Regulating valve, power system and rocket

Abstract

The invention relates to the technical field of rocket accessories, in particular to a regulating valve, a power system and a rocket. The regulating valve comprises a valve body, a valve seat, a valve core, an elastic piece and a driving device, the valve body is provided with an inlet. The valve seat is connected with the valve body and is provided with an outlet; the valve element is movably arranged in the valve body and provided with a throttling part, and the throttling part is used for being matched with the valve seat so as to seal the outlet or adjust the flow of the outlet. The elastic piece is provided with a first end and a second end, and the first end of the elastic piece is connected with the valve element. The driving end of the driving device is connected with the valve element through the second end of the elastic piece. According to the adjusting valve, the power system and the rocket, the flow adjusting function and the sealing function are integrated, an auxiliary system valve, a flow adjusting valve and a venturi tube in the prior art can be replaced, the functions of the parts can be achieved, and the advantages of being simple in structure and rich in function are achieved.

Description

Technical Field

[0001] This invention relates to the field of rocket component technology, and in particular to a regulating valve, a power system, and a rocket. Background Technology

[0002] To achieve variable thrust in a liquid rocket engine, a portion of the high-temperature, high-pressure gas generated by the gas generator can be discharged through a gas bypass valve. The remaining high-temperature, high-pressure gas then enters the turbopump, regulating the amount of gas entering the turbopump and thus its rotational speed. This rotational speed, in turn, regulates the amount of fuel entering the engine, thereby adjusting the engine thrust. Alternatively, the amount of high-temperature, high-pressure gas generated by the gas generator can be directly adjusted by regulating the flow rate of the secondary system, ultimately achieving thrust regulation. This is typically done through a regulating valve.

[0003] Currently, in order to ensure the effectiveness of sealing and flow regulation, auxiliary system valves and regulating valves need to be used in conjunction, which results in the engine's variable thrust system having many parts and a complex structure. Summary of the Invention

[0004] This invention provides a regulating valve, a power system, and a rocket to solve the problem that existing technologies require multiple parts to work together to meet the functions of sealing and regulating flow, resulting in complex structures.

[0005] This invention provides a regulating valve, comprising: Valve body, with inlet; A valve seat, connected to the valve body, and having an outlet; The valve core is movably disposed inside the valve body, and the valve core has a throttling part, which is used to cooperate with the valve seat to close the outlet or regulate the flow rate of the outlet; An elastic element has a first end and a second end, wherein the first end of the elastic element is connected to the valve core; A driving device, wherein the driving end of the driving device is connected to the valve core through the second end of the elastic element.

[0006] According to a regulating valve provided by the present invention, the valve core has a groove, and the groove is located at one end opposite to the throttling portion, and the elastic body is disposed in the groove.

[0007] A regulating valve according to the present invention further includes: A valve stem has a first end and a second end, the first end of which is connected to the drive device, and the second end of which is inserted into the groove and adapted to be connected to the groove via the elastic element.

[0008] According to a regulating valve provided by the present invention, the elastic element includes: Multiple disc springs, wherein the multiple disc springs are stacked sequentially along the depth direction of the groove; A gasket is provided between two adjacent disc springs; The second end of the valve stem has a pressing surface and a positioning post. The positioning post is disposed on the pressing surface, and the pressing surface is used to press against the disc spring. The positioning post is inserted into the disc spring, and there is an axial gap between the positioning post and the groove.

[0009] According to a regulating valve provided by the present invention, a radial gap is formed between the second end of the valve stem and the groove, and the second end of the valve stem has a limiting surface; The regulating valve also includes: A limiting member is fixed and inserted into the groove to axially limit the valve stem by contacting the limiting member.

[0010] According to a regulating valve provided by the present invention, the throttling section is a conical structure, and the radius of the conical structure gradually decreases along the medium discharge direction of the outlet; the outlet is a flared structure, and the inner diameter of the flared structure gradually increases along the medium discharge direction.

[0011] A regulating valve according to the present invention further includes: A cover is disposed on the valve body, and a contraction structure for the passage of medium is formed between the cover and the inlet. The cover has a guide groove, and the valve core is movably disposed in the guide groove, which defines the direction of movement of the valve core.

[0012] A regulating valve according to the present invention further includes: A bracket is provided between the cover and the drive device; A first sealing element is disposed between the valve body and the valve seat; A back pressure ring is disposed within the space enclosed by the bracket, the cover, and the valve stem; The second sealing element is disposed within the space enclosed by the bracket, the cover and the valve stem; The third sealing element is located between the cover and the valve body.

