At the gear level, the engine's speed can be transmitted to the output rod via two sets of gears. The main reducer is completed by the planetary gear, the secondary reducer is realized by the worm wheel, which is fixed in the center position by a set of taut springs. In the case of overload, that is, the output rod exceeds the set torque of the spring, the central worm wheel will occur axial displacement, the switch and signal device to fine-tune, to provide protection for the system. The output rod is coupled with the worm wheel while the engine is operating, and is coupled with the handwheel when operated manually, by the coupling of the external change joystick. When the engine is not working, it is easy to disconnect the motor drive, and just press the joystick to connect the upper wheel. Because the motor drive takes precedence over manual operation, reverse action occurs automatically when the engine starts again.
This avoids the opening of the handwheel when the engine is running, which is beneficial to the protection system.
Since the handwheel is directly coupled to the output rod, it is possible to ensure the normal manual operation of the valve in the event of failure or damage to the internal gear.
The switch and signal device mounted on the gear is a sealed housing that protects its internal components to achieve the following functions:
Local or remote display of valve position
Overload protection for actuators/valves
Limit Valve Stroke range
Electrical interface The actuator installation on different types of valves is done by means of an output lever, which can be applied to a variety of existing stem configurations.