Aircraft and its engine unit

Abstract

To provide a flying body and its engine unit capable of improving the accuracy of speed control during landing etc. [Solution] The aircraft has an engine 20 driven by turbopumps 22, 23 rotated by an electric motor 21. The aircraft may have at least one first engine 10 driven by turbopumps 12, 13 rotated by a turbine 11, and at least two second engines 20 driven by turbopumps 22, 23 rotated by electric motors 21. The aircraft may further have a control device 30 that transmits attitude control signals during landing to the electric motors 21 of the at least two second engines 20 to control the drive of the electric motors 21 and control the attitude of the aircraft during landing.

Description

[Technical Field]

[0001] The present invention relates to an aircraft and its engine unit. [Background technology]

[0002] When landing a rocket (in this specification, a flying object that flies in space, such as a rocket, is referred to as a spacecraft), a technique is known in which the steering angle of the engine's gimbal mechanism and the steering angle of the attitude control fins are controlled to land the rocket vertically (see, for example, Patent Document 1). It is also known to control the rocket body's attitude using engine thrust (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-019120 [Patent Document 2] Japanese Patent Publication No. 2022-131923 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional rocket engines, for example in rockets that land vertically, the response when adjusting (throttling) the engine thrust is not good, which reduces the accuracy of speed control during landing.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an aircraft and its engine unit that can improve the accuracy of speed control during landing and other times. [Means for solving the problem]

[0006] One aspect of the present invention is a flying vehicle that has a rocket engine driven by a turbopump rotated by an electric motor, and that can land by controlling the thrust of the rocket engine.

[0007] With this type of aircraft, vertical landing is possible by driving the engine with a turbopump rotated by an electric motor that has high responsiveness in thrust adjustment, making it possible to land by controlling the landing speed with high precision.

[0008] Another aspect of the present invention is an aircraft having at least one first engine driven by a turbopump rotated by a turbine, and at least two second engines driven by turbopumps rotated by electric motors.

[0009] The aircraft of the above-described aspect may further include a control device that controls the driving of the electric motors of at least two second engines via inverters that drive the electric motors, and controls the attitude of the aircraft during landing.

[0010] In the aircraft of the above aspect, the first engine may be located in the center of the rear end of the aircraft, and the second engine may be located on the periphery of the rear end.

[0011] The flying vehicle of the above embodiment may further include a switching device for switching the supply of oxidizer and fuel from the first engine to the second engine.

[0012] In the flying vehicle of the above aspect, oxidizer and fuel may be supplied to the first engine or both the first and second engines during ascent, and to the second engine during landing, by switching operation using a switching device.

[0013] Another aspect of the present invention is an engine unit for an aircraft having at least one first engine driven by a turbopump rotated by a turbine, and at least two second engines driven by turbopumps rotated by electric motors. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an aircraft and its engine unit that can improve the accuracy of speed control during landing. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing an example of a basic configuration of a rocket (aircraft) according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example configuration of a rocket fuel tank, an electric pump, a turbine pump, a first engine, and a second engine. [Figure 3] FIG. 2 is a diagram showing an example of the arrangement of a first engine and a second engine. [Figure 4] FIG. 2 is a perspective view showing an example of the arrangement of a first engine and a second engine. [Figure 5] This is a diagram showing an example of a supply and command system for a rocket's fuel tank, electric pump, turbine pump, first engine, second engine, etc. DETAILED DESCRIPTION OF THE INVENTION

[0016] The configuration of the present invention will be described in detail below based on an example of an embodiment shown in the drawings (see FIGS. 1 to 5).

[0017] A rocket 100 according to one embodiment of the present invention is configured as an aircraft equipped with an engine unit 1, a control device 30, a switching device 40, a fuel tank 50, a liquid oxygen tank 60, and at least three (e.g., four) landing legs 80 mounted on the outer periphery of the housing 110, which extend below the engine unit 1 as shown by the dashed lines when the rocket 100 lands vertically from the engine unit 1 side and touch down at the landing site (see Figure 1, etc.).

