Upsized Hydraulic Clyinders for Loaders

[mike69440]

I'm looking a my options to obtain exact fit interchangeable up sized hydraulic cylinders for my tractor's loaders.

These will have to be custom built due to port location, that they are metric sized, and have non standard weird piston stroke and retracted lengths, as well as having metric pin bores.
The replacement DA Hydraulic Cylinders need to be 3000 # welded cylinders.

I have my two tractors that primarily want to increase the curl force on the attachment (Bucket attachment) cylinders. I would not mind also boosting the Lift a bit also.

Attached ismy spreadsheet on the info for the OEM cylinders and the up-rated version, just as an example.

I'm making CAD models and details dimension prints also.

I have a few leads as to where I can source these, but want to first get an idea of the potetial quantity.

PM me if interested in doing a group buy or you just want a copy of the worksheet in Excel format.

 

[100 td]

Just remember you will slow your curl speed down by the corresponding volume change percentage. Boosting lift usually results in bending and failing arms as they are built with the cylinder as the limiting factor. Of course similar things can happen when increasing any cylinders..........

 

[mike69440]

Of course you can kill yourself or break your tractor. The Kubota TLB loaders are twice as stiff/strong as your average Ag Tractor.

Also if your stupid enough to pry with the edge of the bucket, you deserve what will probably happen.

My machine is ballasted over 8,000 Lbs, and I don't plan at trying to lift max capacity to max height.

I just want a small super strong machine that can take full bites out of wet hard piles of gravel really easy. The L39 does this better than most, but I want a bit more. It also has 11-1/2 GPM to the front loader dedicated pump, as it is upgraded from a farm tractor. Most Kubota's have fairly quick loader speed.
Note I have not gone nuts, as a bit of cylinder upsizing affects capacity a lot.

 

[repete]

When considering changes like these it is critical to analyze the load path to the ground. Yes, perhaps you can increase the lift potential with a larger diameter cylinder but that increases the load weight that is transferred through the lift arms, which are connected to the loader frame. From there the frame is connected to most likely the casting of the tractor which is supported by the front axle pivot arrangement. Next in line are the axle bearings and finally the tires (check the rating) before being supported ultimately by the dirt. Get quotes on all of these parts before you do more than perhaps the original design capability of the tractor.

 

[MtnViewRanch]

Why not just increase the PSI, much easier and zero $$$ spent.

 

[mike69440]

When considering changes like these it is critical to analyze the load path to the ground. Yes, perhaps you can increase the lift potential with a larger diameter cylinder but that increases the load weight that is transferred through the lift arms, which are connected to the loader frame. From there the frame is connected to most likely the casting of the tractor which is supported by the front axle pivot arrangement. Next in line are the axle bearings and finally the tires (check the rating) before being supported ultimately by the dirt. Get quotes on all of these parts before you do more than perhaps the original design capability of the tractor.

I am a mechanical engineer. Primarily my career has been designing industrial rotating equipment.

Been doing that for a living for 35 years.

I've had the L39 for 10 years so I am aware of it's capabilities and limitations.

L39 has integrated loader frame, 8 & 10 Ply tires upgraded from OEM 6, I'm running the safe max pressure relief of 2900 PSI

Only real weak point of a L39 is the Grand L front axle. I broke it once when I hit the L39 with my excavator. Just be reasonable when pushing into a pile and lifting, it is fine.

The Max28 is also capable of more than what it leaves the factory also.

I have a 600hp 03 Cobra, plus a lot of other experience of just how far you can push a design.

 

[repete]

I am a mechanical engineer. Primarily my career has been designing industrial rotating equipment.

Been doing that for a living for 35 years.

I've had the L39 for 10 years so I am aware of it's capabilities and limitations.

L39 has integrated loader frame, 8 & 10 Ply tires upgraded from OEM 6, I'm running the safe max pressure relief of 2900 PSI

Only real weak point of a L39 is the Grand L front axle. I broke it once when I hit the L39 with my excavator. Just be reasonable when pushing into a pile and lifting, it is fine.

The Max28 is also capable of more than what it leaves the factory also.

