Backhoe Jinma LW-6

[TheSheriff]

I don't know the answer to your problem, but I was considering your BH when I bought my 284. During my research, I recall reading a thread much like this one. The "Experts" in that thread determined the poster was supplied the wrong pump with the BH.

Here's an example of a PTO pump if that helps.

https://affordabletractorsalesco.co...d=&PHPSESSID=2f33eaf8638216e9c977f3234ec353b9

Brad

 

[Rich Waugh]

Trelli,

As I understand it, there are two options for supplying hydraulic pressure to the backhoe. First is a pump that attaches to the PTO output shaft (the 6-splined one for implements). That type of pump is usually physically larger than the hydraulic pump that handles the your TPH, loader, etc, since it has internal gearing to get up to speed from the 540 PTO rpm. The other method of supplying power to the hoe is by using a hydraulic pump that looks pretty much like your regular CBN-type pump, but it is mounted directly to the rear of the lift box just above the PTO output shaft. There is a cover there with 4 bolts that you remove and install the pump in its place. The pump has a tang that engages a slotted shaft inside the lift box. That shaft turns at engine rpm so the pump delivers full pressure.

From what you've said, it sounds like you're using a pump designed for direct drive on the low-rpm PTO shaft. That ain't gonna work.

Hope this clears things up.

Rich

 

[TheSheriff]

And though it's not relevant to this thread, the third option is to use your existing engine mounted hyd pump... which works for me.

Brad

 

[RonMar]

Thanks Ron for the reply but I must admit that I'm getting confused, the pump that was supplied with the backhoe simply fits onto the PTO shaft at the back of the tractor, The four bolts and that bracket is simply to stop it from moving and twsiting with the PTO shaft. This shaft that I connect the backhoe's pump to is not ahead of the gear box becasue I can disengage it and change its speed from 540/750. It's the same shaft that I connect every thing to - flail mower slasher etc. There isn't two shafts , just the single one at the back of the tractor. Am I missing something?

I was under the understanding that the PTO shaft will acheive the speeds of 540 or 750 at a given RPM, I just checked my manual and it's 2200rpm on the JM354.

So that means that the pump from the backhoe that fits on the PTO shaft is supposed to be spinning at 2000rpm to acheive 16mpa, which means that currently It's jsut not spinning fast enough becasue at most I am giving it 750+rpm.

sorry for my ignorance if I am missing something.

The pump in this pic that YOU posted slips over the splined PTO shaft?
http://www.tractorbynet.com/forums/.../166116d1274425886-jinma-lw-6-back-loader.jpg

 

[Red55]

The pump in this pic that YOU posted slips over the splined PTO shaft?
http://www.tractorbynet.com/forums/.../166116d1274425886-jinma-lw-6-back-loader.jpg

Sure looks like the one I have mount to the shaft behind the plate. Not all tractors are shipped with the tabbed shaft for the direct mount pump

 

[trelli]

I think you guys have solved it for me. I took off the four bolts of the cover above the pto shaft and saw a splined female shaft with many splines. I then rand the PTO and noticed that it spun faster than the lower PTO shaft. This must be what you guys are talking about, that the pump should have been connected to this all along. However i've been trying to get it going with the lower PTo shaft because when it was sent from the factory the pump was mounted onto a bracket that slotted over the bottom shaft. I jsut assumed that that was the correct match. The company I got the backhoe off was not Jinma but another mob that makes loaders, the also modify backhoes etc. So really, it was the factory's mistake to even make that bracket that fitted over the lower PTO shaft and matching it with an incorrect pump.

I'll now be fabricating something to fit over that tang on that upper shaft and modifying the pump shaft to fit.

I'll keep you all posted.

thanks so much for the help.

 

[erj]

I'll now be fabricating something to fit over that tang on that upper shaft and modifying the pump shaft to fit.

