Double-acting flow reversal valve with bistable state

Abstract

A valve assembly (10) configured to passively switch between first and second modes of operation. The valve assembly (10) comprises a first valve seat insert (24) and a second valve seat insert (24 ') acting on the respective first and second valve seat inserts (24; 44), and a first valve body (20) and a second valve body (40) having a first valve seat (26) and a second valve seat (46) corresponding to the first valve seat (26) and the second valve seat (46). The valve bodies are connected by a valve stem (70) such that, in a first operating mode, movement of the first valve body to the closed position moves the second valve body to the open position; and in a second operating mode, when the force of the fluid acting on the first valve body overcomes the closing force and any pressure (F1) of the elastic element (22), the first valve body can be moved into the open position while simultaneously moving the second valve body (40) into the closed position. In order to enhance functionality and maintain the valve in a bistable position, a first sleeve-like wall (30) and a second sleeve-like wall (50) are provided at respective valve seats.

Description

Technical Field

[0001] The present invention relates to valves, and more particularly to a valve assembly that reverses or changes flow based on a pressure differential acting across the valve. Background Art

[0002] The systems described in the applicant's co-pending applications, filed on the same date as the present application and entitled "Heat Exchanger with Integrated Double-Acting Flow Reversing Valve" and "Double-Acting Backwash Valve with Linked Valve Body" (both by inventor Stephen J. Harrison), describe valve assemblies having linked valve bodies that can be used in various applications, including backwashing of water heaters.

[0003] It may be desirable for such applications to provide a valve that has bi-stable switching operation and switches between states at a desired pressure and / or flow rate. Summary of the Invention

[0004] In one aspect, the present disclosure relates to a valve assembly configured to passively switch between first and second operating modes. The valve assembly, preferably in a valve housing, includes a first port, a second port, and a third port. A first valve body is biased by a resilient element to a closed position against a first valve seat of a first valve seat insert, the first valve seat insert being located at or adjacent to a third port, so as to close the third port in the first operating mode. The valve assembly also includes a second valve body, the second valve body acting on a second valve seat of a second valve seat insert, the second valve seat insert being located at or adjacent to the second port, and in the first operating mode, the second valve body is in an open position spaced apart from the second valve seat, such that fluid is suitable for circulation from the first port to the second port. A valve stem extends axially between the second valve body and the first valve body, such that in the first operating mode, movement of the first valve body to the closed position moves the second valve body to an open position, allowing fluid to circulate between the first port and the second port. In a second operating mode, when the force of fluid from the third port acting on the first valve body overcomes the closing force of the elastic element and any pressure of the fluid from the first port and / or the second port, the first valve body can be moved to an open position while simultaneously moving the second valve body to a closed position against the second valve seat, such that the fluid from the third port is suitable for circulation through the first port. A first, preferably cylindrical, sleeve-like wall is provided on or in the first valve seat insert, extending in an axial direction and configured to radially surround the first valve body when the first valve body is in the closed position. A second, preferably cylindrical, sleeve-like wall is provided on or in the second valve seat insert, extending in an axial direction and configured to radially surround the second valve body when the second valve body is in the closed position. In order to provide a bistable position of the valve body with minimized switching time between the first and second operating modes, the first valve body, the second valve body and the valve stem are arranged so that when the first valve body moves toward the open position, the first sleeve-shaped wall axially overlaps a portion of the first valve body until the second valve body moves to a position before reaching the closed position, in which position the second valve body is at least partially overlapped by the second sleeve-shaped wall.

[0005] In one embodiment of the present invention, the second valve body has at least one pressure relief groove on its valve seat side. Therefore, even in the closed position, the valve seat side and the valve stem side of the second valve body remain in fluid communication through the second valve seat. This helps prevent a large pressure differential from developing across the second valve seat, which could cause the second valve body to be drawn into its seat.

[0006] In one embodiment of the present invention, a damper acts on the valve stem to damp the movement of the compressed elastic element. This can help reduce the water hammer effect when closing the second valve seat.

[0007] In one embodiment of the present invention, the damper applies less damping to the valve stem in the expansion direction of the elastic element than in the compression direction of the elastic element, which allows the second valve seat to open faster.

[0008] In one embodiment of the invention, the damper acting on the valve stem (e.g., the damper) comprises at least one elastomeric element (e.g., at least one lip seal) and / or at least one bypass channel (e.g., a bypass groove) formed in the valve stem. The combination of the bypass channel (e.g., the bypass groove) and the elastomeric element for sealing (e.g., the lip seal) is particularly advantageous because the element or lip seal closes more during rapid movements or at higher pressures, thereby increasing damping.

[0009] In one embodiment of the invention, the damper (such as described) acting on the valve stem (70) comprises at least two lip seals facing each other. Thus, a simple way for providing a damper is described.

[0010] Additionally, when the spring force and any pressure from the first or second port overcomes the pressure of the fluid at the third port, the valve assembly is configured to return to a first operating mode, wherein the second valve body moves back toward the open position, with the second sleeve-shaped wall axially overlapping a portion of the second valve body, until the first valve body moves to a position before reaching the closed position, in which position the first valve body is at least partially overlapped by the first sleeve-shaped wall.

[0011] With this arrangement structure, when the valve body moves toward the closed position, the sleeve-shaped wall guides the fluid toward the valve stem side of each valve body in the corresponding valve body, enhancing the switching performance and the stability of the corresponding first or second valve body in the corresponding closed position (that is, based on the comparison of the fluid pressure at the third port with the force of the elastic element and the force of the fluid at the first and / or second port, the valve assembly has a bistable closed position of the first or second valve body).

[0012] Preferably, at least one of the first and / or second valve bodies (and preferably both) is cup-shaped and has an axially extending wall section (preferably cylindrical) that fits within the corresponding first or second sleeve-shaped wall section. A clearance fit is provided here so that no additional friction forces need to be overcome to move the valve body between the first and second operating modes.

[0013] In another embodiment, a shroud is connected to the valve housing, and more preferably to the second valve seat insert, adjacent the second port. The shroud includes a receiving space facing the stem side of the second valve body and, in a first operating mode, surrounds a peripheral area of the second valve body when the second valve body is in the open position. Preferably, the shroud circumferentially surrounds at least a portion of an axially extending wall segment of the second valve body. This generally prevents fluid flow through the valve assembly from acting on the stem side of the second valve body in the first operating mode. When the valve assembly is moved to the second operating mode, the second valve body moves axially out of the receiving space of the shroud, allowing fluid flow through the valve assembly to act on the stem side of the second valve body, exerting a force on the second valve body to assist in moving the second valve body against the second valve seat in the second operating mode.

