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  1. FluidPowerUser

    Hydraulic motors in series Problem!

    You can put an orifice in the outlet of the last motor to increase the decrease the pressure drop over the motors so that is barely enough torque to keep them turning. Then, when the motors need to do work, you can bypass the orifice with a valve, either manual or solenoid controlled. The...
  2. FluidPowerUser

    Hydraulic motors in series Problem!

    Yes, it does make sense. The inertia in the discs is trying to drive the motors, so the system pulses as the work required to drive the motors goes up and down. If you dampen the affect of the inertia by sticking the discs in the ground or by giving them some work to do, they will settle...
  3. FluidPowerUser

    Hydraulic cylinder end position situation

    From a purely hydraulic point of view, you can go with a simple pump, a simple valve and just let the cylinder run to end of stroke or stop it with a mechanical end stop. Alternatively, you could spend money on a proportional control system that will detect the cylinder position and stop it...
  4. FluidPowerUser

    Hydraulic cylinder end position situation

    "Cylinders are slow-moving; no dynamic or inertia forces are coming into play" - Wanna bet? If it's moving, there will be some forces. You can either take up the forces within the structure or you can absorb the forces in the gland of the cylinder. If your cylinder manufacturer has done a good...
  5. FluidPowerUser

    I hope someone can help me . I have

    There is no adjustment for this valve. As stated, you will need to reset the Imin value to keep the spool in the neutral position. If the cylinder is still moving with the Imin set below the deadband of the valve, it's because there is excess leakage across the spool.
  6. FluidPowerUser

    I hope someone can help me . I have

    What’s the part number for the valve? The screws are most likely offset, ramp, gain or max current. With the product details known, I can give you more details.
  7. FluidPowerUser

    HYDRAULIC DAMPING - TRY TO UNDERSTAND THE DIAGRAM

    Yes, my mistake, just connects to tank. Not regen, just float.
  8. FluidPowerUser

    HYDRAULIC DAMPING - TRY TO UNDERSTAND THE DIAGRAM

    Snubbing switch will move the cylinder in and out Damp/lock will do as it says. Either dampen the operation or lock the cylinder. The valves will operate independently of each other. In other words, one will operate the direction and one will turn on the damping, you don't need to operate them...
  9. FluidPowerUser

    HYDRAULIC DAMPING - TRY TO UNDERSTAND THE DIAGRAM

    The valves on the left control the extend and retract of the damping cylinder. The idea being that the recovered item, boat or buoy or whatever, is pulled up against the damper. Or, it is offering some controlled "docking" when the assembly is luffed. The valve on the right, when not operated...
  10. FluidPowerUser

    Geroler Motor Speed Control

    Waterman valves are now Parker valves. Parker purchased Waterman a few years ago. Bear in mind that the pump is a gerotor/geroler type. Very leaky and not able to produce much pressure.
  11. FluidPowerUser

    Geroler Motor Speed Control

    To be clear, the "system" drawn above is the most basic form and probably not appropriate as the system is restrictive and would simply generate heat and hardly affect the motor speed. As stated, it would be better to use a 3 port priority flow control valve or a proportional pressure control...
  12. FluidPowerUser

    Geroler Motor Speed Control

    Rotating systems have a tendency to overrun. The inertia of rotating mass can sometimes be an issue and the motor needs to be able to pull oil in, otherwise it will cause cavitation at the inlet port. Linear systems can have the same problem, but they tend to have more friction than rotating...
  13. FluidPowerUser

    Geroler Motor Speed Control

    You need a directional flow control valve in one leg of the motor. Free flow in one direction, controlled flow in the other direction. Check valve with an orifice will do the job. Turn the check valve over if you want to meter the flow out of the motor. The orifice is not pressure...
  14. FluidPowerUser

    Hydraulic symbol identification needed, please.

    It's a manual control valve - rotary type You turn the knob or lever to change which cylinder is operated.
  15. FluidPowerUser

    LS remains at high pressure standby.

    Great to hear. No problem, happy to help. You fixed your tractor and learned something on the way too. All good. Cheers
  16. FluidPowerUser

    Function of the gap inside the displacement chamber of a constant speed drive?

    Unswept volume is oil that is not displaced by the movement of the piston. Each of the 9 sleeves and pistons have to be the same in terms of position and interaction with the slipper plate and the response to the forces applied when the pump is running. They all need to be the same length and...
  17. FluidPowerUser

    LS remains at high pressure standby.

    Yes, that could cause a slight offset off the rotor and sleeve. Just to add The post above shows the marks on the sleeve and rotor that need to be aligned for the LS pressure to drain to tank.
  18. FluidPowerUser

    Function of the gap inside the displacement chamber of a constant speed drive?

    Supporting previous comment. It is an undercut help with the manufacturing. The bore that the piston sits in might be sleeved and the undercut avoids having to clean the bottom face up to make sure that the sleeve sits flush or under the face of the piston block at the slipper end. If there is...
  19. FluidPowerUser

    LS remains at high pressure standby.

    The OSPD steering units with LSR have dynamic load sensing and have reaction steering. The actual schematic drawing for the steering unit looks like this: In neutral, the load sense signal should drain back through the spool and into the tank line of the steering unit, then back to tank...
  20. FluidPowerUser

    LS remains at high pressure standby.

    It's looking more and more likely that you have a blocked orifice in the steering unit. Do you happen to know the manufacturer of the steering unit? Is it a Danfoss unit? Or perhaps Eaton? If you can find the model number, we can help you locate the orifice that is blocked.
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