Determine the effect on power transmission in the following cases:

i) Initial tension in the belt is increased by 8%

ii) Initial tension in the belt is decreased by 8%

iii) Angle of lap is increased by 8% by the use of an idler pulley, for the same speed and the tension on the tight side, and

iv) Coefficient of friction is increased by 8% by suitable dressing to the friction surface of the belt.

Subject: Kinematics of Machinery

Topic: Belts, Chains and Brakes

Difficulty: High

P= 2.5 kw, $\mu$ =0.3, $\theta$ =165$^{\circ}$, ν = 2.5 m/s

P=($T_{1}$ – $T_{2}$) ν

2500 = ($T_{1}$ – $T_{2}$) ×2.5 or $T_{1}$ – $T_{2}$ =1000N.

$\frac{T_{1}}{T_{2}}=e^{\mu\theta}=e^{0.3\times 165 \frac{\pi}{180}} $=2.37

or $T_{1}$ = 2.37$T_{2}$ - $T_{2}$ =1000 OR $T_{2}$ =729.9N.

$T_{2}$ =729.9 ×2.37 = 1729.9 N.

Initial Tension, $T_{0}$ = …