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Why is a generator governor important? What are the characteristics of single, dual and full governors?

June 30, 2022
The governor is an important part of the diesel generator set, which can automatically adjust the oil supply according to the change of the load of the set to ensure that the diesel generator set works stably within the specified speed range. As we know, when the general diesel generator sets work, the load will often produce great changes, if the oil supply is not adjusted in time, the unit will probably have a "flying" accident, in the diesel generator set work, in the case of frequent changes in the load, rely on the operator to adjust the oil supply to maintain a stable speed is impossible, so Must be installed governor.
The governor can be divided into two categories, mechanical governor and electronic governor, according to the different working principles.
Mechanical governor is the use of heavy rotation, the principle of centrifugal force and work: Figure 1-1 shows the schematic diagram of the principle of centrifugal force. A heavy weight is suspended from the rotating shaft, and a slide set is attached to the rotating shaft and connected to the weight through a tie rod. When the rotating shaft stops, as shown in Figure 1-1 (a), the hammer drops downward under the action of gravity, and the slide sleeve is located at the lowermost position. The higher the rotating speed of the shaft, as shown in Figure 1-1 (c), the greater the centrifugal force, the greater the angle of opening of the hammer, and the greater the distance upward of the slide sleeve H. If the oil injection pump oil volume adjustment rack is connected to the slide sleeve, the centrifugal force can be sensed by the hammer as it rotates. The centrifugal force of the rotation of the hammer can sense the change in speed to achieve automatic adjustment of the oil supply. Mechanical governor, according to the control speed range, can be divided into three types of single system, double system and full system.
Single-speed governor
Single system governor can only control the maximum speed of diesel engine, Figure 1-2 shows the working principle of single system governor, the governor shaft drives the rotation of the ball. The ball moves outward under the action of centrifugal force, when the speed is lower than the maximum speed, the spring force through the lever and the tapered surface on the slide sleeve, squeezing the steel ball, so that the ball is restricted to the center of rotation near the governor does not work. When the engine speed exceeds the maximum speed, the centrifugal force of the ball overcomes the spring force to move outward, through the cone will slide the sleeve to the right, and through the lever to drive the injection pump rack to the left, reducing the amount of engine fuel supply, so that the engine speed drops. Once the engine speed drops, the centrifugal force decreases and the spring pushes the slip-on to the original position, limiting the engine speed to the specified range.
Dual system governor
Dual system governor consists of a fly ball, low-speed spring (installed inside, soft and long), high-speed spring (installed outside, hard and short), sliding disc and lever, etc. Its function is to control the engine does not exceed the maximum speed, but also to ensure stable operation at the lowest speed, between the highest and lowest speed, it does not work.
Full system governor
The full control governor consists of a lever, a support disc, a fly ball, a sliding disc, a governor spring, a lever and a rack, etc. It can control the diesel generator to run stably at any speed between the lowest and highest speed. The speed controlled by the full system governor depends on the position of the joystick. If the joystick is moved to the right, the spring force of the governor becomes bigger, and the speed of the governor becomes higher, i.e. the steady working speed of the diesel engine increases. On the contrary, the joystick moves to the left, so that the spring force of the governor decreases. The steady speed of the diesel engine becomes lower. When the joystick position is not moving. The tension of the governor spring is certain, and the thrust of the flying ball is certain. They keep the balance between them, the diesel engine will keep working at the corresponding speed, and the speed range of the diesel engine will change only when the position of the joystick is changed to establish a new balance. Therefore, the speed range in which the full system governor works is artificially determined.
From the single system, double system and full system governor principle of operation can be seen, the full system governor spring tension, can be adjusted by the joystick, the double system governor of high speed and low speed, single system governor of high speed spring tension can not be changed. As the spring tension of the full system governor can be adjusted within a certain range, so the diesel engine can run at any speed within the specified range.