WO2000017550A1

WO2000017550A1 - Butterfly valve

Info

Publication number: WO2000017550A1
Application number: PCT/KR1999/000576
Authority: WO
Inventors: Jongchul Lee
Original assignee: Jongchul Lee
Priority date: 1998-09-24
Filing date: 1999-09-22
Publication date: 2000-03-30
Also published as: KR100287815B1; AU5763799A; KR20000020920A

Abstract

The present invention relates to a butterfly valve which can achieve a markedly increased fluid-tight sealing on the valve axle (20) by providing a sealing keeping movable ring (50) and roller pins (60) on the valve axle (20), in such a manner that the ring (50) is moved in the axial direction by means of roller pins (60) when the valve axle (20) is rotated to cause the valve disk (30) to close the flow path (11), to thereby press the part of the rubber seat ring (40) surrounding the through-hole (41) for receiving the valve axle (20), whereby the leakage of fluid through the hollow hole of the valve body (10) can be completely prevented under such a high fluid pressure.

Description

BUTTERFLY VALVE

BACKGROUND OF INVENTION

"'Field of Invention

The present invention relates to a butterfly valve and more particularly to a butterfly valve including a sealing keeping movable ring, disposed on a valve axle through a valve body to be movable linearly, wherein the valve axle is provided with roller pins to enable the sealing keeping movable ring to make a linear movement through their revolving travel around the valve axle, so that the sealing keeping movable ring can be linearly moved by the movement of roller pins following the valve axle to be pressed against the part of rubber seat ring surrounding the through-hole therein for a secured fluid-tightness in the direction of the valve axle at the time of closing the flow path in the butterfly valve when the fluid pressure is increased, whereby an excellent sealing against high hydraulic pressure can be achieved with a small-sized butterfly valve.

Description of the Prior Art

Generally a butterfly valve, which is installed in a path for a fluid such as water, oil or gas to open or close the path of flow, is characterized in that it takes less space for installation than other kinds of valves.

Figure 1 shows a perspective view of a butterfly valve according to a conventional art in partial cross section. As shown in the drawing, the butterfly valve comprises a valve body 10 including a flow path 11 to permit a flow from one side to the other side, a valve disk 30 for opening or closing the flow path 11 in the valve body 10, a valve axle 20 for rotating the valve disk 30 within the flow path 11 of the valve body 10, the valve axle being connected to the valve disk 30 through multiple bolts 23, and a rubber seat ring 40 disposed in the region of the flow opening 11, for maintaining sealing-up between the valve body 10 and the valve disk 30, at the time of closing the flow path 11 in the valve body 10 by means of the valve disk 30.

The valve axle 20, which is disposed through a hollow hole 12 in the valve body 10, is provided with a packing 21 and a bush 22 to secure axial sealing. Furthermore, the valve axle 20 is provided on its top area with a handle or an actuating unit, not shown, to cause manual or automatic rotation of the valve axle 20 to open or close the valve disk 30.

In the drawing, the reference number 13 stands for a flange 13 and the number 14 stands for bolt openings formed in the flange 13 for permitting connection of pipelines on both sides of the flange.

In the state as shown in Figure 1, the valve disk 30 is positioned as rotated 90° with respect to the diametric direction of the flow path opening 11 within the valve body 10 in order to permit full flow. With the valve disk 30 positioned for full opening, naturally the flow will have its maximum flow rate.

On the other hand, when the valve axle 20 is turned 90° from the position mentioned above by an actuating means not shown, the valve disk 30 will completely close the flow path 11 of the valve body 10 to block the flow of the fluid flowing through the butterfly valve, as the valve disk 30 is, with its outer peripheral surface, tightly pressed against the inner peripheral surface of the rubber seat ring 40.

A high pressure is built up in the flow path 11, when the flow of fluid is blocked by the valve disk 30 pressed against the rubber seat ring 40. Then, the pressure will cause a part of the fluid to flow to the hollow hole 12 in the valve body 10 via the through-hole 41 in the rubber seat ring 40, through which through-hole the valve axle 20 is fitted, and the flow will be stopped by virtue of the packing 21 disposed in the hollow hole 12.

When the flow of fluid is blocked by closing the flow path by means of a valve disk 30 as described above, the fluid flowing through the clearance portion of the hollow hole 12 via also the clearance portion of the through-hole 41 may reach the packing 21 and cause a leakage problem if the increased pressure due to the blocking exceeds the tolerant pressure. ^""^'-"Particularly, because the fluid leakage through the packing 21 is further deteriorated, as the packing 21 is worn out by the valve axle 20 which is turned back and forth with the repeated opening/closing motion of the valve disk 30, the butterfly valve, which is installed in a line for securing leak-proof for a dangerous gas or the like, may constitute the cause for an unexpected accident due to the gas leakage.

