Classification of shafts in machine design A crankshaft used in engines is to be classified by type (e.g., transmission shaft, line shaft, machine shaft). Choose the most appropriate classification.

Concept
In machine design, shafts are broadly grouped as transmission shafts (line/counter shafts used to transmit power between machines) and machine shafts (integral parts of machines). A crankshaft is a built, shaped member inside an engine that converts reciprocating motion to rotary motion and carries cranks, pins, and webs—hence it is a machine shaft.

Why other options are incorrect
• Transmission, line, and counter shafts transmit power between machine elements but are not integral kinematic members like a crankshaft.

Final Answer
Machine shaft