The embodiments described below relate to fluid control devices and, more particularly, to valves.
Valves, such as butterfly valves, employ rotatable shafts to regulate the flow of fluids flowing in a conduit. The butterfly valves are typically coupled to at least one side of the conduit with the shaft going through a wall of the conduit. Flaps or some other means of regulating the fluid are typically disposed in the conduit and coupled to the shaft. By rotating the shaft, a cross sectional area in the conduit through which the fluid flows changes thereby regulating the flow of the fluid.
Typically, the shaft is rotatably coupled to the conduit via one or more bearings that are subject to conditions in the fluid. For example, the bearings may be coupled directed to the conduit without thermal or fluid isolation. In some prior art, the bearings are disposed in the fluid. In others, the bearings are thermally coupled to the conduit via a metal plate or some other conductor. For relatively cool, lubricating, and non-corrosive fluids, these arrangements of the bearings may be appropriate.
However, in applications where the bearings are subject to adverse conditions, such as high temperatures and corrosion from hot and corrosive gases, such arrangement of the bearings is not appropriate and the bearings will fail. Some of the typical failure modes of the bearings may include fluids leaking out of the conduit or the friction in the bearings increasing to an undesirable level. The bearings may also fail by unexpectedly seizing thereby preventing the shaft from rotating.
What is needed, therefore, is a valve to reliably regulate the flow of fluids. The fluids may have adverse conditions such as high temperatures or corrosiveness.
According to an aspect, a valve (100, 600) coupled to a conduit carrying a fluid, comprises:
Preferably, the one or more isolation means of (120, 130) includes a plate (120) or an isolation gasket (130).
Preferably, the shaft (210, 610) comprises a cantilevered shaft (210) or a thru shaft (610) configuration.
Preferably, the rotatable support means (110, 320) is coupled to the shaft (210, 610) at a distal end (330) of the shaft (210, 610).
Preferably, the shaft (210, 610) comprises an inner shaft portion (410) and an outer shaft portion (420).
Preferably, the inner shaft portion (410) includes a hollow (450) and is configured to prevent the fluid in the conduit from entering the hollow (450).
Preferably, the inner shaft portion (410) includes a material selected to substantially isolate the proximate bearing (310).
Preferably, the shaft (210, 610) wherein the inner shaft portion (410) is coupled to the outer shaft portion (420) at a shaft junction (230).
Preferably, the valve (100, 600) wherein the proximate bearing (310) is coupled to the shaft (210, 610) at the shaft junction (230).
Preferably, the valve (100, 600) further comprising a secondary seal (460) and a primary seal (470) coupled to the shaft (210, 610) between the proximate bearing (310) and the conduit.
Preferably, the valve (100, 600) wherein the proximate bearing (310) is coupled to a valve body (140) that forms a portion of the conduit via one or more isolation means (120, 130).
Preferably, the rotatable support means (110, 320) comprises one or more motors (110) or one or more outer bearings (320).
Preferably, the valve (100, 600) wherein the fluid flow regulating means (230) in the conduit comprises a c-arm (220) coupled to the fluid flow regulating means (230) and the shaft (210, 610).
According to an aspect, a method of forming a valve (100, 600) coupled to a conduit carrying a fluid comprises:
Preferably, the forming one or more isolation means of (120, 130) claim 14 includes forming a plate (120) or forming an isolation gasket (130).
Preferably, the forming the shaft (210, 610) comprises forming a cantilevered shaft (210) or forming a thru shaft (610) configuration.
Preferably, the coupling the rotatable support means (110, 320) to the shaft (210, 610) comprises coupling the rotatable support means (110, 320) to the shaft (210, 610) at a distal end (330) of the shaft (210, 610).
Preferably, the forming the shaft (210, 610) comprises forming an inner shaft portion (410) and an outer shaft portion (420).
Preferably, the forming the inner shaft portion (410) includes forming a hollow (450) and configuring the inner shaft portion (410) to prevent the fluid from entering the hollow (450).
Preferably, the forming the inner shaft portion (410) includes selecting a material to substantially isolate the proximate bearing (310).
Preferably, the forming the inner shaft portion (410) and the outer shaft portion (420) includes coupling the inner shaft portion (410) and the outer shaft portion (420) at a shaft junction (230).
Preferably, the forming the valve (100, 600) further comprises coupling the proximate bearing (310) to the shaft (210, 610) at the shaft junction (230).
Preferably, the forming the valve (100, 600) further comprising forming and coupling a secondary seal (460) and a primary seal (470) to the shaft (210, 610) between the proximate bearing (310) and the conduit.
