Non-circular gear
（重定向自Noncircular gear）
A non-circular gear (NCG) is a special gear design with special characteristics and purpose. While a regular gear is optimized to transmit torque to another engaged member with minimum noise and wear and with maximum efficiency, a non-circular gear's main objective might be ratio variations, axle displacement oscillations and more. Common applications include textile machines, potentiometers, CVTs (continuously variable transmissions), window shade panel drives, mechanical presses and high torque hydraulic engines.