Adam, you are right on top of some very important and tender issues for a circuit like this. On this exact machine, the load mass is always the same, and the rate of motion is very slow. Therefor a counterbalance is not needed. There will not be a runaway, which is where a counterbalance valve shows it's capabilities. Of course a counterbalance is not a flow (speed) control per se. If you look closely at the symbol, you will see an extra inline arrowhead in each flow control (older ANSI symbol shows the extra arrow head at 90 degrees to the flow line). This denotes a pressure compensated flow control, which is the type with a small floating spool inside that can make minor adjustments to the orifice opening automatically if pressure fluctuates a little on one side or the other of the flow control. In so doing it keeps the flow rate very steady. I have oversimplified a little on the p. comp flow control explanation. We will do a video soon on the pressure compensated flow control as a component. In my experience, the p. comp. flow control can only provide 'compensated' flow control in one direction. Haven't seen one yet that can do both. So two flow controls are needed to provide truly pressure compensated flow, one for each direction. That's a second reason to use two FCs. Chad Jessup who commented earlier, picked up on the other. Thanks for commenting/playing along! - Carl
This is a new animation of an old machine actually. The trick of using both meter-in and meter-out together, is not new. Sometimes it causes confusion for the technician who has to adjust the flow controls.
sir. i really thankful to you for your lessons. i have a request, may i watch a video on practical working of ' bent axis axial piston pump with power control.' please.
