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Post by traktorz on May 12, 2011 7:29:57 GMT -5
Background: Having had problems with the gearbox also damaging the hydraulic pump itself, we decided to invest in a Prince HC-PTO-7A pump.  
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Post by traktorz on May 12, 2011 7:34:19 GMT -5
HC-PTO-7A
3.6 CI/REV (motsvarar 59 cc/varv; 540 [varv/min] => 31.8 [minutliter])
design rpm: 540, maximum rpm: 600
FLOW AT DESIGN RPM Numbers based on 2000 psi (140 Kg/cm): 7.1 gpm (26.9 l/min)
INPUT POWER AT DESIGN RPM: 11.9 HP (8.9 kW)
A=1.26" B=1.54" C=1.63" D=2.78" E=5.23"
PUMP MODEL: HC-PTO-7A
INLET PORT: #16 SAE O-RING
INLET PORT TO HOSE ADAPTER: 1" (25.4 mm) HOSE (PRINCE PART No.)(270011017)
AUXILIARY OUTLET PORT: #12 SAE O-RING
REAR OUTLET PORT: #12 SAE O-RING
OUTLET PORT TO PIPE ADAPTER: 3/4" (19.1 mm) F. PIPE (PRINCE PART No.)(500204011)
INLET PORT: #16 SAE 2)
OUTLET PORT: #12 SAE 3)
RECOMMENDED HOSE SIZES: 1” IN, 1/2 “OUT
REQUIRED DRIVE SHAFT: 1 3/8" DIA. 6 TOOTH (34.9 mm)
SHIP WT (LB): 33
2) Barbed adapter for 1” hose included. #270011015
270011015 1” NPTF Male, 1” Hose Barb Fig. 2
3) Female pipe adaptor for 3/4” NPT included. #500204011
500204011 #12 SAE (1 1/16-12) Male, 3/4-NPTF Female Fig. 1
45° Flared Fittings (SAE): SAE flared fittings seal in the same manner as described for JIC, however the mating surfaces are machined at 45°. These couplings are usually used for low pressure applications such as refrigerant and fuel lines in conjunction with copper tubing which flares easily to 45°.
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Post by traktorz on May 12, 2011 7:52:02 GMT -5
First thing was to get the pump. Since it's not available in Sweden, we had to order and have it shipped from the US. It was delivered with adapters for the inlet/outlet, so first thing was to figure out what those were. The easiest way was to bring those with me to the Hydraulic shop, so we now have the 90-degree angle fittings for the inlet/outlet, see the images.      The next step will be to put the PTO pump with the new fittings onto our tractor, and see what's the best orientation for the attaching hydraulic hoses. Since the hydraulic tank for the Backhoe is located above the PTO, we are considering a Quick Connect on the low pressure inlet side of the pump. It will both ease the mount/dismount of the Backhoe to the tractor, as well as preventing hydraulic oil leak from the tank. But on the high pressure side, we are going to dierectly connect the hydraulic hose to the Backhoes valve assembly. We would like to hear any comments, suggestions, ideas, and experiences using a Prince pump together with a Backhoe. By the way, our tractor is a Foton 404, and the Backhoe is a LW-7. |
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psj12
CTW Member
KAMA 554
Posts: 93
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Post by psj12 on May 12, 2011 8:38:54 GMT -5
I also have the LW-7 but it is mounted on my KAMA 554. I found it easier to remove the tank and pump and use the tractor hydraulic remotes to operate the BH.
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Post by traktorz on May 12, 2011 14:32:27 GMT -5
I also have the LW-7 but it is mounted on my KAMA 554. I found it easier to remove the tank and pump and use the tractor hydraulic remotes to operate the BH. That's a good point, and would make the attach & detach of the Backhoe much easier. I've seen some BH brands being sold that way in Sweden. However, doing some digging work on somewhat distant forest roads, we wanted to have a bit of a safety margin, that we think we can get by having separated hydraulic systems. Once in a while a hydraulic hose or fitting breaks or starts to leak. Independent of using the tractors own hydraulic system or an extra PTO pump, we would consider a tank return filter:   Edit: -Don't you need a hydraulic oil cooler, since the tank is probably not that big for the flow. Rule of thumb is tank volume = liter/min flow in number. |
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Post by bradblazer on May 12, 2011 22:32:04 GMT -5
My only concern with a quick-connect between the tank and pump is the flow restriction of the spring valves in the QC fittings. That suction line should be as free-flowing as possible. I'm surprised it's not easiest to have the pump always connected to the hoses.
