A leader faced conical clutch has a cone angle of $30^0$ . If the intensity of pressure between the contact surfaces is limited to $0.35 N/mm^2$ and the breadth of the conical surfaces is not to exceed one-third of the mean radius, find the dimensions of the contact surfaces to transmit 22.5 KW at 2000rpm. Assume uniform rate of wear and take coefficient of friction as 0.15. -

Mumbai University > MECH > Sem 5 > Theory Of Machines 2

Marks: 10 M

Year: May 2015

Given:

Θ=30

Semicone angle = α = 30/2 = 15

pmax = 0.35 Mpa

B=Rm/3

P=22.5 kW

N= 2000 rpm

μ= 0.15

Fig: side view of the clutch

Solution:

Torque $= T = P/w = P \times 60/ 2πN = 22500 \times 60 / 2 π \times 2000 \\ = 107.5 Nm$

T $= μ \cos ec α \times F \times Rm \\ = 0.15 \times 3.86 \times (p \times A) \times Rm \\ = 0.15 \times 3.86 \times (0.35 \times 106) \times (2π \times Rm \times B \cos α) \times Rm \\ 107.5 = 0.15 \times 3.86 \times (0.35 \times 106) \times (2π \times Rm \times Rm/3) \times Rm \\ Rm = 0.063m = 6.3cm$

B = 2.1 cm

Also,

$B \sin α = R2- R1 \\ R2 – R1 = 0.52cm .......................................i \\ R2 + R1 = 2 Rm = 12.6 cm ..........................ii$

From i and ii

R2 = 6.56 ≈ 6.6cm

R1 = 6.04 ≈ 6cm