BX 2380 throttler/power lever question

[JSL]

This is a ridiculous question I'm sure but I have to ask. Does the throttle/power lever control the potential speed of the tractor OR the power (such as for FEL or axle or pto etc), or both? The manual is kind of sketchy on the relationship of the throttle to the forward/reverse (accelerator ?) pedal, not to mention the "fast"/"slow" speed lever, and the FEL/attachments. The manual refers to the throttle lever as controlling the "engine speed". I know the throttle gauge must be within the "orange" arc to distribute power to the FEL/implements, but how much is good? what are the ranges for operation, and what will damage the machine? I'm concerned that I am underpowering or overpowering the machine for the task at hand. Also the throttle is really stiff so I set it and never change it cause it requires pounding on it with a fist and so incremental adjustments are impossible. I found a thread that explained I had to take the cowling/dash off and find the adjustment nut to fix this, but haven't done that yet. Thanks for your patience and help in advance.

 

[North Idaho Wolfman]

Your not going to "damage it" by running it at any available settings of the throttle.
These engines are smart and wont over rev.
The higher the RPM's the more power and speed that is available.
If you run PTO powered implements run it at PTO speed.

 

[NCL4701]

The “throttle” isn’t really a throttle like the accelerator pedal on a car/truck as it doesn’t directly control the amount of fuel or air going into the engine. The “throttle” adjusts a governor that controls the amount of fuel going into the engine to keep it running at the RPM you set with the “throttle”. I suspect you’ve used similar setups if you’ve used a lawnmower. So, although it may be just semantics, quit thinking of it and calling it a throttle; it is an engine speed control. Because it’s an engine speed control, it’s set up so you can’t over rev it.

You indicate it has a “fast/slow” lever and a forward/reverse pedal (which is NOT an accelerator pedal). So that indicates you have a HST transmission (a rather fancy variable speed hydraulic motor) hooked to a two speed gear box. The forward/reverse pedal controls the direction and speed of the hydraulic motor. Like any other hydraulic anything, it’s performance is impacted by two things: pressure (which gives it torque) and flow (which gives it speed). Hydraulic pressure is relatively constant due to the type hydraulic pumps on these machines. Flow is controlled by how fast the pump is turning so it’s impacted by engine RPM (the engine speed control): more RPM = more flow. So: if you don’t have enough speed (flow) increase engine RPM; if you don’t have enough torque (pressure) give it LESS pedal to maximize pressure.

The fast/slow lever is a simple gearbox. There’s a high gear and a low gear: whatever speed the HST is running is modified by that gearbox before going on to the wheels. High for travel (low torque, high speed); low for work (low speed, high torque).

Same principles apply for running loader, backhoe, or anything else hydraulic. More RPM has little effect on power (theoretically it has no effect but theoretical hydraulic systems have perfect seals that never wear or leak). More RPM directly increases speed. So if you’re running a hydraulic thing such as loader or backhoe and you want it to move more quickly, increase RPM. Want it to move more slowly to be easier to control fine movement; decrease RPM.

Engine speed, HST pedal position, and gear selection all work together to provide adequate speed and torque to the wheels. Engine speed alone sets response speed of hydraulic cylinders on attachments. If the machine is straining: lower gear, less pedal, more RPM.

PTO speed (I believe yours has two PTOs but doesn’t matter) is directly proportional to engine speed. If you’re running something such as a mower, generator, etc. that is designed to run at rated PTO speed, run it with the engine speed at the PTO mark on the tach.

That is not intended to be an engineer level perfect explanation of the theory and maintenance of your machine. It’s intended to be a practical guide for an operator.

 

[Orangeglow]

Not a great idea to keep banging on the throttle lever to get it to move.
There are adjustments you can make very easily, to be able to use the throttle lever as it was designed, and intended. You don,t have to take the dash off to make the proper adjustment. Remove the cowling under the steering wheel, and look for the adjustment point. It,s a matter of loosing a nut, to provide just the correct amount of friction so you can move the throttle lever, and it stays put to whatever position you move it to while the tractor is being used.

 

[JSL]

Thanks to all for the super helpful explanations. NCL471--your detailed explanation helps me understand how the different mechanisms work together which is both reassuring AND confidence building. I'm doing a lot of land clearing and learning as I go is OK but I really don't want to wreck the machine. Thanks Orangeglow too for the instructions about the cowling/throttle adjustment process--I am going to do that ASAP so I can then play around with different power/speed combinations. Appreciate you all giving my question your attention.

 

[Mlarv]

There is also one other thing that is backwards form normal. These are HST tranny's so if you want more power let off the peddle. It sounds stupid but I know for a fact it works.

 

[GreensvilleJay]

re: Does the throttle/power lever control the potential speed of the tractor OR the power (such as for FEL or axle or pto etc), or both?

both really.
speed , since it controls the engine speed which through the HST does get to the wheels
power, since it spins the 'pumps' that control the hydraulics,that do 'work'.

Think of the HST as being similar to a cars automatic transmission BUT instead of several gears, it's continuously variable ( more like a snow sled...)

 

[ejb11235]

The engine runs the hydraulic pump, so increasing the engine speed increased the volume per time that pump can supply to whatever hydraulic device is using it, be it the transmission, front-end loader cylinders, etc. I have a BX23S, so it has a backhoe, and I can definitely tell the difference in how increasing the engine speed results in fast movement of the backhoe. I don't know what the pressure generated by the pump changes as a function of engine speed, but I have noticed on a couple of occasions I had to bump up the engine speed in order to get the FEL to lift a load. My guess is that the pressure increases with engine speed and then levels off.

+1 on adjusting the engine speed control so you don't have to bang on it. When I first got my tractor, the lever was fairly stiff, and I was a bit afraid I was going to break it, partially because I wasn't completely sure which way to turn it! It's still on the stiff side but I've never taken the time to adjust it. I will admit that I hold it a certain way so I don't put extra stress on it, but I've never had to bang on it.

 

[Dieseldonato]

Pressure is the resistance to flow. Flow Is dictated by pump size and rpm. Flow and pressure are independent of each other. The pump will continue to Flow fluid unless it is stopped.
Pressure will rise and fall depending on the resistance to flow, depending on what you are doing, up to system relief setting. Then excess flow is deverted back to the tank (typically). When the relief valve opens this give the hydraulic flow from the pump a low resistance path. You cannot stop the flow, just devert it to do work or push it around the system back to the tank.

 

[ejb11235]

Pressure is the resistance to flow. Flow Is dictated by pump size and rpm. Flow and pressure are independent of each other. The pump will continue to Flow fluid unless it is stopped.
Pressure will rise and fall depending on the resistance to flow, depending on what you are doing, up to system relief setting. Then excess flow is deverted back to the tank (typically). When the relief valve opens this give the hydraulic flow from the pump a low resistance path. You cannot stop the flow, just devert it to do work or push it around the system back to the tank.

Oh yeah ... forgot that little tidbit. So why does it seem like I have to increase the engine speed past a certain amount before the FEL will lift a heavy load? Am I just misperceiving what's actually happening?

 

[Dieseldonato]

Oh yeah ... forgot that little tidbit. So why does it seem like I have to increase the engine speed past a certain amount before the FEL will lift a heavy load? Am I just misperceiving what's actually happening?

It's the lack of flow at low rpm that makes hydraulics slow. They are a fixed displacement (for the most part) they will only move X amount of fluid for 1 revolution of the pump. So you have to spin the pump faster to get decent flow, ie give a faster reaction rate. The cylinders will lift however much weight at whatever pressure. Till they are fully extended, or hit a load they cannot over come. (Relief opens at that point. ) this will happen if your flowing 1cc per revolution or 30cc per revolution (of the pump) just takes a lot longer with 1cc per revolution.

 

[ejb11235]

It's the lack of flow at low rpm that makes hydraulics slow. They are a fixed displacement (for the most part) they will only move X amount of fluid for 1 revolution of the pump. So you have to spin the pump faster to get decent flow, ie give a faster reaction rate. The cylinders will lift however much weight at whatever pressure. Till they are fully extended, or hit a load they cannot over come. (Relief opens at that point. ) this will happen if your flowing 1cc per revolution or 30cc per revolution (of the pump) just takes a lot longer with 1cc per revolution.

Hmmm, I actually was aware of that (I watched an entire 43 episode series recently on hydraulics). Next time I have a bucket full of rocks, I'll have to pay more attention to what's actually going on. Thanks!

 

[OrangeKrush]

Hmmm, I actually was aware of that (I watched an entire 43 episode series recently on hydraulics). Next time I have a bucket full of rocks, I'll have to pay more attention to what's actually going on. Thanks!

Was this on YouTube or ?? I wouldn't mind learning more on it.

 

[ejb11235]

Was this on YouTube or ?? I wouldn't mind learning more on it.

Here's a Link to the YouTube playlist ... 47 videos

Excellent series by Jim Pytel. I'm really quite chagrined that I forgot one of the basic things I learned, (pump speed affects flow, not pressure) which lead to @Dieseldonato correcting me.

Jim Pytel has a bunch of videos on all sorts of topics. I'm just finishing up the series on Programmable Logic Controllers. He is an Electro-Mechanical Technology Instructor and CTE Department Co-Chair at Columbia Gorge Community College.

Jim Pytel | Columbia Gorge Community College

www.cgcc.edu

 

[OrangeKrush]

Here's a Link to the YouTube playlist ... 47 videos

Excellent series by Jim Pytel. I'm really quite chagrined that I forgot one of the basic things I learned, (pump speed affects flow, not pressure) which lead to @Dieseldonato correcting me.

Jim Pytel has a bunch of videos on all sorts of topics. I'm just finishing up the series on Programmable Logic Controllers. He is an Electro-Mechanical Technology Instructor and CTE Department Co-Chair at Columbia Gorge Community College.

Jim Pytel | Columbia Gorge Community College

www.cgcc.edu

Thanks ejb, I'll check it out!