Push-Pull Valve

Abstract

The valve includes a valve body having a flow passage connecting an inlet and an outlet. A seal is disposed within the flow passage. The seal has a closed state that blocks flow through the flow passage and an open state that allows flow through the flow passage. An armature is disposed within the valve body and is movable relative to the seal. An electromagnet is configured to selectively receive electrical current in a first current direction or an opposite second current direction. When the electrical current is in the first current direction, the electromagnet actuates the armature to move the seal from closed to open, and when the electrical current is in the second current direction, the electromagnet magnetically actuates the armature to move the seal from open to closed.

Description

[Background technology]

[0001] Valves are widespread in systems that handle fluids. One example is a motor that controls the flow of fuel for combustion. Such valves include a valve armature with a valve member that fits tightly against a valve seat. A spring biases the armature to a closed position, where the valve member seats on the valve seat and blocks flow. A solenoid coil acts as an actuator. When current is applied to the coil, a magnetic field is created that moves the armature against the force of the spring, lifting the valve member off the valve seat and allowing flow. When power to the solenoid is turned off, the spring returns the armature to the closed position. Summary of the Invention [Means for solving the problem]

[0002] A valve according to one example of the disclosure includes a valve body having a flow passage and a seal disposed within the flow passage. The seal has a default closed state sealed against a seal seat to block flow through the flow passage and an open state spaced from the seal seat to allow flow through the flow passage. An armature is disposed within the valve body and is movable relative to the seal. An electromagnet is configured to selectively receive electrical current in a first current direction or an opposite second current direction. When the electrical current is in the first current direction, the electromagnet actuates the armature to move the seal from the closed state to the open state, and when the electrical current is in the second current direction, the electromagnet actuates the armature to move the seal from the open state to the closed state.

[0003] In a further embodiment of any of the preceding embodiments, the electromagnet includes first and second coil windings wound in opposite directions relative to one another.

[0004] In a further embodiment of any of the preceding embodiments, the armature includes a rod portion, a yoke consisting of a permanent magnet and a keeper surrounding the permanent magnet, and a shell surrounding the yoke.

[0005] In a further embodiment of any of the preceding embodiments, the rod portion has a tip that contacts the seal.

[0006] In a further embodiment of any of the preceding embodiments, the shell is non-ferromagnetic and formed of a titanium-based alloy.

[0007] In a further embodiment of any of the preceding embodiments, the seal is elastomeric.

[0008] In a further embodiment of any of the preceding embodiments, the shell is a material selected from the group consisting of a titanium-based alloy, an aluminum-based alloy, and a polymer.

[0009] In a further embodiment of any of the preceding embodiments, when current is in a first current direction, the electromagnet magnetically pushes the rod portion to apply a force to the seal, thereby moving the seal from a closed state to an open state, and when current is applied in a second current direction, the electromagnet magnetically pulls the rod portion to remove the force applied to the seal, thereby moving the seal from an open state to a closed state.

[0010] In a further embodiment of any of the preceding embodiments, the force causes a portion of the seal to flex and lift off the seal seat, thereby opening flow through the flow passage.

[0011] A further embodiment of any of the preceding embodiments includes a controller coupled to the electromagnet and configured to selectively apply a current in the first current direction or the second current direction.

[0012] In a further embodiment of any of the preceding embodiments, the controller is configured to apply the current in the second current direction for a preset time to move the seal from the open state to the closed state.

[0013] A valve according to one example of the disclosure includes a valve body having a flow passage and a seal disposed within the flow passage. The seal has a default closed state sealed against a seal seat to block flow through the flow passage and an open state to allow flow through the flow passage. An armature is disposed within the valve body. An electromagnet is configured to magnetically push the armature to apply a force to the seal, thereby moving the seal from the closed state to the open state. The force causes a portion of the seal to deflect, thereby separating from the seal seat to open flow through the flow passage.

[0014] In a further embodiment of any of the preceding embodiments, the electromagnet includes first and second coil windings wound in opposite directions relative to one another, and the armature includes a rod portion, a yoke consisting of a permanent magnet and a keeper surrounding the permanent magnet, and a shell surrounding the yoke.

[0015] In a further embodiment of any of the preceding embodiments, the rod portion has a distal end in contact with a seal, and the seal is an elastomer.

[0016] In a further embodiment of any of the preceding embodiments, the shell is non-ferromagnetic and formed of a titanium-based alloy.

[0017] In a further embodiment of any of the preceding embodiments, the shell is a material selected from the group consisting of a titanium-based alloy, an aluminum-based alloy, and a polymer.

[0018] In a further embodiment of any of the foregoing embodiments, the electromagnet is configured to selectively receive electrical current in a first current direction or an opposite second current direction, such that when the current is in the first current direction, the electromagnet magnetically pushes the armature to apply a force to the seal, and when the current is in the second current direction, the electromagnet magnetically pulls the armature to reduce the force applied to the seal, causing a portion of the seal to move, thereby seating the portion of the seal against the seal seat to close flow through the flow path.

[0019] A rocket motor according to one example of the present disclosure includes a propellant tank for holding propellant, a combustor, a nozzle attached to the combustor, a supply line fluidly connecting the propellant tank and the combustor, and a valve according to any of the previously described embodiments disposed in the supply line.

[0020] The present disclosure may include one or more of the individual features disclosed above and / or below, taken alone or in any combination thereof.

[0021] The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 illustrates an example of a rocket motor. [Diagram 2] FIG. 2 shows the rocket motor valve in a closed state. [Diagram 3] FIG. 2 shows the rocket motor valve in an open state. [Figure 4] FIG. 2 shows a valve with magnetic field lines. [Diagram 5] FIG. 13 shows the sealing area of ​​the valve in the closed state. [Figure 6] FIG. 13 shows the sealing area of ​​the valve in an open state. [Figure 7] FIG. 2 is a cross-sectional view of a valve seal. [Figure 8] FIG. 2 shows the valve in a latched state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] 1 illustrates a rocket motor 10 to illustrate an exemplary embodiment of the valve disclosed herein, however, it will be understood that applications other than rocket motors will also benefit from this disclosure.

[0024] The rocket motor 10 generally includes a rocket motor body 12, a combustor 14, a nozzle 16 attached to the combustor 14, a propellant tank 18 that holds propellant 18a, and a supply line 20 that connects the propellant tank 18 to the combustor 14. The supply line 20 includes a valve 22 and a controller 24 that communicates with the valve 22 to control its operation, i.e., the flow of propellant 18a to the combustor 14. As will be appreciated, the rocket motor 10 includes additional components beyond the scope of this disclosure.

[0025] 2 shows a cross-sectional view of one example of valve 22. Valve 22 includes a valve body 26 having an inlet 26a, an outlet 26b, and a flow passage P connecting inlet 26a to outlet 26b. Valve body 26 may be formed from a single integral piece or multiple pieces secured together to surround flow passage P, or a portion thereof.

[0026] The valve 22 further includes a seal 28 disposed in an outlet cavity 28a along a portion of the flow path P. For example, the seal 28 is an elastomer that maintains good properties of the fluid conveyed through the valve 22. In a rocket motor using hydrazine as the propellant 18a, the elastomer may be an ethylene propylene terpolymer. An example is known by the trade name AF-E-411 (Parker-Hannifin), although other elastomers may be used. In FIG. 2, the seal 28 is in a default closed state, sealed against a seal seat 30 to block flow through the flow path P. When the seal 28 moves away from the seal seat 30 (FIG. 3), it allows flow through the flow path P.

[0027] The valve 22 also includes an armature 32 and an electromagnet 34. The armature 32 is disposed within the valve body 26 and is movable relative to the seal 28. The electromagnet 34 is connected to the controller 24 and includes first and second coil windings 34a / 34b wound in opposite directions. The coil windings 34a / 34b are connected in series. For example, there may be a single continuous wire having a portion wound in one direction to form the first coil winding 34a and another portion wound in the opposite direction to form the second coil winding 34b. The controller 24 may include hardware, software, or both configured and / or programmed to perform the functions herein with respect to controlling the valve 22. The hardware may include, but is not limited to, a microprocessor module, circuitry, control logic, memory modules, and / or power sources.

[0028] The armature 32 is composed of several subcomponents, including a rod portion 36, a yoke 38, and a shell 40 that surrounds the yoke 38 and prevents fluid within the valve 22 from contacting the yoke 38. The yoke 38 is composed of a permanent magnet 42 and a keeper 44 that surrounds the permanent magnet 42. The keeper 44 is made of a magnetic material. The rod portion 36 has a tip 36a that contacts the seal 28, the function of which will be described in more detail below.

