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 Art

[0001] Valves are widely used in systems that handle fluids. An example is a motor that controls the flow of fuel for combustion. Such valves include a valve armature having a valve member that adheres to a valve seat. A spring biases the armature to the closed position, where the valve member seats on the valve seat to block the flow. A solenoid coil functions as an actuator. When current is supplied to the coil, a magnetic field is generated, causing the armature to move against the force of the spring, lifting the valve member off the valve seat to allow flow. When the power to the solenoid is turned off, the spring returns the armature to the closed position.

Summary of the Invention

Means for Solving the Problems

[0002] A valve according to an example of the present disclosure includes a valve body having a flow path and a seal disposed within the flow path. The seal has a default closed state sealed against a seal seat to block flow through the flow path and an open state away from the seal seat to allow flow through the flow path. An armature is disposed within the valve body and is movable relative to the seal. An electromagnet is configured to selectively receive current in a first current direction or a second current direction opposite thereto. When the 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 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 foregoing embodiments, the electromagnet includes first and second coil windings wound in opposite directions relative to each other.

[0004] <http: / / www.google.com / patents / US20180283474A1?cl=en&q=US20180283474A1&dq=US20180283474A1&hl=en&sa=X&ved=0ahUKEwjf666M7c3dAhXJ72MKHf5fD9MQ6AEIKTAA>In a further embodiment of any of the foregoing 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 any further embodiment of the above-described embodiments, the rod portion has a tip that contacts the seal.

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

[0007] In any further embodiment of the above-described embodiments, the seal is an elastomer.

[0008] In further embodiments of any of the embodiments described above, the shell is a material selected from the group consisting of titanium alloys, aluminum alloys, and polymers.

[0009] In a further embodiment of any of the embodiments described above, when the current is in a first current direction, the electromagnet magnetically pushes the rod portion, applying a force to the seal, thereby moving the seal from a closed state to an open state, and when the current is applied in a second current direction, the electromagnet magnetically pulls the rod portion, removing 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 embodiments described above, a force causes a portion of the seal to flex and lift away from the seal sheet, thereby opening up the flow through the channel.

[0011] In any further embodiment of the above-described embodiments, a controller is included, which is connected to an electromagnet and configured to selectively apply current in a first current direction or a second current direction.

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

[0013] An example of a valve according to the present disclosure includes a valve body having a flow path and a seal disposed within the flow path. The seal has a default closed state, sealed to a seal sheet to block flow through the flow path, and an open state, which allows flow through the flow path. An armature is disposed within the valve body. An electromagnet is configured to magnetically push the armature and apply force to the seal, thereby moving the seal from the closed state to the open state. This force causes a portion of the seal to flex, thereby separating it from the seal sheet and opening the flow through the flow path.

[0014] In a further embodiment of any of the embodiments described above, the electromagnet includes first and second coil windings wound in opposite directions to each other, 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 embodiments described above, the rod portion has a distal end that contacts a seal, and the seal is an elastomer.

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

[0017] In any further embodiment of the above-described embodiments, the shell is a material selected from the group consisting of titanium alloys, aluminum alloys, and polymers.

[0018] In a further embodiment of any of the embodiments described above, the electromagnet is configured to selectively receive a current in a first current direction or a second current direction opposite to that, when the current is in the first current direction, the electromagnet magnetically pushes the armature and applies a force to the seal, and when the current is in the second current direction, the electromagnet magnetically pulls the armature and reduces the force applied to the seal. This reduction in force causes a portion of the seal to move, thereby seating a portion of the seal on the seal sheet and closing the flow through the channel.

[0019] A rocket motor according to an example of the present disclosure includes a propellant tank that holds a propellant, a combustor, a nozzle attached to the combustor, a supply line that fluidly connects the propellant tank and the combustor, and a valve according to any of the foregoing embodiments disposed in the supply line.

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

[0021] Various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The accompanying drawings, which are incorporated in and constitute a part of this specification, can be briefly described as follows.

Brief Description of the Drawings

[0022] [Figure 1] It is a diagram showing an example of a rocket motor. [Figure 2] It is a diagram showing a state where the valve of the rocket motor is closed. [Figure 3] It is a diagram showing a state where the valve of the rocket motor is open. [Figure 4] It is a diagram showing a valve having magnetic field lines. [Figure 5] It is a diagram showing the sealing area of the valve in the closed state. [Figure 6] It is a diagram showing the sealing area of the valve in the open state. [Figure 7] It is a cross-sectional view of the seal of the valve. [Figure 8] It is a diagram showing the valve in the latched state.

Mode for Carrying Out the Invention

[0023] FIG. 1 shows a rocket motor 10 for showing an exemplary aspect of a valve disclosed herein. However, it will be understood that other applications than rocket motors may 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 for holding propellant 18a, and a supply line 20 connecting 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 understood, the rocket motor 10 includes additional components beyond the scope of this disclosure.

[0025] Figure 2 shows a cross-sectional view of an example of a valve 22. The valve 22 includes a valve body 26 having an inlet 26a, an outlet 26b, and a flow path P connecting the inlet 26a to the outlet 26b. The valve body 26 may be formed from a single, integrated part or multiple parts fixed to each other so as to surround the flow path P or a portion thereof.

[0026] The valve 22 further includes a seal 28 positioned 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 being transported through the valve 22. In a rocket motor using hydrazine as the propellant 18a, the elastomer may be an ethylene propylene polymer. One example is the trademarked name AF-E-411 (Parker Hannifin), but other elastomers are also usable. In Figure 2, the seal 28 is in its default closed state, sealed against the seal sheet 30 to block the flow through the flow path P. When the seal 28 separates from the seal sheet 30 (Figure 3), it allows the flow through the flow path P.

[0027] The valve 22 also includes an armature 32 and an electromagnet 34. The armature 32 is located 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, each wound in opposite directions. The coil windings 34a / 34b are connected in series. For example, there is 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 specified herein with respect to the control of the valve 22. Hardware includes, but is not limited to, a microprocessor module, circuitry, control logic, memory modules, and / or power supplies.

[0028] The armature 32 consists of several subcomponents, including a rod 36, a yoke 38, and a shell 40 that surrounds the yoke 38 and prevents the fluid in the valve 22 from coming into contact with the yoke 38. The yoke 38 consists 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 36 has a tip 36a that contacts the seal 28, and its function will be described in more detail below.

[0029] The fluid intended to be transported through valve 22 may not be compatible with the material used for the yoke 38. For example, the fluid may accelerate the corrosion of the material. In a non-limiting example in the rocket motor 10, when hydrazine is used as the propellant 18a, it may be desirable to avoid contact with stainless steel (e.g., keeper 44) and magnets. In this regard, the shell 40 seals and encloses the yoke 38, thereby preventing the fluid from coming into contact with the subcomponents of the yoke 38. In one example, the shell 40 is a covering material applied around the yoke 38. In another example, the shell 40 may be a configuration of pre-fabricated pieces joined together to enclose 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 magnet 42 and the electromagnet 34. For example, the material can be selected from titanium alloys, aluminum alloys, or polymers. 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 compared to at least one or more materials of the subcomponents of the yoke 38. Furthermore, by benefiting from this disclosure, those skilled in the art will recognize that the selected material also possesses other strength and durability properties to meet the design requirements of a particular implementation. For example, aluminum alloys are excellent in strength, durability and corrosion resistance, and titanium alloys are excellent in strength, durability and corrosion resistance. Polymers may also be used for ease of manufacture and chemical resistance, but generally do not have the same strength as titanium or aluminum alloys.

[0032] In the operation of valve 22, the electromagnet 34 selectively receives current in either a first current direction or a second, opposite current direction. As described above, the controller 24 is responsible for operating valve 22 and controlling the direction and magnitude of the current. When current flows in the first current direction, the electromagnet 34 magnetically acts on the armature 32 to move the seal 28 from its default closed state (Figure 1) to the open state (Figure 2). When current flows in the second current direction, the electromagnet 34 magnetically acts on the armature 32 to move the seal 28 from the open state to the closed state. As can be understood, the closed state is the default ready position in the illustrated example, but different default positions such as a default ready open position or a latched inactive state may also be used.

[0033] Figure 4 shows a cross-sectional view of the valve 22 having magnetic field lines L1 representing the magnetic field generated by the permanent magnet 42. The electric field generated by the coil portions 34a / 34b of the electromagnet 34 intersects with the magnetic field of the permanent magnet 42. This interaction causes the polarity, strength, and timing of the electric field generated by the electromagnet 34 to act in a manner that manipulates the magnetic field of the permanent magnet 42 to open and close the seal 28.

[0034] Figures 5 and 6 illustrate the operation of the seal 28. As shown in Figure 5, the seal 28 is positioned within the seal cavity 28a. The seal 28 is confined within the cavity 28a in a compressed state, substantially preventing movement of the seal 28 along the axial direction of the rod portion 36 of the armature 32 and preloading the seal sheet 30. In the closed state as shown in Figure 5, the seal surface 28b abuts against the seal sheet 30, thereby preventing flow from passing through. The tip 36a of the rod portion 36 is nominally in contact with the seal 28 or slightly away from it. The force applied to the seal 28 by the rod portion 36 is minimal or nonexistent.

[0035] To open the seal 28, the controller 24 sends current through 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 applying a force to the seal 28 via the tip 36a of the rod portion 36. As shown in Figure 6, the force applied to the seal 28 causes a portion of the seal 28 to flex, thereby lifting the seal surface 28b away from the seal sheet 30. Once the seal surface 28b is lifted, the fluid flows between the seal surface 28b and the seal sheet 30, through the flow path 28c (Figure 7) around the seal 28, and exits through the outlet 26b of the valve 22. The terms “pushing” and “pulling” used herein refer to the force applied to the armature 32, particularly the tip 36a of the rod portion 36, and the direction of movement relative to the electromagnet 34. When pushed, the tip 36a tends to move away from the electromagnet 34, that is, away from the coil of the electromagnet 34. However, when pulled, the tip 36a tends to move towards the electromagnet 34, that is, into the coil of the 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 by the seal 28 is a function of the amount of force applied and the material properties of the seal 28. Deflection provides the cross-sectional area of ​​the fluid flow through the seal 28. In some examples, metering is provided in a smaller cross-sectional area of ​​the flow path located upstream of the seal 28, such as between the rod portion 36 and the wall of the orifice 46 (Figure 5). Thus, metering is established between the metal parts, and the metering does not change even if the cross-sectional area of ​​the flow through the seal 28 changes due to changes in the material of the seal 28 over time, allowing for the use of a wide range of materials for the seal 28.

[0037] To close the seal 28, the controller 24 causes the electromagnet 34 to flow current in a second current direction, i.e., reverses its polarity. The electric field of the coil section 34a / 34b interacts with the magnetic field of the permanent magnet 42, pulling the armature 32 and thereby removing the force applied to the seal 28. As the force decreases, the portion of the seal 28 that was deflected to open the seal 28 moves back to the closed state, and the seal interface 28b seats on the seal sheet 30, blocking the flow of fluid.

[0038] Valve 22 operates to open and close without using 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 in only one direction against the spring, regardless of the direction of the current. In contrast, in valve 22, the force is proportional to the current, and reversing the current causes the armature 32 to move in the opposite direction (push-pull). The push-pull function eliminates the need for a spring, while the linear proportionality improves force control and thus the valve's performance.

[0039] In one example of the control method, the controller 24 executes an open command to open the seal 28 by applying a predetermined magnitude of current to the electromagnet 34 in a first current direction. The current is kept constant for a certain period of time, keeping the seal 28 open and thereby providing fluid flow (for example, flowing to the combustor 14 to generate thrust). When the fluid flow is no longer needed, the controller 24 executes a close command to close the seal 28 by applying a predetermined magnitude of current to the electromagnet 34 in a second current direction. The current in the second direction is applied for a predetermined time to remove the force from the seal 28. After the predetermined time has elapsed, the current is turned off (zero current). For example, the preset time is 10 to 100 milliseconds, after which the position of the armature 32 is maintained by the magnetic field of the permanent magnet 42, and the seal 28 remains closed.

[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 position completely upstream of the inlet side of the valve body 26. The permanent magnet 42 maintains the armature in this position when the current in the electromagnet 34 is zero. In this position, the tip 36a of the rod portion 36 is substantially separated from the seal 28. For example, before the valve 22 is opened or closed, the valve 22 may be subjected to vibrations that can cause chattering of the armature 32. Chattering can cause the tip 36a of the rod portion 36 to move back and forth by a small distance. If the tip 36a is in contact with or close to the seal 28, chattering can cause the rod portion 36 to apply a temporary force to the seal 28. This can cause the seal 28 to open temporarily, resulting in a small amount of fluid leakage. However, in the latched state, the armature 32, specifically its tip 36a, is separated from the seal 28 by a distance substantially larger than the amplitude of the chattering vibration. As a result, even if there is chattering in the armature 32, it will not be able to contact the seal 28 or cause transient leakage. Furthermore, since the armature 32 is in contact with the opening of the inlet 26a, the armature 32 can provide a sealing function that restricts the flow of fluid into the valve 22. The latched state is obtained by passing current in a second direction until the armature 32 contacts the inlet end of the body.

[0041] While the illustrated examples illustrate combinations of features, it is not necessary to combine all of them to realize the advantages of the various embodiments of this disclosure. In other words, a system designed according to embodiments of this disclosure does not necessarily include all the features shown in any of the figures, or all the parts schematically shown in the figures. Furthermore, selected features from one exemplary embodiment can be combined with selected features from other exemplary embodiments.

[0042] The foregoing description is illustrative and not restrictive in nature. It will be apparent to those skilled in the art that variations and modifications to the disclosed examples will not necessarily deviate from this disclosure. The scope of legal protection granted by this disclosure can only be determined by considering the following claims.

