Yaozhuang Power Station reported that the connecting rod of the servomotor and the speed control ring was bent (see the following picture)
Description of the problem that the shaft of the external servomotor of the governor is bent over
Explanation of the problem that the shaft of the external servomotor of the governor is bent
problem analysis:
    Because it is a transformation of the power station, the suitable installation position of the servomotor is far away from the speed control ring, and the push-pull rod is longer. This is easy to cause bending deformation of the push-pull rod when the thrust of the servomotor is large. Once it is bent, the radial force on the entire shaft will be doubled, causing serious permanent deformation (bending force) at the thinner part (threaded connection) caused).
    Refer to the above figure, the connecting shaft is thin, and the connecting thread is also very thin, and the exposed part of the thread is too long.
Avoid method:
   When the connecting rod of the servomotor is too long, the diameter of the connecting rod should be as large as possible. The larger the diameter, the stronger the bending resistance. At the same time, the connecting thread should be as thick as possible, and the exposed part of the thread should be as short as possible.
The correct installation method is shown in the figure below:
Explanation of the problem that the shaft of the external servomotor of the governor is bent
This power station is about 3 meters from the installation surface of the servomotor to the installation position of the speed control ring.
The diameter of the connecting shaft is almost the same as the diameter of the servomotor piston.
Almost all the threads of the servomotor and the connecting shaft are screwed into the connecting shaft (if it is indeed impossible to screw all in, it is recommended to add an additional lock nut).

Summary: When installing a power station, the distance from the servomotor to the speed control ring should be as short as possible. When the distance is long, the diameter of the connecting rod should be enlarged during design, and the exposed connecting thread should be minimized during design and installation. When there is more exposed, increase the lock nut to reduce the exposed threads.