[0014] In a preferred embodiment, the shield defines a bottleneck for fluid flowing from the first port and / or the third port to the second port, and the second valve body is spaced apart from the bottleneck in its open position. This prevents the second valve body from being drawn out of its receiving space due to a low-pressure area downstream of the bottleneck. To this end, a preferred embodiment includes a second valve body that is fully accommodated within the receiving space.

[0015] The shroud is preferably frustoconical and supported by one or more fins extending from the surrounding valve housing or, more preferably, the second valve seat insert. A stem receptacle on the stem side of the valve stem or second valve body, to which the valve stem is connected, extends through an opening in the shroud. Preferably, a stem receiving sleeve is connected to the shroud and the opening is defined through the stem receiving sleeve.

[0016] In another aspect, the second valve body preferably includes a ramp section on its second valve seat side. This ramp section is preferably frustoconical in shape, and when the valve assembly is in the first operating mode, fluid flowing through the valve assembly acts on the ramp section to apply an additional force in the axial direction toward the first valve body. This force acts in addition to the spring force to maintain the first valve body under pressure in the closed position against the first valve seat in the first operating mode. If a shroud is used, this force also serves to maintain the second valve body in position within at least a portion of the axially extending wall section of the shroud that circumferentially surrounds the second valve body. This helps prevent unintended movement of the second valve body toward the second valve seat due to fluid flow between the first and second ports in the first operating mode. Preferably, utilizing one or more of these features, the valve assembly is maintained in the first operating mode, with the first valve body in the closed position against the first valve seat, to achieve a flow rate of 6 liters / minute or greater. This design can be adjusted based on the spring force, valve body size, shroud shape, and position to accommodate different flow rates depending on the specific application.

[0017] On the other hand, the valve stem is preferably formed to provide an adjustable length in use to compensate for tolerances. Here, the valve stem includes at least one protrusion at each of the first and second axial ends. This can be an annular protrusion or one or more circumferentially spaced protrusions at each axial end. The first and second valve bodies each include a respective first and second socket connected to the respective valve stem side of the valve body, the respective first and second sockets being configured to receive the respective first or second axial end of the valve stem. The first and second sockets each include an internal groove in which the respective at least one protrusion is received, preferably with a snap fit.

[0018] At least one (and preferably both) of the internal grooves has an axial dimension that is longer than the axial width of at least one projection received therein, thereby providing an axial compensating movement that is equal to the difference between the axial dimension of the groove and the width of the projection, and that is twice that value if axial compensation is provided at the connection between the valve stem and both the first and second valve bodies.

[0019] Preferably, both axial ends of the valve stem are tapered to allow for "blind" assembly of the valve assembly into the valve housing. For example, a first valve body can be assembled with a resilient element and retained in a first valve seat insert, and the first axial end of the valve stem can be inserted into a first receptacle on the stem side of the first valve body with a snap fit. This first assembly can involve inserting the valve stem first into the third port of the valve housing. The second valve body, assembled with a second valve seat insert and a shroud, can be inserted into the second port of the valve housing, with the tapered second end of the valve stem received in a second receptacle on the second valve body and then connected with a snap fit. The first and second valve seat inserts can be retained in the valve housing by various means, such as a retaining ring and groove, a washer or other protrusion extending beyond the ends of the respective third and second ports as part of the assembly or during connection to other piping or fittings, against a shoulder within the valve housing, a press fit, or by various other means as would be apparent to one skilled in the art from this disclosure. The first and second valve seat inserts may further include seals (integral or separately retained) around their peripheries that contact the walls of the third and second ports when the first and second valve seat inserts are installed.

[0020] For certain applications, where slight leakage through the first or second valve body when in the closed position against the respective first and second valve seats is acceptable for operation of the valve assembly, separate seals are not provided at these locations.

[0021] Preferably, all components of the valve assembly are made of polymer material, with the possible exception of the spring element, which may be a metal spring. Preferably, these polymer components may be injection moulded.

[0022] The valve assembly allows for fully passive operation between first and second operating positions based on a comparison of the fluid pressure at the third port with the force of the resilient element and the pressure at the first and / or second ports.

[0023] The elastic element is a spring, preferably a metal coil spring.

[0024] Preferably, the second and third ports are axially aligned.

[0025] This arrangement is particularly useful for flow reversal valves or backwash valves used with or integrated in a heat exchanger, and the heat exchanger body itself may form the valve housing.

[0026] The above features may be used alone or in various combinations to provide the desired level of functionality.

[0027] For example, in another embodiment, a valve assembly configured to passively switch between first and second operating modes—preferably in a valve housing—also has first, second, and third ports, and includes a first valve body biased by a resilient element to a closed position against a first valve seat of a first valve seat insert (the first valve seat insert is located at or adjacent to the third port so as to close the third port in the first operating mode); and a second valve body acting on a second valve seat of a second valve seat insert (the second valve seat insert is located at or adjacent to the second port, and in the first operating mode, the second valve body is in an open position spaced apart from the second valve seat so that fluid is suitable for circulating from the first port to the second port). The valve stem extends between the second valve body and the first valve body, such that in a first operating mode, movement of the first valve body toward a closed position moves the second valve body to an open position, allowing fluid to circulate between the first and second ports; and in a second operating mode, when the force of fluid from the third port acting on the first valve body overcomes the closing force of the elastic element and any pressure of fluid from the first and / or second ports, the first valve body can be moved to the open position while simultaneously moving the second valve body to a closed position against the second valve seat, such that fluid from the third port is suitable for circulation through the first port. In this embodiment, a shroud is adjacent to the second port and includes a receiving space facing the valve stem side of the second valve body, and in the first operating mode, when the second valve body is in the open position, the shroud surrounds a peripheral area of the second valve body.

[0028] This embodiment does not utilize first and second sleeve-like wall sections, but may utilize other features described herein.