Preferably, the forming the valve (100, 600) wherein the coupling the proximate bearing (310) to the conduit via one or more isolation means (120, 130) comprises coupling the proximate bearing (310) via one or more isolation means (120, 130) to a valve body (140) that forms a portion of the conduit.
Preferably, the forming the rotatable support means (110, 320) comprises forming one or more motors (110) or one or more outer bearings (320).
Preferably, the coupling the fluid flow regulating means (230) to the shaft (210, 610) comprises coupling the fluid flow regulating means (230) to the shaft (210, 610) via a c-arm (220).
According to an aspect, a method of operating a valve (100, 600) coupled to a conduit carrying a flowing fluid comprises:
Preferably, the method of operating a valve (100, 600) includes drawing an adverse condition away from the proximate bearing (310) with the one or more isolation means (120, 130).
Preferably, the method of operating a valve (100, 600) includes impeding a transfer of an adverse condition to the proximate bearing (310).
The same reference number represents the same element on all drawings. It should be understood that the drawings are not necessarily to scale.
The inventors realized that low friction bearings were desirable to provide robust performance parameters such as long life, reliability, and low rotational friction. The inventors also realized that using such bearings in the conduits carrying the fluid with adverse conditions presented a considerable challenge given the numerous past failures by others to design a workable solution. The inventors overcame this considerable challenge by providing, among other things, configurations that substantially isolates the bearings.
In one configuration, a cantilever arrangement of the shaft may substantially isolate the bearings while still providing sufficient support to regulate the flow of the fluid. In another configuration, a thru shaft may be coupled to bearings that are substantially isolated and, similar to the cantilever configuration, provides sufficient support to the shaft. Substantially isolating of the bearings may include impeding the transfer of adverse conditions to the bearings and/or drawing the adverse conditions away from the bearings. The adverse conditions may include high temperatures, corrosiveness, etc. The bearings are therefore able to operate without failures caused by the fluids. Accordingly, the valve can reliably regulate the flow of the fluid.
In the embodiment of
The plate 120 is an isolation means that may substantially isolate a bearing (not shown). For example, the plate 120 may be a heat sink. That is, the plate 120 may have a mass that is larger than the mass of the bearing thereby adsorbing the heat from the bearings. The plate 120 may couple the cantilevered shaft 210 to the valve body 140 via the bearing. In the depicted embodiment, the plate 120 is comprised of a material with high thermal conductivity such as aluminum. In alternative embodiments, the plate 120 may be comprised of copper or any other suitable material. The plate 120 may also be comprised various materials such as a combination of aluminum and copper. The plate 120 is depicted as tangential to the outer surface of the valve body 140 although other orientations may be employed. The plate 120 may be further adapted to convey some adverse conditions, such as heat, away from the valve 100 as will be described in more detail later.
Still referring to
Also, the cantilevered shaft 210, the c-arm 220, the flap 230, and the couplers 240 are depicted with a cylindrical cross section. For example, the embodiments depicted in
Still with reference to
In the depicted embodiment, the proximate bearing 310 is located above the isolation gasket 130. As discussed in the foregoing with reference to
The outer bearing 320 is depicted as coupled to the cantilevered shaft 210 at a distance from the proximate bearing 310. The distance may be sufficient to provide mechanical support for the cantilevered shaft 210 so that the cantilevered shaft 210 is desirably stable when the fluid is flowing. For example, viscous fluids flowing at a high rate may apply a substantial force to the cantilevered shaft 210. Accordingly, the outer bearing 320 is coupled to the cantilevered shaft 210 at the distance that ensures the shaft performs in the desirable manner. The embodiment depicted in
The outer bearing 320 is also depicted as located at a distal end 330 of the cantilevered shaft 210. By being so located, it is at a distance away from the proximate bearing 310. Such location may be desirable to maximize the distance of the outer bearing 320 from the proximate bearing 310 while still minimizing other factors such as material costs, mass of the cantilevered shaft 210, size of the valve 100, etc.
In some embodiments, the proximate bearing 310 and the outer bearing 320 may be substantially isolated by disposing the proximate bearing 310 and the outer bearing 320 outside the valve body 140 with an isolation means that does not include the plate 120 and the isolation gasket 130. The proximate bearing 310 and the outer bearing 320 may be any appropriate bearing such as roller ball or needle bearings. As mentioned in the foregoing, the proximate bearing 310 and outer bearing 320 may be low friction and reliable bearings such as deep groove ball bearings.
In alternative embodiments, the proximate bearing 310 may be coupled to the cantilevered shaft 210 without the outer bearing 320. For example, in applications involving relatively low viscous fluids with low flow rates such as a heated gas at sub-atmospheric pressures, the proximate bearing 310 may provide sufficient support to the shaft to regulate the flow of the fluid without an additional bearing. In the same or alternative embodiment a rotating support means such as a bushing or the motor 110 may, with the proximate bearing 310, provide sufficient support to regulate the flow of the fluid in the conduit. In such embodiments the motor 110 may be coupled directly to the cantilevered shaft 210.