[0013] The present invention also provides a power system, including: the regulating valve provided by the present invention.

[0014] The present invention also provides a rocket, comprising: a regulating valve or a propulsion system provided by the present invention.

[0015] This invention provides a regulating valve comprising: a valve body, a valve seat, a valve core, an elastic element, and a driving device; the valve body has an inlet; the valve seat is connected to the valve body and has an outlet; the valve core is movably disposed inside the valve body and has a throttling section, which cooperates with the valve seat to close the outlet or regulate the flow rate at the outlet; the elastic element has a first end and a second end, the first end of the elastic element being connected to the valve core; the driving end of the driving device is connected to the valve core through the second end of the elastic element. This invention provides a regulating valve that, through the driving device driving the valve core to move up and down, achieves the function of regulating the flow rate of the medium; by providing an elastic element between the driving device and the valve core, when the driving device drives the valve core to descend, the clamping force applied to the valve core by the elastic element allows the valve core to be pressed against the outlet of the valve seat, thereby achieving a sealing function; furthermore, the throttling section provided in the valve core can form a Venturi structure with the inlet of the valve body and the outlet of the valve seat, thereby achieving the function of regulating the flow rate. The present invention provides a regulating valve that integrates flow regulation and sealing functions. It can replace the sub-system valve, flow regulating valve and venturi tube in the prior art and realize the functions of the above-mentioned parts. It has the advantages of simple structure and rich functions.

[0016] Furthermore, the power system provided by the present invention, since it includes the regulating valve in the above embodiments of the present invention, has the same advantages as described above.

[0017] Furthermore, the rocket provided by the present invention has the same advantages as described above because it includes the regulating valve or power system in the above embodiments of the present invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the internal structure of the regulating valve provided by the present invention.

[0020] Figure 2 yes Figure 1 A schematic diagram of the partial structure of A in the middle.

[0021] Figure 3 This is a schematic diagram of the overall structure of the regulating valve provided by the present invention.

[0022] Figure label: 1: Valve core; 2: Valve body; 21: Inlet; 3: Valve seat; 31: Outlet; 4: Valve stem; 41: Positioning pin; 5: Limiting element; 6: Cover; 7: Back pressure ring; 8: Disc spring; 9: Gasket; 10: Bracket; 11: First seal; 12: Second seal; 13: Third seal; 14: Drive device. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this embodiment and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this embodiment.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this embodiment, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] In this embodiment, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0027] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0028] The following is combined with Figures 1-3 This invention describes a regulating valve. The regulating valve includes: a valve body 2, a valve seat 3, a valve core 1, an elastic element, and a drive device 14, etc.

[0029] The valve body 2 has an inlet 21; the valve seat 3 is connected to the valve body 2 and has an outlet 31; the valve core 1 is movably disposed inside the valve body 2 and has a throttling part, which is used to cooperate with the valve seat 3 to close the outlet 31 or regulate the flow rate of the outlet 31; the elastic element has a first end and a second end, the first end of the elastic element is connected to the valve core 1; the driving end of the driving device 14 is connected to the valve core 1 through the second end of the elastic element.

[0030] Specifically, such as Figure 1 As shown, the valve body 2 has an inlet 21 on the left side for introducing the medium. The valve seat 3 is installed at the bottom of the valve body 2 and can be connected to the valve body 2 by a threaded connection. The drive device 14 is installed at the top of the valve body 2 to provide power for the movement of the valve core 1.

[0031] Optionally, the drive device 14 employs a servo motor and may be equipped with a linkage or other structure to convert the rotational motion of the servo motor output shaft into linear reciprocating motion, thereby driving the valve core 1 to move up and down. Alternatively, the drive device 14 may employ a cylinder or hydraulic cylinder in conjunction with a push rod to provide power for the up-and-down movement of the valve core 1. In short, the end of the drive device 14 provides the power required for the up-and-down movement of the valve core 1. As the end of the drive device 14 continuously descends, the gap between the throttling section and the outlet 31 continuously decreases, thereby continuously reducing the flow rate through the outlet 31. The flow rate of the discharged medium can be adjusted by the rising and falling of the end of the drive device 14, thus realizing the function of the regulating valve in regulating flow.

