What is the role of a jaw coupling in a drive system?

• A. It provides a flexible connection between shafts
• B. It locks shafts rigidly
• C. It reduces electrical noise
• D. It changes gear ratio

Answer: (A)

A jaw coupling’s main job is to provide a flexible, torsionally stiff connection between shafts so torque can be transmitted while allowing for small misalignments and absorbing shocks. It uses two hubs with interlocking jaw teeth and an elastomeric insert (the spider) that cushions and flexes as torque is transmitted. This flexibility helps accommodate parallel and angular misalignment and vibration from mounting tolerances or runout, keeping the drive running smoothly without the need for perfectly aligned shafts. It isn’t meant to lock shafts rigidly, which would transfer misalignment forces directly; it doesn’t alter the gear ratio, and it doesn’t specifically reduce electrical noise.