SUMMARY OF THE INVENTION

The present invention, which is created to resolve the problem of conventional art as described above, has its object of providing a butterfly valve which can achieve a markedly increased fluid-tight sealing on the valve axle by providing a sealing keeping movable ring and roller pins on the valve axle, in such a manner that the ring is moved in the axial direction by means of roller pins, when the valve axle is rotated to cause the valve disk to close the flow path, to thereby press the part of the rubber seat ring surrounding the through-hole for receiving the valve axle, whereby the leakage of fluid through the hollow hole of the valve body can be completely prevented under such a high fluid pressure.

The above object is achieved according to the present invention by this butterfly valve which comprises a valve body including a flow path for allowing the flow of fluid from one side to the other side therein, a valve disk for opening or closing the flow path of said valve body, a valve axle for turning said valve disk within the fluid path of said valve body and a rubber seat ring for fluid-tight sealing the valve body with the valve disk at the time of closing the fluid path by means of the valve disk, wherein there are further provided a sealing keeping movable ring disposed slidingly on a valve axle through a hollow hole of the valve body in a manner capable of linear movement in the axial direction, said sealing keeping movable ring being provided on its top surface with cam surfaces inclined opposite to each other and said sealing keeping movable ring being capable of contacting, with its bottom surface, the rubber seat ring in the vicinity of a through-hole, and a plurality of roller pins securely disposed on the valve axle perpendicularly to the axial direction and opposite to each other, said plural roller pins being positioned on the cam surfaces of the sealing keeping movable ring and being capable of rotating along with the rotation of the valve axle to cause a linear movement of the sealing keeping movable ring for sealing the rubber seat ring in the direction of a valve axle at the time of closing the valve disk.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the perspective view of a butterfly valve according to a conventional art in partial cross section,

Figure 2 shows a butterfly valve according to a preferred embodiment of the present invention in cross section when the valve is open,

Figure 3 shows the perspective view of the major part of the valve as depicted in Figure 2,

Figure 4 shows the same butterfly valve as shown in Figure 2, when the valve is however closed in this case, and

Figure 5 shows the perspective view of the major part of the valve as depicted in Figure 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A preferred embodiment of the present invention will be described below in conjunction with the attached drawings . The reference numbers in Figures 2 to 5 for the present embodiment will be the same as in Figure 1 for a conventional art for the same or similar parts.

As shown in Figures 2 to 5, a butterfly valve includes a valve body 10 having a flow path 11 for allowing the flow of fluid from one side to the other side therein, a valve disk 30 for opening or closing the flow path 11 of said valve body 10, a valve axle 20 for turning said valve disk 30 within the fluid path 11 of said valve body 10 and a rubber seat ring 40 for fluid-tight sealing the valve body 10 with the valve disk 30 at the time of closure of the fluid path 11 of the valve body 10.

Furthermore, the hollow hole 12, in which the valve axle 20 is disposed, is provided with a sealing keeping movable ring 50 by means of keys 70, which ring is slidingly fitted on the valve axle 20 and able to make a vertical linear movement within the hollow hole 12.

The sealing keeping movable ring 50 is formed on its top surface with cam surfaces 52 inclined opposite to each other, which surfaces each include a low contacting part 52a and a high contacting part 52b having different heights, on which surfaces there can be rolled the roller pins 60 fixed on the valve axle 20 in opposite positions with respect to the valve axis.

The bottom surface 54 of the sealing keeping movable ring 50 is contacted with the part of the rubber seat ring 40 surrounding the through-hole 41.

In Figures 2 and 3, there is shown a butterfly valve according to the present invention constructed as described above, when it takes a position of full opening to permit maximum flow, with the valve disk 30 turned 90° with respect to the diametric direction of the flow path 11 of the valve body 10.

At that time, the roller pins 60 secured on the valve axle 20 are positioned on the low contacting parts 52a of the cam surfaces 52.

On the other hand, as depicted in Figures 4 and 5, when the valve axle 20 is turned back 90° by an actuator not shown from the state as described above, the valve disk 30 fully closes the flow path 11 of the valve body 10 to cut the flow of the fluid flowing through the butterfly valve, wherein the outer peripheral surface of the valve disk 30 is pressed against the inner peripheral surface of the rubber seat ring 40.

Along with the rotation of the valve axle 20, the roller pins 60 fixed on the valve axle are also rotated on the cam surfaces 52 to travel slidingly to the high contacting part 52b from the former low contacting part 52a, resulting in a linear movement (downward movement in the case of Figure 4 or 5) of the sealing keeping movable ring 50 through the hollow hole 12 corresponding to the difference in height for the contacting parts 52a and b, whereby the part of the rubber seat ring 40 adjacent to the through-hole 41 is tight pressed by the bottom surface 54 of the movable ring 50, so that complete prevention of any fluid from flowing through the through-hole 41 to reach the hollow hole 12 can be guaranteed.