[0032] The elastic body is located between the drive device 14 and the valve core 1. As the drive device 14 moves downward continuously, the elastic body provides an elastic clamping force on the valve core 1. As the end of the drive device 14 continues to descend, the gap between the throttling section and the outlet 31 continuously decreases, thereby reducing the flow rate through the outlet 31. Through the action of the elastic body on the valve core 1, the throttling section presses against the sealing surface of the valve seat 3, achieving a seal and realizing the sealing function of the sub-system valve.

[0033] Furthermore, based on the structure of inlet 21, its medium passage area is relatively large. During the downward movement of valve core 1, the medium passage area is reduced through the cooperation of the throttling section and outlet 31, which is equivalent to the contraction section of a venturi tube. The throat of the venturi tube is located at the position closest to the inner wall of the throttling section and outlet 31. The outlet 31 of valve seat 3 can adopt the expansion section structure of a venturi tube. Therefore, through the combination of the above structures, the function of regulating flow rate with a venturi tube is realized.

[0034] As can be seen, the regulating valve provided by the present invention achieves the function of regulating the medium flow rate by driving the valve core 1 up and down through the drive device 14; by setting an elastic body between the drive device 14 and the valve core 1, when the drive device 14 drives the valve core 1 to descend, the clamping force applied to the valve core 1 by the elastic body allows the valve core 1 to be pressed against the outlet 31 of the valve seat 3, thereby achieving the sealing function; in addition, the throttling part set in the valve core 1 can form a Venturi structure with the inlet 21 of the valve body 2 and the outlet 31 of the valve seat 3, thereby achieving the function of regulating the flow rate. The regulating valve provided by the present invention integrates the functions of flow regulation and sealing, and can replace the sub-system valve, flow regulating valve and Venturi tube in the prior art and achieve the functions of the above-mentioned components, with the advantages of simple structure and rich functions.

[0035] The present invention provides a regulating valve comprising: a valve body 2, a valve seat 3, a valve core 1, an elastic element, and a drive device 14; the valve body 2 has an inlet 21; the valve seat 3 is connected to the valve body 2 and has an outlet 31; the valve core 1 is movably disposed inside the valve body 2 and has a throttling section, which cooperates with the valve seat 3 to close the outlet 31 or regulate the flow rate of the outlet 31; the elastic element has a first end and a second end, the first end of the elastic element being connected to the valve core 1; the drive end of the drive device 14 is connected to the valve core 1 through the second end of the elastic element. The regulating valve provided by the present invention integrates flow regulation and sealing functions, and can replace the sub-system valve, flow regulating valve, and venturi tube in the prior art, achieving the functions of the aforementioned components. It has the advantages of simple structure and rich functionality.

[0036] In one embodiment of the present invention, the valve core 1 has a groove, and the groove is located at the end opposite to the throttling portion, with an elastic body disposed within the groove. Specifically, in such... Figure 2 In the structure shown, a groove is set on the top of the valve core 1, and an elastic body is set in the groove accordingly. The drive device 14 moves downward and the elastic body acts on the bottom inner wall of the groove to achieve the seal between the valve core 1 and the outlet 31.

[0037] In one embodiment of the present invention, the regulating valve further includes a valve stem 4 having a first end and a second end. The first end of the valve stem 4 is connected to the drive device 14, and the second end of the valve stem 4 is inserted into a groove and adapted to be connected to the groove via an elastic element. Specifically, the upper end of the valve stem 4 is the first end, and the lower end is the second end. The drive device 14 can transmit a downward force through the valve stem 4; the lower end of the valve stem 4 is inserted into the groove of the valve core 1 and applies a downward force to the elastic element. In this embodiment, the force exerted by the drive device 14 on the elastic element and the valve core 1 is transmitted through the valve stem 4.

[0038] In one embodiment of the invention, the elastic element includes: a plurality of disc springs 8 and a plurality of washers 9. The plurality of disc springs 8 are stacked sequentially along the depth direction of the groove; the washers 9 are disposed between two adjacent disc springs 8. The second end of the valve stem 4 has a pressing surface and a positioning post 41. The positioning post 41 is disposed on the pressing surface, which is used to press against the disc springs 8. The positioning post 41 is inserted into the disc springs 8, and there is an axial gap between the positioning post 41 and the groove. Figure 2 In the structure shown, multiple disc springs 8 are sleeved on the positioning post 41 of the valve stem 4 along the height direction. The pressing surface is the lower end face of the valve stem 4, and the positioning post 41 has a structure with the pressing surface protruding downwards. The outer diameter of the positioning post 41 is smaller than the outer diameter of the pressing surface, so that the upper surface of the disc spring 8 can contact the pressing surface. In addition, in order to prevent the drive device 14 from jamming, a certain gap is provided at the bottom between the valve stem 4 and the valve core 1 as a margin for the motor stroke in the sealed state. That is, when the disc spring 8 is in the compressed state, there is an axial gap between the positioning post 41 and the groove.

