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.

Solution

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
A suspended walkway in an underground cavern consists of a deck supported by three tie rods placed symmetrically about the centre as shown below: The rods are each of

Explain Numerical Control (N.C) Procedure a) Process Planning: - This is listing of the sequence of operation to be performed during manufacturing of a part. This as well lists

(a) Explain safety features of latest vehicles. (b) Discuss the advantages and disadvantages of front wheel drive vehicles over rear wheel drive vehicles.

I am am Mtech student of Machine design and I am willing to join some core companies so is this the right time for learning some software''s if yes which are they...

Petrol: Work in a well-ventilated area. Keep flames or sparks away from the work area or where petrol is stored.

A three phase squirrel cage induction motor has the nameplate data shown in Table I below  Table I : Induction Motor Nameplate Data. a)  Calculate the induction motor ef

Answer any five questions. a) Describe calibration and state its types. b) Which are the kinds of test signals? c) What is the basic working principle of piezo-electric tr

what is the difference between intrinsic and extrinsic process?

Inspection of Electrical Equipment STEPS All electrical equipment are checked for proper functioning. The starting and lighting of the motorcycle should be prope

The different advantages of alloy steel are as: (a) Higher strength, toughness and hardness upon surface and over bigger cross-section. (b) Better harden-ability and retentio