Butterfly valve plate sealing assembly

Butterfly valve plate sealing assemblies are provided that include a sealing ring and a retention spacer disposed at least partially within a sealing ring groove formed about a periphery of a butterfly valve plate. The sealing ring includes a first portion, a second portion configured substantially perpendicular to the first portion, and a substantially L-shaped cross-section. The sealing ring is positioned at least partially within a groove opening and a groove body defining the sealing ring groove. The retention spacer is positioned at least partially within the groove opening and adjacent the first portion of the sealing ring. The retention spacer is configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow. The second portion of the sealing ring may be configured to optimize stiffness for a desired sealing ring tension.

TECHNICAL FIELD

The inventive subject matter relates to butterfly valve assemblies and, more particularly, to a butterfly valve sealing ring assembly for use with a single piece butterfly plate.

BACKGROUND

Valves may be employed in any one of numerous situations. For example, valves may be used in an air distribution system to allow, control, or shut off airflow from one portion of an aircraft's ducting to another. In this regard, pneumatic valves may be disposed in a duct between an air source and one or more outlets to control the flow of the received air that is distributed to other components or areas in the aircraft, such as, for example, the environmental control system or an aircraft cabin.

One exemplary type of pneumatic valve that has been employed in aircraft is a butterfly valve. A butterfly valve is typically made up of a valve flowbody and a butterfly plate. The valve flowbody may be made of a rigid material, such as metal, and includes a channel or bore therethrough, defined by an inner surface. The valve flowbody is configured to be disposed between two ducts or disposed in a portion of a single duct. The butterfly plate is made of a rigid material as well and is rotationally mounted to the valve flowbody. Conventionally, the butterfly plate is positioned in the channel such that a minimum clearance is formed with the inner surface of the valve flowbody. An actuator and a spring may be used to control the rotation of the butterfly plate.

Typically, the butterfly plate is moved between closed, open, and partially open positions. When in the closed position, where the butterfly plate is perpendicular or near perpendicular in the flowbody bore, the butterfly plate substantially blocks the channel to prevent, or at least inhibit, fluid from flowing therethrough. When fluid flows through the valve flowbody in a forward direction, the butterfly plate moves to the open or partially open position to allow fluid flow through the channel. To provide for sealing of the butterfly valve plate relative to the channel, the butterfly valve plate includes a sealing ring groove about a periphery into which is seated a sealing ring. During rotation of the butterfly valve plate, the sealing ring engages the channel wall, and provides sealing about the periphery of the butterfly valve plate. The sealing ring must be properly positioned during installation and maintained in proper alignment with respect to the periphery of the butterfly valve plate to achieve adequate sealing effects. During operation of the valve, the sealing ring has a tendency to expand outwards from the butterfly valve plate when under the influence of a pressure. More particularly, when the butterfly valve plate is in an open position, the sealing ring is not in direct contact with the channel and may come out of the sealing ring groove into which it is positioned. In particular, the flow of fluid through the channel may cause a downstream portion of the sealing ring to expand and become misaligned relative to the sealing ring groove. When the butterfly valve plate is then closed, increased closing forces may exist as a result of the misaligned sealing ring. In some cases, the misaligned sealing ring may prevent the butterfly valve plate from fully closing when the sealing ring becomes lodged between the periphery of the butterfly valve plate and the channel.

Accordingly, there is a need for a butterfly valve plate sealing assembly that includes a means for constraining a sealing ring within a sealing ring groove with limited expansion of the sealing ring. More specifically, there is a need for a means to minimize misalignment of the sealing ring from within the sealing ring groove when the valve is pressurized. In addition, it would be desirable for the sealing assembly to be relatively inexpensive to implement. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

BRIEF SUMMARY

A butterfly valve sealing assembly is provided that includes a means for minimizing expansion of a butterfly valve sealing ring from within a sealing ring groove formed about a periphery of a butterfly valve plate in a butterfly valve.

In an embodiment, by way of example only, the butterfly valve sealing assembly includes a sealing ring disposed at least partially within the sealing ring groove; and a retention spacer, positioned adjacent the sealing ring and disposed at least partially within the sealing ring groove, the retention spacer configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow.

In another embodiment, by way of example only, the butterfly valve sealing assembly includes a sealing ring disposed at least partially within the sealing ring groove, the sealing ring having a first portion, a second portion configured substantially perpendicular to the first portion, and a substantially L-shaped cross-section; and a retention spacer, positioned adjacent the sealing ring and disposed at least partially within the sealing ring groove, the retention spacer configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow.

In yet another embodiment, by way of example only, a butterfly valve assembly includes a flowbody having an inner surface defining a channel; a butterfly plate disposed in the channel and rotationally mounted to the flowbody, the butterfly plate having a valve shaft coupled thereto and a sealing ring groove formed about a periphery of the butterfly plate; an actuator having an actuator output shaft coupled to the valve shaft, the actuator configured to actuate the butterfly plate; and a butterfly valve plate sealing assembly comprising: a sealing ring disposed at least partially within the sealing ring groove; and a retention spacer, positioned adjacent the sealing ring and disposed at least partially within the sealing ring groove, the retention spacer configured to limit expansion of the sealing ring when under the influence of a pressurized fluid flow.

Other independent features and advantages of the preferred means for retaining a butterfly valve sealing ring within a sealing ring groove formed about a periphery of a butterfly valve plate in a butterfly valve will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the inventive subject matter.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The following detailed description of the inventive subject matter is merely exemplary in nature and is not intended to limit the inventive subject matter or the application and uses of the inventive subject matter. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the inventive subject matter or the following detailed description of the inventive subject matter.

It is contemplated that the present invention is particularly well suited for use with butterfly type valves, more particularly with butterfly type valves that are used in cabin environmental control systems. However, the present invention may also be applicable in other types of valves where a part or assembly rotates about a shaft, the sealing assembly includes dual components for sealing about a periphery of the rotating assembly and it is desirable to prevent unwanted movement of the sealing component from about the periphery of the rotating assembly when under the influence of a downstream pressure. In some instances it may also be applicable to non-valve assemblies as well.

It is contemplated that alternative embodiments will likely comprise elements in addition to those described in relation toFIGS. 1-7, and/or may include different numbers or types of the described elements. It is also contemplated that any element may be formed from any reasonable material or combination of materials.

FIG. 1is a simplified schematic diagram illustrating an air distribution system100disposed within an aircraft102, according to an embodiment. The air distribution system100includes an inlet duct104, two outlet ducts106,108and a valve assembly110positioned between the ducts104,106,108. The inlet duct104receives air from an air source, such as, for example, engine bleed air, and the outlet ducts106,108exhaust air into desired sections of the aircraft102. In one exemplary embodiment, the outlet ducts106,108exhaust air into an aircraft underfloor. It will be appreciated that although two outlet ducts106,108are depicted herein, fewer or more outlet ducts may be incorporated into the air distribution system100. The valve assembly110regulates air flow through one or more of the outlet ducts106,108by opening or closing in response to the presence or absence of a pressure differential across the valve assembly110that exceeds a predetermined value. It should be understood that although a three-way butterfly valve configuration is illustrated inFIG. 1, this is merely for exemplary purposes and that two-way butterfly valve configurations are anticipated by this disclosure.

FIG. 2is a cross-sectional view of a valve assembly110that may be implemented into the air distribution system100shown inFIG. 1, according to an embodiment. The valve assembly110includes a valve flowbody112having an inner surface114that defines a channel116and an outer surface118. The valve flowbody112is generally made of a metallic material, although alternate non-metallic materials are anticipated by this disclosure. Examples of suitable materials may include, but are not limited to, aluminum alloys, steel or titanium. Although a single channel116is shown formed in the valve flowbody112, it will be appreciated that multiple channels may alternatively be incorporated. In an embodiment, the valve flowbody112may be surrounded by an insulator113.

The channel116defines a flow path, indicated by arrows117, through the valve assembly110which is opened and closed via rotation of a butterfly valve plate120disposed in the channel116and rotationally mounted to the valve flowbody112. The actual size and shape of the channel116into which the butterfly valve plate120is disposed is not critical to the present invention. However, it is contemplated that the present invention is particularly advantageous when used in valves where the segment of the channel116within which the butterfly valve plate120rotates is cylindrical and has an internal diameter approximately equal to the diameter of the butterfly valve plate120.

