2 hydro pumps vs 1 (Cub Cadet) vs (Kubota)

[quarencia]

Actually...Cub Cadet is Yanmar and Yanmar is Cub Cadet, at least for new tractors. They formed a Joint Venture called C.U.T. Supply. That was over two years ago. Link to press release

Looked up the SC2400 Yanmar/Cub Cadet to see what they say about the dual pumps. They have a gear pump operating at 3.6 GPM for PS, FEL, and 3p. The second pump is a trochoid pushing 3.5 GPM for PTO Clutch and HST charge. Didn't see pressure info, but trochoids are like automotive oil pumps. Can't see what this arrangement really does for you. If I recall correctly, trochoids aren't good for generating very high pressures. Perhaps there is an efficiency gain from using this pump. But I really don't see the advantage that an operator would ever notice. With the PS and work ports on the same circuit, there doesn't appear to be a big advantage. I suppose if you don't have to regulate the high pressure back down to lower pressure before it gets to PTO clutch and HST charge, you're removing a heat source from the loop, but the complexity of the second pump and plumbing seems to negate that advantage.

 

[Volfandt]

Looked up the SC2400 Yanmar/Cub Cadet to see what they say about the dual pumps. They have a gear pump operating at 3.6 GPM for PS, FEL, and 3p. The second pump is a trochoid pushing 3.5 GPM for PTO Clutch and HST charge. Didn't see pressure info, but trochoids are like automotive oil pumps. Can't see what this arrangement really does for you.

quarencia, I cut your quote down to save space otherwise it's unaltered and I totally agree with you.

The BX's use a priority valve to "split" the implements hydraulic pump output between the PS and the rest of the implement controls. In this way even when the FEL or 3ph is lifting a max load there is still some hydraulic power available for the PS to function. In a tractor the size of a SCUT this is perfectly acceptable. I personally have only run into one occasion where the PS seemed to be temporarily robbed of power when I was doing some very strenuos FEL work leveling a gravel driveway but it was only for a sec or so and it didn;t detract from the work.

With the info provided by quarencia, it appears that the Cub/Yanmar has to use a similar priority valve type setup. and if so theres no advantage.......

Marketing can be an amazing thing

 

[LBrown59]

It would take more than an extra pump to make a CC superior to a Kubota.

 

[N80]

I don't know anything about SCUT's and very little about the larger Kubotas with 2 pumps, but I do have a 45 HP CUT with one pump. There has never been any evidence or symptom of a problem related to that pump also running the power steering. There have been times when a larger GPM pump might be handy but that has nothing to do with how many pumps there are. So as far as I am concerned, any salesman that hyped any tractor because it had an additional pump, the first thing I'd ask was what was wrong with the first one!

But, as others have mentioned, as soon as it becomes market lingo, others will follow whether there is a benefit or not. As far as I am concerned, it just sounds like one more extra to pay for and one more thing to break.