When the valve axle 20 is turned by an actuator not shown to open the flow opening 11 of the valve body 10 by means of the valve disk 30, the roller pins 60 fixed on the valve axle are revolved together with the axle on the cam surfaces 52 to travel slidingly to the low contacting part 52a from the high contacting part 52b, resulting in a linear movement (upward movement in the case of Figure 2 or 3) of the sealing keeping movable ring 50 through the hollow hole 12 corresponding to the difference in height for the contacting parts of cam surfaces 52a and b, so that the previous compression in the region of the rubber seat ring 40 around the through-hole 41 may be recovered, wherein no flow leakage through the through-hole 41 however takes place due to the moderate pressure prevailing in the fluid flowing through the flow opening 11. As described above, the butterfly valve according to the present invention can be free from any leakage through the hollow hole 12 in the valve body 10 under a high fluid pressure, because a sealing keeping movable ring 50 is pressed against the rubber seat ring 40 in the vicinity of the through-hole 41 when the flow opening 11 is closed. In addition, a low friction coefficient is attained, as the above-described roller pins are so constructed as to conduct a rolling motion when traveling on the cam surfaces 52.

,, Furthermore, the bottom surface 54 of the sealing keeping movable ring 50 is made flat and the part of rubber seat ring 40 surrounding the through-hole 41 to be in contact with the bottom surface 54 is also formed as a flat surface 42, therefore the pressing load exerted on the part of rubber seat ring 40 surrounding the through-hole 41 by the movable ring 50 can be uniformly distributed and so the sealing performance is further improved.

While in the present embodiment, separate keys 70 were used for the movable ring 50 arranged in the hollow hole 12 to be rotation-proof and to perform only a linear movement, alternately the movable ring 50 could be mounted in the hollow hole, by means of keys integrally formed on the movable ring itself and protruding into the hollow hole 12. As clear from the above description, the present invention has the advantage in that it provides a butterfly valve which includes a sealing keeping movable ring, disposed on a valve axle through a valve body to be movable linearly, wherein the valve axle is provided with roller pins to enable the sealing keeping movable ring to make a linear movement through their revolving travel around the valve axle, so that the sealing keeping movable ring can be linearly moved by the movement of roller pins following the valve axle to be pressed against the part of rubber seat ring surrounding the through-hole therein for a secured fluid-tightness in the direction of the valve axle at the time of closing the flow path in the butterfly valve when the fluid pressure is increased, whereby an excellent sealing against high hydraulic pressure can be achieved with a small-sized butterfly valve. It is to be understood that, while the invention was described mainly with respect to a specific embodiment, the invention is never restricted to the embodiment and a variety of modifications and alterations would be possible to a man skilled in the art by referring to the description or drawings presented here and within the spirit of the invention and thus those modifications or alterations would fall within the scope of the invention, which scope should be limited only by the attached claims.

Claims

WHAT IS CLAIMED IS:

1. A butterfly valve which comprises a valve body 10 including a flow path 11 for allowing the flow of fluid from one side to the other side therein, a valve disk 30 for opening or closing the flow path 11 of said valve body 10, a valve axle 20 for turning said valve disk 30 within the fluid path 11 of said valve body 10 and a rubber seat ring 40 for fluid-tight sealing the valve body 10 with the valve disk 30 at the time of closing the fluid path 11 by means of the valve disk 30, wherein there are further provided a sealing keeping movable ring 50 disposed slidingly on a valve axle 20 through a hollow hole 12 of the valve body 10 in a manner capable of linear movement in the axial direction, said sealing keeping movable ring being provided on its top surface with cam surfaces 52 inclined opposite to each other and said sealing keeping movable ring being capable of contacting, with its bottom surface 54, the rubber seat ring 40 in the vicinity of a through-hole 41, and a plurality of roller pins 60 securely disposed on the valve axle 20 perpendicularly to the axial direction and opposite to each other, said plural roller pins being positioned on the cam surfaces 52 of the sealing keeping movable ring 50 and being capable of rotating along with the rotation of the valve axle 20 to cause a linear movement of the sealing keeping movable ring 50 for sealing the rubber seat ring 40 in the direction of valve axle 20 at the time of closing the valve disk 30.

2. The butterfly valve according to Claim 1, wherein the bottom surface 54 of said sealing keeping movable ring is formed flat and the part of rubber seat ring 40 surrounding the through-hole 41 to be in contact with the bottom surface 54 is also formed as a flat surface 42.

3. The butterfly valve according to Claim 1, wherein the cam surfaces 52 each include a low contacting part 52a and a high contacting part 52b at different elevations, both parts being connected by an inclined part.