Which of the following is NOT a primary component of a belt drive system?

• A. Lubrication
• B. Belt
• C. Driver Sheave
• D. Driven Sheave

Answer: (A)

A belt drive transmits power by wrapping a belt around two pulleys and using friction between the belt and the pulleys to transfer torque. The belt itself is essential because it carries the power from the input side to the output side. The driver sheave provides the input motion and torque, while the driven sheave receives that motion and delivers it to the load. Lubrication, while important for overall machine maintenance, is not part of the belt-pulley power-transfer path; the belt-to-pulley contact is typically kept dry to maintain sufficient friction and prevent slipping. Lubrication is generally applied to bearings and other moving parts, not to the belt contact surfaces, so it isn’t a primary component of the belt drive system.