....

[MossRoad]

As many/most PT owners in cold weather areas know, our three hydraulic pumps are directly connected to our engines, and cranking them over, both gas and diesel, in cold weather can be, um.... hard! :laughing:

We've been pondering why there's no clutch(es) to disconnect the pumps for easier starting of the engines?

Anyhow, I have no plans to do this, so it's just food for thought.

I am more familiar with the electric clutches on mowers that engage/disengage the belt pulley from the PTO shaft. These types of clutches would not work for our applications.

While going through one of my Kohler manuals, I came across a mechanical PTO clutch diagram. See screenshot.




Anyone familiar with these types of clutches, and if they are even made anymore? Are these just for belt driven implements, or could it power a shaft driven pump?

 

[BobRip]

I can certainly see the advantages of a clutch. The screen shot was not very readable on my phone. I will try the computer.

 

[Marks481]

While going through one of my Kohler manuals, I came across a mechanical PTO clutch diagram. See screenshot.

No problem. Just weld a 12" extension onto the engine compartment and you can shoehorn that baby right in.

Of course, since you have pumps on front and back of your engine...

 

[BobRip]

OK, the drawing looks good with my computer. You could do what I did and have an attached garage with R50 insulation in the wall and R55 in the attic. Never gets below 60 (well rarely).

 

[/pine]

Compression release maybe??

 

[MossRoad]

OK, the drawing looks good with my computer. You could do what I did and have an attached garage with R50 insulation in the wall and R55 in the attic. Never gets below 60 (well rarely).

Don't get me wrong, I can start the Kohler to -5. It's just a huge strain on the engine and battery, etc... I'm fairly certain it would just POP right off if it didn't have that load. And it might help a lot of the folks that had the starting issues with the Robin engines.

It's an interesting thing to discuss, that's for sure.

 

[MossRoad]

Compression release maybe??

The starter would still have to push over all three pumps and the cold hydraulic oil. But that might take quite a load off.

 

[MossRoad]

I can't find any compression release for a CH25.

 

[Tractor Tech]

So, I will say right up front I'm not familiar with the Power Trac, but wouldn't it be easier to figure out a bypass at the pumps so that you're not trying to move oil through the whole system? Just asking

 

[MossRoad]

So, I will say right up front I'm not familiar with the Power Trac, but wouldn't it be easier to figure out a bypass at the pumps so that you're not trying to move oil through the whole system? Just asking

Well, that's a good question.... I'll give it my best shot.

When the treadle pedal is not pushed, the swash plate in the tram pump is neutral, so no oil is being pumped outside of that pump through the wheel motors at that point. However, hydraulic oil is still constantly being pulled from the tank, through the filter and then through the charge pump on the tram pump, then back to the tank.

Then we have the two other pumps.

One is for the main PTO pump.
The main PTO is bypassed from pump to tank and back to pump until the PTO diverter switch is turned on to divert the fluid out the hoses on the FEL arms. So that circuit is already about as short as it can be with very little resistance in the plumbing.

The other pump is for steering/lift/quick attach/AUX PTO.
That one goes from the pump to the steering valve, through the power beyond port on the steering valve, then to the 3 spool valve bank on the FEL/AUX PTO circuit, then back to the tank. So there's some resistance to flow in that circuit. But it's open center, so the steering valve and 3 spool valve are just open pipes until the valves are manually activated by the operator.

So, I think all of the resistance that we're pushing against with the starter is already about as bypassed as we can get.

Even though everything is pretty much bypassed, when it's cold, it's still like stirring a cold honey pot.

Disengaging the pump shaft(s) with a clutch would be where we'd get the most bang for freeing up the engine with no load.