[0029] The fluid intended to be conveyed through the valve 22 may be incompatible with the material used for the yoke 38. For example, the fluid may accelerate corrosion of the material. As a non-limiting example in the rocket motor 10, when using hydrazine as the propellant 18a, it may be desirable to avoid contact with stainless steel (e.g., the keeper 44) and magnets. In this regard, the shell 40 hermetically encases the yoke 38, thereby preventing the fluid from contacting subcomponents of the yoke 38. In one example, the shell 40 is a cladding material applied around the yoke 38. In another example, the shell 40 may be a construction of pre-fabricated pieces joined together to encase the yoke 38.

[0030] The shell 40 may be formed of a non-ferromagnetic material (not attracted to magnets) to avoid substantial interference with the magnetic fields of the permanent magnets 42 and the electromagnets 34. For example, the material may be selected from a titanium-based alloy, an aluminum-based alloy, or a polymer. Other non-ferromagnetic alloys, such as non-magnetic nickel alloys (e.g., Inconel 625), may also be used.

[0031] The material selected for the shell 40 is compatible with the fluid conveyed through the valve 22, at least as compared to the material of one or more of the subcomponents of the yoke 38. Moreover, one of ordinary skill in the art, with the benefit of this disclosure, will recognize that the selected material may also have other strength and durability characteristics to meet the design requirements of a particular implementation. For example, aluminum alloys provide good strength, durability, and corrosion resistance, while titanium alloys provide good strength, durability, and corrosion resistance. Polymers may also be used for ease of manufacture and chemical resistance, but are generally not as strong as titanium or aluminum alloys.

[0032] In operation of the valve 22, the electromagnet 34 selectively receives electrical current in a first current direction or a second, opposite current direction. As discussed above, the controller 24 serves to operate the valve 22 and control the direction and magnitude of electrical current. When electrical current is applied in the first current direction, the electromagnet 34 magnetically actuates the armature 32 to move the seal 28 from a default closed state (FIG. 1) to an open state (FIG. 2). When electrical current is applied in the second current direction, the electromagnet 34 magnetically actuates the armature 32 to move the seal 28 from an open state to a closed state. As will be appreciated, the closed state is the default ready position in the illustrated example, but a different default position, such as a default ready open position or a latched inactive state, may also be used.

[0033] 4 shows a cross-sectional view of valve 22 with magnetic field lines L1 representing the magnetic field generated by permanent magnet 42. The electric field generated by coil portions 34a / 34b of electromagnet 34 intersects with the magnetic field of permanent magnet 42. Due to this interaction, the polarity, strength, and timing of the electric field generated by electromagnet 34 acts to manipulate the magnetic field of permanent magnet 42 to open and close seal 28.

[0034] 5 and 6 illustrate the operation of the seal 28. As shown in FIG. 5, the seal 28 is disposed in a seal cavity 28a. The seal 28 is confined in the cavity 28a under compression, substantially preventing movement of the seal 28 along the axial direction of the rod portion 36 of the armature 32 and preloading it against the seal seat 30. In the closed position as in FIG. 5, the seal face 28b abuts the seal seat 30, thereby preventing flow therethrough. The tip 36a of the rod portion 36 is nominally in contact with the seal 28 or is spaced a short distance from the seal 28. Little or no force is exerted on the seal 28 by the rod portion 36.

[0035] To open the seal 28, the controller 24 energizes the electromagnet 34 in a first current direction. The electric field of the first coil portion 34a interacts with the magnetic field of the permanent magnet 42 to magnetically push the armature 32, thereby exerting a force on the seal 28 via the tip 36a of the rod portion 36. As shown in FIG. 6, the force exerted on the seal 28 deflects a portion of the seal 28, thereby lifting the seal face 28b from the seal seat 30. As the seal face 28b lifts, fluid flows between the seal face 28b and the seal seat 30, through the flow passage 28c (FIG. 7) around the seal 28 and out the outlet 26b of the valve 22. As used herein, the terms "push" and "pull" refer to the applied force and direction of movement of the armature 32, and in particular the tip 36a of the rod portion 36, relative to the electromagnet 34. When pushed, tip 36a tends to move in a direction away from electromagnet 34, i.e., out of the coil of electromagnet 34, whereas when pulled, tip 36a tends to move in a direction toward electromagnet 34, i.e., into the coil of electromagnet 34.

