Original 4914090 Speed Controller Governor Parts For Cummins Diesel Engine. The engine governor is responsible for automatically adjusting the engine speed to ensure stable operation under various loads. Working Principle: Through the engine speed and load, the governor automatically adjusts to maintain the set speed. Various types: Applicable to different fields and needs. Composition: It is mainly composed of controller, actuator and sensor, which work together to realize the precise control of rotational speed. To improve the operation efficiency and reliability.