[0029] In another embodiment, a valve assembly configured to passively switch between first and second operating modes—preferably in a valve housing—also has first, second, and third ports and includes a first valve body biased by a resilient element to a closed position against a first valve seat of a first valve seat insert (the first valve seat insert is located at or adjacent to the third port so as to close the third port in the first operating mode); and a second valve body acting on a second valve seat of a second valve seat insert (the second valve seat insert is located at or adjacent to the second port and, in the first operating mode, the second valve body is in an open position spaced apart from the second valve seat so that fluid is suitable for circulation from the first port to the second port). The valve stem extends between the second valve body and the first valve body, such that in a first operating mode, movement of the first valve body toward a closed position moves the second valve body to an open position, allowing fluid to circulate between the first and second ports; and in a second operating mode, when the force of fluid from the third port acting on the first valve body overcomes the closing force of the elastic element and any pressure of fluid from the first and / or second ports, the first valve body can be moved to the open position while simultaneously moving the second valve body to a closed position against the second valve seat, such that fluid from the third port is suitable for circulation through the first port. In this embodiment, the second valve body includes a ramp section on its second valve seat side.

[0030] This embodiment also does not use first and second sleeve-like wall sections, but may use the other features described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further advantages and features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings, in which:

[0032] Figure 1 is a cross-sectional view through a valve assembly according to the present disclosure, shown in a first operating mode.

[0033] Figure 2 is with Figure 1 A similar cross-sectional view shows a valve assembly according to the present disclosure in a second operating mode.

[0034] Figure 3 is a view showing the exterior of a valve housing of a valve assembly according to the present disclosure, partially broken away, illustrating the assembly of the valve assembly in the valve housing.

[0035] Figure 4 is a perspective view showing only the operative portion of the valve assembly, including first and second valve seat inserts including first and second valve bodies respectively located therein, the first and second valve bodies being connected by a valve stem and respectively disposable in third and second ports of the valve housing.

[0036] Figure 5 is with Figure 4A similar perspective view, partially broken away, illustrates internal components including first and second valve bodies within first and second valve seat inserts.

[0037] Figure 6 It is along Figure 4 The cross-sectional view along line 6-6 in FIG. 1 shows the first and second valve bodies connected by the valve stem in the first operating mode.

[0038] Figure 7 is with Figure 6 A similar cross-sectional view shows the first and second valve bodies connected by the valve stem transitioning from a first operating mode to a second operating mode.

[0039] Figure 8 is with Figure 6 and Figure 7 A similar cross-sectional view shows the first and second valve bodies connected by the valve stem in a second operating mode.

[0040] Figure 9 is an enlarged detail view of the second valve body within the second valve seat insert, shown in the first operating mode, wherein the shroud covers the stem side of the second valve body, illustrating the force of the fluid flow portion acting on the seat side surface of the second valve body to maintain the second valve body in a position in the first operating mode.

[0041] Figure 10 is with Figure 6 A similar cross-sectional view shows the first and second valve bodies connected by the valve stem in a first operating mode, wherein the first valve body is closed against the first valve seat and there is a compensating connection between the valve stem and the valve bodies.

[0042] Figure 11 is an enlarged detail showing the connection of the valve stem to the second valve body, wherein compensating clearance is provided at the connection.

[0043] Figure 12 is a cross-sectional view of another embodiment, wherein the second valve body is in its closed position.

[0044] Figure 13 yes Figure 12 3D view of the valve stem.

[0045] Figure 14 yes Figure 12 A cross-sectional view of an embodiment of the present invention, wherein the second valve body is in its open position. The inset shows an enlarged view of the damper of this embodiment.

[0046] Figure 15 yes Figure 12 and Figure 14 3D view of an isolated shield.

[0047] Figure 16 It is along Figure 14 A cross-sectional view of the cutting plane indicated in FIG. DETAILED DESCRIPTION

[0048] Certain terms are used in the following description for convenience only and are not limiting. The words "right," "left," "upper," and "lower" indicate directions in the accompanying drawings with reference to them. The words "a" and "an," as used in the claims and corresponding portions of the specification, are defined to include one or more of the items referenced, unless otherwise specified. Such terms include the words specifically mentioned above, their derivatives, and words of similar meaning. The phrase "at least one" followed by a list of two or more items (e.g., "A, B, or C") refers to any individual item of A, B, or C, as well as any combination thereof. The terms "approximately" or "substantially" generally mean within ±10% of a specified value, unless otherwise specified; and within ±25° of a specified angle or direction. "Passively," as used in connection with the present valve assembly, means that the valve assembly can automatically switch between the first and second operating modes based on the pressure differential between the fluid at the third port and the fluid pressure at the first and / or second ports, without the need for an external actuator acting on the valve assembly.

[0049] refer to Figure 1 and Figure 2 , generally showing a valve assembly 10 according to the present disclosure. The valve assembly 10 comprises a valve housing 12 having first, second and third ports 13, 14, 15. The valve housing 12 may be T-shaped or Y-shaped, or may have any other desired shape with three ports, and may also be formed from a heat exchanger body. A first valve body 20 is provided and is biased by a resilient element 22, preferably a spring, into a closed position against a first valve seat 26 which is provided in a first valve seat insert 24 which is located at or adjacent the third port 15. In Figure 1 In the first operating mode shown in FIG, the first valve body 20 is opened by the force of the spring (as indicated by the arrow F R 2 and any fluid flow through the first and / or second ports 13, 14 acts on the stem side 20b of the first valve body 20 to close against the first valve seat 26. The valve seat side 20a of the first valve body 20 is also shown. A spring retainer 28 is also shown, which is connected to the first valve seat insert 24 and supports the elastic element 22 to apply the force F1 against the stem side 20b of the first valve body 20. R .

[0050] Still refer to Figure 1 and Figure 2, shows a second valve body 40 acting on a second valve seat 46 of a second valve seat insert 44 located at or adjacent to the second port 14. In a first operating mode, the second valve body 40 is in an open position spaced apart from the second valve seat 46, such that fluid is suitable for circulation from the first port 13 to the second port 14, as shown. Figure 1 The second valve body 40 further includes a valve seat side 40a and a valve stem side 40b.