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Post by traktorz on May 13, 2011 1:40:10 GMT -5
My only concern with a quick-connect between the tank and pump is the flow restriction of the spring valves in the QC fittings. That suction line should be as free-flowing as possible. I'm surprised it's not easiest to have the pump always connected to the hoses. It's a bit of a puzzle to attach the backhoe to the tractor, also with the both hoses intertwined with the stabilizers. Having at least one hose loose, would ease the mounting task we think. Therefore we came up with the idea of using the quick connector for the tank side. Reading the Prince recommended hose sizes: 1” IN emphasizes your concern of flow restriction argument. We'll look into this in detail when figuring out the routing of the new hoses and their required lengths and adapters.  |
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arto
CTW Member
Posts: 9
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Post by arto on May 13, 2011 9:40:01 GMT -5
My only concern with a quick-connect between the tank and pump is the flow restriction of the spring valves in the QC fittings. That suction line should be as free-flowing as possible. I'm surprised it's not easiest to have the pump always connected to the hoses. It's a bit of a puzzle to attach the backhoe to the tractor, also with the both hoses intertwined with the stabilizers. Having at least one hose loose, would ease the mounting task we think. Therefore we came up with the idea of using the quick connector for the tank side. Reading the Prince recommended hose sizes: 1” IN emphasizes your concern of flow restriction argument. We'll look into this in detail when figuring out the routing of the new hoses and their required lengths and adapters. Hej Traktorz. I agree with Bradblazer, that you should keep the restriction at a minimum on the suction side. On the other hand you have no suction head what so ever on your setup so maybe there will be no problem with a QC. Is the problem with keeping the lines always attached to the pump due to "stiff" hydraulic hoses with bad bending radius? On the suction side you can use a single wire SAE R4 suction hose which is much easier to route than a 2 wire R2 hose. I have upgraded my tractor pump from a 15cc to a 25cc. I change the suction hard pipe to a 1.25" R4 suction hose. Works very good and was really easy to route. I bought it at swedol.se handla.swedol.se/shop/showItemList.asp?IT3=336handla.swedol.se/ |
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Post by bradblazer on May 14, 2011 6:46:59 GMT -5
I see your picture and still don't see the advantage of a quick connect. It is very cramped with the hoe attached. The hoses should be made long enough to allow you to stop almost 1m away as you approach to connect the pump to the pto and connect the pump torque linkage. Then you just back in the rest of the way and you can operate the backhoe to help align everything. Once you have it hooked up you can arrange the slack in the hoses. The prince pump is more compact than the original gearbox and pump so the hoses will attach pretty much under the PTO guard. You can use a sleeve or wrap to keep the 2 hoses together coming off the pump if you want.
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ronj
CTW Member
Posts: 72 
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Post by ronj on May 15, 2011 2:43:04 GMT -5
I guess that I do not understand why the pump would not just be left with the backhoe when it was disconnected.
The picture that was posted shows numbers 1-6. Should this mean something to us?
RonJ
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Post by traktorz on Jul 16, 2011 9:52:46 GMT -5
Hej Traktorz. I agree with Bradblazer, that you should keep the restriction at a minimum on the suction side. On the other hand you have no suction head what so ever on your setup so maybe there will be no problem with a QC. Is the problem with keeping the lines always attached to the pump due to "stiff" hydraulic hoses with bad bending radius? On the suction side you can use a single wire SAE R4 suction hose which is much easier to route than a 2 wire R2 hose. I have upgraded my tractor pump from a 15cc to a 25cc. I change the suction hard pipe to a 1.25" R4 suction hose. Works very good and was really easy to route. I bought it at swedol.se -I now have a SAE 100 R4 suction hose, 3/4", which is lower than Prince recommends, 1". But it's a short distance at a slightly lower level, so it will be fine I think. -I've also thrown away all plans of using Quick Connect, purely to avoid any flow restriction problems. P.S. -What do you mean by upgrading your pump. Is that one on the tractor itself, or is it a PTO type as well? How many liter/min will you feed your backhoe with? The Prince is 59cc/rotation, equals to 31.8 minute-liters. But it's speced to 26.9 liter/minute, I haven't figured out the discrepancy. |
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Post by traktorz on Jul 16, 2011 9:57:53 GMT -5
I guess that I do not understand why the pump would not just be left with the backhoe when it was disconnected. The picture that was posted shows numbers 1-6. Should this mean something to us? RonJ Reading about and hearing your concerns here about flow restrictions, I've eliminated the ideas of those Quick Disconnect completely. I've found suitable soft hoses and custom made fittings. Regarding the numbers in the picture, I made it for a question in a swedish forum, someone asking on how to stabilize his backhoe. |
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