JPH082535Y2 - Butterfly valve shaft seal device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft seal device for a butterfly valve, and more particularly to a shaft seal device for improving the sealing performance between a seat ring and a valve rod.

[0002]

2. Description of the Related Art A seat ring made of an elastic sealing material is fixed to an inner peripheral surface of a hollow cylindrical main body extending in a fluid flow direction,
A butterfly valve in which a disc-shaped valve body whose outer peripheral surface is brought into contact with and separated from the seat ring is attached to a valve rod and the valve rod is rotated by driving the valve rod from outside the main body to open and close the valve is It is conventionally known.

The valve rod of such a butterfly valve penetrates the main body and the seat ring and is fixed to the valve body, and the valve shaft portion prevents the fluid from leaking from the valve shaft portion by the close contact between the valve body and the seat ring. However, there is a possibility that the elastic deformation of the seat ring may deform the shaft hole of the seat ring, and the sealing performance between the valve body and the seat ring in the valve shaft may deteriorate.

Therefore, as shown in FIG. 5, an annular groove (4) is formed near the shaft hole (1) on the outer peripheral surface of the seat ring (2), that is, on the contact surface side with the main body (3). It has been proposed to insert a rigid ring (5) into the groove (4) to prevent the shaft hole (1) from being deformed. For example, in Japanese Utility Model Laid-Open No. 55-14425.
No. 5 and Japanese Utility Model Laid-Open No. 61-101153.

However, in such a structure, the rotation of the valve rod causes the rotational movement of the ring (5) through the twisting movement of the rubber, so that the seat ring may be deformed in the valve shaft portion and the sealing performance of the valve shaft portion may be impaired. There is. Also, if a cylindrical ring is placed in the main body having a cylindrical inner surface, the contact with the main body becomes point contact, and the ring moves in the direction orthogonal to the axial direction due to internal pressure and rotational movement of the valve body. Since the rocking motion occurs, the sealing property may be impaired as well. It is conceivable to machine one end surface of the ring into a circular arc shape that is the same as the inner surface of the main body, but if the orientation is wrong during assembly or the ring is rotated by the rotation of the valve rod, the opposite effect will result. There was a risk.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to provide a shaft seal device having a ring which prevents elastic deformation of a seat ring and is not affected by rotation of a valve rod.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the means adopted by the present invention is a concentric annular ring in the vicinity of a shaft hole of a seat ring fixed to the inner peripheral surface of a hollow cylindrical butterfly valve body. Groove is formed on the outer peripheral surface of the seat ring, and a rigid ring is inserted in the annular groove to form a cylindrical portion that extends outward in the axial direction integrally with the ring. It is characterized in that it is fitted in the shaft hole.

[0008]

[Operation] A part of the ring embedded in the seat ring is cylindrically extended in the valve rod direction and fitted into the valve shaft hole of the main body, so the rotation of the ring can be reliably prevented. At the same time, movement of the ring due to point contact between the ring and the inner peripheral surface of the main body can be prevented.

[0009]

According to this invention, since the seat ring can be prevented from elastically deforming by burying the ring, the valve seat sealing property can be improved, and the rotation and movement of the ring can be reliably prevented. It is possible to effectively prevent the leakage of fluid without the fear that the shaft sealability will deteriorate. Furthermore, there is no possibility of misdirection when assembling the ring.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. Referring to FIGS. 1 to 4, in the figure, (10) is a hollow cylindrical butterfly valve body,
The seat ring (11) is fixed to the inner peripheral surface. (12) is the body (1
It is a disc-shaped valve element rotatably arranged in (0), and when the outer peripheral surface is in close contact with the seat ring (11), it is in a valve closing position and stops the flow of fluid. (13) is a valve rod that rotatably supports the valve body (12), and the shaft hole (14) of the seat ring (11)
Also, it extends to the outside through the main body (10) and can be driven from outside the main body.

An annular groove (15) is formed on the outer periphery of the axial hole (14) of the seat ring (11) on the outer peripheral surface of the seat ring (11), that is, on the contact surface side with the main body (10). A rigid ring (16) is inserted in (15). 2 to 4, the ring (16) has a cylindrical portion (17) extending toward the main body (10), and the cylindrical portion (17) has a valve shaft hole (18) of the main body (10). ) Is inserted.

A cylindrical portion (17) is integrally formed with the ring (16),
Since the cylindrical portion (17) is fitted in the valve shaft hole (18), the ring
(16) is no longer rotating or moving,
A stable seat ring valve seat sealing property and a valve shaft sealing property are exhibited. Further, the cylindrical portion (17) has an advantage that it has a bearing function for the valve rod (13).

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a butterfly valve equipped with a shaft seal device of the present invention.

FIG. 2 is an enlarged perspective view of a main part of a butterfly valve equipped with the shaft seal device of the present invention.

FIG. 3 is a perspective view showing a state in which the ring is fitted into the main body.

FIG. 4 is a perspective view in which a part of the ring is cut away.

FIG. 5 is an enlarged cross-sectional view of a conventional sealing device.

[Explanation of symbols]

 (10) Main body (11) Seat ring (12) Valve body (13) Valve rod (14) Shaft hole (15) Annular groove (16) Ring (17) Cylindrical part (18) Valve shaft hole

Claims (1)

[Scope of utility model registration request] 1. A concentric annular groove is formed on the outer peripheral surface of the seat ring in the vicinity of the axial hole of the seat ring fixed on the inner peripheral surface of the hollow cylindrical butterfly valve body, and a rigid groove is formed in the annular groove. A shaft seal device for a butterfly valve, wherein a ring is inserted, a cylindrical portion is formed integrally with the ring and extends outward in the axial direction, and the cylindrical portion is fitted into a valve shaft hole of a main body.