[0051] The valve stem 70 extends between the second valve body 40 and the first valve body 22 so that Figure 1 In the first operating mode shown in FIG, movement of the first valve body 22 to the closed position moves the second valve body 40 to the open position, allowing fluid to circulate between the first and second ports 13, 14. Figure 2 In the second operating mode shown in FIG, when the force F3 of the fluid from the third port 15 acting on the first valve body 20 overcomes the closing force F of the elastic element 22 R When any pressure F1 acts on the first valve body 20 and / or the second valve body 40 due to the flow of fluid from the first and / or second ports 13, 14, the first valve body 20 can be moved to the open position while simultaneously moving the second valve body 40 to the closed position against the second valve seat 46, so that the fluid from the third port 15 is suitable for circulating through the first port 13, such as by Figure 2 Indicated by the arrow in .

[0052] like Figure 1 and Figure 2 shown in and Figures 5 to 8 As shown in detail in FIG, the first sleeve-shaped wall 30 of the first insert 24 extends in the axial direction X and is configured to be closed when the first valve body 20 is in the closed position (eg Figure 1 、 Figure 5 and Figure 6 ) radially surrounds the first valve body 20. Preferably, the valve body 20 has a circular periphery, and the first sleeve-shaped wall 30 is cylindrical.

[0053] Still refer to Figure 1 、 Figure 2 and Figures 5 to 8 The second sleeve-shaped wall 50 of the second valve seat insert 44 extends in the axial direction X and is configured to be Figure 8 ) radially surrounds the second valve body 40. The second valve body 40 preferably also has a circular configuration, and the second sleeve-shaped wall 50 is preferably cylindrical.

[0054] like Figure 7As shown in detail in FIG, the first and second valve bodies 20, 40 and the valve stem 70 are arranged such that when the first valve body 20 moves toward the open position, the first sleeve-shaped wall 30 axially overlaps a portion of the first valve body 20 until the second valve body 40 moves to a position before reaching the closed position, in which position the second valve body 40 is at least partially overlapped by the second sleeve-shaped wall 50. This arrangement promotes a bistable position of the valve bodies 20, 40 depending on the applied pressures F3 and F1, wherein for the first and second operating modes, the first valve body 20 is in the closed position or the second valve body 40 is in the closed position, so that the third and second ports 15, 14 are fully open or fully closed, minimizing switching time. When the valve assembly transitions to the second operating mode (e.g., Figure 7 ), the fluid flow portion is directed primarily toward the stem side 40a of the second valve body 40 once it enters the sleeve-shaped wall 50, largely eliminating the force F1 exerted by any fluid flow portion from the first port 13 on the seat side 40a of the second valve body 40.

[0055] In order to Figure 2 and Figure 8 The second operating mode shown in Figure 1 and Figure 6 In the first operating mode shown in FIG, when the closing force F of the elastic element 22 R When the pressure F1 from at least one of the first or second ports 13, 14 overcomes the force F3 of the fluid at the third port 15, the second valve body 40 moves back toward the open position, and the second sleeve-shaped wall 50 axially overlaps a portion of the second valve body 40 until the first valve body 20 moves to a position before reaching the closed position, in which position the first valve body 20 is at least partially overlapped by the first sleeve-shaped wall 30. With this arrangement, the force F1 of the fluid from the first and / or second ports 13, 14 is directed primarily toward the stem side 20b of the first valve body 20 before the first valve body 20 reaches the closed position because the sleeve-shaped wall 30 prevents the force F1 of the fluid from the first and / or second ports 13, 14 from acting on the valve seat side 20a of the first valve body 20.

[0056] like Figures 6 to 8 As shown in detail in FIG, the first and second valve bodies 20, 40 are each cup-shaped and have axially extending wall sections 21, 41 that fit with a clearance fit within the respective first or second sleeve-shaped walls 30, 50. Here, the clearance fit is 0.1 mm–0.8 mm, but can vary depending on the specific application and component size. This clearance fit reduces or eliminates any potential friction when the respective valve bodies 20, 40 transition to their respective closed positions.

[0057] Now refer to Figures 5 to 9Preferably, the shroud 52 is connected to the valve housing 12 adjacent the second port 14, and more preferably to the second valve seat insert 44. The shroud 52 includes a receiving space 54 (preferably defined as a shoulder 56) and faces the valve stem side 40b of the second valve body 40. Figure 6 and Figure 9 In the first operating mode shown in FIG, when the second valve body 40 is in the open position, a shroud 52 surrounds the peripheral area of the second valve body 40, preventing fluid from flowing directly against the stem side 40b of the second valve body 40. In a preferred arrangement, the shroud 52 is formed as a separate component that is attached to the second valve seat insert 44, preferably with a snap-fit connection. As shown, the cup-shaped second valve body 40 preferably has an axially extending wall section 41 that is circumferentially surrounded by the shroud 52 in the first operating mode. With this arrangement, fluid flow between the first port 13 and the second port 14 is restricted to the stem side 40b of the second valve body 40, thereby maintaining a stable position of the first valve body 20 closed against the first valve seat 26. This provides stability for maintaining the valve bodies 20, 40 in the first operating mode when the fluid flow from the first port 13 to the second port 14 is 6 liters / minute or greater. The specific flow rate may vary depending on the specific application; however, the use of the sleeve achieves the purpose of providing a bistable position for the valve assembly 10.

[0058] like Figure 7 and Figure 8 As shown in FIG, in the second operating mode, the second valve body 40 is axially moved out of the receiving space 54 of the shroud 52, so that the fluid flowing through the valve assembly 10 acts on the valve stem side 40b of the second valve body 40 and exerts a force F2 (at Figure 8 ), to assist in moving the second valve body 40 toward the second valve seat 46.

[0059] In a preferred arrangement, the shroud 52 has a frusto-conical shape with a narrower portion facing the valve stem 70 , and is supported by one or more fins 58 extending from at least one of the valve housing 12 or the second valve seat insert 44 .

[0060] like Figures 6 to 9 As shown in FIG, the shield 52 preferably includes a central opening 60, and the valve stem 70 and / or the second socket 66 of the second valve body 40 that receives the valve stem 70 extends through the opening 60. Figure 9 As shown in detail in FIG, the shroud 52 preferably includes a stem receiving sleeve 62. The opening 60 is defined through the stem receiving sleeve 62. Here, a clearance fit is preferably provided between the stem 70 or the second socket 66 and the opening 60 to reduce potential water flow toward the stem side 40b of the second valve body 40 in the first operating mode. Figure 6). The clearance fit is preferably 0.02-1.0 mm. However, the dimensions may vary depending on the specific application.

