TVET COLLEGE SUPPORT

CLUTCHES

 

Friction clutches
A friction clutch is part of a machine, such as a car, which uses direct contact and friction to operate another part of the machine, generally by causing it to rotate. In the case of an automobile, the clutch allows the transmission and the engine to rotate at the same speed, which transmits rotational movement to the wheels, and the car moves forward. The friction between the flywheel on the engine and the clutch plate or clutch disc from the transmission creates the force which rotates the wheels and moves the car. Clutches fall into either the wet or the dry category depending on whether they are lubricated, and may also be divided into a push or pull type depending on how they disengage. When the friction clutch is engaged, friction between the flywheel and the clutch plate creates movement, and when the clutch is disengaged, the lack of friction causes the wheels to lose their forward momentum and eventually stop turning all together.
 
There are two three of positive clutches:
Application of friction clutch
A friction clutch plate is used in vehicles to allow the transmission input shaft and engine to run at the same speed when rotating. The friction that is created between the engine and the transmission is what provides the force required to move the vehicle.

Advantages

Disadvantages
  • The working of engagement and disengagement is very smooth in a friction clutch.
  • Power losses are very less.
  • As sufficient surface area is available for heat dissipation in such clutches, no cooling oil is required.
  • Friction clutches have a quick operation and respond fast.
  • It makes it easier to change gears than a cone type.
  • Friction clutches have high wear and tear rate.
  • It has less torque transmitting capacity.
  • The springs have to be the more stiff hence greater force requires to disengage.
  • It requires high maintenance.
  • The space required to accommodate the clutch is more as compared to the multi-plate clutch.