ABSTRACT
Gears are used to transmit torque, rotary motion, and power from one shaft to another. They have a long history. In about 2600 bc, the Chinese used primitive gearsets, most likely made of wood and their teeth merely pegs inserted in wheels. In the fteenth century ad, Leonardo da Vinci showed many gear arrangements in his drawings. Presently, a wide variety of gear types have been developed that operate quietly and with very low friction losses. Smooth, vibrationless action is secured by giving the proper geometric form to the outline of the teeth.
