Question

If the crank rotation angle varies from 45 degrees to 135 degrees, Using three precision points with chebyshev’s spacing, synthesize a slider crank mechanism where where displacement of slider is square of the crank rotation. From the above information calculate ‘c’ in mm.

(a) 148.2

(b) 158.2

(c) 135.7

(d) 120.2

I got this question in an internship interview.

This interesting question is from Analytical Synthesis for Slider Crank Mechanism topic in chapter Computer Aided Analysis and Synthesis of Mechanisms of Machine Dynamics

Answer 1

Right option is (c) 135.7

For explanation I would say: From the above data θs=45° and θf=135°, assuming starting displacement and final displacement of slider as 100mm and 30mm respectively,

We calculate k1 = 96.4mm

k1 = 2a

Therefore a = 48.2mm

Now k2 = 2.a.c = 13084

Therefore c = 135.7mm.