The butterfly valve plate120may be coupled to an actuator124that causes it to selectively open or close via a single drive shaft, two drive shaft segments, or to some other mechanism suitable for rotating the butterfly valve plate120about an axis of rotation passing through the channel116. In some instances the axis of rotation may be perpendicular to the centerline of the channel116while in other instances it may not. In addition, the butterfly valve plate120may be tilted relative to the centerline of a drive shaft. The majority of the butterfly valve plate120is in the form of a cylindrical disk with the center line of the disk being substantially collinear with the center line of the channel116when the butterfly valve plate120is in a closed position, i.e. rotated such that the disk substantially or completely blocks the channel116. The actuator124may be any actuating mechanism such that in some instances pressure differentials will be used to open and close the valve assembly110. In an alternate embodiment, electrical power will be used to open and close the valve assembly110. More particularly, the actuator124may include, but is not limited to, an electric actuator, a pneumatic actuator, a hydraulic actuator, or a manual actuator.

The butterfly valve plate120may comprise any reasonable size or shape such that it operates to at least partially open and close the flow path117defined by the channel116. In a preferred embodiment, the butterfly valve plate120comprises a unitary structure cast or otherwise formed from steel, a metallic alloy, or some other material or combination of materials. The butterfly valve plate120includes a sealing ring groove122formed about a periphery125of the butterfly valve plate120. A butterfly sealing assembly126, retained within the sealing ring groove122, provides for sealing of the butterfly valve plate120with the inner surface114that defines the channel116.

Referring now toFIG. 3, illustrated is a close up cross-sectional view of a portion of the valve assembly shown inFIG. 2, according to an embodiment. Illustrated is a portion of the valve assembly110, including the butterfly valve plate120, a valve drive shaft130coupled to the butterfly valve plate120, and the butterfly sealing assembly126. The valve drive shaft130may be coupled at a first or upper end (not shown) to an output shaft of the actuator124(FIG. 2). As best illustrated inFIG. 3, the sealing assembly126provides sealing of the butterfly valve plate120against the inner surface114of the valve flowbody112. The butterfly valve plate120and the butterfly sealing assembly126provide for the sealing of the flow of a fluid from upstream132the channel116to downstream134the channel116.

According to an embodiment,FIG. 4illustrates a close-up cross-sectional view of the butterfly sealing assembly126, positioned within a periphery125of the butterfly valve plate120, of the valve assembly110indicated by a dotted line4shown inFIG. 3in which a means for restraining a butterfly valve sealing ring (described presently) is implemented. The butterfly sealing assembly126may include a sealing ring136and a retention spacer138positioned to retain the sealing ring136within the sealing ring groove122. In this embodiment, the sealing ring136is formed having a substantially L-shaped cross-section. In an alternate embodiment, the sealing ring136may include a sloped portion, yet maintain a substantially L-shaped cross-section. In preferred embodiments the sealing ring136comprises a unitary structure formed from a non-metallic, steel, a metallic alloy, or some other material or combination of materials. The sealing ring groove122is preferably formed in a peripheral surface of the butterfly valve plate120and is defined by a groove opening144and a groove body145. Alternatively, the sealing ring groove122may be formed in a surface of an element coupled to the butterfly valve plate120, or by defining walls by adding members to the butterfly valve plate120while using a surface of the butterfly valve plate120as the floor of any such groove. In preferred embodiments, the sealing ring groove122is of uniform width and also of uniform depth. However, it is contemplated that alternative sealing ring groove configurations may be used.

During operation of the valve assembly110, downstream portion of the sealing ring136has a tendency to expand outwards from the butterfly valve plate120. When the butterfly valve plate120is opened and the sealing ring136is not in direct contact with the channel116, the sealing ring136can further come out of the sealing ring groove122. This displacement of the sealing ring136relative to the sealing ring groove122results in increased closing forces when trying to close the butterfly valve plate120and in some cases may prevent the butterfly valve plate120from fully closing when the sealing ring136becomes lodged between the butterfly valve plate120and the channel116. The L-shaped cross-sectional feature limits the expansion of the sealing ring136when the valve assembly110is pressurized and minimizes the displacement of the sealing ring136from within the sealing ring groove122.

