Brakes and
Dynamometer
A brake is an appliance used to apply frictional resistance to a moving body to
stop or retard it by absorbing its kinetic energy.
Clutch: Connects two moving members of a machine
Brake: Connects a moving member to a stationary member.
Types of Brakes:
I. Block or shoe brake
II. Band brake
III. Band and block brake
IV. Internal expanding shoe brake
Nomenclature:
Taking moment about pivot point ‘O’
Numerical:
Band brake:
It consists of a rope, belt or flexible steel band (lined
with friction material) which is pressed against the
external surface of a cylindrical drum when the brake is
applied. The force is applied at the free end of a lever.
Brake torque on the drum= 𝑇1 − 𝑇2 𝑟
The effectiveness of the force F depends upon the
• Direction of rotation of the drum
• Ratio of lengths a and b
• Direction of the applied force F
Numerical: