AND A VALVE WITH THE SAME

FIELD OF THE PRESENT INVENTION

The present invention generally relates to a valve, and more particularly to a sealing device in the valve.

BACKGROUND OF THE PRESENT INVENTION

The valve is generally used in an industry controlling system to control the flow of the fluid in the system. In order to control the flow of the fluid, a typical valve includes a valve stem and a valve seat, wherein a valve port is defined on the valve seat, and the valve stem may move relative to the valve seat so as to control the open, closure or the opening degree of the valve port. Generally, different portions of the valve stem and the valve seat are in different fluid pressures, thus a sealing device is needed to be arranged between the valve stem and the valve seat so as to prevent the undesired pressure leakage. Fig.l illustrates a known sealing device 10. The sealing device 10 includes a valve stem 11, a valve seat 12 and an annular groove 13 arranged on the outer surface of the valve stem 11. When assembled, a sealing member such as an O-ring is positioned into the annular groove 13, thus the sealing member forms a sealing between the valve stem 11 and the valve seat 12 during the operation. However, the sealing device 10 of Fig.l may have a problem: since the groove structure is formed on the valve stem 11, the manufacturing process of the valve stem 11 is relatively complex and thus has a high cost. Additionally, the groove structure formed on the valve stem 11 reduces the structural integrity of the valve stem 11.

Fig.2 illustrates another known sealing device 20. The sealing device 20 includes a valve stem 21 coupled to a diaphragm 26 by coupling members 24 and 25, and a valve seat 22. The valve seat 22 is provided with a groove 23 and the coupling member 24 is provided with a projection 27. When assembled, the projection 27 restricts a sealing member 28 such as an O-ring into the groove 23, thus the sealing member 28 forms a sealing between the valve stem 21 and the valve seat 22 during the operation.

However, the sealing device 20 of Fig.2 may have a problem: as shown in Fig.2, the gap between the lower surface of the coupling member 24 and the upper surface of the valve seat 22 is relatively large, and the gap between the side surface of the coupling member 24 and the side surface of the valve seat 22 is also relatively large, thus the fluid pressure may be discharged through the gaps due to the failure of the sealing member 28, for example, the aging of the O-ring, which is not desired.

Thus, other sealing devices are needed.

SUMMARY OF THE PRESENT INVENTION In one embodiment, the present invention provides a sealing device in a valve, comprising: a first member having a convex portion, a second member having a concave portion and a sealing member; wherein the convex portion of the first member is mated with the concave portion of the second member, and the convex portion of the first member is configured to be received into the concave portion of the second member; the sealing member is arranged between the convex portion of the first member and the concave portion of the second member; and the convex portion of the first member is mated with the concave portion of the second member dynamically and oppositely.

In an example, the convex portion of the first member being mated with the concave portion of the second member dynamically and oppositely means that one of the first member and the second member is fixed, and the other is movably mated, or both of the first member and the second member are movably mated with each other.

In an example, the convex portion of the first member has a first circumferential outer surface, a first annular end surface extending radially inward from the edge of the first circumferenti l outer surface and a second circumferential outer surface extending from the inner edge of the first annular end surface towards a direction away from the first circumferential outer surface; and the concave portion of the second member has a first circumferential inner surface, a second annular end surface extending radially inward from the edge of the first circumferential inner surface and a second circumferential inner surface extending from the inner edge of the second annular end surface towards a direction away from the first circumferential inner surface; wherein the first circumferential outer surface and the first circumferential inner surface are sized to form a clearance fit, and the second circumferential outer surface and the second circumferential inner surface are sized to form a clearance fit.

In an example, the sealing member is an O-ring.

In an example, the first member is a valve stem and the second member is a valve seat.

In another embodiment, a valve comprising the sealing device in a valve of the present invention is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiment of the present invention may be better understood with reference to the following drawings. The members in the drawings are not drawn proportionally.

