Mechanical Engg Simple Notes ,Solved problems and Videos

A simple band brake drum:

A turning moment diagram for a four stroke cycle internal combustion engine, we know that in a four stroke cycle internal combustion engine, there is one working stroke after a crank has turned through two revolution i.e.7200 . Since the pressure inside the engine cylinder is less than the atmospheric pressure during suction stroke therefore a negative loop is formed. During the compression stroke, the work is done on gases, therefore a higher negative loop is obtained.

Slip of Belt:- Ans:- When driver pulley rotates firm grip between its surface and the belt. This firm grip between pulley and belt is because of friction and known as frictional grip. If this frictional grip becomes insufficient to transmit the motion of pulley to belt. Then there will be. 1) Forward motion of driver pulley without carrying belt called as slip on driving side.

ii) cam profile:

Calculations:

i) Velocity of crank AO:

V_AO = (r X ω ) X (480 X 20)

a_ab  = l(ab) X Scale = 4.3 X 40 X 10³

 a_ab = 172 X 10 mm/sec²

Data :

Construction and Working of Eddy current dynamometer :