|
LW-7 BH
Apr 25, 2008 5:51:45 GMT -5
Post by kbone1 on Apr 25, 2008 5:51:45 GMT -5
I would like to hear from someone who has installed a Prince PTO pump on their LW series Hoe. I have purchased one for my LW-7 hoe and the fittings to be able to hook it up. What worries me is that the PTO pump fittings are something like 1" on the suction side and 3/4'' on the pressure side. My LW-7 hoe, the suction side diameter is fine but the pressure line to the valve is like 3/8 of an inch. The actual fitting thread size is 27 x1.5 suction and 18 x 1.5 pressure. This seems to me to be to much of a reduction in diameter from the Prince pump to the Hoe. The PTO pump states on it " Do not reduce or restrict flow in/out of pump or damage could occur. How are others using this set-up working? My tractor is a JM 354 like Larry G's
Thank you, kbone1
|
|
|
LW-7 BH
Apr 25, 2008 12:27:29 GMT -5
Post by bobrooks on Apr 25, 2008 12:27:29 GMT -5
Which Prince pump did you get? I had my Prince pump powering my LW-6, now it powers my LiTW BH7600.
|
|
|
LW-7 BH
Apr 25, 2008 14:40:42 GMT -5
Post by bradblazer on Apr 25, 2008 14:40:42 GMT -5
I am guessing you would not run more than 10gpm or so through the backhoe. I can't remember where I saw the recommended line sizes for various flows but 3/8" should be fine. On the outlet side you have a lot of pressure available to push the fluid. On the inlet side you only get about 15psi before cavitation.
The warning may be directed against trying to throttle the flow which of course will not work on a positive displacement pump.
Brad
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
LW-7 BH
Apr 25, 2008 22:35:40 GMT -5
Post by GuglioLS on Apr 25, 2008 22:35:40 GMT -5
From the surplus center web site: www.surpluscenter.com/techhelp.asp?UID=2008042521401350&catname=hydraulicwww.surpluscenter.com/Hydraulic.htmHydraulic Hose Sizing: Recommended Flow Speed (ft/s)
Return side in feet per second 4-13
Pressure side in feet per second: 7-18 Flow speeds at the lower end of the ranges should be used when designing for a continuous duty system. The inside diameter of the hoses should be chosen such that the needed flow rates can be supplied at fluid speeds within the acceptable ranges listed above. The following equation can be used to relate desired flow rate to hose diameter:
Q = D2 *V _________ 4*231
Where Q is fluid flow rate in gallons per minute, D is the inside diameter of the hose in inches and V is fluid speed in feet per second.Unfortunately these recommendations and formula do not specify how to choose suction hose size. For as short a run your going to have on the suction side, I would go with 3/4". I have an 11 GPM pump on my ford for the Back Hoe and FEL, the suction line is 3/4" and about 4' long. FWIW - The pump is 25 years old and has never needed to be rebuilt. Larry
|
|
|
LW-7 BH
Apr 26, 2008 22:25:38 GMT -5
Post by kbone1 on Apr 26, 2008 22:25:38 GMT -5
The Prince pump I ordered is the one that everyone used that I read about on the various forums. It puts out 10 GPM, without looking at it, it is a "7a" series I think. OK Larry, I know you are "eshelons" above my reasoning ability especially after that calculated reply I noticed today when I put the pump on the tractor that the PTO shaft only engaged about half of the pumps PTO reciever. Will it be OK to use it this way? Thank you in advance, kbone1
|
|
|
LW-7 BH
Apr 27, 2008 0:08:53 GMT -5
Post by bradblazer on Apr 27, 2008 0:08:53 GMT -5
Larry, shouldn't the formula be Q = D^2*V*2.45? Solving for V: V = Q/(D^2*2.45) For 10gpm and a 3/8" ID, V = 29 1/2" ID brings it down to 16.
|
|
GuglioLS
Administrator
Jinma354 LE
Posts: 1,276
|
LW-7 BH
Apr 27, 2008 11:35:22 GMT -5
Post by GuglioLS on Apr 27, 2008 11:35:22 GMT -5
Brad,
Glad you caught that. I don't know what happened?, the formula was copied and pasted over from the SC site, I see it's corrected now. The Surplus Center site now lists the optimum suction hose velocities as well, where as just a day or two ago it did not. OR I was going to an old outdated link?
Optimum intake / suction side velocities should be in the 2-4 feet per second range.
As usual Brad is correct:
Q= 2.45xD^2 x V
Where Q is fluid flow rate in gallons per minute, D^2 is the inside diameter of the hose in inches (^ = squared) and V is fluid speed in feet per second.
Kbone1 - At 10 GPM, the suction hose size should be 1". A one inch size hose will give a velocity of 4.08 FPS.
A table of Velocity vs hose sizes vs GPM, would be beneficial as a reference. I can do that at a later date, unless of course our resident mathematical genius Brad beats me to it.
Larry
|
|
|
LW-7 BH
Apr 27, 2008 11:59:16 GMT -5
Post by bobrooks on Apr 27, 2008 11:59:16 GMT -5
The Prince pump I ordered is the one that everyone used that I read about on the various forums. It puts out 10 GPM, without looking at it, it is a 7a series I think. I noticed today when I put the pump on the tractor that the PTO shaft only engaged about half of the pumps PTO reciever. Will it be OK to use it this way? kbone1 kbone, That is the same pump I'm using. It's rated at ~7+ gpm @ 540 r/m, and it only slips onto the splined PTO shaft about half way (which is enough because you have the reaction bar & chain holding it on). I believe the 10 gpm pump would be too much.
|
|
|
LW-7 BH
Feb 16, 2010 10:06:12 GMT -5
Post by traktorz on Feb 16, 2010 10:06:12 GMT -5
Is it possible to use Category 2 Implement on Category 1 Hitch? Our Foton FT404 tractor is using Cat 1 hitch bolts, but I think the suitable LW-7 is using Cat 2 hitch bolts.
Quick attach hydraulic or a separate pump from PTO? Do these 3 Point Hitch Backhoes come with their own hydraulic PTO pump, or am I supposed to use the same hydraulic system, that I am using for the Front End Loader (FEL)? There is a free set of quick attach hydraulic connector pair available on the tractor. Any pro/con comments on each hydraulic supply method?
Considering we have a 40hp tractor, it seems the LW-7 is the matchinq Quick Attach Type 3-Point Hitch Backhoe. Any other recommendations? Experiences from using the LW-7?
What about safety and risks with a 3-point BH ? What precautions to consider?
|
|
|
LW-7 BH
Feb 16, 2010 15:01:50 GMT -5
Post by bradblazer on Feb 16, 2010 15:01:50 GMT -5
Here is a relavent thread on the LW7: www.tractorbynet.com/forums/chinese-tractors/117350-what-your-opinion-lw-7-a.htmlbobrooks and psj12 can provide first-hand experience. I would be a little surprised if the LW7 is only available with cat 2 pins. On many implements the pins can be swapped out. If you have rear hydraulic remotes available, the hookup is probably more convenient than a PTO pump. My tractor has a 316 pump which seems to be plenty for the backhoe. The PTO pump is usually an added cost option. Several people with your size tractor have had a problem with the toplink connection of a backhoe causing the hydraulic control/reservoir box under the seat to work loose where it is bolted to the transmission. The other risk is high stress on the bell-housing casting at the center of the tractor. You at least need a subframe from the loader mounts to the back axle. A subframe that extends to the backhoe will provide the best protection for the tractor.
|
|
|
Post by traktorz on Apr 7, 2010 1:13:02 GMT -5
Thanks for the link. We're still investigating whether we're going to invest in a Backhoe or not. Any information on user experiences are of interest, and specific with a 40hp tractor like ours. If you have rear hydraulic remotes available, the hookup is probably more convenient than a PTO pump. My tractor has a 316 pump which seems to be plenty for the backhoe. The PTO pump is usually an added cost option. We're probably add a PTO hydraulic pump with a separate oil tank, since we're expecting a better performance & flexibility. Several people with your size tractor have had a problem with the toplink connection of a backhoe causing the hydraulic control/reservoir box under the seat to work loose where it is bolted to the transmission. The other risk is high stress on the bell-housing casting at the center of the tractor. You at least need a subframe from the loader mounts to the back axle. A subframe that extends to the backhoe will provide the best protection for the tractor. Thank you for the interesting/worrying remarks on the need for a subframe. Is this problem apparent both when actually digging or is it worse during transports? We'll need to discuss and solve this problem together with our supplier of the eventual BH kit. Furthermore, we found a single feature that makes us willing to invest some more money in a Backhoe, and that's a hydraulic planning hoe (40liter/80cm/35kg). Two extra hydraulic cylinders on the backhoearm mount, will allow for a sideways adjustment of the hoe. This feature will add great flexibility for cleaning/restoring our forest road including ditches. It will allow us to do more digging at each stop, before running between the drivers and the diggers seat of the tractor for moving further.
|
|
|
LW-7 BH
Apr 7, 2010 16:11:10 GMT -5
Post by bradblazer on Apr 7, 2010 16:11:10 GMT -5
Is this the one? www.hanmey.com/products.asp?Action=Detail&ID=53&classID=61Looks pretty cool. The design looks more modern than the LW series. The transport mode looks nice and compact but the 3-point mount in the picture puts the whole attachment far back on the tractor. Notice all of the bracing going to the top link connection. I would definitely recommend beefing up that attachment point like 3RRL did and/or or using a subframe to counter the torque of the backhoe. I would say that the max stress occurs while digging or of you do something like suddenly stop while lowering the extended boom.
|
|
|
LW-7 BH
Apr 11, 2010 1:36:35 GMT -5
Post by traktorz on Apr 11, 2010 1:36:35 GMT -5
My english in this area is still in the phase of learning the for me new terminology. However, while the Hanmey product looks interesting, but I actually meant the other end of the backhoe arm. Here below some picture examples to illustrate the attachment of a tiltable bucket. We believe this bucket is ideal for landscaping and grading work, especially on a tractor mounted excavator. Thanks for elaborating on the need for strengthening the top link connection. I've tried using the search function to find any further illustrations and details in this matter, but to no avail. I would appreciate some help in improving my search results, or even a link if possible.
|
|
|
LW-7 BH
Apr 21, 2010 13:22:06 GMT -5
Post by traktorz on Apr 21, 2010 13:22:06 GMT -5
Thanks for elaborating on the need for strengthening the top link connection. I've tried using the search function to find any further illustrations and details in this matter, but to no avail. I would appreciate some help in improving my search results, or even a link if possible. I've searched further and found the referenced info regarding strengthening the top link to reduce the torsional stress: • Building a Two-Piece Subframe - by 3RRLInteresting to see the Nardi BH and the custom subframe. If we decide to invest in a BH, certainly some kind of stabilization we might consider as well, however not as sophisticated as the one implemented by 3RRL.
|
|
red
CTW Advanced Member
Posts: 306
|
LW-7 BH
Apr 21, 2010 15:35:59 GMT -5
Post by red on Apr 21, 2010 15:35:59 GMT -5
Traktorz, If I knew what I know now I would not have brought a Chinese Backhoe. (Both Ranchhand and Affordable DON'T sell them) The Korean and Italian backhoes are much better products for not much more money.
|
|