Compute the diameter of a solid shaft, Mechanical Engineering

Compute the diameter of a solid shaft:

Compute the diameter of a solid shaft transmitting 150 kW at 25 rpm, if the maximum shear stress in the shaft is not to exceed 70 MPa. Compare it with the shaft delivering similar power at 25000 rpm.


Power transmitted, P = 150 kW = 150 × 103  W

Number of revolutions, N = 25 rpm

Since, 1 Pa = 1 N/m2 and 1 Mega Pascal = 106 N/m2 = 1 N/mm2

Then, maximum shear stress, τm = 70 MPa = 70 N/mm2

Let T be the torque transmitted in N m.

P = 2πNT /60

150 ×103  = (2π × 25/60 ) × T

T = 57.28 × 103 N m

T = 57.28 × 106 N mm

T/  J= τm /(d/2)

d = 160.9 mm

If          N = 25000 rpm, then P = 2πNT /60   

150 ×103  = (2π × 25000 × T )/60

T = 57.28 N m = 57.28 ×103 N mm

T/ J= τm/(d/2)

57.28 × 103 / (π/32) d 4     =   70/(d/2)

d = 16.09 mm

It is seen from this example that the size of the shaft is decreased very much if the power is transmitted at high speed. That is the cause for the modern tendency to utilize high speed machines, those results in considerable saving in the material cost.

Posted Date: 1/21/2013 2:42:00 AM | Location : United States

Related Discussions:- Compute the diameter of a solid shaft, Assignment Help, Ask Question on Compute the diameter of a solid shaft, Get Answer, Expert's Help, Compute the diameter of a solid shaft Discussions

Write discussion on Compute the diameter of a solid shaft
Your posts are moderated
Related Questions
The Bronzes The coinage bronze employed for making coins in earlier days contains 95% copper, 4% Sn and 1 % Zn. The Zn acts as a deoxidizer. Such alloy is soft and ductile.

work done by an impulse turbine

Lubrication Complaints If the engine oil level is too low, check for the following things: External oil leaks Worn out piston rings Worn out valve guide and/o

Derive the shape functions N1...N10 for a 10 node triangular element in terms of area coordinates L 1 , L 2 , L 3 .  Nodes are equally spaced on the edges and node 10 is at the cen

Derive the finite element formulation  for a tapered bar element using Galerkin's method.                                                 1- Start with. 2- Use and as shap

explain the following terms in brief:- point function and path funtion

Contrary to the misconception that the growth in automobile industry has catered only to the higher income-stratum of society by producing mostly passenger cars, the fastest growt

What is the tesisting force