[0061] Note that the shroud 52 may be used in the valve assembly 10 without the first and second sleeve-like walls 30 , 50 , depending on the functionality desired for a particular application.

[0062] Reference again Figure 9 , the second valve body 40 preferably further includes a ramp section 42 on its valve seat side 40b. The ramp section 42 is preferably truncated conical with a narrower end facing the second valve seat 46, and when the valve assembly 10 is in the first operating mode, a force F4 of the fluid flow portion of the valve assembly 10 acts on the ramp section 42 to apply an additional force in the axial direction X toward the first valve body 20. This is in addition to the elastic force F of the elastic element 22. R The sum of the forces F1 acts on the first valve body 20 to hold the first valve body 20 under pressure in the closed position against the first valve seat 26. This further holds the second valve body in the receiving space 54 of the shroud 52 and promotes a bistable position maintained by the valve bodies 20, 40 in the first and second operating modes, with a limited switching time between these positions.

[0063] Note that the ramp section 42 may also be used in the valve assembly 10 without the first and second sleeve-shaped walls 30, 50 and / or the shroud 52, depending on the functionality desired for a particular application. Figure 10 and Figure 11 The valve stem 70 includes at least one protrusion 74a, 74b at each of the first and second axial ends 72a, 72b. The first and second valve bodies 20, 40 each include a respective first and second socket 36, 66 connected to their respective stem sides 20b, 40b. The first and second sockets 36, 66 are configured to receive the respective first or second axial ends 72a, 72b of the valve stem 70. These first and second sockets 36, 66 also each include an internal groove 38, 68 in which the respective at least one protrusion 74a, 74b is received with a snap fit.

[0064] The at least one protrusion 74a, 74b at each of the first and second axial ends 72a, 72b of the valve stem 70 may include one or more circumferentially spaced protrusions or a single annular protrusion.

[0065] like Figure 11 As shown in detail in FIG. 7 , with respect to the second axial end 72 b of the valve stem 70 , and also applicable to Figure 10At the first axial end 72a shown in FIG, at least one of the internal grooves 38, 68 has an axial dimension X1, X2 that is longer than the axial width W1, W2 of the at least one projection 74, 74b received therein. This allows for axial compensating movement of one or both valve bodies 20, 40 relative to the valve stem 70. This allows for tolerance differences in installation in different valve housings 12 and ensures that both closed positions are achievable.

[0066] like Figure 10 and Figure 11 As shown in detail in FIG, the first and second axial ends 72a, 72b of the valve stem are preferably tapered. This allows for easier alignment and assembly of the valve stem 70 with the respective first and second valve bodies 20, 40.

[0067] In another aspect, a method of assembling the valve assembly 10 is provided. The method includes forming a first subassembly by assembling the first valve body 20 and the resilient element 22 in the first valve seat insert 24 including the first valve seat 26 and inserting the first axial end 72a of the valve stem 70 into the first socket 36 on the valve stem side 20b of the first valve body 20 with a snap fit. The first subassembly is then inserted into the port 15 of the valve housing 12 with the valve stem first.

[0068] The method further includes forming a second subassembly by assembling the second valve body 40 with the second valve seat insert 44 including the second valve seat 46 and the shroud 52, which partially surrounds the second valve body 40 in the open position of the second valve body 40. The second subassembly is then inserted into the second port 14 of the valve housing 12, wherein the second axial end 72b of the valve stem 70 is received in the second receptacle 66 of the second valve body 40, wherein the valve stem 70 and / or the sleeve receptacle 66 extend through the opening 60 in the shroud 52. The second axial end 72a of the valve stem 72 is connected to the second receptacle 66 by a snap fit, such that the valve assembly is connected in the valve housing 12 with the valve stem 70 extending between the second valve body 40 and the first valve body 40. This allows the valve assembly 10 to operate in the first and second operating modes as described above.

[0069] In certain applications, the first and second valve bodies 20, 40 do not require additional seals as slight leakage can be tolerated, particularly in reverse flow applications used in conjunction with a heat exchanger.Here, the valve housing 12 may be an integral part of the heat exchanger.

[0070] Preferably, the valve bodies 20, 40, the valve seat inserts 24, 44 and the valve stem 70 are formed as injection molded polymer parts. However, these valve bodies, valve seat inserts and valve stems can be formed by other means, such as machining or casting.

[0071] Additionally, in a preferred embodiment, the second and third ports 14 , 15 are axially aligned, and the first port 13 extends generally normal thereto, such that the ports are connected in a “T” configuration within the valve housing 12 .

[0072] The first and second valve seat inserts 24, 44 may be held against shoulders within the valve housing 12, such as Figures 1 to 3 , and the seat inserts 24, 44 may have lip seals (shown but not labeled) integrally formed therewith that contact the interior of the valve housing 12, or separate seals may be applied to seal the seat inserts 24, 44 within the valve housing 12. A snap ring, retainer, or external gaskets or couplers applied at the ends of the second and third ports 14, 15, respectively, may be used to hold the seat inserts 24, 44 in place within the valve housing 12. However, other types of retaining arrangements may also be used.

[0073] Figures 12 to 14 Another embodiment of the present invention is shown. Functionally similar or identical components to the previous embodiment are given the same reference numerals. Figures 1 to 11 The explanation can be applied to Figures 12 to 14 .

[0074] Figures 12 to 14 The embodiment of the present invention comprises a damper 82 acting on the valve stem 70. More precisely, the damper 82 damps the compression of the elastic element 22.

[0075] This is achieved by the lip seal 83 cooperating with the bypass groove 84. Thus, when the resilient element 22 is compressed, fluid between the lip seals 83 and 85 will be forced to pass through the bypass groove 84 because the lip seals 83, 85 face each other.

[0076] In the opposite direction, that is, when the elastic element 22 expands, the inflowing fluid can easily deform the lip seal 83. Therefore, the elastic element 22 can expand without damping.

[0077] Instead of the lip seals 83 , 85 , other seals may be used.

[0078] Two pressure relief grooves 86 are formed on the valve seat side 40a of the second valve body 40. The pressure relief grooves 86 prevent a large pressure difference from being established across the closed second valve body 40, which would otherwise prevent the elastic element 22 from expanding.

