Difference between Drum Brake and Disc Brake

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Brake is a mechanical device which is used to absorb the energy from a moving system by means of friction. The main purpose of brake is to slow down or completely stop the motion of the moving system like wheels of automobiles, rotating drum and any kind of machinery. We can say that brakes are the important part of any moving system and works as a safety device also. Braking is done due to the friction between two surfaces. Brakes can also be used to hold the objects in rest position. Brake absorbers energy in two form i.e. kinetic and potential energy. In case of running automobile brake absorb the kinetic energy of moving vehicles. In elevators and hoists brake absorbers the potential energy released during the braking. The brakes are applies by means of friction so the energy absorbed by the brakes is converted into heat energy which is dissipate to the surrounding. The heat generation during the braking is a major problem in brake applications. Now a day’s different types of brake are used where this heating problem is resolved up to some extent. Generally brakes are classified in three main categories these are mechanical brake, hydraulic and pneumatic brakes and electric brakes.

Here we will study about the main differences between the drum bake and disc brakes. Both the brakes come under the category of mechanical brakes. The braking capacity of different types of brakes is depends upon the various factors like pressure between the braking surfaces, area of contact between braking surfaces, diameter/radius of the brake drum, coefficient of friction between contact surfaces and the rate of heat dissipation.

Difference between disc brake and drum brake:

Following are the difference between Drum brake and Disc brake:-

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                 DRUM BRAKE                           DISC BRAKE
Drum brake is a small drum which rotates with the wheel in case of automobile and has a pair of shoes known as brake shoes inside it. When the brake paddle is pressed then the brake shoes are forced against the side of the walls of the drum and apply brake by means of friction.


Disc brake has a disc shaped metal plate and a caliper which is attached to the wheel and disc is rotates with the wheel of automobile. The caliper is used to exert force on the pads.  The friction lining of the caliper comes in contact with a small portion of the disc. The reaming portion of disc helps in dissipation of the heat to the surrounding. Two pads on either side of the disc are used and the friction lining is attached to the both pad. Caliper is attached to the non rotating member and exerts force on both the pads. When brake paddle is pressed then pads are also pressed against the rotating disc then the friction between the disc and pads retards the speed and stop the disc.
Drum brakes are pure mechanically operated. Disc brakes are mechanically operated but they can also be linked with ABS system and some other advance technologies.
In drum brake water is collected inside the drum when vehicle runs in water or at washing time. This water accumulating affects the efficiency of the braking. They work efficiently in adverse conditions like in heavy rains and there is no such effect of water in case of disc brakes.
Drum brakes are not effective at high speed because at high speed when brake is applied then due to friction lager amount of heat generates due to this over heating occurs. As temperature increases the coefficient of friction decreases due to this friction lining fade away and loss of torque transmitting capacity of friction lining at higher temperature. In case of disc brakes no overheating occurs because only a small portion of the disc is come in contact with the friction pads and rest area of disc helps in better dissipation of heat. So they can be used in high speed applications. The coefficient of friction is not change very easily and the friction lining not fade away easily.
Drum brakes has less torque transmitting capacity. Disc brakes have high torque transmitting capacity in small volume.
Its response time is high as compare to disc brakes Disc brakes as easy to control and has fast response time as compare to drum brake.
This may be self locking Disc brakes never be self locking
Drum brakes are used in heavy vehicles due to the self actuating properties i.e. when the corner edges of the brake pad comes in contact with outer cover then the rest of brake pad is comes in contact itself so less effect is required by the driver. Disc brakes generally used in medium and low vehicles because there is no self actuating property.
Less effective in different applications and heavy in weight as compare to disc brakes More effective in different applications and light in weight.
Here is no fluid is used so it is not require any kind of maintenance when vehicle is used after long time. When vehicle is not in use for long time then the chances of damage of brake fluid pipe increases which causes failure in braking and require maintenance and braking fluid may loss its viscosity which should be replaced.
In case of drum brakes for inspections and service of brake; wheel and drum are dissemble first because brake parts like pad brake shoes etc are attached inside the drum. Disc brakes are easily inspected without removal of the wheel because it is mounted with the wheel so the defaults in the brake visually inspected very easily.
Drum brakes are not completely self adjusting and less efficient than disc brakes. Disc brakes are better stopping power than drum brake and completely self adjusting, so overall performance of the disc brake is better than the drum brake.
The maintenance of drum brake is cheaper than disc brake Maintenance cost is high if we used disc brakes.

This is all about main difference between disc brake and drum brake. If you have any query regarding this article, ask by commenting. If you like this article, don’t forget to share it on social networks. Subscribe our website for more informative articles. Thanks for reading it.

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