Does this mean that the pump that you showed back in post 20 does not simply bolt onto the spot where you removed the plate?
RonJ

 

[Nuno]

If i understand it right, you have a Pump without Gearbox and with a Shaft that doesn't fit to the Shaft behind the Plate above the 6 splined PTO Shaft.

maybe it will help if you show some pictures of the Pump Shaft and the Shaft inside the Transmission Box.

My BH have an PTO Pump like this one

with an heavy weight cast iron Gearbox.

The Pump have an tang style drive shaft so that i can remove it from the Gearbox and install it to the Backside of the Tractor when i remove the plate above the PTO Shaft.
Your Pump Shaft must look like the right one in the following picture


if not, than i am sure they have send you the wrong Pump but if yes, they must fit without any modifications.

i am not sure but i think, the LW Series have an PTO Pump with Gearbox and the Pump without Gearbox that must be mounted fix to the Tractor is only for the Framemounted HW-03 Series Bachkoe.

 

[Nuno]

Just got a few photos here, it's been raining so I had tarps over them. There are a few items on that I cannot identify or recognise.Any help is greatly appreciated. The manual does not identify these.

thanks

ok,
the BH Valve is similar or maybe the same as mine and if i am not wrong the two extra RVs are for the Swing Cylinders but maybe the plumbing is not correct.
I have these 2 extra RVs also but not at the same place.

This is the Spool for the Dipper and i have caused by the RVs a minimal Breakforce when i pull the Dipper in.
The Plumbing is incorrect and different then showed in the Manual and the BH self.

 

[trelli]

here are some pics of the pump. It's definitely the wrong thype of pump to fit on the 6 splined PTO shaft.

 

[Nuno]

in the first of your pictures, for what is this balck piece for?
it looks like an adapter for the PTO 6Spline PTO shaft.

if you can slip the Pump Shaft into this piece and on the other side you have the the Female for the PTO Shaft?
if it is so, i am sure that this Metal Brace is for the Pump and you must run the Pump with the higher 1000rpm PTO Gear because there is no Gearbox to increase the 540 rpm.

 

[Rich Waugh]

Doing that is still going to result in low flow and pressure as that pump is designed to operate at about twice that RPM to develop full pressure and volume. You'd need either a gearbox to up the PTO rpm to around 2000 for the pump or you need to get the proper pump, I'm afraid. I don't see any other alternatives.

Rich

 

[Nuno]

if i am not wrong, the Standart setup from factory for the LW-6 is a CBN-E310 Pump that have a lot less Flowrate running with Gearbox on 540 rpm at the PTO than the CBN-E 325 driven direct by the 1000 PTO.

it don't hurts to try this setup if all the parts will fit together like i am thinking and by The way, the Pump don't need 2000 rpm to develop the full pressure but yes the full capacity of volume and this may be with a 25ccm Pump more than enough at 2000rpm and at half speed more than the 10ccm Pump will develop at full speed.

 

[trelli]

Ok I'll try to explain. Basically the setup you see has come from the factory that makes the loaders and backhoe. It's all set up to go on to the 6 splined pto shaft. However, becasue of the type of the pump, it's more suited to the faster spinning shaft above the 6 splined PT) shaft, This other shaft is the
3rd picture in my last post.

Spinning this pump on the 6 splined pto shaft can only get me 750rpm at 2200engine rpms, this is not enough to get the pressure. My options are 540/750 for my pto.

SO, what I'm going to do is to modify the pump shaft to fit over the tang on that upper pto shaft which seems to be spinning at engine RPMS, thus I can run the engine at 1500rpm + and get a decent pressure out of the pump, given that it has a nominal 2000rpm, I think 1500 engine rpms should be ok.

so In essence, the factory should have put a gearbox on that black brackt to step up the speed, or givien me somer kinf of adapter to hook up to the shaft above the 6 splined PTO. Or a pump that could generate such pressures with 540/750 PTO rpms.

