Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Recent content by fluidlearning

  1. fluidlearning

    Hydraulic drive for small tractor

    I have a 'real' motor coming, but the pump I was trying to use as a motor was a gear pump. Let me see if in underatand the function of the RV (standalone) I used one on the first backhoe I built. It basically was a spring valve that would open when it reached the pressure setting and bybass...
  2. fluidlearning

    Hydraulic drive for small tractor

    I have a spool valve in series with the pump output to the motor, it is intended to operate a cylinder that I have not hooked up yet. I ran a test and with the motor stalled, quite a bit of fluid did flow through it. I cannot see how it can get that much flow past the gears and wearplates, I...
  3. fluidlearning

    Hydraulic drive for small tractor

    The engine was at idle, 300 PSI was observed when the enging PRM's increased. If the motor was turning, the pressure was around 50 PSI. I think you are correct, by the way the motor was acting the pressure must have been equal on both sides of the gear, so that it would not start, and when I...
  4. fluidlearning

    Hydraulic drive for small tractor

    Well, I got it all hooked up, basically like this Tank-pump-(guage)motor-return to tank. I found that the motor would not always start on it's own, after a push it took off running. With the gas engine at idle and the motor stalled, the pressure was about 300 PSI, I could feel the outlet hoses...
  5. fluidlearning

    Hydraulic drive for small tractor

    A quick question. I have a dual pump (cannot find specs on it) but of course one has a larger displacement than the other. Since I am using one pump to drive another pump as a motor, should I use the first stage of the dual pump as a charge pump and feed the 2nd stage of the pump, getting higher...
  6. fluidlearning

    Hydraulic drive for small tractor

    kcj, To see the video go to http://www.qsl.net//wd5bjw and click on backhoe, that should download it. It was built with a positive displacement pump (old pressure washer), using glycol as the fluid. It was driven off the lawn mower engine, which was also coupled to the transmission. The problem...
  7. fluidlearning

    Hydraulic drive for small tractor

    Thanks, I have a video (mpeg) clip of a backhoe I built, I would like to send you, or include in post if that is possible. Any idea's how?
  8. fluidlearning

    Hydraulic drive for small tractor

    OK, now that I have gotten further along on this project, thanks to your help. I now need to use the hydraulic power to do other work. The pump is directly (fluidly) connected to the motor, and I need to add a valve to power a cylinder. My question is, can I "tee" off the output of the pump...
  9. fluidlearning

    Hydraulic drive for small tractor

    Yes, the formulas would be helpful. Thanks for your insightful information; it will be a great help in understanding what’s happing. ps: I used those numbers from a mfg. spec sheet, I have not been able to find any information on the pump I have (although it is bigger than the one I used for...
  10. fluidlearning

    Hydraulic drive for small tractor

    kcj, I don't understand how RPM figures into the equation (per the spec sheets). I know if RPM goes up, then GPM goes up. Let's take a typical gear pump, the spec sheet says displacement .144 - RPM 1800 and at 1500 PSI yields .71 GPM. What is the formula for figuring GPM from these three variables?
  11. fluidlearning

    Hydraulic drive for small tractor

    I have decided to use an idler clutch at the transmission, which means the pump connected directly to the motor. But I was trying to figure out the horsepower and something was not coming out right, The formula for HP is flow X pressure over 1714, right? I ran a rough estimate on the pump /...
  12. fluidlearning

    Free Space Optical :What are the Problems?

    Scott, I would try wireless 2.4 Ghz. It is less sensitive to atmospheric conditions that the 5 Ghz stuff. Optical is going to be a nightmare. At the new location with it's old wiring, I would try the LRE solution that Cisco sells, it's like DSL, and runs on single pair copper.
  13. fluidlearning

    Hydraulic drive for small tractor

    That will be great, because of the difficulty in getting the mechanical linkage from the motor in front to the transmission in the rear, fluid power will be the way to go. I want to make sure that I can deliver the horsepower to the transmission As far as variable speed, I can vary the engine...
  14. fluidlearning

    Hydraulic drive for small tractor

    Thanks, The info off the pump (it's a dual and I was just going to use the larger bottom section) is Bosch D86 1518 222 000 I have not had any luck searching the web or Bosch/Rexroth for that number, it must be an older numbering system. The other pump that I plan to use as a motor has RK 040...
  15. fluidlearning

    Hydraulic drive for small tractor

    Hi. I need to transfer 12 Hp from a gas engine to a differential transmission, it is too difficult to do it by mechanical means, and so I chose hydraulic drive. I have a gear pump that will couple to the engine, and would like to use a gear pump as a motor to drive the transaxle input. It looks...

Part and Inventory Search