In automotive axles, what does the term Constant-Velocity stand for?

• A. Constant-velocity joint
• B. Continuous velocity joint
• C. Camshaft-velocity joint
• D. Constant velocity gear

Answer: (A)

Constant-Velocity refers to a Constant-Velocity joint. This joint is designed to transmit power from the drive shaft to the wheels while the axle angles change as the suspension moves and the vehicle steers. It keeps the output speed of the wheel almost constant relative to the input speed, even when the angle between shaft sections varies, which smooths power delivery and reduces vibrations. Inside the joint, the design—often using ball bearings in a spherical housing or a tripod arrangement—allows articulation without causing significant changes in rotational speed. This is why CV joints are used in vehicle axles that must accommodate steering and suspension movement. The other terms aren’t standard names for this mechanism.