I have a 600hp 03 Cobra, plus a lot of other experience of just how far you can push a design.

Then you are golden as you have examined the situation . I have multiple tractors and multiple trucks and dump trucks and learned lessons the hard way (AKA, expensive way). I have found that many people see solutions to specific problems and fail to look at the total package. Just because it can lift it does not mean when you have a fully loaded bucket and hit a chuckhole in the driveway that everything will be fine.

 

[mike69440]

Then you are golden as you have examined the situation . I have multiple tractors and multiple trucks and dump trucks and learned lessons the hard way (AKA, expensive way). I have found that many people see solutions to specific problems and fail to look at the total package. Just because it can lift it does not mean when you have a fully loaded bucket and hit a chuckhole in the driveway that everything will be fine.

One thing that I think any serious piece of hydraulic equipment needs is an accumulator. I design my hydraulic fixtures with these, and have one on the L39.

The stick response has a 1/2 second delay, that I am very used to. However when you hit the chuck hole, the shock is quite a bit less.

 

[Baby Grand]

Just a suggestion if you decide to use an accumulator: try to design the system so that the accumulator automatically "unloads" when the system is shut down. You can really economize pump/motor size if you use one.

 

[mike69440]

Just a suggestion if you decide to use an accumulator: try to design the system so that the accumulator automatically "unloads" when the system is shut down. You can really economize pump/motor size if you use one.

Yes I agree however, I'm not using the Accumulator like you would in a large excavator., The one on the L39 has a 16 oz. working capacity just to reduce shock.
It's tucked away under the frame.

When the tractor was new I was robbing some gravel down the road, and while traveling back hit some potholes that caused such a pressure spike, ruined the quad seal rings on the main pump. It was covered under warrantee, as they may have not been installed correctly originally. I now drive slower and the tiny accumulator really helps.

 

[repete]

One thing that I think any serious piece of hydraulic equipment needs is an accumulator. I design my hydraulic fixtures with these, and have one on the L39.

The stick response has a 1/2 second delay, that I am very used to. However when you hit the chuck hole, the shock is quite a bit less.

Do you pressurize your accumulator with nitrogen? I believe that is what we used on our Mack Aerialscope ladder truck years ago.

 

[kcender]

Mike,have you looked at this http://www.tractorbynet.com/forums/...ing-kubota-super-l45.html?highlight=super+l45

 

[Luke'sScreenName]

Is NH Hydraulics building them?

 

[mike69440]

Mike,have you looked at this http://www.tractorbynet.com/forums/...ing-kubota-super-l45.html?highlight=super+l45

I've Posted to that thread actually.
Lauren may have his pressures set low, as mine were from the factory. If he has increased his lift capacity 50%, that is over 4000Lbs!. See the attached loader curve Lift graphs from my manual.
The OEM stock lift capacity IS quite a bit more at mid lift than full height. Plus 2 ton lift ability is too much for the L39/L45. Even Lauren's foamed tires and cab will not keep weight on rears.
I'd be completely happy with another 15-20% extra lift. Even with that I'll be grabbing a boulder with the BH thumb for safety.
The Curl is the L39 weak point, designed that way to protect the front Axle. As long as I'm careful, I think I'll get away with boosting the Curl 35-35%.

 

[mike69440]

Is NH Hydraulics building them?

I have not approached them yet.

They Repaired the boom cylinder on my Komatsu. . I'll ask them to quote once I get it all spec'd out.

 

[mike69440]

Do you pressurize your accumulator with nitrogen? I believe that is what we used on our Mack Aerialscope ladder truck years ago.

Sure Did, 2200 Psi Initial fill, Hope it is still there! Air filled accumulators are dangerous, especially large ones that leak a and then diesel (BOOM!)

 

[Luke'sScreenName]

I have not approached them yet.

They Repaired the boom cylinder on my Komatsu. . I'll ask them to quote once I get it all spec'd out.

Very, very, proud ($$$) of their work in my experience. Just FYI. Heard nothing bad about quality though.