[0018] The engine unit 1 is a device that generates thrust for the rocket 100. The engine unit 1 of the rocket 100 of this embodiment is composed of a first engine 10 and a second engine 20. Both the first engine 10 and the second engine 20 are methane-fueled engines, and are installed so that fuel and oxidizer are supplied to them from the same fuel tank 50 and liquid oxygen tank 60 (see FIGS. 2 and 5).

[0019] The first engine 10 is an engine driven by turbopumps 12 and 13 rotated by a turbine 11. The turbopump 12 is a device for sending fuel to a combustor in the first engine 10, and the turbopump 13 is a device for sending oxygen to the combustor in the first engine 10 (see FIG. 5). The turbine 11 is rotated by combustion gases generated when fuel and oxygen are combusted, and drives the turbopumps 12 and 13 connected by a shaft 14 (see FIG. 5). In the rocket 100 of this embodiment, a single (one) first engine 10 is disposed in the center of the lower end 110L of the casing 110 (see FIGS. 2 to 4). The first engine 10 is used as a thrust device that generates thrust, particularly during ascent (takeoff).

[0020] The second engine 20 is an engine driven by turbopumps 22 and 23 rotated by an electric motor 21, and is mainly used for attitude control of the rocket 100 during landing. The turbopump 22 is a device for sending fuel to a combustor in the second engine 20, and the turbopump 23 is a device for sending oxygen to the combustor in the second engine 20 (see FIG. 5). The electric motor 21 is driven to rotate by power supplied from a battery 70 via an inverter 25, and drives the turbopumps 22 and 23 connected by a shaft 24 (see FIG. 5).

[0021] In the rocket 100 of this embodiment, four second engines 20 are evenly arranged at the four corners of the periphery of the lower end 110L of the casing 110 so as to surround the first engine 10 arranged in the center (see FIGS. 2 to 4. Note that in FIG. 4, the arrangement of each engine is shown by showing the nozzles rather than the engines themselves). An electric motor 21, turbopumps 22 and 23, and a shaft 24 are provided for each of the four second engines 20, so that the output of each of the four second engines 20 can be controlled individually (see FIG. 5).

[0022] As described above, the engine unit 1 of the rocket 100 of this embodiment has a clustered configuration of four second engines 20 and the first engine 10 arranged between them. The first engine 10 may be one that generates a thrust greater than that of the second engine 20. This first engine 10 may be used only during the ascent (takeoff) of the rocket 100, and only the second engine 20 may be used during landing. Considering that most of the propellant, which accounts for more than 90% of the weight, is consumed during launch, and the weight at landing is about one-tenth of that at launch, the engine unit 1 of this embodiment can be applied to large rockets by using a turbine-driven pump-type first engine 10 with a high thrust ratio as the engine used only during ascent.

[0023] The control device 30 is a device that controls the engine unit 1 and the like of the rocket 100. In this embodiment, the control device 30 controls the driving of each electric motor 21 connected to the second engine 20 via an inverter 25, and adjusts the thrust of each second engine 20 to control the attitude of the body (casing 110) of the rocket 100 at the time of landing (see FIG. 5, etc.). By controlling the attitude in this way, the rocket 100 is able to land vertically on a landing facility provided on the ground or ocean.

[0024] The switching device 40 is a device for switching the supply destination of oxidizer and fuel from the first engine 10 to the second engine 20, or vice versa. The switching device 40 in the engine unit 1 of this embodiment is composed of a switching valve provided in the oxidizer supply path and a switching valve provided in the fuel supply path (see FIG. 5). By using this switching device 40 to appropriately switch the supply destination of oxidizer and fuel between the first engine 10 and the second engine 20, it is possible to realize an operation such as supplying oxidizer and fuel to the first engine 10 during ascent and to the second engine 20 during landing.

[0025] The fuel tank 50 is a tank for storing fuel, such as liquefied methane, liquefied hydrogen, kerosene, etc. The liquid oxygen tank 60 is a tank for storing liquid oxygen.