[0036] The amount of force applied can be adjusted by the amount of current and the selection of the cross-sectional area of ​​the tip 36a of the rod portion 36. The amount of flow deflection through the seal 28 is a function of the amount of force applied and the properties of the material of the seal 28. The deflection provides a cross-sectional area for fluid flow through the seal 28. In some instances, the metering function is provided by a smaller cross-sectional area of ​​the flow passage upstream of the seal 28, such as between the rod portion 36 and the wall of the orifice 46 (FIG. 5). Thus, a wider range of materials can be used for the seal 28 because metering is established between the metal parts and does not change even if the cross-sectional flow area of ​​the seal 28 changes due to changes in the material of the seal 28 over time.

[0037] To close the seal 28, the controller 24 energizes the electromagnet 34 in a second current direction, i.e., reverses polarity. The electric field of the coil sections 34a / 34b interacts with the magnetic field of the permanent magnet 42 to pull on the armature 32, thereby removing the force applied to the seal 28. As the force is reduced, the portions of the seal 28 that were deflected to open the seal 28 move back to a closed state, with the seal interface 28b seating against the seal seat 30 to block fluid flow.

[0038] Valve 22 operates to open and close without the use of a spring. In a valve with a solenoid coil and spring, the force is proportional to the square of the coil current, and the armature is pulled against the spring in only one direction, regardless of the direction of the current. In valve 22, on the other hand, the force is proportional to the current, and reversing the current moves the armature 32 in the opposite direction (push-pull). The push-pull feature eliminates the need for a spring, while linear proportionality provides better control of the force, improving valve performance.

[0039] In one example of a control scheme, the controller 24 executes an open command to apply a current of a predetermined magnitude in a first current direction to the electromagnet 34 to open the seal 28. The current is held constant for a period of time to keep the seal 28 open and thereby provide fluid flow (e.g., to the combustor 14 to generate thrust). When fluid flow is no longer required, the controller 24 executes a close command to apply a current of a predetermined magnitude in a second current direction to the electromagnet 34 to close the seal 28. The current in the second direction is applied for a predetermined period of time to remove force from the seal 28. Once the predetermined period of time has expired, the current is turned off (zero current). For example, the preset period of time may be 10-100 milliseconds, after which the magnetic field of the permanent magnet 42 maintains the position of the armature 32 and the seal 28 is in a closed state.

[0040] In a further example, the valve 22 also has a third state, the latched state, in which the armature 32 is latched. In the latched state, the armature 32 is moved to a fully upstream position relative to the inlet side of the valve body 26. The permanent magnet 42 maintains the armature in this position with zero current in the electromagnet 34. In this position, the tip 36a of the rod portion 36 is substantially spaced apart from the seal 28. For example, prior to actuation of the valve 22 to open or close, the valve 22 may be subject to vibrations that may cause the armature 32 to chatter. The chattering may cause the tip 36a of the rod portion 36 to move back and forth a small distance. If the tip 36a is in contact with or close to the seal 28, the chattering may cause the rod portion 36 to exert a momentary force on the seal 28, which may cause the seal 28 to momentarily open and allow a small amount of fluid to leak. However, in the latched state, the armature 32, and thus the tip 36a, is spaced from the seal 28 by a distance substantially greater than the amplitude of the chatter vibration. As a result, any chatter in the armature 32 will not be able to contact the seal 28 and cause a temporary leak. Furthermore, because the armature 32 abuts the opening of the inlet 26a, the armature 32 can provide a sealing function to limit the inflow of fluid into the valve 22. The latched state is obtained by passing a current in the second direction until the armature 32 abuts the inlet end of the body.

[0041] Although combinations of features are shown in the illustrated examples, not all of them need to be combined to realize the advantages of the various embodiments of the present disclosure. In other words, a system designed in accordance with an embodiment of the present disclosure will not necessarily include all of the features shown in any of the figures, or all of the parts shown diagrammatically in the figures. Furthermore, selected features of one exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0042] The foregoing description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples will be apparent to those skilled in the art that do not necessarily depart from the present disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.

Claims

1. a valve body having a flow passage; a seal disposed within the flow passage, the seal having a default closed state sealed against a seal seat to block flow through the flow passage and an open state spaced away from the seal seat to allow flow through the flow passage; an armature disposed within the valve body and movable relative to the seal; an electromagnet configured to selectively receive electrical current in a first current direction or an opposite second current direction, the electromagnet actuating the armature to move the seal from the closed state to the open state when the electrical current is in the first current direction and actuating the armature to move the seal from the open state to the closed state when the electrical current is in the second current direction; A valve equipped with

2. 2. The valve of claim 1, wherein the electromagnet includes first and second coil windings wound in opposite directions relative to one another.