 

[mike69440]

Very, very, proud ($$$) of their work in my experience. Just FYI. Heard nothing bad about quality though.

Maybe you got my drift I was hinting at that?

 

[MHarryE]

Your accumulator sounds like the accusatory that is the basis of the Kubota Ride System (KRS) on large Ag tractors. It really softens the bumps when gathering up large round bales. Increasing curl force that loads your axle - I'm trying to understand the load condition. My L5740 is extremely weak in curl when having the bucket curled completely flown and try to push myself out of the hole in which I'm stuck. Major difference between this and the L3710 I traded in. The problem here is mechanical advantage - almost zero in straightening the bucket after its tilted completely. The Grand L front axle is weak, especially in bearings judging by the info I found when I failed the LH side bearings on mine at about 600 hours. My dealer said one customer has the system down - he pulls both fronts when one side fails and takes them to the dealer to repair because the other side is always likely to go soon. So which curl load is hard on the axle? When I curl in the bank I think I am just rotating the bucket around the rear corner do the axle is not getting extra load; however, I could get a more full bucket which would hurt it.

 

[mike69440]

Re: Upsized Hydraulic Clyinders for Loaders (Attached drawings)

Your accumulator sounds like the accusatory that is the basis of the Kubota Ride System (KRS) on large Ag tractors. It really softens the bumps when gathering up large round bales. Increasing curl force that loads your axle - I'm trying to understand the load condition. My L5740 is extremely weak in curl when having the bucket curled completely flown and try to push myself out of the hole in which I'm stuck. Major difference between this and the L3710 I traded in. The problem here is mechanical advantage - almost zero in straightening the bucket after its tilted completely. The Grand L front axle is weak, especially in bearings judging by the info I found when I failed the LH side bearings on mine at about 600 hours. My dealer said one customer has the system down - he pulls both fronts when one side fails and takes them to the dealer to repair because the other side is always likely to go soon. So which curl load is hard on the axle? When I curl in the bank I think I am just rotating the bucket around the rear corner do the axle is not getting extra load; however, I could get a more full bucket which would hurt it.

I believe construction full size TLB's have a system as a option Similar to the Kubota Ride System (KRS).

Regarding increasing the curl force, this can put a lot of strain on the front axle. The best way to avoid is as yon mention, go in with the bucket a little high and bury the bucket in the pile as best you can in rear wheel drive.

Then curl the bucket back, while not Lifting or driving forward aggressively.

The works thing you can do to the front axle, aside from hitting a loaded tractor with an excavator, is to be in 4Wd, bucket under a stump, etc. driving hard forward and lifting an curling at the same time. The little bevel gears in the front axle are torque aversive, along with the spindles and just about every other component, including the steering. If your doing this with the edge of the bucket you may also rack the loader.

I suspect tractors are designed with weak loaders for safety during operation, and protection against abusive use.
Me, i respect a machine that can hurt itself with a little help.
On a well designed tractor, the safety factor has to be huge to give the tractor a degree of idiot resistance. The world is growing better more advance idiots on an exponential scale, so lots of bad stuff is going to happen.

Regarding your L5740 that like the Kubota Construction TLB´s and many better designed loaders the bucket linkage has 4 pivots, vs. 2 so as to get a getter amount of dump and curl back angle. At the extremes of motion, that type of linkage has very little leverage.

But wait, there's more!

Your L5740 has a regeneration circuit on the dump cycle. During dump full pressure is applied to the extend and retract ports,. Motion occurs due to the area difference of the rod, speeding up the dump cycle.
Some loader control valves have the flow dump back to supply tank ant the beginning of the jioystick movement to dump, then go regen.
A suspect that Kubota's are 100% regen.

GrandL's crap front bearings and seals just because the are not that beefy. Knock on wood, my front axle is not leaking after +500 hours since the repair. I think there are several seal kit versions Kubota has cycled thru over times

Carefully moving heavy pallets and rocks with my pallet forks is where I want the extra curl and lift as from the photo's below, execpt in hard digging, the L39 is adequate. I try to be as gentle a front axle abuser as possible.
Attacthed are my resized cylinder drawings.