During assembly of the butterfly valve plate120, a portion of the sealing ring136is positioned within the sealing ring groove122via the groove opening144. To facilitate this assembly, the sealing ring groove122, including the groove opening144and the groove body145, must be of a dimension sufficiently large to accommodate installation of the L-shaped cross-sectional shape of the sealing ring136. Subsequent to position of the sealing ring136, a retention spacer138is positioned within the sealing ring groove122to fill any gap that remains in the groove opening144and provide for retainment of the sealing ring136within the sealing ring groove122during pressurization.

In a preferred embodiment, the retention spacer138comprises a unitary structure formed from steel, a metallic alloy, or some other material or combination of materials. The retention spacer138is generally formed having a stiffness factor that is greater than a stiffness factor of the sealing ring136to minimize expansion of the retention spacer138from within the sealing ring groove122. The retention spacer138is dimensioned to provide for retention of the sealing ring136within the sealing ring groove122.

Referring again toFIG. 4, in the illustrated embodiment, the sealing ring136includes a substantially L-shaped cross-section, and includes a first portion140and a second portion142disposed substantially perpendicular to the first portion140. The retention spacer138is positioned within the groove opening144that forms a portion of the sealing ring groove122and adjacent the first portion140of the sealing ring136. As best illustrated inFIG. 5, an alternate embodiment provides for positioning of the retention spacer138adjacent the first portion140of the sealing ring136and resting upon an uppermost aspect143of the second portion142. In this embodiment, the retention spacer138provides for minimizing expansion of the sealing ring136and retainment of the sealing ring136within the sealing ring groove122during pressurization.

As previously described, the sealing ring136includes a retention means for retaining the sealing ring136within the sealing ring groove122in the form of the second portion142. In an attempt to optimize the stiffness of the sealing ring136and achieve desired ring tension in light of the inclusion of the retention spacer138as a part of the butterfly sealing assembly126, the sealing ring136may include a plurality of interruptions in the second portion142. More specifically, the sealing ring136may include a plurality of interruptions150in the second portion142, in the form of a plurality of cut-away portions, or the like, as best illustrated inFIG. 6. The plurality of interruptions150may be dimensioned to provide for desired ring tension in light of the addition of the retention spacer138to the butterfly sealing assembly126. In addition, the sealing ring136may include an opening152to allow for installation about the periphery of the butterfly valve plate120. Alternatively, and as best illustrated inFIG. 7, the sealing ring136may include a retention means in localized areas. More specifically, the sealing ring136may include the second portion142in a localized area sufficient to provide retention of the sealing ring136within the sealing ring groove122when the valve is pressurized. Similar to the embodiment illustrated inFIG. 6, the sealing ring136illustrated inFIG. 7may include the opening152to allow for installation about the periphery of the butterfly valve plate120.

A butterfly valve sealing assembly has now been provided that includes a means for retaining a butterfly sealing ring within a butterfly valve groove formed about a periphery of a butterfly valve plate when under the influence of pressurized fluid forces. The sealing ring includes a retaining means generally in the form of a second portion that extends substantially perpendicular from a first portion. A retention spacer is positioned within an opening of the sealing ring groove and adjacent the first portion of the sealing ring to further retain the sealing ring within the sealing ring groove. The sealing assembly may have an increased life expectancy as compared to conventional valves incorporating traditional sealing rings that may become displaced when under the influence of a pressurized flow. In addition, the sealing assembly may be lightweight and relatively inexpensive to implement.

While the inventive subject matter has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the inventive subject matter. In addition, many modifications may be made to adapt to a particular situation or material to the teachings of the inventive subject matter without departing from the essential scope thereof. Therefore, it is intended that the inventive subject matter not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this inventive subject matter, but that the inventive subject matter will include all embodiments falling within the scope of the appended claims.