It actually adds an elastic link to the "Rigid Federation" device -buffer and spring. One end of the spring is connected to a fixed fulcrum, while the other end is connected to the piston of the buffer. The piston of the buffer's oil cylinder is connected with a rigid body.

When the engine load is reduced, the speed increases, and the centrifugal power of the flying ball increases. Similarly, the slide valve moves right, while the servo piston moves left to reduce the fuel supply of the fuel injection pump. When the speed of the piston is very high, the buffer and the buffer piston are moving like a rigid body. With the left movement of the servo piston 5, the point A on the buffer and AC leverage also move to the left. This process is exactly the same as the speed regulator of the above -mentioned rigid feedback system. However, when the speed adjustment speed is approaching, the slide valve has returned to the original position, covering the oil circuit to the servo oil cylinder. At this time, the buffer and servo piston have stayed on the corresponding position of the new load. Due to the elastic recovery effect of the compressed spring, the point A drives the buffer piston movement to the right compared to the buffer oil cylinder and return to the original position. The oil flowing valve in the right tank of the right tank of the piston flows to the left. As a result, the points on AC leverage are restored to the original position. At this time, the sleeve of the speed regulator also returned to the original position due to the recovery of the speed. In this way, the speed of the engine remains unchanged. When the load increases, the action process is the opposite. The stable regulator of this speed regulator D is zero.