Servo mechanism

 Any mechanism which adds to the drivers effort in applying the brakes is called Servo mechanism although that effort remains a considerable part of the total breaking effort required.

As  the weight of the vehicle goes on increasing more breaking effort is needed to stop the vehicle when a limit is reached above which it is not possible for an ordinary driver to apply the effort needed conveniently this limit is normally reached at about returns the weight of the vehicle beyond this the help of the server action or self energization of the break is taken
Mechanical Servo mechanism mechanical service where used initially but after the introduction of vacuum operated service this have been obsolete a brief description of mechanical server principal is given here however the vacuum Servo mechanism is dead in the next article

Disk a is always revolving when the vehicle is in motion it being attached to some rotating part of the vehicle example gearbox main shaft or propeller shaft there is another disk B which can be pressed against disk a as in ordinary single plate clutch. Adivasi is fixed to the shaft of B and is connected by a Rod De to break linkage
suppose disk is revolving restaurant then if disk b is pressed on two Disc a with a force f a driving torque will act upon be pending to rotate it in the same direction the disk we will turn slightly under the action of the stock there by pulling the rod be and applying the brakes to such an extent that the pool in road b x exerts a torque equal and opposite to the driving torque between the disc when this condition is reached there will be no for the motion of the disk be and sleepy take place between the discs
The system described above can still be modified for the case when the server action will be obtained for both the directions this may be done as explained below enter inter

Referring to figure change x and y are flexible and on that account they can transmit force only intention if the disk b is turning in clockwise direction only chain X will transmit the force and pull the arm of bell crank Lever up there by applying the brakes if the disk b is turning in anticlockwise direction the chain X will not transmit any force and change why will pull the arm of the liver up and thus the brakes will be applied under 


Disc brake with Servo action a simple diagram of disc brakes which provides also the Servo action is shown in figure disk is fixed against rotation on the axle casing with a key while disk b is free to rotate on the axle casing disk a contains an annular to act as Surinder wildest B has the corresponding and neula Piston to fit in the cylinder as shown the fluid under pressure is introduced in the cylinder and the brakes are to be applied what is a and b have a series of gross which contain was one of which is visible in the figure
When the brake pedal is pressed the fluid in the cylinder pushes the Piston there by pressing limit lining on be against the brake drum which is already in motion and thereby the disk be is set into rotation by the describing fixed against rotation cannot rotate the result is that was in the group tend to write up the shopping sites of the gross which introduces force at right angles to disk A and B which further press Linings On A and B to the brake drum does providing the desired Servo action
The degree of Servo action depends upon the slope of the group sides the larger the slope the higher is the degree of Servo action or ever increasing the slope beyond a certain value about 35 degree increases the chances of jamming and rocking of the breaks due to the walls being to slide tree West between praise A and B moreover in case of a sharper slope the displacement of the disk with respect to each other to develop desired Servo action will also be much more due to which reason disc brakes with higher degree of Servo action are highly sensitive to the lining wear