 

[Affordable]

Here is a pic of the E-310 backhoe pump that mounts above the PTO shaft,and the pump drive coupling that is used to run it.

Tommy
Affordable Tractor Sales
"Your Jinma Parts Superstore"
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[Nuno]

Spinning this pump on the 6 splined pto shaft can only get me 750rpm at 2200engine rpms, this is not enough to get the pressure. My options are 540/750 for my pto.

are you sure? the pressure is not a question of enough rev.
the Pump develop 160 Bar in any RPM range provided that your Tractor have enough Power on the PTO to handle the 25ccm Pump. the only that may vary is the L/min or let me say the Gpm at different rev.

SO, what I'm going to do is to modify the pump shaft to fit over the tang on that upper pto shaft which seems to be spinning at engine RPMS, thus I can run the engine at 1500rpm + and get a decent pressure out of the pump, given that it has a nominal 2000rpm, I think 1500 engine rpms should be ok.

like i say before, the Pressure that the Pump develope will be the same, it does't matter if you run the Pump at 2000, 1500 or at 540/720 rpm
what you need is Flow and this will be with the 25ccm Pump at 2000rpm round about 50 L/min, at 1500 rpm 37,5 L/min, at 720 rpm 18 L/min and at 540 rpm 13,5 L/min.
it means, that the 325 Pump have nearly the same Flowrate directly driven by the PTO at 720rpm like the Standart Factory Setup with 310 Pump and 3,8:1 Gear Ratio Gearbox at the 540 rpm PTO.
it means also that you need to run the engine at the same (in your case 2200 rpm) speed to get the same or nearly the same output with booth Setups.

so In essence, the factory should have put a gearbox on that black brackt to step up the speed, or givien me somer kinf of adapter to hook up to the shaft above the 6 splined PTO. Or a pump that could generate such pressures with 540/750 PTO rpms.

If you try to run the Pump directly driven by the inner PTO (in your third Picture) that seems to spin at the same speed as the Engine don't forget that you need about 14,8 Kw or it will be 19,68 HP of your Engine Power to drive the Pump with the nominal specification and at 1500 rpm about 11,11 KW or 14,9 HP.
Don't know if your Tractor can handle this without Gear reduction.

i will not smash down your ideas, these are only the things that come to my mind and advices i will give you.

 

[SPIKER]

FYI: my 2002 JW03 hoe uses the 4 bolt on engine rpm pump, came from china this way. I run my tractor in the 1200 rpm to 1500 rpm range, any more the flow rate is too high from this pump and the hoe becomes hard to control.


Mark

 

[trelli]

Thanks Nuno but I don't quite understand how you got those calculations. It seems to me that that innershaft above the 6 splined PTO is meant for hydraulic pumps as shown in Tommy's picture with that coupling. That's what I am going to try to make.

If you read the earlier posts, you'll see that I dead headed the pump running it off the 6 splined PTO and the most pressure I could get out of it was 1500psi. The pump didn't break the engine did not struggle and when I lowered revs the pressure dropped accordingly, there's enough space in the pump gears to relieve pressure once it stops turning, and even when it is turning there is some loss of pressure within the tolerances of the bore and gears. Dead heading it at 750 PTO rpm could only get 1500psi, but i'm sure that If I could increase the rpm the pressure would reach in the vicinity of 2200psi which is what I need. This is why i 'll be attempting to fabricate that coupling to atach to the pump.

 

[trelli]

Just found this picture, this is the setup I am going for, though now I'm realising that the pump that came with most LW6s are E10, rather that the CBN-E3 pump I have with a really long shaft. If all else fails, them I'm going to plumb the backhoe into the tractors hydraulics, what do you all reckon about that? good or bad idea?

 

[trelli]

Does this mean that the pump that you showed back in post 20 does not simply bolt onto the spot where you removed the plate?
RonJ

Correct Ron, it's a bigger bracket that also uses 4 bolts to with the 6 splined lower PTO shaft as centre.