Q7Basic Mechanical Engineering
Question
Q.7 Why gear drive is called positive drive?
Answer
A mechanical gear drive is universally classified strictly as a positive drive because the rigid geometric interlocking of machined gear teeth absolutely prevents any physical slippage during continuous power transmission.
In mechanical power transmission systems, physical 'slip' is the highly undesirable relative motion exactly between the driving mechanism and the driven mechanism, which mathematically ruins the exact kinematic velocity ratio.
Friction-based systems like flat belts or ropes inherently experience varying degrees of physical slip under heavy fluctuating loads. Conversely, gear drives systematically transmit torque entirely through the direct, rigid mechanical meshing and interference of solid metal teeth. Because these teeth are structurally interlocked, absolutely zero slip can physically occur, strictly guaranteeing an exactly constant, mathematically perfect angular velocity ratio. Thus, it is rigorously termed a 'positive drive'.