Question

A power transmission mechanism consists of a belt drive and a gear train as shown in the figure.

Diameters of pulleys of belt drive and number of teeth (T) on the gears 2 to 7 are indicated in the figure. The speed and direction of rotation of gear 7, respectively, are

• A. 255.68 rpm; clockwise
• B. 575.28 rpm; clockwise
• C. 575.28 rpm; anticlockwise
• D. 255.68 rpm; anticlockwise

Answer 1

The correct option is A 255.68 rpm; clockwise

Given data:

$T_3=44$
$T_6=36$
$T_2=18$
$T_4=15$

$\frac{N_1}{N_0}=\frac{d_0}{d_1}$

$\Rightarrow N_1=\frac{150}{250}\times 2500$

$N_1=15,00=N_2$

$N_3=\frac{N_2\times T_2}{T_3}$

$=\frac{1500\times 18}{44}=613.63636=N_4$

$N_6=\frac{N_4\times T_4}{N_6}=\frac{613.63636\times 15}{36}$

$=255.6818=N_7\left(\text{Clockwise}\right)$

Gear 5 is idler.