[0039] Preferably, in order to prevent excessive pressure and stress on the disc springs 8, four disc springs 8 are installed back to back to reduce the variation in the compression of a single disc spring 8 caused by tolerance, and the disc springs 8 are separated from each other by flat washers 9.

[0040] In one embodiment of the present invention, a radial gap exists between the second end of the valve stem 4 and the groove, and the second end of the valve stem 4 has a limiting surface. The regulating valve of the present invention further includes a limiting member 5, which is fixed and inserted into the groove for axially limiting the valve stem 4 by contacting the limiting member 5.

[0041] Preferably, the limiting member 5 can be an external threaded bolt and has an internal through hole. The valve stem 4 is inserted into the groove through the internal through hole. The external threaded bolt is inserted into the groove and threadedly connected to it. The valve stem 4 is limited by the locking action of the external threaded bolt on the second end of the valve stem 4, preventing the valve stem 4 from coming out of the groove upward.

[0042] Furthermore, the radial clearance between the second end of the valve stem 4 and the groove is between the outer surface of the valve stem 4 and the inner surface of the groove, allowing the valve core 1 to be adjusted within a certain radial range of the valve stem 4, thereby ensuring the coaxiality of the valve core 1 and the valve seat 3. Preferably, the radial clearance between the second end of the valve stem 4 and the groove is an annular clearance of approximately 0.2 mm, ensuring that the valve core 1 has a certain margin in all directions of the annular clearance, thereby ensuring the coaxiality between the valve core 1 and the valve seat 3.

[0043] In one embodiment of the present invention, the throttling section is a conical structure, and the radius of the conical structure gradually decreases along the medium discharge direction of the outlet 31; the outlet 31 is a flared structure, and the inner diameter of the flared structure gradually increases along the medium discharge direction. Figure 1 In the structure shown, as the valve core 1 descends, the gap between its conical structure and the outlet 31 continuously decreases, and the discharge flow of the regulating valve gradually decreases. Meanwhile, the outlet 31 of the valve seat 3 adopts a flared structure, which is equivalent to the diffuser section in a venturi tube.

[0044] In one embodiment of the invention, the regulating valve further includes: a cover 6 disposed on the valve body 2, the cover 6 forming a contraction structure between itself and the inlet 21 for the passage of a medium, and the cover 6 having a guide groove, the valve core 1 being movably disposed within the guide groove, the guide groove defining the direction of movement of the valve core 1. Figure 1 In the structure shown, the cover 6 is located at the top of the valve body 2, and the lower end of the cover 6 extends into the interior of the valve body 2. The portion extending into the interior of the valve body 2 forms a guide groove, which is a longitudinally extending channel. The valve core 1 is located within this channel and can move up and down. The guide groove guides the movement of the valve core 1. In addition, a contraction section is formed between the bottom of the cover 6 and the inlet 21 of the valve body 2, which is the contraction structure in this embodiment. It is equivalent to the contraction section in a venturi tube, and the gap between the throttling section and the outlet 31 after it descends is equivalent to the throat in a venturi tube.

[0045] In one embodiment of the present invention, the regulating valve further includes: a bracket 10, a first seal 11, a back pressure ring 7, a second seal 12, and a third seal 13. The bracket 10 is disposed between the cover 6 and the drive device 14. The first seal 11 is disposed between the valve body 2 and the valve seat 3; the back pressure ring 7 is disposed within the space enclosed by the bracket 10, the cover 6, and the valve stem 4; the second seal 12 is disposed within the space enclosed by the bracket 10, the cover 6, and the valve stem 4; and the third seal 13 is disposed between the cover 6 and the valve body 2. Preferably, the first seal 11, the second seal 12, and the third seal 13 can be made of polyetheretherketone (PEEK) material to achieve sealing between the parts.

[0046] Preferably, the bracket 10 is located between the valve body 2 and the drive device 14. The bracket 10 and the valve body 2 are connected by screws, and the bracket 10 and the drive device 14 are also connected by screws. The bracket 10 has a chamber into which the end of the drive device 14 and the first end of the valve stem 4 extend. In addition, in order to reduce heat conduction between the drive device 14 and the bracket 10, the bracket 10 is made of titanium alloy material with low thermal conductivity, and a boss is designed on the bracket 10 to reduce the contact area between the bracket 10 and the drive device 14.

