13/13 I would like to reiterate the fact that THERE IS NO HEAVY TECHNICAL VOCABULARY! It is refreshing to watch an engineering video that is straightforward and visually aiding.
@@martynasvizbaras1180 basically everything is built into the closed loop system . enough room for oil and the control valves. seems like the open system is more user friendly. easier to repair.
I also taught hyd and some folks just never really unstand how it works 😊 No matter how you explain it to them 😢 I loved working but had to retire at 68
Good presentation. In summary from my past experience as an ex hydraulic engineer. Closed loop systems primarily used in mobile applications where a compact design is needed and a direct, dual direction connection is required between a single pump and motor or motors. Advantages: compact design due to smaller tank, smaller hydraulic pipes, less valves. Disadvantages: expensive components, often variable dual direction pumps and/or motors, design limitations in adding additional end uses, unequal displacement end users users (such as standard cylinders). Open loop systems primarily used in static industrial systems. Advantages: lower component costs and unlimited design options, multi independent actuators from a single system. Disadvantages: bigger tank capacity required, bigger pipes on the return side, separate valves.
@Ask APT No, moved out of the field 21 years ago. Still very passionate about all hydraulic. While mechanically I would imagine the systems remained similar, I am sure on the control side, there have been good developments over the past 20 years. All the best.
Really many many thanks for your your existence, and the videos you upload. I've been trying to understand the hydraulic system on the bulk carrier ships i work and you are definitely helping.
A very good video. Very well explained with the help of equipment. There are no clutters in the explanation and hence easy to understand. Thanks very much...
Great video mate very descriptive. My favourite part was how you drew the hoses on the white board demostrating whats happening then showing us physically afterwards. Thank you for the content
Very helpful and informative! I loved the way you demonstrated your point: by sequentially adding parts and explaining the differences in the state of the loop as you went.
But here is a flaw concerning the open loop system. Directional control valves are usually proportional. You can control the speed with the lever pretty well. You don't normally need any flow control valve that increases unneccessary pressure, energy consumption, heating and wear on the pump. On every tractor, loader, excavator etc with a fixed displacement pump for the working functions you control the hydraulic cylinders and even motors by the levers on the control valve and rarely any flow control valve is used. Controlling the speed of a cylinder is pretty much like controlling the speed of a motor.
@@ontheroadagain4773 Exactly. In most cases, you don't need a flow valve when you have a control valve that will do the same. The systems with solenoid control valves you do if you don't want full flow on part of the circuit.
I just bought tons of hydraulic Pistons, a pump, line and valves, also a big ram with absolutely no clear understanding of how to make them work or what to do with them... 😄😄😄😄 RU-vid to the rescue AGAIN.😎💯👍
Very well done. I am fluid power certified hydraulic mechanic with 40 yrs. Exp. Best video i have seen. Here in the US we say Open Center and Closed Center. But great job
Awesome video. I learned practical things that i did not fully understand due to the limitation that i studied it through books only. Thanks. Keep it up please
Just watched your Great video, very well done!. I learnt hydraulics 35 years ago, as a mechanical fitter working on presses and factory equipment, just a mention that the swash plate in a axial piston pump changing positions may not just change displacement volume, but also can change its relative position to the inlet and outlet ports on certain pumps!. What amazes me is the service life of some equipment may have been from WW2.😂 All gone now I imagine!
closed loop is used in transmissions in just about every construction, forestry and farming machines these days, open loop is for hydraulic cylinders where the oil needs to be returned to a tank as the oil amount varies to and from the hydraulic rams/cylinders.
@@braddavis4377Automatic cars have a torque converter, comparable to this closed loop with a fixed swash plate angle. Pumping fluid creates drag so its really only good for high torque low speed
On a car, the open loop system is the better choice for a lot of reasons! The variable speed ability is taken over by the engine, and gives you the ability to use sliding vane or gerotor pumps for simplicity and longevity. An example is a power-steering assembly. These systems pump fluid through an a little hole (called an orifice). At low engine speed, the orifice is too big to be a restriction, and the car is likely parked or has low duty requirements, so drag isn't a problem. You can turn your power steering pump with your hand! Pressure gain has exponential characteristics. Doubling engine speed will quadruple the pressure, and the engine often goes over 10-times the idle speed. Any shock loads against these systems are typically resolved with the tremendous amounts of momentum in the engine. For an Electric motor that rotates at a fixed frequency (60hz, geared down to whatever suits your nominal shaft torque requirements and pump speeds), the closed loop system makes sense, but has its own sacrifices. For example, we might need a sudden burst of speed. The motor often can't cope with this, or becomes a reactive load for the power source. The work-around is to have a huge flywheel on the motor. If you're dealing with shock loading, the flywheel will give you all of the load you could ever want, but the shock loads can trigger your safety valves, causing the system to go backwards.
Automatic transmissions have open-loop systems that are optimized for the duty at hand. You have control over engine speed and should be mature enough to know what kind of gear shifting duty the transmission would ever need to do. Given that information, an open loop system can be made, such that its mode of failure is known and forced to happen for safety reasons.
Good explanation . Closed loop systems would generally have some kind of top up or boost pump incorperated to keep a contant gpm. also without a top up a possibility of cavitation could occur. If there was some kind of drag/force holding the wheel then pressure would build up thats why a PRV would be installed to divert back to tank. hense the reason for a boost pump to keep the fliud topped up. and hense the reason the tank is still there.
Thank you that was very informative, a question on this though, in case I want to control not just the direction of the tyre but also the I need multiple functions using the same pump(HPU) in that case an open loop system would be the only option as I can have the feed line to the pump on a control panel and the return line on the tank section of the control panel and have multiple ports at the panel for different functions. and this cannot be achieved in a closed loop system as the return isn't going to the tank but the pump itself, am I right?
Hey mate, how do I hook up a hydraulic motor running a conveyor to my log splitter? Where abouts on the splitter system should I tap into? It's gota high volume single stage pump. Kind regards from nz.
But here is a flaw concerning the open loop system. Directional control valves are usually proportional. You can control the speed with the lever pretty well. You don't normally need any flow control valve that increases unneccessary pressure, energy consumption, heating and wear on the pump. On every tractor, loader, excavator etc with a fixed displacement pump for the working functions you control the hydraulic cylinders and even motors by the levers on the control valve and rarely any flow control valve is used. Controlling the speed of a cylinder is pretty much like controlling the speed of a motor.
Great video , can you make a video on how to correctly add a oil cooler , return side , with all the components and options like how much oil to put through the cooler , GPM flow etc . Cheers
But this isn't how an open loop system works in practice. Directional control valves are usually proportional. You can control the speed with the lever pretty well. You don't normally need any flow control valve that increases unneccessary pressure, energy consumption, heating and wear on the pump. But in systems with solenoid control (on-off function) valves you need flow control valves if you don't want full flow on part of the circuit.
Question. I was changing oil on my zeroturn mower hydraulics. When I filled back up it didn't take anywhere near as much oil as the manual says. So obviously there is still oil in the motors and pump. My question is how do I get that old oil out? Is it ok to start mower with wheels off ground and engage back and forth back and forth. Will this pump excess oil back onto tank safely without wrecking anything? Cheers
Very cool I am watching this and all of a sudden a light comes on and this is my John Deere transmission driving lawn mower I rebuilt, basically I changed about 40 Orings & a couple of shaft seals they wanted a thousand dollars for a new one I bought a rebuild kit for 80 dollars I must of fixed it still working after two years !! LOL
