Cams

Cams are rotating or sliding machine elements with irregular profiles that convert motion in one component into controlled motion in another. The cam profile shapes how far the follower is displaced, and how that displacement changes over time, producing non-uniform, precise motion. As the cam turns, or moves, the follower rides on the cam surface and follows its contour, creating specific timing and movement for the driven part.

Common cam types include disc (radial) cams, where the follower moves perpendicular to the cam’s axis; cylindrical cams, where the follower slides along the cam axis; plate cams, which use a profile on a flat plate with a separate guided follower; and barrel cams, where motion follows a helical groove. Cam profiles can be flat-faced, rounded, or roller-based, and followers may be flat, roller, knife-edge, or ball-bearing types. Some systems use multiple cams in sequence to achieve complex motions.

Key concepts in cam design include dwell (periods when the follower is stationary), lift (maximum follower displacement), and the desired velocity and acceleration profiles. Design considerations address strength and stiffness of the cam and follower, contact geometry, surface finish, lubrication, and wear. Manufacturing methods typically involve milling, turning, or grinding the cam profile, with precision grinding for smooth operation.

Applications span a wide range of mechanisms, including valve timing and actuation in internal combustion engines, automation and indexing equipment, textile and printing machinery, and timing devices in clocks and toys. Cams remain a foundational element in converting continuous rotational motion into controlled, programmable motion.