These and other embodiments provide the cantilever configuration that substantially isolates the proximate bearing 310. Accordingly, the proximate bearing 310 may be selected without taking into account the adverse conditions in the fluid. For example, low friction bearings may be selected that would otherwise not be sufficiently robust to withstand the adverse conditions. Such low friction bearings may include needle or deep groove roller ball bearings. Other bearings may be employed. The bearings may also include lubricants such as grease or silicon that would otherwise corrode or deteriorate if not substantially isolated.
The cantilevered configuration may also minimize the distance of the proximate bearing 310 from the conduit while still substantially isolating the proximate bearing 310 from the adverse conditions. This minimal distance may maximize support for the cantilevered shaft 210. Maximizing support (e.g. maximizing the moment arm applied to the cantilevered shaft 210 by the proximate bearing 310) for the cantilevered shaft 210 may reduce the forces applied by the flowing fluid to the proximate bearing 310. By reducing the forces applied to the proximate bearing 310, the valve 100 may be more reliable.
The outer shaft portion 420 includes a male portion 440 that is coupled to an inside surface of the inner shaft portion 410. The outer shaft portion 420 may rotate the inner shaft portion 410 via the male portion 440 at the shaft junction 430 to regulate the flow of the fluid in the valve body 140. The inner shaft portion 410 and the outer shaft portion 420 may be comprised of any suitable material such as materials with low thermal conductivity. For example, the inner shaft portion 410 and the outer shaft portion 420 may be comprised of a ceramic material. They may also be comprised of different materials. For example, the outer shaft portion 420 may be aluminum and the inner shaft portion 410 may be ceramic.
The inner shaft portion 410 may substantially isolate the proximate bearing 310 and the outer bearing 320. For example, as depicted, the inner shaft portion 410 has a hollow 450. The hollow 450 may provide a relatively small cross section for heat transfer. This may limit the heat transfer up the shaft 210 past the isolation gasket 130. Since the heat transfer is limited, the size of the plate 120 and other things related to conveying heat away from the proximate bearing 310 and the outer bearing 320 may be minimized, simplified, eliminated, or like.
The outer shaft portion 420 may also substantially isolate the proximate bearing 310 and the outer bearing 320. For example, the outer shaft portion 420 may be a heat sink that removes heat from the proximate bearing 310 and the inner shaft portion 410. As can be seen, proximate bearing 310 may surround the inner shaft portion 410 and outer shaft portion 420 at the shaft junction 430. Such a location of the proximate bearing 310 may be desirable to optimize the heat sink capacity of the outer shaft portion 420 while minimizing the mass of the cantilevered shaft 210. The cantilevered shaft 210 may also be adapted to remove heat from the proximate bearing 310 and the outer bearing 320 as discussed in the following with reference to
In addition to the isolation gasket 130, the proximate bearing 310 may be isolated from the adverse conditions additional isolation means such as a secondary seal 460 and a primary seal 470 depicted in
As mentioned in the foregoing with respect to
The embodiments described above provide an improved valve. For example, the plate 120 may substantially isolate the proximate bearing 310 and the outer bearing 320 by removing heat from the proximate bearing 310 and the outer bearing 320. The isolation gasket 130 may substantially isolate the proximate bearing 310 and the outer bearing 320 from the adverse conditions in the fluid by insulating the bottom of the plate 120 from the valve body 140 thereby limiting the cross sectional area available for heat transfer. The isolation gasket 130 may also provide a fluid seal that substantially isolates the fluid with the adverse conditions from the proximate bearing 310 and the outer bearing 320.
The detailed descriptions of the above embodiments are not exhaustive descriptions of all embodiments contemplated by the inventors to be within the scope of the present description. Indeed, persons skilled in the art will recognize that certain elements of the above-described embodiments may variously be combined or eliminated to create further embodiments, and such further embodiments fall within the scope and teachings of the present description. It will also be apparent to those of ordinary skill in the art that the above-described embodiments may be combined in whole or in part to create additional embodiments within the scope and teachings of the present description.
Thus, although specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the present description, as those skilled in the relevant art will recognize. The teachings provided herein can be applied to other valves, and not just to the embodiments described above and shown in the accompanying figures. Accordingly, the scope of the embodiments described above should be determined from the following claims.
Number | Date | Country | Kind |
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1422844.9 | Dec 2014 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2015/053537 | 11/19/2015 | WO | 00 |