Hydraulic clutch: What is it, Diagram, Construction, Working [with pdf]

Hydraulic clutch

What is hydraulic clutch:-

  • Hydraulic Clutch is one of the Type of Automobile Clutch.
  • In this Type of Clutch, Fluid is used to Operate the Clutch. The advantage of Hydraulic Clutch is Less Effort is required to Press the Clutch Pedal. 
  • As compared to Plate type clutch, In the Hydraulic clutch, Diaphragm is used at a place of spring to keep Pressure on Pressure Plate.

Hydraulic clutch diagram:-

hydraulic clutch


It is consists of Flywheel, Pressure Plate, Friction Plate/Clutch Plate, Diaphragm, Master Cylinder, Release Bearing, Release Fork, Hose/Pipe, Slave Cylinder and Clutch Pedal.

1) Flywheel:- Flywheel is Connected to Engine Crankshaft. When Pressure Plate Press the Friction Plate Against the Flywheel, Power/Torque Transmits from Flywheel to Clutch Shaft Due to Friction Between Plates & Flywheel.

2) Pressure Plate:- Pressure Plate is use to Press the Friction Plate Against the Flywheel. The Diaphragm Spring is Use to keep Pressure on Pressure Plate.

3) Friction Plate :- Friction Plate has friction Lining on both Side Surface. Pressure Plate Press the Friction Plate against the Flywheel.

Hence Contact made Between this two Plates & Flywheel. Friction between them is Responsible for the Power/Torque Transmission.

4) Diaphragm :- Diaphragm has Circular shape. It is One of the Type of Spring. It is use to keep Pressure on the friction plate.

5) Release Bearing :- It Is mounted on Clutch Shaft. When Driver Press the Clutch Pedal, through a linkage , Release Bearing apply Pressure on Diaphragm at middle portion to Disengage the Clutch.

6) Release Fork :- It is Use to Press Release Bearing Against Diaphragm. One end of Release Fork Piston Rod of Slave Cylinder & Other End is attached to Clutch Shaft.

7) Slave Cylinder :- It is Use to Press the Release Fork. Piston is use in this Cylinder, Piston Rod is Connected to Release Fork. When Fluid enters in Slave Cylinder, Piston Press the Release Fork.

8) Hose/Pipe :- It is use to Transfer fluid from Master Cylinder to Slave Cylinder to Operate the Clutch.

9) Master Cylinder :- It is Hydraulic Cylinder, use to Operate Clutch. Piston is Use in Master Cylinder. Piston Rod is Connected to Clutch Pedal. When Driver press Clutch Pedal , Piston moves & press the fluid in the Cylinder.

10) Clutch Pedal :- It is Use to Operate Clutch when desired. Clutch pedal is Connected to Master Cylinder Piston Rod. When Clutch Pedal Press, Fluid press & flows from master Cylinder to Slave Cylinder to Operate Clutch.

Hydraulic clutch working:-


When Vehicle is Running, Clutch is in Engage Postion. When Driver Press the Clutch Pedal, In Master Cylinder, Piston Press the fluid . Hence Fluid flows from Master Cylinder to Slave Cylinder through hose/pipe.

When Fluid enters into Slave Cylinder, fluid acts on piston therefore Piston Rod press the Release Fork.

When Piston Rod press Release Fork, Release Fork press the Release Bearing. Release Bearing press the middle portion of the Diaphragm to move left side.

Due to Left Side movement of middle portion of Diaphragm, Outside part of Diaphragm moves Right side as well as Pressure Plate also moves towards Right Side.

Therefore Pressure on Friction plate is Remove. So No Friction between Plates & Flywheel. Hence No Power Transmission take Place. Hence Clutch Disengages.


When Driver Release the Clutch Pedal, Pressure on Fluid Removes hence Resulting in Diaphragm again comes to original Position. 

Hence Outside Part of Diaphragm moves left side & Press the Pressure Plate on Friction Plate & Flywheel. Therefore Friction Occurs Between them. Hence Power/Torque Transmits From Flywheel to Clutch Shaft. Hence Clutch Engages.

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Pratik is a Graduated Mechanical engineer. He enjoys sharing the engineering knowledge learned by him with people.

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