[0079] exist Figure 14 It is obvious that a bottleneck 81 is formed near the shroud 52, which accelerates the flow through. This creates a low pressure side near the second valve body.

[0080] In order to prevent the second valve body 40 from being dragged too easily by the passing fluid, Figure 14In the open position of the second valve body, the second valve body is completely covered by the shield and is spaced apart from the bottleneck 81 .

[0081] After a certain movement of the valve stem 70 caused by the fluid entering the second port 14, the second valve member 40 will leave the receiving space 54. Only then will the fluid passing through the bottleneck be able to drag along the second valve body 40 into its closed position.

[0082] Figure 14 The illustration in shows the damper 82 in more detail. The valve stem 70 is in a sliding arrangement within a guide element 87, which may be formed as a sleeve.

[0083] Between the guide element 87 and the valve stem 70, there is a chamber 88, which is defined by the (first) lip seal 83 (or any other elastomeric element with sealing capabilities) and the (second) lip seal 85 (or any other elastomeric element with sealing capabilities). When the valve stem 70 slides within the guide element 87, the chamber 88 will expand or contract. Since it is filled with water or any other preferably incompressible fluid, the fluid will be pressed out or in during the movement of the valve stem 70.

[0084] This is only possible due to the presence of at least one bypass channel (here bypass groove 84) which allows the filling of chamber 88 to flow out and in when needed. If the pressure difference inside the chamber is higher than the pressure difference outside the chamber, the lip seal 83 (or any other suitable seal) will be pressed against the valve stem 70, thereby reducing the free cross section of the bypass groove 84. This will result in greater friction against the compression of the chamber 88.

[0085] Figure 15 87, wherein the valve stem 70 has been removed. Outside the shield 52 and inside the second sleeve-shaped wall 50, the bottleneck 81 as described above can be seen. In use, as shown from Figure 14 It is obvious that the valve seat side 40 a of the second valve body 40 is seated in the receiving space 54 and is covered from the side by the protruding edge of the protective cover 52 .

[0086] Figure 16 Shown Figure 14 The cross section is at Figure 14 The V-shaped cross section of the bypass groove 84 is clearly visible. This shape is specifically adapted to cooperate with the lip seal 83 in the manner described.

[0087] It should be understood that the foregoing is presented in an exemplary and non-limiting manner only. It is contemplated that various substitutions and modifications may be made to the embodiments without departing from the spirit and scope of the present invention. Therefore, after describing the present invention in detail, it will be understood by those skilled in the art and it will be apparent to those skilled in the art that many physical changes (only some of these physical changes are exemplified in the detailed description of the present invention) may be made without changing the innovative concepts and principles of the present invention. It will also be understood that numerous embodiments comprising only a portion of the preferred embodiment may be implemented without changing the innovative concepts and principles contained therein with respect to these portions. Therefore, the present embodiment and optional configurations are to be considered exemplary and / or illustrative in all respects and not restrictive, and the scope of the present invention is indicated by the appended claims rather than the foregoing description, and all alternative embodiments and modifications to the present embodiment falling within the meaning and equivalent scope of the claims should be included therein.

[0088] Reference Signs List

[0089] 10 valve assembly

[0090] 12 valve housing

[0091] 13 First Port

[0092] 14 Second Port

[0093] 15Third port

[0094] 20 first valve body

[0095] 20b stem side

[0096] 20a valve seat side

[0097] 22 elastic elements

[0098] 24 First valve seat insert

[0099] 26 first valve seat

[0100] 28 Spring retainer

[0101] 30 first sleeve-shaped wall

[0102] 36 First Socket

[0103] 38 internal grooves

[0104] 40 Second valve body

[0105] 40a valve seat side

[0106] 40b stem side

[0107] 44 Second valve seat insert

[0108] 46 Second valve seat

[0109] 50 second sleeve-shaped wall

[0110] 52 shield

[0111] 54 Receiving Space

[0112] 56 Shoulders

[0113] 58 fins

[0114] 62 valve stem receiving sleeve

[0115] 60 openings

[0116] 66 second socket

[0117] 68 internal grooves

[0118] 70 valve stem

[0119] 72a first axial end

[0120] 72b second axial end

[0121] 74a protrusion

[0122] 74b protrusion

[0123] 81 bottleneck

[0124] 82 damper

[0125] 83 lip seal

[0126] 84 bypass groove

[0127] 85 lip seal

[0128] 86 pressure relief groove

[0129] 87 guide element

[0130] Chamber 88

[0131] F R force

[0132] F1 pressure

[0133] F2 force

[0134] F3 force

[0135] F4 force

[0136] W1 width

[0137] W2 width

[0138] X-axis direction

[0139] X1 axial dimension

[0140] X2 axial dimension

Claims

1. A valve assembly (10) configured to passively switch between first and second operating modes, the valve assembly (10) comprising: a first port (13), a second port (14) and a third port (15); a first valve body (20) biased by a resilient element (22) to a closed position against a first valve seat (26) of a first valve seat insert (24), the first valve seat insert being located at or adjacent to the third port (15) to close the third port (15) in the first operating mode; a second valve body (40) acting on a second valve seat (46) of a second valve seat insert (44), the second valve seat insert being located at or adjacent to the second port (14), and wherein in a first operating mode, the second valve body (40) is in an open position spaced from the second valve seat (46) such that fluid is adapted to circulate from the first port (13) to the second port (14); a valve stem (70) extending between the second valve body (40) and the first valve body (20) such that, in a first operating mode, movement of the first valve body (20) to the closed position moves the second valve body (40) to the open position, allowing fluid to circulate between the first port (13) and the second port (14), and, in a second operating mode, when the force of fluid from the third port (15) acting on the first valve body (20) overcomes the closing force of the elastic element (22) and any pressure (F1) of the fluid from the first port (13) and / or the second port (14), the first valve body (20) can be moved to the open position while simultaneously moving the second valve body (40) to the closed position against the second valve seat (46), such that fluid from the third port (15) is suitable for circulation through the first port (13); a first sleeve-shaped wall (30) of the first valve seat insert (24), extending in an axial direction (X) and configured to radially surround the first valve body (20) when the first valve body (20) is in a closed position; a second sleeve-shaped wall (50) of the second valve seat insert (44), extending along the axial direction (X) and configured to radially surround the second valve body (40) when the second valve body (40) is in the closed position; The first valve body (20), the second valve body (40) and the valve stem (70) are arranged so that when the first valve body (20) moves toward the open position, the first sleeve-shaped wall (30) axially overlaps with a portion of the first valve body (20) until the second valve body (40) moves to a position before reaching the closed position, in which position the second valve body (40) is at least partially overlapped by the second sleeve-shaped wall (50).

