what is the difference between a closed loop and an open loop circuit in hydraulics?

Answer 1

Same as it is in electricity... feedback. Part of the output is fed back to the input side, in the opposite sense and in proportion to the output. Used to control the output to stop it getting too excessive or building up too quickly.

Minty has the system a little wrong in that you can use a closed loop with a centre open valve. If you feed the pressure to both the cap and rod of a jack it can be finely balanced and only a little extra force on one side or the other will make it move, the amount of movement will be proportional to the force and then feedback is used to integrate acceleration to get speed and integrated again to get distance so you can tell how far the jack has moved. This is the basic principle of a hydraulic motion platform that flight simulators use, including the rides that can be seen on many fairgrounds. The centre open valve acts in a similar way to an electronic transistor where a small amount of energy can control a much larger amount.

Answer 2

Closed Loop Hydraulic System

Answer 3

A closed -loop hydraulic system it totally contained. It is a fixed-volume arangement.
An open -loop system allows for a variation of the fluid volume.
The normally operating cooling system in your automobile is both. It is usually closed and also sometimes open . When operating normally it is a closed (loop) circulating system. When the engine stops, residual heat from the engine block caused overpressure and /or expansion of the coolant. The spring-loaded valve in the radiator cap allows the excess to be vented into the overflow chamber. THen the cap valve closes and the system is closed again. When the engine cools a vacuum is formed and the fluid is drawn back into the system through the vacuum relief in the same radiator cap. Then it becomes a closed system again.

Answer 4

A closed loop system is one in which the fluid is recirculated and the cycle continues. Example: a hydraulic damper in which fluid moves from one cylinder to another via a restricted aperture.

In an open loop system fluid is replaced from a reservoir after each cycle. Examples: hydraulic ram on a digger, brake system on a car.

Answer 5

A closed loop contains the fluid within it's own sealed system.
For example, a cars clutch or braking system.
An open loop uses fluid from a continuous source which just passes through the system. This could be any fluid which is manufactured by the process which is using the loop,or water.
Sorry I can't explain it any better!

Answer 6

I believe the advantages and disadvantages vary depending on application. For instance, a closed loop system when talking about the valve being open or closed center will determine what type of pump you sould use. You do not want to use a fixed displacement pump on a closed system (the center condition of your valve being closed). This would cause the volume of your pump to be discharged over your system relief and cause heating issues. Conversely, you don't want to use a variable displacement pump with an open center valve (center condition set as p to t) This would cause the pump to constantly flow and thereby negate the efficiency and power savings by using this type of pump. If you are talking about a closed loop where the fluid goes from the pump to the actuator and then back to the pump, one of the biggest advantages is being able to use a smaller reservoir. One of the biggest disadvantages is that the same fluid is being constantly used. This results in faster fluid breakdown.

Answer 7

The difference between close loop and open loop.Hydraulic schematic diagram circuit operation. Close loop operation the pump suction from charge pump.Open loop operation the pump suction from tank

Answer 8

in closed loop fluid is recirculated and the cycle continues .

in open loop fluid is replaced after each or fixed cycle.

Answer 9

Simply .. in OPEN-LOOP u don't get FEEDBACK form the system but in closed loop ,, u get feedback and use it to correct the system performance !!!