Question

Which of the following constitute kinematic link?

(A) Piston, piston rod and crosshead

(B) Connecting rod with big and small end bearings

(C) Crank, crankshaft and flywheel

(D) Cylinder, engine frame and main bearings

Choose the correct answer from the options given below:

• A. (A), (B) and (C) only
• B. (B), (C) and (D) only
• C. (A), (C) and (D) only
• D. (A), (B), (C) and (D)

Hint:

Recall the four links used to describe a slider crank mechanism in a reciprocating engine.

Answer 1

The Correct Option is D

We can also check this by elimination instead of confirming each group directly.

Option 1 drops (D), the cylinder-frame-bearings assembly. This assembly is fixed and its parts do not move relative to each other, so it still meets the definition of a link, which means option 1 is incomplete.

Option 2 drops (A), the piston-piston rod-crosshead assembly, which clearly moves as a single rigid unit and is a standard example of a slider link. So option 2 is incomplete.

Option 3 drops (B), the connecting rod with its bearings, one of the most common textbook examples of a link. So option 3 is incomplete.

Since each of (A), (B), (C) and (D) independently satisfies the definition of a kinematic link, none of them can be left out, leaving only option 4 as correct.

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