[0047] To minimize the impact of the absolute position accuracy of the motor output on the valve stroke accuracy, the total stroke of the valve (i.e., valve core 1) is maximized. To ensure that the throttling position of the valve within the design adjustment range is always maintained at the throat, the valve has a minimum opening degree by utilizing the cavitation characteristics of the venturi tube. That is, the range from fully closed to this minimum opening degree is not considered part of the valve's usable stroke. Due to the axial clearance between the valve stem 4 and the valve core 1, the actual stroke of the valve stem 4 is slightly larger than that of the valve core 1. The total stroke range of the valve stem 4 is located in the middle section of the motor stroke range, and there is a gap between the valve core 1 and the upper cover when the valve is fully open, ensuring that the motor does not jam.

[0048] The present invention also provides a power system. This power system includes the regulating valve described in the above embodiments of the present invention.

[0049] The power system provided by the present invention has the same advantages as described above because it includes the regulating valve in the above embodiments of the present invention.

[0050] The present invention also provides a rocket. The rocket includes: the regulating valve or propulsion system described in the above embodiments of the present invention.

[0051] The rocket provided by the present invention has the same advantages as described above because it includes the regulating valve or power system in the above embodiments of the present invention.

[0052] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A regulating valve, characterized in that Comprising: a valve body (2) having an inlet (21); a valve seat (3) connected with the valve body (2) and having an outlet (31); a valve core (1) movably arranged inside the valve body (2), and the valve core (1) has a throttling part for cooperating with the valve seat (3) to close the outlet (31) or adjust the flow of the outlet (31); a resilient member having a first end and a second end, the first end of the resilient member being connected with the valve core (1); a driving device (14), and the driving end of the driving device (14) is connected with the valve core (1) through the second end of the resilient member.

2. The regulating valve according to claim 1, characterized in that The valve core (1) has a groove, and the groove is located at one end away from the throttling part, and the resilient body is arranged in the groove.

3. The regulating valve according to claim 2, characterized in that Further comprising: a valve stem (4) having a first end and a second end, the first end of the valve stem (4) being connected with the driving device (14), and the second end of the valve stem (4) being inserted into the groove and being adapted to be connected with the groove through the resilient member.

4. The regulating valve according to claim 3, wherein The resilient member comprises: a plurality of disc springs (8) stacked in sequence along the depth direction of the groove; a gasket (9) arranged between adjacent two disc springs (8); The second end of the valve stem (4) has a press surface and a positioning column (41), the positioning column (41) is arranged on the press surface, the press surface is used for pressing on the disc spring (8), the positioning column (41) is inserted into the disc spring (8), and the positioning column (41) and the groove have an axial gap.

5. The regulating valve according to claim 3, characterized in that The second end of the valve stem (4) and the groove have a radial gap, and the second end of the valve stem (4) has a limiting surface; The regulating valve further comprises: a limiting member (5) fixedly inserted into the groove, for axially limiting the valve stem (4) by contacting the limiting member (5).

6. The regulating valve according to claim 1, characterized in that The throttling part is a conical structure, and the radius of the conical structure gradually decreases along the medium discharge direction of the outlet (31); the outlet (31) is an expanding structure, and the inner diameter of the expanding structure gradually increases along the medium discharge direction.

7. The regulating valve according to any one of claims 3 to 5, characterized in that Further comprising: a cover body (6) arranged on the valve body (2), a contraction structure for passing medium being formed between the cover body (6) and the inlet (21), and the cover body (6) having a guide groove, the valve core (1) being movably arranged in the guide groove, and the guide groove being used for limiting the moving direction of the valve core (1).

8. The regulating valve according to claim 7, characterized in that Further comprising: a bracket (10) arranged between the cover body (6) and the driving device (14); a first sealing member (11) arranged between the valve body (2) and the valve seat (3); a back pressure ring (7) arranged in the space surrounded by the bracket (10), the cover body (6) and the valve stem (4); a second sealing member (12) arranged in the space surrounded by the bracket (10), the cover body (6) and the valve stem (4); a third sealing member (13) arranged between the cover body (6) and the valve body (2).

9. A power system characterized by, Comprising: The regulating valve according to any one of claims 1 to 8.

10. A rocket, characterized by Comprising: The regulating valve of any one of claims 1 to 8 or the power system of claim 9.

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