V belt
Belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement.Friction drive belts rely on the friction between the belt and pulley to transmit power. They require tension to maintain the right amount of friction. Flat belts are the purest form of friction drive while V-belts have a friction multiplying effect because of wedging action on the pulley.
