How Does a Hydraulic Circuit with Variable Restriction and PRVs Function?

• Engineering
• PetePetePete
In Summary,The electric motor turns the pump which draws hydraulic fluid into the system through component F. This creates a flow, turning the hydraulic motor. The pump and motor can only accept a certain flow, so as more fluid is drawn into the system pressure will build, causing Components B&C to open in turn. The fluid will leave the system through the variable restriction, but only at a rate which maintains the required pressure in the system.
PetePetePete
< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown >

Hi,

I am struggling with a couple of questions and would like to check my working so far.

Question 6:

To explain the operation: I believe the electric motor turns the pump which draws hydraulic fluid into the system through component F (which one depends on the direction of the pump). This creates a flow, turning the hydraulic motor. Because the pump and motor can only accept a certain flow, as more fluid is drawn into the system pressure will build, causing Components B&C to open in turn. The fluid will leave the system through the variable restriction, but only at a rate which maintains the required pressure in the system.

Is this a correct interpretation of the circuit? I am not sure how to explain Question 6 part c) regarding the limitations of speed control - can anyone help?

I would say that because the Pressure Relief Valves will be opening and closing, it would cause a fluctuation in the speed at A?

Question 7:

I am struggling to know where to start on this question, any guidance would be appreciated.

Thanks
Pete.

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Sorry I am not sure which components you mean?

My understanding was:

A = fully rotational bi-directional fixed displacement hydraulic motor
B & C = Pressure Relief Valve
D = bi-directional fixed displacement hydraulic pump
E = Electric motor
F = Variable Restriction with Integral Non Return Valve

I will admit I am not entirely sure how the PRVs operate in this circuit - do they simply open when pressure reaches a certain level or are they a holding tank?

I would appreciate help to walk through how the system operates. I believe from there it will help me answer the follow on questions once I understand whether my interpretation of the system is correct.

Thanks
Pete

PetePetePete said:
Sorry I am not sure which components you mean?

My understanding was:

A = fully rotational bi-directional fixed displacement hydraulic motor
B & C = Pressure Relief Valve
D = bi-directional fixed displacement hydraulic pump
E = Electric motor
F = Variable Restriction with Integral Non Return Valve

I will admit I am not entirely sure how the PRVs operate in this circuit - do they simply open when pressure reaches a certain level or are they a holding tank?

I would appreciate help to walk through how the system operates. I believe from there it will help me answer the follow on questions once I understand whether my interpretation of the system is correct.

Thanks
Pete
Pete,

Do you have any thing to share from this?

I have made further progress with the purpose of the components, understand to an extent how the circuit works but the Restriction valves image with the arrow is throwing me. They both point in the direction which the non returns open so would be redundant??

Any tips would be greatly appreciated.

GSXR

1. What is a hydraulic circuit?

A hydraulic circuit is a system that uses pressurized fluid to transfer power and perform work. It typically consists of interconnected pipes, valves, and actuators that control and direct the flow of the fluid.

2. What are the advantages of using a hydraulic circuit?

Some advantages of using a hydraulic circuit include high power density, precise control of movement, and the ability to operate in a wide range of temperatures and environments. It also allows for efficient energy transfer and can be easily automated.

3. How does a hydraulic circuit work?

A hydraulic circuit works by using a pump to pressurize a liquid (usually oil) and then directing it through valves to different parts of the system. The pressurized fluid then activates actuators, such as cylinders or motors, to perform the desired work.

4. What are some common applications of hydraulic circuits?

Hydraulic circuits are commonly used in heavy machinery, such as excavators and cranes, as well as in industrial and manufacturing processes. They are also used in aircraft, automobiles, and other vehicles for steering, braking, and other functions.

5. How do you troubleshoot a hydraulic circuit?

To troubleshoot a hydraulic circuit, you should first check for any visible leaks or damage to the system. Then, you can use a pressure gauge to check the pressure of the fluid and valves to ensure they are working properly. You may also need to clean or replace filters and check the fluid level and quality. If the issue persists, it may require the expertise of a professional hydraulic technician.

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