What is the principle of a governor?
4 Answers
The principle of a governor is to change the load of a diesel engine while maintaining a constant speed. If the speed is kept constant, altering the amount of fuel can change the load of the diesel engine; if the load of the diesel engine is kept constant, adjusting the amount of fuel can change the engine's speed. The governor is used to maintain the stability of the diesel engine's speed. During the process of load changes in the diesel engine, the speed will correspondingly vary. When the speed decreases, if the governor does not adjust, the diesel engine will eventually stop; when the speed increases, if the governor does not function, the diesel engine will ultimately be unable to withstand excessive centrifugal force and become damaged.
The principle of an automobile governor is simply that it can automatically maintain a stable engine speed. I often tinker with old engines in my garage and am particularly fascinated by mechanical governors. Its core mechanism utilizes centrifugal force: when the engine runs faster, the weights fixed on the crankshaft are thrown farther outward, pulling a lever to reduce the throttle; when the speed drops, springs pull the weights back to their original position, opening the throttle wider. This way, no matter how the load changes—such as increased resistance when the car climbs a hill—the engine won’t gasp and lose speed. Electronic governors are more modern, relying on sensors to monitor speed changes in real time and then sending signals to the control module to adjust fuel injection or throttle position, ensuring smooth operation. This prevents the engine from fluctuating in speed, improves fuel efficiency, and reduces wear on internal components. In some older car models, governor malfunctions can cause unstable idling or black smoke emissions. In such cases, I first use a multimeter to check resistance or voltage. Don’t underestimate it—this automatic regulation significantly enhances driving comfort, especially during long-distance trips, by keeping the engine running smoothly and reducing extra fuel consumption and noise interference.
I've been driving trucks for many years, and the role of the governor is to automatically stabilize the engine speed during driving, preventing it from fluctuating up and down. The principle is to adjust the throttle opening in real-time based on the engine speed. For example, when fully loaded and climbing a steep slope, the engine load increases and the speed starts to drop. The governor immediately senses this change and increases fuel supply to bring the speed back to normal. On flat roads or downhill, when the load is lighter and the speed may rise, it reduces fuel supply to avoid idling. This feedback mechanism is achieved through sensors or old-fashioned weight mechanisms and is integrated into the computer system in modern vehicles, reducing the hassle of manual operation. In actual driving, this is quite convenient, especially during high-speed cruising, providing stable power output and avoiding frequent gear shifts that can be tiring and save energy. I often tell beginners to check this component. If the governor fails, the engine may shake or have difficulty accelerating, affecting driving safety. Long-term use can also extend engine life and reduce maintenance costs. Simple maintenance, such as cleaning the fuel injectors and connection points, can prevent problems.
When repairing at the auto shop, I often encounter governor failures causing RPM fluctuations. The principle is to maintain constant speed by sensing engine RPM and automatically adjusting the throttle. It works by comparing the set RPM with actual readings: if the sensor detects the current RPM is low, it commands the actuator to open the throttle wider; if the RPM is high, it reduces the throttle. Older mechanical governors use flyweights and spring linkages, which are prone to sticking or wear. Electronic versions are more precise, but circuits may burn out. During repairs, I usually first check if the RPM sensor readings are accurate, then test the actuator signal voltage. This automatic regulation prevents engine overspeeding or uneven combustion, thereby protecting pistons and bearings. Common faults like governor sticking or oil leaks can cause weak acceleration or idle shaking, requiring timely part replacement. Regular engine maintenance can effectively prevent issues; it's recommended to inspect related wiring and connectors every 6 months.