Claims

1. A valve body having a flow path, A seal disposed within the flow path, having a default closed state in which it is sealed to a seal sheet to block the flow through the flow path, and an open state away from the seal sheet to allow the flow through the flow path, An armature is disposed within the valve body and is movable relative to the seal, An electromagnet configured to selectively receive a current in a first current direction or a second current direction opposite to that, wherein when the current is in the first current direction, the armature is activated to move the seal from the closed state to the open state, and when the current is in the second current direction, the armature is activated to move the seal from the open state to the closed state, Equipped with, 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. When the current is in the first current direction, the electromagnet magnetically pushes the rod portion, applying force to the seal, thereby moving the seal from the closed state to the open state; when the current is applied in the second current direction, the electromagnet magnetically pulls the rod portion, removing the force applied to the seal, thereby moving the seal from the open state to the closed state. A valve in which a part of the seal flexes and lifts away from the seal sheet due to the aforementioned force, thereby opening the flow through the passage.

2. The valve according to claim 1, characterized in that the electromagnet includes first and second coil windings wound in opposite directions to each other.

3. The valve according to claim 1, characterized in that the rod portion has a tip portion that contacts the seal.

4. The valve according to claim 1, characterized in that the shell is non-ferromagnetic and is formed of a titanium alloy.

5. The valve according to claim 4, characterized in that the seal is an elastomer.

6. The valve according to claim 1, characterized in that the shell is made of a material selected from the group consisting of titanium alloys, aluminum alloys, and polymers.

7. The valve according to claim 1, further comprising a controller connected to the electromagnet and configured to selectively apply current in the first current direction or the second current direction.

8. The valve according to claim 7, characterized in that the controller is configured to apply current in the second current direction for a predetermined time in order to move the seal from the open state to the closed state.

9. A valve body having a flow path, A seal disposed within the flow path, having a default closed state in which it is sealed to a seal sheet to block the flow through the flow path, and an open state in which it allows the flow through the flow path, The armature is disposed within the valve body, An electromagnet configured to magnetically push the armature and apply force to the seal, thereby moving the seal from the closed state to the open state, wherein the force causes a portion of the seal to bend, thereby separating a portion of the seal from the seal sheet and opening the flow through the channel, Equipped with, A valve wherein the electromagnet is configured to selectively receive a current in a first current direction or a second current direction opposite to it, and when the current is in the first current direction, the electromagnet magnetically pushes the armature and applies force to the seal, and when the current is in the second current direction, the electromagnet magnetically pulls the armature and reduces the force applied to the seal, thereby moving a part of the seal and causing the part of the seal to seat on the seal sheet, thereby closing the flow through the flow path.

10. The valve according to claim 9, wherein the electromagnet includes first and second coil windings wound in opposite directions to each other, 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.

11. The valve according to claim 10, characterized in that the rod portion has a distal end that contacts the seal, and the seal is made of elastomer.

12. The valve according to claim 10, characterized in that the shell is non-ferromagnetic and is formed of a titanium alloy.

13. The valve according to claim 10, characterized in that the shell is made of a material selected from the group consisting of titanium alloys, aluminum alloys, and polymers.

14. A propellant tank for holding propellant, Combustor and A nozzle attached to the aforementioned combustion device, A supply line that fluidly connects the propellant tank and the combustor, A valve located in the aforementioned supply line, A rocket motor equipped with, The aforementioned valve, A valve body having a flow path connecting the inlet and outlet, A seal disposed within the flow path, having a default closed state in which it is sealed to a seal sheet to block the flow through the flow path, and an open state in which it is moved away from the seal sheet to allow the flow through the flow path, An armature is disposed within the valve body and is movable relative to the seal, An electromagnet configured to selectively receive a current in a first current direction or a second current direction opposite to that, wherein when the current is in the first current direction, the armature is activated to move the seal from the closed state to the open state, and when the current is in the second current direction, the armature is activated to move the seal from the open state to the closed state, Equipped with, 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. When the current is in the first current direction, the electromagnet magnetically pushes the rod portion, applying force to the seal, thereby moving the seal from the closed state to the open state; when the current is applied in the second current direction, the electromagnet magnetically pulls the rod portion, removing the force applied to the seal, thereby moving the seal from the open state to the closed state. A rocket motor in which a portion of the seal flexes and lifts away from the seal sheet due to the aforementioned force, thereby opening up the flow through the channel.

15. The rocket motor according to claim 14, characterized in that the electromagnet includes first and second coil windings wound in opposite directions to each other, and the shell is non-ferromagnetic and formed of a titanium alloy.

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