[0026] According to the engine unit 1 of this embodiment or the rocket 100 equipped with it as described above, vertical landing is possible by driving the second engine 20 with an engine that has high responsiveness in thrust adjustment, i.e., the turbo pump 23 rotated by the electric motor 21, and therefore it is possible to land by controlling the landing speed with high precision.

[0027] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited to this and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the present invention is applied to a rocket 100, which is an example of a flying object, but this is merely a preferred example. In addition, the present invention can be applied to various flying objects, such as a spacecraft such as a suborbital flying object, by mounting an engine unit 1 such as that of this embodiment on the spacecraft.

[0028] Furthermore, although the term "space vehicle" has been used in the above explanation, please note that the "space vehicle" referred to here is positioned as a type of flying object. In other words, in light of the fact that the term "space" is generally defined as an altitude of 80 km or above, or 100 km or above, the rocket 100 of the above-described embodiment can be said to be a type of space vehicle. However, in terms of the essence of the present invention, the present invention is not limited to space vehicles, and can be applied to various flying objects that go close to space.

[0029] In the above embodiment, the rocket 100 is described in which one first engine 10 is disposed at the center of the lower end 110L of the casing 110 and four second engines 20 are evenly spaced around it (see FIGS. 2 to 4 ). However, this is merely one suitable example. The arrangement and number of the first engines 10 and the second engines 20 may be different. For example, there may be multiple first engines 10 and multiple second engines 20, or the first engine 10 may be disposed on the periphery of the second engine 20. Two second engines 20 may be sufficient, or in some cases, one second engine 20 may be sufficient. An example of a case in which one engine is sufficient is when the attitude of the rocket 100 can be controlled by changing the direction of the injection nozzle and controlling it in coordination with the output of the first engine 10. The switching device 40 may not only switch the supply destination of oxidizer and fuel to either the first engine 10 or the second engine 20, but also send them to both. In this case, for example, during takeoff, oxidizer and fuel are supplied not only to the first engine but also to the second engine 20, and the thrust of the second engine can be adjusted with good responsiveness and high precision to control the attitude of the rocket 100. Also, the location of the switching device 40 is not limited to the location shown in Figure 5, and for example, opening and closing switches may be provided on the inlet side of each turbopump 12, 13, 22, 23, and switching may be performed by turning these switches on and off. [Industrial Applicability]

[0030] The present invention is suitable for application to a flying object such as a rocket and its engine unit. [Explanation of symbols]

[0031] 1...Engine unit 10...1st engine 11...Turbine 12,13...Turbo pump 14...Shaft 20...Second engine (rocket engine) 21...Electric motor 22, 23...Turbo pump 24...shaft 25...Inverter 30...Control device 40...Switching device 50...Fuel tank 60...Liquid oxygen tank 70...Battery 80...landing legs 100...Rocket (aircraft) 110…Housing 110L...Bottom end of the housing

Claims

1. A flying vehicle that has a rocket engine driven by a turbopump rotated by an electric motor and can land by controlling the thrust of the rocket engine.

2. An aircraft having at least one first engine driven by a turbopump rotated by a turbine, and at least two second engines driven by the turbopumps rotated by the electric motors.

3. 3. The aircraft of claim 2, further comprising a control device that controls the driving of the electric motors of at least two of the second engines via inverters that drive the electric motors, and controls the attitude of the aircraft during landing.

4. 3. The air vehicle of claim 2, wherein the first engine is disposed in a central portion of the aft end of the air vehicle, and the second engine is disposed on a periphery of the aft end.

5. 3. The air vehicle of claim 2, further comprising a switching device for switching the supply of oxidizer and fuel from the first engine to the second engine.

6. 6. The flying vehicle according to claim 5, wherein the switching operation of the switching device supplies oxidizer and fuel to the first engine or both the first and second engines during ascent, and to the second engine during landing.

7. An engine unit of an aircraft, comprising: at least one first engine driven by a turbopump rotated by a turbine; and at least two second engines driven by turbopumps rotated by electric motors.

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