Why do CUT manufacturers not install larger hydraulic pumps?

[tlm720]

When I bought my Deere 4120 one of the deciding factors was the capacity of the hydraulic pump compared to other brands. I see the new Deere 4 series have REDUCED the size of the pump. I have never found myself thinking, "Wow, this hydraulic pump is way too big." A 40 Hp engine will run a pump twice the size as what is normally on the tractors. To me it is about fuel savings. I don't want to run my tractor at 2500 rpms to use 20 Hp on my wood splitter or backhoe just to reduce the cycle times. Put a bigger pump on the tractors and let me throttle back to 1800 or 2000 Rpms, save some fuel, make less noise, and put less wear on my engine. It can't cost much more to put on a bigger pump and I'll gladly pay the the difference because I'll save it back in fuel or time. No different than the epto.

Am I the only one to feel this way?

 

[J_J]

There should be enough HP to run the tractor and enough HP to run the hyd pump or pumps.

Plus a little extra.


If you have a 10 GPM pump and 2500 psi limit, then you are using about 17 HP.

 

[tlm720]

A 40+ Hp tractor still has plenty of power to run a larger capacity pump. Industrial equipment of the same size have much more hydraulic capacity. Look at the 110 TLB for example. Just because I can use more hp through the hydraulics doesn't mean I have to. I just can't see any advantage to the small pumps that are used other than everyone trying to save a buck on the cost so they can compete on price.

 

[DK35vince]

My 35 HP tractor has very good cycle times for the loader and backhoe with the pump that's on it.
A much higher volume pump would simply suck up unnecessary power IMO.

 

[newbury]

There should be enough HP to run the tractor and enough HP to run the hyd pump or pumps.

Plus a little extra.


If you have a 10 GPM pump and 2500 psi limit, then you are using about 17 HP.

So would that mean on on my 51HP M4700 with a rated 9.2 GPM I'm using about 15.6HP just for the hydraulics? (numbers from Tractordat.com)

Just wondering.

 

[banjodunn]

So would that mean on on my 51HP M4700 with a rated 9.2 GPM I'm using about 15.6HP just for the hydraulics? (numbers from Tractordat.com)

Just wondering.

Yes when you are operating the pump to max capacity then that is about the hp you will need.

As to the OP the reason they don't offer bigger/ option purely comes down to cost, big companies do alot of market research ( so they tell us ) as to what the average machine in this category is doing / expected to do so they come up with a machine they can produce at the cheapest possible price. For them to offer a bigger pump then there would be all sorts of new designing/ testing and this would have to be added to the cost of the upgrade so your $400 dollar difference in the pump price gets blown out to a couple of grand including different pipes/fittings and fitting cost.

"fit it up on assembly" i hear you say, but they don't make units to order so how many do they make with the upgraded pump and have sitting in their holding yard? And when it comes down to the dealer ordering units for his stock display which ones does he buy? 2 or 3 units might not sound like alot extra if the dealer has 10 on the lot but he still has to sell them at that increased price or cut into their profits by selling at a dicounted price start doing that and they won't be round for long, the same thing happens when a newer model comes out.


Jon

 

[J_J]

Yes.

If you are running the engine wide open, then you are using the 15 HP when the hyd are doing work at 2500 psi.

At low idle doing work at 2 GPM, you might only be using 3 HP.

 

[k0ua]

Your the one that wants more hydraulic flow. I don't. And I don't want to pay for it. I have 10gpm, and it is more than enough to run all I want to run (loader, 3pt and grapple) I have WAY more than enough extra flow. Now on the other hand you need more.. Well you could reduce the bore size of your cylinder to increase speed with your given flow, but you probably don't want to do that as you would give up splitting pressure of the larger bore. So how about putting a PTO driven pump on your PTO and get more flow at a given pressure? Would that work for you?

 

[newbury]

What James wrote.
YOU put a $600 pump on your tractor without jacking up the prices on all tractors.

Prince PTO Tractor Pump — 23 GPM, Model# HC-PTO-3A | Hydraulic Pumps| Northern Tool + Equipment

 

[MHarryE]

Most, if not all, of the CUTs have open center hydraulics. The implement gear pump is pumping say 20 gpm all the time. Shift one valve for a circuit that uses only a small flow but requires a lot of pressure and all 20 gpm output of the pump will be at that pressure and consequently sucking a lot of power. It's also why they tend to use a double section pump, one section for steering with low displacement and a larger section for implement flow. The steering is almost always in use so the low flow circuit minimizes horsepower loss.