Fig.l shows a known sealing device;

Fig.2 shows another known sealing device;

Fig.3 is an exploded view of one embodiment of the sealing device in the valve according to the present invention;

Fig.4 is an assembly view of the sealing device of Fig.3;

Fig.5 is a sectional view of one embodiment of the valve according to the present invention;

Fig.6 shows the pressure difference curve of the known valve; and

Fig.7 shows the pressure difference curve of the valve of Fig.5.

In the above drawings, similar reference numerals may be understood to denote the same, similar or corresponding features or functions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe the preferable embodiments with reference to the drawings which constitute one part of the present invention. The attached drawings illustrate the specific embodiments for achieving the present invention by way of example. The illustrated embodiments are not intended to limit all of the embodiments of the present invention. It may be appreciated that without departing from the scope of the present invention, other embodiments may be used, or some structural or logical changes may be possible. Therefore, the following specific explanations are not meant as a limitation of the present invention, and the scope of the present invention is defined by the attached claims.

In the following description, the attached drawings are referred to. The drawings constitute a part of the present invention, and some specific embodiments for implementing the present invention are shown by way of example in the drawings. In this regard, some orientation terms, such as "left", "right", "top", "bottom", "front", "back", "guide", "forwards", and "backwards", etc., are used with reference to the directions shown in the drawings. Thus, the members of the embodiments of the present invention may be arranged in different directions, and the orientation terms are used as example rather than limitation. It may be appreciated that without departing from the scope of the present invention, other embodiments may be used, or some structural or logical changes may be possible. Therefore, the following specific explanations are not meant as a limitation of the present invention, and the scope of the present invention is defined by the attached claims.

In one embodiment, the present invention provides a sealing device in a valve, comprising: a first member having a convex portion, a second member having a concave portion and a sealing member; wherein the convex portion of the first member is mated with the concave portion of the second member, and the convex portion of the first member is configured to be received into the concave portion of the second member; the sealing member is arranged between the convex portion of the first member and the concave portion of the second member; and the convex portion of the first member is mated with the concave portion of the second member dynamically and oppositely.

In an example, the convex portion of the first member being mated with the concave portion of the second member dynamically and oppositely means that, one of the first member and the second member is fixed, and the other is movably mated, or both of the first member and the second member are movably mated with each other.

Fig.3 illustrates an exploded view of one embodiment of the sealing device 30 in the valve according to the present invention. As shown in Fig.3, the sealing device 30 comprises a first member 31, a second member 32 and a sealing member 39. The first member 31 has a first outer surface 33 arranged in an axial direction (Y-direction as shown in the drawing), a second outer surface 35 arranged inward in a lateral direction (X-direction as shown in the drawing) relative to the first outer surface 33, and a third outer surface 34 arranged between the first outer surface 33 and the second outer surface

35 in the lateral direction. The second member 32 has a first inner surface 36 arranged in the axial direction (Y-direction as shown in the drawing), a second inner surface 38 arranged inward in the lateral direction (X-direction as shown in the drawing) relative to the first inner surface 36, and a third inner surface 37 arranged between the first inner surface 36 and the second inner surface 38 in the lateral direction.

Fig.4 illustrates the assembly view of the sealing device of Fig.3. As shown in Fig.4, when assembled, the sealing member 39 is located in a gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37 so as to provide a sealing. The first outer surface 33 and the first inner surface

36 form a clearance fit therebetween, and the second outer surface 35 and the second inner surface 38 form a clearance fit therebetween. According to an exemplary installation sequence, the sealing member 39 is surrounded around the second outer surface 35 of the first member 31, and then the first member 31 together with the sealing member 39 are installed into the second member 32.

During the operation, the first member 31 and the second member 32 may axially move relative to each other, thus the size of the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37 is changed accordingly, but the sealing member 39 is still restricted in the gap.

As compared with the known sealing devices of Figs.1 and 2, the sealing device 30 of Figs.3 and 4 may have one or more of the following advantages.

Since the first member 31 does not need a groove structure thereon for accommodating the sealing member, the manufacturing process of the first member 31 is simple, and the processing cost is relatively low.

