Valve shaft sealing structure and butterfly valve comprising same

Abstract

The invention discloses a valve shaft sealing structure and a butterfly valve comprising the same. The valve shaft sealing structure comprises a valve body, a driving device is installed at the upper portion of the valve body, an upper shaft hole is formed in the valve body, an upper shaft sleeve is arranged in the upper shaft hole, an upper valve shaft is arranged in the upper shaft sleeve, a stuffing box is arranged at the upper end of the upper shaft hole, and stuffings are arranged in the stuffing box. A containing groove is formed between the valve body and the driving device, a stuffing pressing plate capable of moving in the axial direction of the upper valve shaft is arranged in the containing groove, an adjusting screw rod is arranged on the stuffing pressing plate, and the adjusting screw rod penetrates through the valve body and then is in threaded connection with a first nut. The stuffing pressing plate can move up and down in the containing groove, the pressed state of the stuffings can be adjusted by rotating the first nut, and enough sealing specific pressure is obtained. The valve body is in threaded connection with a jacking screw, the upper end of the jacking screw abuts against the driving device, and the lower end of the jacking screw extends out of the valve body. The driving device can be conveniently jacked up by screwing the jacking screw, and enough open-type space for adjusting and replacing the stuffings can be conveniently obtained without dismounting the driving device.

Description

technical field [0001] The invention relates to the technical field of valves, in particular to a valve shaft sealing structure and a butterfly valve comprising the sealing structure. Background technique [0002] The extended end of the butterfly valve on which the upper valve shaft 4 extends out of the valve body 2 needs to be designed and provided with a sealing structure so that the medium will not flow out when the upper valve shaft 4 is stationary and rotates. Existing technical scheme mainly contains two kinds, prior art scheme 1 such as Figure 1-4 As shown, the stuffing box is set on the valve body 2, the stuffing gland 19 is connected to the valve body 2 by using connecting parts such as studs, and the stuffing 7, stuffing pad 17, etc. are compressed and fixed in the stuffing box, The packing 7 is elastically deformed by the packing gland 19 extrusion and limit, so a certain sealing specific pressure is established between the inner wall of the stuffing box and the...

AI Technical Summary

Problems solved by technology

The disadvantage is that the driving device 1 needs to be removed when replacing the packing, which brings inconvenience to maintenance and replacement of packing

[0004] In addition, another common shortcoming of the above two prior art solutions is that there is no valve shaft anti-protrusion structure, so it is easy to make (the valve shaft breaks) after the drive device 1 is completely removed when the upper valve shaft 4 is under internal pressure. Or when the connecting pin 7 between the valve shaft and the butterfly plate is missing or fails) the valve shaft protrudes from the valve body 2, causing an accident

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