3. 2. The valve of claim 1, wherein the armature includes a rod portion, a yoke comprising a permanent magnet and a keeper surrounding the permanent magnet, and a shell surrounding the yoke.

4. 4. The valve of claim 3, wherein the rod portion has a tip portion in contact with the seal.

5. 4. The valve of claim 3, wherein the shell is non-ferromagnetic and formed from a titanium-based alloy.

6. 6. The valve of claim 5, wherein the seal is elastomeric.

7. 4. The valve of claim 3, wherein the shell is a material selected from the group consisting of titanium-based alloys, aluminum-based alloys, and polymers.

8. 4. The valve of claim 3, wherein when the current is in the first current direction, the electromagnet magnetically pushes the rod portion to apply a force to the seal, thereby moving the seal from the closed state to the open state, and when the current is applied in the second current direction, the electromagnet magnetically pulls the rod portion to remove the force applied to the seal, thereby moving the seal from the open state to the closed state.

9. 9. The valve of claim 8, wherein the force causes a portion of the seal to flex and lift off the seal seat, thereby opening flow through the flow passage.

10. 10. The valve of claim 1, further comprising a controller coupled to the electromagnet and configured to selectively apply electrical current in the first current direction or the second current direction.

11. 11. The valve of claim 10, wherein the controller is configured to apply current in the second current direction for a preset time to move the seal from the open state to the closed state.

12. a valve body having a flow passage; a seal disposed within the flow passage, the seal having a default closed state sealed against a seal seat to block flow through the flow passage and an open state allowing flow through the flow passage; an armature disposed within the valve body; an electromagnet configured to magnetically push the armature to apply a force to the seal, thereby moving the seal from the closed state to the open state, the force causing a portion of the seal to deflect, thereby causing the portion of the seal to separate from the seal seat to open flow through the flow passage; and A valve equipped with

13. 13. The valve of claim 12, wherein the electromagnet includes first and second coil windings wound in opposite directions relative to one another, and the armature includes a rod portion, a yoke comprising a permanent magnet and a keeper surrounding the permanent magnet, and a shell surrounding the yoke.

14. 14. The valve of claim 13, wherein the rod portion has a distal end in contact with the seal, the seal being elastomeric.

15. 14. The valve of claim 13, wherein the shell is non-ferromagnetic and formed from a titanium-based alloy.

16. 14. The valve of claim 13, wherein the shell is a material selected from the group consisting of titanium-based alloys, aluminum-based alloys, and polymers.

17. 14. The valve of claim 13, wherein the electromagnet is configured to selectively receive electrical current in a first current direction or an opposite second current direction, such that when the electrical current is in the first current direction, the electromagnet magnetically pushes the armature applying a force to the seal and when the electrical current is in the second current direction, the electromagnet magnetically pulls the armature reducing the force applied to the seal which reduces the force causing a portion of the seal to move, thereby seating the portion of the seal against the seal seat to close flow through the flow passage.

18. a propellant tank for holding a propellant; A combustor; a nozzle attached to the combustor; a supply line fluidly connecting the propellant tank and the combustor; a valve disposed in the supply line; A rocket motor comprising: The valve, a valve body having a flow passage connecting an inlet and an outlet; a seal disposed within the flow passage, the seal having a default closed state sealed against a seal seat to block flow through the flow passage and an open state moved from the seal seat to allow flow through the flow passage; an armature disposed within the valve body and movable relative to the seal; an electromagnet configured to selectively receive electrical current in a first current direction or an opposite second current direction, the electromagnet actuating the armature to move the seal from the closed state to the open state when the electrical current is in the first current direction and actuating the armature to move the seal from the open state to the closed state when the electrical current is in the second current direction; A rocket motor equipped with

19. 20. The rocket motor of claim 18, wherein the electromagnet includes first and second coil windings wound in opposite directions relative to one another, the armature includes a rod portion, a yoke comprising a permanent magnet and a keeper surrounding the permanent magnet, and a shell surrounding the yoke, the shell being non-ferromagnetic and formed from a titanium-based alloy.

Images