Additionally, since the first member 31 does not need a groove structure thereon for accommodating the sealing member, the structure integrity of the first member 31 is good, and the working life is relatively long. Additionally, since the first outer surface 33 and the first inner surface 36 form a clearance fit therebetween, and the second outer surface 35 and the second inner surface 38 form a clearance fit therebetween, the fluid pressure can not be discharged between the first outer surface 33 and the first inner surface 36 or between the second outer surface 35 and the second inner surface 38 even in the case of the failure of the sealing member 39. Additionally, the sealing member of Fig.1 has the possibility of disengaging from the groove 13, and the sealing member of Fig.2 trends to disengage from the groove 23 when the first member 21 moves upwards too much relative to the second member 22. As compared with the sealing members of Fig.l or Fig.2, the sealing member 39 would not disengage since the sealing member 39 is always restricted in the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37 during the relative movement of the first member 31 and the second member 32.

Additionally, the sealing device 30 may be assembled and maintained simply.

In one example, the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 are cylindrical. The outer diameter of the first outer surface 33 is larger than that of the second outer cylindrical 35, and the inner diameter of the first inner surface 36 is larger than that of the second inner surface 38. Further, the sealing member 39 is an O-ring.

It should be noted that the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 may have any suitable shape. For example, the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 may also be square, rectangular or oval, and so on. The outer diameter of the first outer surface 33 may also be smaller than that of the second outer surface 35, and the inner diameter of the first inner surface 36 may also be smaller than that of the second inner surface 38 accordingly, thus the sealing member 39 is still restricted in the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37.

It should also be noted that the sealing member 39 may have any other structures and materials. For example, the sealing member 3 may be X-ring or PTFE -ring.

In an example, the lateral direction is perpendicular to the axial direction. In another example, the lateral direction is not perpendicular to the axial direction, for example, the lateral direction has an angle of 85 ° relative to the axial direction.

Those skilled in the art may appreciate that the sealing device of the present invention may be used in any application in which a sealing, especially a dynamic sealing, is required. The following will explain the embodiment in which the sealing device is used in a valve.

Fig.5 illustrates a sectional view of one embodiment of the valve 50 according to the present invention. The valve 50 is shown as a directing valve, and comprises a diaphragm 51 fixed between a valve body 52 and a valve cover 53, a valve stem 31 coupled to the diaphragm 51, a chamber 54 arranged on one side of the diaphragm 51, a valve seat 32 fixed to the valve body 52 in which a valve port 57 is defined by the valve seat 32, and a valve port gasket 55 biased by a biasing member 56 towards the valve port 57. The valve stem 31 can move relative to the valve seat 32 so as to control the opening degree of the valve port 57.

Specifically, as shown in Fig.5, the valve stem 31 has a first outer surface 33 arranged in an axial direction, a second outer surface 35 arranged inward in a lateral direction relative to the first outer surface 33, and a third outer surface 34 arranged in the lateral direction between the first outer surface 33 and the second outer surface 35. The valve seat 32 has a first inner surface 36 arranged in the axial direction, a second inner surface 38 arranged inward in the lateral direction relative to the first inner surface 36, and a third inner surface 37 arranged in the lateral direction between the first inner surface 36 and the second inner surface 38.

As shown in Fig.5, when assembled, the sealing member 39 is located in the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37 so as to provide a sealing. The first outer surface 33 and the first inner surface 36 form a clearance fit therebetween, and the second outer surface 35 and the second inner surface 38 form a clearance fit therebetween. According to an exemplary installation sequence, the sealing member 39 is surrounded around the second outer surface 35 of the valve stem 31, and then the valve stem 31 together with the sealing member 3 are installed into the valve seat 32.

During the operation, the valve stem 31 and the valve seat 32 may axially move relative to each other, thus the size of the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37 is changed accordingly, but the sealing member 39 is still restricted in the gap.

The valve comprising the sealing device 30 of Figs.3 and 4 may have one or more of the following advantages.