2. The valve assembly (10) according to claim 1, wherein A first port (13), a second port (14), and a third port (15) are formed in the valve housing (12).

3. A valve assembly (10) according to any one of the preceding claims, wherein: The second valve body (40) has at least one pressure relief groove (86) on its valve seat side (40a).

4. A valve assembly (10) according to any one of the preceding claims, wherein A damper (82) acts on the valve stem (70) to dampen the movement of compressing the elastic element (22).

5. A valve assembly (10) according to any one of the preceding claims, wherein The damper (82) applies smaller damping to the valve stem (70) in the expansion direction of the elastic element (22) than in the compression direction of the elastic element (22).

6. A valve assembly (10) according to any one of the preceding claims, wherein: The damper (82) acting on the valve stem (70) comprises at least one elastomeric component, in particular a lip seal (83) and / or at least one bypass channel, in particular a bypass groove (84) formed in the valve stem (70).

7. A valve assembly (10) according to any one of the preceding claims, wherein: A damper (82) acting on the valve stem (70) comprises at least two lip seals (83, 85) facing each other.

8. A valve assembly (10) according to any one of the preceding claims, wherein When the closing force of the elastic element (22) and the pressure (F1) from at least one of the first or second ports (14) overcome the force of the fluid at the third port (15), the valve assembly (10) is configured to return to a first operating mode, wherein the second valve body (40) moves back toward the open position and the second sleeve-shaped wall (50) axially overlaps a portion of the second valve body (40) until the first valve body (20) moves to a position before reaching the closed position in which the first valve body (20) is at least partially overlapped by the first sleeve-shaped wall (30).

9. A valve assembly (10) according to any one of the preceding claims, wherein: At least one of the first or second valve bodies is cup-shaped and has an axially extending wall section that fits with a clearance fit within the corresponding first or second sleeve-shaped wall (50).

10. The valve assembly (10) according to any one of the preceding claims, further comprising a shroud (52) connected to the valve housing (12) adjacent to the second port (14), the shroud (52) comprising a receiving space (54) facing the stem side (40b) of the second valve body (40), and in the first operating mode, when the second valve body (40) is in the open position, the shroud (52) surrounds a peripheral area of the second valve body (40).

11. A valve assembly (10) according to any one of the preceding claims, wherein The shield (52) defines a bottleneck (81) for fluid flowing from the first port (13) and / or the third port (15) to the second port (14), and the second valve body (40) is spaced apart from the bottleneck (81) and / or is completely received in the receiving space (54) in its open position.

12. The valve assembly (10) according to claim 11, wherein The shroud (52) is connected to the second valve seat insert (44).

13. The valve assembly (10) according to claim 11 or 12, wherein: The second valve body (40) is cup-shaped and has an axially extending wall section that fits with a clearance fit within the second sleeve-shaped wall (50), and the shroud (52) circumferentially surrounds at least a portion of the axially extending wall section of the second valve body (40) in a first operating mode.

14. The valve assembly (10) according to any one of claims 11 to 13, wherein: In the second operating mode, the second valve body (40) moves axially out of the receiving space (54) of the shield (52), so that the fluid flow portion through the valve assembly (10) acts on the valve stem side (40b) of the second valve body (40), exerting a force on the second valve body (40) to assist in moving the second valve body (40) toward the second valve seat (46).

15. The valve assembly (10) according to any one of claims 11 to 14, wherein: The shroud (52) is frusto-conical in shape and is supported by one or more fins (58) extending from at least one of the valve housing (12) or the second valve seat insert (44).

16. The valve assembly (10) according to claim 15, wherein The valve stem extends from the first valve body (20) through an opening (60) in the shroud (52) to the second valve body (40).

17. The valve assembly (10) of claim 16, further comprising a stem receiving sleeve (62) connected to the shroud (52), and wherein the opening (60) is defined through the stem receiving sleeve (62).

18. A valve assembly (10) according to any one of the preceding claims, wherein The second valve body (40) includes a ramp section on a second valve seat (46) side (40a) thereof.

19. The valve assembly (10) according to claim 18, wherein The ramp section is truncated conical, and when the valve assembly (10) is in a first operating mode, a fluid flow portion through the valve assembly (10) acts on the ramp section to apply an additional force to the second valve body (40) in an axial direction (X) toward the first valve body (20), and this force acts in addition to the force of the elastic element (22) to maintain the first valve body (20) in a closed position against the first valve seat (26) under pressure.

20. The valve assembly (10) according to any one of the preceding claims, wherein The valve stem (70) includes at least one protrusion (74a; 74b) at each of the first axial end (72a) and the second axial end (72b), and the first and second valve bodies each include a respective first socket (36) and a second socket (66) connected to their respective valve stem sides (20b; 40b), the respective first socket and the second socket being configured to receive the respective first axial end (72a) or the second axial end (72b) of the valve stem, and the first socket (36) and the second socket (66) each include an internal groove (38; 68), the respective at least one protrusion (74a; 74b) being received in the internal groove with a snap fit.

21. The valve assembly (10) according to claim 20, wherein The axial dimension (X1; X2) of at least one internal groove (38; 68) is longer than the axial width (W1; W2) of at least one protrusion (74a; 74b) received therein, which allows axial compensating movement.

22. The valve assembly (10) according to claim 20 or 21, wherein The at least one protrusion (74a; 74b) on each of the first axial end (72a) and the second axial end (72b) of the valve stem is an annular boss.

23. The valve assembly (10) according to any one of claims 20 to 22, wherein: The first axial end (72a) and the second axial end (72b) of the valve stem are tapered.

