Working Principle of Single Program Governor for Diesel Generator Set 2

The sensing element of the governor introduced in the previous article is a flying ball, and the actuator is a thrust plate and transmission plate. When the external load changes and causes a change in rotational speed, the centrifugal force of the flying ball changes accordingly. Due to the direct proportionality between the force and the square of the rotational speed, the flying ball can sensitively sense changes in rotational speed. The centrifugal force of the flying ball acts on the thrust plate and generates an axial component force Fa, forcing the thrust plate to move to the right. Due to the elastic force of the speed regulating spring acting on the right side of the thrust plate, the position of the thrust plate depends on whether the two forces are balanced. The working process of the speed regulator is as follows.

When the diesel engine is working, the drive plate and flying ball are driven to rotate by the crankshaft. When the axial force F generated by the flying ball is less than the elastic force Fp of the speed regulating spring, the thrust plate is still in the leftmost position. At this point, the speed regulator has not yet taken effect. When the crankshaft speed increases to the point where force F equals force F, the crankshaft speed is the speed at which the governor begins to take effect. Obviously, the greater the preload force F of the speed regulating spring, the higher the effective speed; Conversely, it is low.

If the diesel engine operates at the operating speed of the governor (Fa=Fp), the external load decreases, the crankshaft speed will increase, and the axial force exerted by the flying ball on the thrust plate will increase (Fa>Fp), pushing the thrust plate to the right and compressing the speed regulating spring. And the transmission plate moves the fuel supply rod in the direction of decreasing fuel supply, reducing the speed and F to adapt to changes in external loads. As the speed regulating spring is compressed, the elastic force Fp also increases continuously, so the thrust plate will reach a new stability at Fa=Fp, and the fuel supply will correspond to the reduced load. If the external load continues to decrease, the speed will continue to increase. The flying ball will cause the thrust plate and transmission plate to move the fuel supply rod to the right again. When the external load is zero, the governor will move the fuel supply rod to the minimum fuel supply position, and the diesel engine will operate at the highest idle speed.

In summary, the working principle of a mechanical single program speed controller can be summarized into the following three points:

1. The sensing element senses changes in diesel engine speed through centrifugal force. When the load decreases and the speed increases, the centrifugal force increases, and the axial component of the centrifugal force is used to push the fuel supply rod to reduce the fuel supply. When the load increases and the speed decreases, its centrifugal force decreases, and the speed regulating spring will push the fuel supply rod to increase the fuel supply.

The speed at which the speed regulator operates is determined by the elastic force of the speed regulating spring.

3. The governor does not keep the engine speed constant, but controls the fluctuation of the engine speed with load changes within an allowable range.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.