Question

In a slider crank mechanism, the crank rotates with a constant angular velocity of 300 rpm, Length of crank is 150mm, and the length of the connecting rod is 600mm. Determine acceleration of the midpoint of the connecting rod in m/s^2. Crank angle = 45° from IDC.

(a) 117

(b) 144

(c) 148

(d) 252

The question was posed to me during an online interview.

My enquiry is from Acceleration in the Slider Crank Mechanism & Coriolis Component topic in chapter Acceleration in Mechanisms of Machine Kinematics

Answer 1

The correct option is (a) 117

Explanation: Let the Intersection point of crank and connecting rod be termed as ‘x’

velocity of x = ωxL(crank)

= 4.713 m/s

We draw a corresponding velocity diagram for the same,

where this velocity is perpendicular to the crank, this diagram when drawn to scale turns out to be a triangle.

From the reference point we can measure the velocity of midpoint of connecting rod V = 4.1 m/s

From the acceleration diagram of the same , we find that acceleration of midpoint of the connecting rod comes out to be

117m/s^2.