Since the valve stem 31 does not need a groove structure thereon for accommodating the sealing member, the manufacturing process of the valve stem 31 is simple, and the processing cost is relatively low;

Additionally, since the valve stem 31 does not need a groove structure thereon for accommodating the sealing member, the structure integrity of the valve stem 31 is good, and the working life is relatively long. Additionally, since the first outer surface 33 and the first inner surface 36 form a clearance fit therebetween, and the second outer surface 35 and the second inner surface 38 form a clearance fit therebetween, the fluid pressure can not discharge between the first outer surface 33 and the first inner surface 36 or between the second outer surface 35 and the second inner surface 38 even in the case of the failure of the sealing member 39. The amount of the leaking fluid therebetween may be arranged by adjusting the gap between the first outer surface 33 and the first inner surface 36 or between the second outer surface 35 and the second inner surface 38. The smaller the gap is, the smaller the amount of the leaking fluid is.

Additionally, the sealing member of Fig.1 has the possibility of disengaging from the groove 13, and the sealing member of Fig.2 trends to disengage from the groove 23 when the first member 21 moves upwards too much relative to the second member 22. As compared with the sealing member of Fig.l or Fig.2, the sealing member 39 would not disengage since the sealing member 39 is always restricted in the gap formed by the second outer surface 35, the first inner surface 36, the third'outer surface 34 and the third inner surface 37 during the relative movement of the valve stem 31 and the valve seat 32.

Additionally, the valve 50 comprising the sealing device 30 may be assembled and maintained simply.

Additionally, the valve 50 comprising the sealing device 30 has a small pressure difference.

Fig.6 shows the pressure difference curve of a known valve. As shown in the drawing, the pressure difference is about 1 psig (pounds per square inch gage) when the flowing speed is 130000 scfh (standard cubic foot per hour).

Fig.7 shows the pressure difference curve of the valve of Fig.5. As shown in Fig.7, the pressure difference is about 0.5 psig (pounds per square inch gage) when the flowing speed is 130000 scfh (standard cubic foot per hour), which is 50% smaller than that of Fig.6. The reason is that, when the valve stem 31 moves downwards, the friction diameter of the sealing member 39 is on the first inner surface 36 of the valve seat 32, and when the valve stem 31 moves upwards, the sealing member 39 will move upwards together with the valve stem 31 under the action of the pushing movement of the high pressure fluid or remains immobile, thus the friction diameter of the sealing member 39 is on the valve stem 31, thereby the friction force of the valve stem 31 moving downwards is larger than that of the valve stem 31 moving upwards.

In one example, the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 are cylindrical. The outer diameter of the first outer surface 33 is larger than that of the second outer surface 35, and the inner diameter of the first inner surface 36 is larger than that of the second inner surface 38. Further, the sealing member 39 is an O-ring.

It should be noted that the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 may have any suitable shape. For example, the first outer surface 33, the second outer surface 35, the first inner surface 36 and the second inner surface 38 may also be square, rectangular or oval, and so on. The outer diameter of the first outer surface 33 may also be smaller than that of the second outer cylindrical 35, and the inner diameter of the first inner surface 36 may also be smaller than of the second inner surface 38 accordingly, thus the sealing member 39 is still restricted in the gap formed by the second outer surface 35, the first inner surface 36, the third outer surface 34 and the third inner surface 37.

It should also be noted that the sealing member 39 may have any other structures and materials. For example, the sealing member 39 may be X-ring or PTFE -ring.

In an example, the lateral direction is perpendicular to the axial direction. In another example, the lateral direction is not perpendicular to the axial direction, for example, the lateral direction has an angle of 85 ° relative to the axial direction.

It should also be noted that in the embodiment of Fig.5, the valve is the directing valve 50, but the valve according to the present invention may be any other valve in which a sealing is required between the valve stem and the valve seat, for example, a main valve coupled to an actuator.

It should be noted that the above-described embodiments are given for describing rather than limiting the invention, and it shall be understood that modifications and variations may be resorted to without departing from the spirit and scope of the invention as those skilled in the art readily understand. Such modifications and variations are considered to be within the scope of the invention and the appended claims. The protection scope of the invention is defined by the accompanying claims. In addition, any of the reference numerals in the claims should not be interpreted as a limitation to the claims. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The indefinite article "a" or "an" preceding an element or step does not exclude the presence of a plurality of such elements or steps.