Structure and working principle of hydraulic drive device of hard seal butterfly valve

Structure of hydraulic drive device of hard seal butterfly valve

The valve hydraulic device is installed on the valve driving shaft. The drive spline is fixed on the valve driving shaft with a key, and the crank (with external spline) is sleeved on the driving shaft.

When the hydraulic system works normally, the transmission spline is connected with the crank through the gear sleeve, so that the hydraulic cylinder drives the crank, and the spline on the crank transmits the torque to the transmission spline through the gear sleeve. Because the drive spline is fixed on the drive shaft, the drive shaft rotates and drives the valve disc to open and close.

At the end of the driving shaft, a section of optical shaft is inserted into the end of the manual shaft (with a clearance fit of H11/h11). Its function is to make the manual shaft concentric with the main transmission shaft.

During normal operation, the optical axis rotates with the driving shaft, but the manual device does not move. When the manual operation is realized from hydraulic operation or from manual operation to hydraulic operation, the shift fork device is composed of nut, handwheel, screw rod, bracket and fork. During the conversion, the handwheel is turned to drive the shift fork to translate through the screw rod. A guide rod is set on the bracket to make the shift fork translation stable.

Working principle of hydraulic drive device of hard seal butterfly valve

1. Manual operation

When the hydraulic system fails suddenly, the valve disc stops at any position. At this time, shake the manual device to make the guide block at the front end of the manual shaft collide with the guide block at the end of the driving shaft, that is, the tooth slot on the manual shaft corresponds to the drive spline tooth slot.

Then, shift the shift fork to the left end through the shift fork drive device, connect the drive spline with the manual shaft through the gear sleeve (the shift fork drive device is equipped with a limit to prevent the gear sleeve from jumping), and release the crank, that is, release the hydraulic cylinder. At this time, turn the manual device, and use the manual device to realize the butterfly plate movement.

2. Hydraulic operation

When the hydraulic system returns to normal operation, it is necessary to turn the drive device from manual to hydraulic operation. First, adjust the hydraulic cylinder to the initial state (i.e. 0 position) or any position, and then use the manual device to adjust the butterfly plate opening to the position corresponding to the cylinder stroke (determine the position of the butterfly plate and the cylinder by observing whether the marks on the gear sleeve correspond to the marks on the crank), Then move the gear sleeve to mesh with the spline on the crank through the shift fork drive device, and then fix the shift fork to prevent it from jumping. At this time, start the hydraulic system to restore hydraulic power.