Help Me Understand Hydraulics: BX2200 and LA211 Loader

[Mingy]

Thanks in advance for the help.

I recently bought a small snowblower for my BX2200 because using my M9000 near the house is a bit scary. The blower has a hydraulic motor for chute rotation.

I figured I'd use the FEL controls for the LA211 to control the blower chute. My reasoning is that i understand you need open center for the motor and the FEL controls are open center (I do not have a remote on this tractor at the moment). However, when I connect the motor to the FEL roll ports the motor only turns in one direction. (I can turn it back by reversing the ports). When I connect the motor to the lift ports it works as expected.

I don't understand why this is happening or how to fix it. The FEL works fine by itself I think.

I have started the process to install rear hydraulics. I bought a valve which has an inlet and an outlet, but when I look at the FEL control it seems to have 3 pipes going to it. The manual refers to these are "tank, pump and power beyond". Should I connect the ear hydraulic to tank and pump or tank and power beyond?

Thanks.

 

[Russell King]

I can’t answer about the motor not reversing.

But on the rear remotes:
The hose from the PB port of the FEL valve goes to the rear remotes Pin port (remove current hose at tractor block end and connect to the new valve). Then a new hose will come from the rear remote PB port (sleeve) back to the tractor block, same open port where you removed the hose end). Then a new tank return line will be added to the rear remote T port. That line connects back to the tractor sump. You can use the same port as the FEL tank return by adding a TEE at the tractor block.

If this is not clear there are diagrams on this forum that show it in more detail

 

[PoTreeBoy]

Thanks in advance for the help.

I recently bought a small snowblower for my BX2200 because using my M9000 near the house is a bit scary. The blower has a hydraulic motor for chute rotation.

I figured I'd use the FEL controls for the LA211 to control the blower chute. My reasoning is that i understand you need open center for the motor and the FEL controls are open center (I do not have a remote on this tractor at the moment). However, when I connect the motor to the FEL roll ports the motor only turns in one direction. (I can turn it back by reversing the ports). When I connect the motor to the lift ports it works as expected.

I don't understand why this is happening or how to fix it. The FEL works fine by itself I think.

I have started the process to install rear hydraulics. I bought a valve which has an inlet and an outlet, but when I look at the FEL control it seems to have 3 pipes going to it. The manual refers to these are "tank, pump and power beyond". Should I connect the ear hydraulic to tank and pump or tank and power beyond?

Thanks.

First, let's address your chute motor. I don't have access to the schematic for your LA211 but below is the schematic for an LA210, which I think is the same.

You seem a little confused as to what 'open center' means. Open center refers to the overall hydraulic system design philosophy. A fixed, positive displacement pump is used to save initial cost (vs a variable displacement pump and associated controls). In order to prevent deadheading the pump when there is no demand, an open path back to the tank is provided.

In order to keep this brief, I won't get into a full discussion. Just note that neither valve on your loader control is a plain double-acting control. Kubota does this to make the loader act faster and more controllable.

The bucket control has a 'regenerative' position. This applies supply pressure to both cylinder ports. You'd think this would stall movement but, since the two sides of the piston have different areas (due to the rod on one side), it doesn't. Instead, the cylinder extends faster than it would normally, but with less available force. This lets the bucket dump faster and the full force isn't needed to dump. That regeneration works with cylinders but not motors, they stall.

Here's where I'm not entirely clear. There seems to be another position that does have double-action. It doesn't have a detent like the float position on your boom, but by pushing the lever only part way (or fully over, here's where I'm not sure) you should have the flow condition that will allow your motor to reverse.

If you've been pushing the control full over, try pushing it part way and see if that works.

 

[Mingy]

I can’t answer about the motor not reversing.

But on the rear remotes:
The hose from the PB port of the FEL valve goes to the rear remotes Pin port (remove current hose at tractor block end and connect to the new valve). Then a new hose will come from the rear remote PB port (sleeve) back to the tractor block, same open port where you removed the hose end). Then a new tank return line will be added to the rear remote T port. That line connects back to the tractor sump. You can use the same port as the FEL tank return by adding a TEE at the tractor block.

If this is not clear there are diagrams on this forum that show it in more detail

Thank you for the reply. I will see if I can figure it out within this context. I figured I'd attack the rear remote when it warms up.

 

[Mingy]

First, let's address your chute motor. I don't have access to the schematic for your LA211 but below is the schematic for an LA210, which I think is the same.

You seem a little confused as to what 'open center' means. Open center refers to the overall hydraulic system design philosophy. A fixed, positive displacement pump is used to save initial cost (vs a variable displacement pump and associated controls). In order to prevent deadheading the pump when there is no demand, an open path back to the tank is provided.

In order to keep this brief, I won't get into a full discussion. Just note that neither valve on your loader control is a plain double-acting control. Kubota does this to make the loader act faster and more controllable.

The bucket control has a 'regenerative' position. This applies supply pressure to both cylinder ports. You'd think this would stall movement but, since the two sides of the piston have different areas (due to the rod on one side), it doesn't. Instead, the cylinder extends faster than it would normally, but with less available force. This lets the bucket dump faster and the full force isn't needed to dump. That regeneration works with cylinders but not motors, they stall.

Here's where I'm not entirely clear. There seems to be another position that does have double-action. It doesn't have a detent like the float position on your boom, but by pushing the lever only part way (or fully over, here's where I'm not sure) you should have the flow condition that will allow your motor to reverse.

If you've been pushing the control full over, try pushing it part way and see if that works.

View attachment 147845

Thank you for your detailed reply. Yes, I was/am confused by open center. I will try and work through what you wrote. The schematics are helpful though I admit reading hydraulics schematics is a bit confusing (I'm an electronics guy).

 

[GreensvilleJay]

FWIW
print out the drawing, say 5 times. cutout the 'squares' that are the positions that the valve can be in. put one over the neutral one. Now you can see where the oil goes. I call this 'playing hydraulics, similar to 'playing computer' where I use graph paper and 'single step' thought machine code.

 

[Henro]

Thank you for your detailed reply. Yes, I was/am confused by open center. I will try and work through what you wrote. The schematics are helpful though I admit reading hydraulics schematics is a bit confusing (I'm an electronics guy).

If you are used to reading electrical and electronic schematics, once you get used to the different hydraulic symbols, hydraulic diagrams should almost be second nature for you...don't worry too much about that...current seems to flow just like hydraulic fluid.

Actually, I guess that is more true if you think in conventional current terms, where electrical current flows from positive to negative...The electron flow approach makes the transition to hydraulics a bit more difficult I suppose.

 

[Donystoy]

If the chute will not rotate when you fully snap the lever to the right, then you have other issues. I was puzzled by this myself when I first got my LX as my B7200 did not have the re-generative feature as explained in post #3.

 

[shelkol]

Due to the bucket curl being a regenerative valve, you will not get it to work as you expect. You will have to add a valve after the loader valve to control the motor rotation.

The regenerative spool in the loader valve connects the 2 ports of the curl cylinder together and then adds more fluid to make it dump faster. Since the two ports of the curl cylinder are connected together, the weight in the bucket helps it dump faster.

After fighting this for years I finally added another valve and now it works as expected.