Question

Design a shajt having permissible shear stres a about 180Mpa and Factor of safety as 4. It transmits 20kW at 200 r.p.m. Find the diameter of Solid Shaft. If Solid shaft is replaced by hollow Shaft then find its inside and outside diameter. The Outside diameter of hollow shaft is double the inner diameter of shaft.

​

Answer 1

N = 200 r.p.m. ;

P = 20 kW = 20 × 103 W; τ= 42 MPa = 42 N/mm2

Let d = Diameter of the shaft.

We know that torque transmitted by the shaft,

= P∗ 60

2πN 3

= 20 ∗ 10 ∗60 2π∗ 200

= 5 N-m

= 955 × 103 N-mm

We also know that torque transmitted by the shaft ( T ),

955 × 103 = π *

τ*d3

16

d3 = 955 × 103 / 8.25

= 115 733 or d

= 48.7 say 50 mm

Answer 2

Answer:

Pls resend the q & foll_ow me...