24. A valve assembly (10) configured to passively switch between first and second operating modes, the valve assembly (10) comprising: a first port (13), a second port (14) and a third port (15); a first valve body (20) biased by a resilient element (22) to a closed position against a first valve seat (26) of a first valve seat insert (24), the first valve seat insert being located at or adjacent to the third port (15) to close the third port (15) in the first operating mode; a second valve body (40) acting on a second valve seat (46) of a second valve seat insert (44), the second valve seat insert being located at or adjacent to the second port (14), and wherein in a first operating mode, the second valve body (40) is in an open position spaced from the second valve seat (46) such that fluid is adapted to circulate from the first port (13) to the second port (14); a valve stem (70) extending between the second valve body (40) and the first valve body (20) such that, in a first operating mode, movement of the first valve body (20) to the closed position moves the second valve body (40) to the open position, allowing fluid to circulate between the first port (13) and the second port (14), and, in a second operating mode, when the force of fluid from the third port (15) acting on the first valve body (20) overcomes the closing force of the elastic element (22) and any pressure (F1) of the fluid from the first port and / or the second port (14), the first valve body (20) can be moved to the open position while simultaneously moving the second valve body (40) to the closed position against the second valve seat (46), such that fluid from the third port (15) is suitable for circulation through the first port (13); and A shroud (52) is connected adjacent to the second port (14), the shroud (52) including a receiving space (54) facing the valve stem side (40b) of the second valve body (40), and in a first operating mode, when the second valve body (40) is in the open position, the shroud (52) surrounds a peripheral area of the second valve body (40).

25. The valve assembly (10) of claim 24, wherein: A first port (13), a second port (14), and a third port (15) are formed in the valve housing (12).

26. The valve assembly (10) according to claim 24 or 25, wherein The shroud (52) is connected to the second valve seat insert (44).

27. The valve assembly (10) according to any one of claims 24 to 26, wherein: The second valve body (40) is cup-shaped and has an axially extending wall section that fits with a clearance fit within the second sleeve-shaped wall (50), and the shroud (52) circumferentially surrounds at least a portion of the axially extending wall section of the second valve body (40) in a first operating mode.

28. The valve assembly (10) according to any one of claims 24 to 27, wherein: In the second operating mode, the second valve body (40) moves axially out of the receiving space (54) of the shield (52), so that the fluid flow portion through the valve assembly (10) acts on the valve stem side (40b) of the second valve body (40), exerting a force on the second valve body (40) to assist in moving the second valve body (40) toward the second valve seat (46).

29. The valve assembly (10) according to any one of claims 24 to 28, wherein: The shroud (52) is frusto-conical in shape and is supported by one or more fins (58) extending from at least one of the valve housing (12) or the second valve seat insert (44).

30. A valve assembly (10) configured to passively switch between first and second operating modes, the valve assembly (10) comprising: a first port (13), a second port (14) and a third port (15); a first valve body (20) biased by a resilient element (22) to a closed position against a first valve seat (26) of a first valve seat insert (24), the first valve seat insert being located at or adjacent to the third port (15) to close the third port (15) in the first operating mode; a second valve body (40) acting on a second valve seat (46) of a second valve seat insert (44), the second valve seat insert being located at or adjacent to the second port (14), and wherein in a first operating mode, the second valve body (40) is in an open position spaced from the second valve seat (46) such that fluid is adapted to circulate from the first port (13) to the second port (14); a valve stem (70) extending between the second valve body (40) and the first valve body (20) such that, in a first operating mode, movement of the first valve body (20) to the closed position moves the second valve body (40) to the open position, allowing fluid to circulate between the first port (13) and the second port (14), and, in a second operating mode, when the force of fluid from the third port (15) acting on the first valve body (20) overcomes the closing force of the elastic element (22) and any pressure (F1) of the fluid from the first port (13) and / or the second port (14), the first valve body (20) can be moved to the open position while simultaneously moving the second valve body (40) to the closed position against the second valve seat (46), such that fluid from the third port (15) is suitable for circulation through the first port (13); and The second valve body (40) includes a ramp section on a second valve seat (46) side (40a) thereof.

31. The valve assembly (10) of claim 28, wherein: The ramp section is truncated conical, and when the valve assembly (10) is in a first operating mode, a fluid flow portion through the valve assembly (10) acts on the ramp section to apply an additional force to the second valve body (40) in an axial direction (X) toward the first valve body (20), and this force acts in addition to the force of the elastic element (22) to maintain the first valve body (20) in a closed position against the first valve seat (26) under pressure.

32. A passively switched valve assembly (10), in particular a valve assembly according to any one of the preceding claims, comprising a first port (13), a second port (14) and a third port (15) and defining at least two switching positions, characterized in that The damper (82) is configured to dampen a transition between the at least two switching positions.

33. Passively switched valve assembly (10) according to the preceding claim, wherein The elastic element (22) provides a restoring force that defines the rest positions of the at least two switching positions, and the damper (82) resists compression of the elastic element (22).

34. A method of assembling a valve assembly (10), the method comprising: forming a first subassembly by assembling a first valve body (20) and a resilient element (22) in a first valve seat insert (24) including a first valve seat (26) and inserting a first axial end (72a) of a valve stem (70) into a first socket (36) on a valve stem side (20b) of the first valve body (20) with a snap fit; Inserting the first subassembly into the third port (15) of the valve housing (12) with the valve stem first; forming a second subassembly by assembling a second valve body (40) with a second valve seat insert (44) including a second valve seat (46) and a shroud (52) that partially surrounds the second valve body (40) in an open position of the second valve body (40); inserting the second subassembly into the second port (14) of the valve housing (12), wherein the second axial end of the valve stem is received in the second socket (66) on the second valve body (40), wherein at least one of the valve stem or the second socket (66) extends through the opening (60) in the shroud (52); and The second axial end (72b) of the valve stem is connected to the second socket (66) with a snap fit so that the valve assembly (10) is connected to the valve housing (12), wherein the valve stem (70) extends between the second valve body (40) and the first valve body (20), wherein in a first operating mode, movement of the first valve body (20) to the closed position moves the second valve body (40) to the open position, allowing fluid to circulate between the first port (13) and the second port (14), and in a second operating mode, when the force of fluid from the third port (15) acting on the first valve body (20) overcomes the closing force of the elastic element (22) and any pressure (F1) of the fluid from the first port (13) and / or the second port (14), the first valve body (20) can be moved to the open position while simultaneously moving the second valve body (40) to the closed position against the second valve seat (46), so that fluid from the third port (15) is suitable for circulation through the first port (13).

Images