A device and method for realizing rocket structure weight reduction by utilizing shaftless electric pump pre-pressurization

Abstract

This application provides a device and method for reducing the weight of a rocket structure by using a shaftless electric pump for pre-pressurization, relating to the field of aerospace launch vehicle propulsion systems. The device includes a liquid oxygen tank located at the front of the second stage of the rocket body for storing liquid oxygen propellant; a fuel tank located after the liquid oxygen tank for storing liquid fuel; a liquid oxygen shaftless electric pump located at the outlet of the liquid oxygen tank and connected to a first main engine circuit; a fuel shaftless electric pump located at the outlet of the fuel tank and connected to a second main engine circuit; main engine circuits one and two are used to deliver the pressurized propellant to the combustion chamber; and a control system electrically connected to the liquid oxygen and fuel shaftless electric pumps. This application reduces the pressure and gravity of the tanks, eliminating the complex high-pressure self-pressurization system or significantly reducing the amount of high-pressure helium cylinders carried, thereby achieving overall weight reduction of the rocket's second-stage structure in terms of both the tanks and the pressurization system, effectively improving launch efficiency.

Description

Technical Field

[0001] This invention relates to the field of aerospace launch vehicle propulsion systems, and more specifically, to a device and method for reducing the weight of a rocket structure by using a shaftless electric pump for pre-pressurization. Background Technology

[0002] With the continuous development of aerospace technology, the design requirements for launch vehicles are becoming increasingly stringent, especially in terms of payload capacity and lightweight rocket structure. Payload capacity directly affects the economics and launch costs of a rocket, making improving payload capacity a key objective. To achieve this goal, lightweight design of each stage of the rocket structure is particularly important.

[0003] In existing technologies, traditional rocket designs typically require liquid oxygen and fuel tanks to have high pressure resistance (usually maintained at 0.4~0.5 MPa) to ensure stable engine startup and sufficient net positive intake head (NPSH). This necessitates a significant increase in tank wall thickness, increasing the rocket's structural mass. Furthermore, maintaining such high pressure necessitates the use of numerous high-pressure booster cylinders, further increasing dead weight and severely reducing the rocket's payload capacity.

[0004] Another existing solution is to use a traditional electric pump for propellant pressurization. However, traditional electric pump systems typically employ a design where the motor and impeller are separate, with pressurization achieved by driving the impeller through a long shaft. This design has significant drawbacks: first, the pump body is bulky, occupying valuable onboard space; second, the separation of the motor and impeller leads to a complex system structure, requiring traditional bearing mechanisms and complex sealing systems, resulting in large installation requirements and a heavy pump body; and third, traditional electric pump systems often cannot balance high flow rates with lightweight design, making it difficult to meet the design requirements of next-generation miniaturized and reusable launch vehicles.

[0005] Therefore, the existing solutions have not effectively solved the problem of excessive weight in the second-stage rocket propellant tank structure, and have drawbacks such as system complexity, large size, and low energy efficiency. There is an urgent need for a new technical solution that can reduce the weight of the rocket structure while ensuring stable pressurization of liquid oxygen and fuel, thereby improving the rocket's payload capacity. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for reducing the weight of rocket structures by using a shaftless electric pump for pre-pressurization, which solves the problem of large wall thickness and heavy structure of rocket second-stage propellant tanks due to high pressure requirements in the prior art.

[0007] The application is as follows:

[0008] A device for reducing rocket structural weight by pre-pressurizing with a shaftless electric pump, comprising: The second-stage rocket body includes a liquid oxygen tank, a fuel tank, a liquid oxygen shaftless electric pump, a fuel shaftless electric pump, engine main line one, engine main line two, and a combustion chamber; The liquid oxygen tank is located at the front of the second-stage rocket body and is used to store liquid oxygen propellant. The fuel storage tank, located after the liquid oxygen storage tank, is used to store liquid fuel; A liquid oxygen shaftless electric pump is installed at the outlet of the liquid oxygen storage tank and connected to the main engine pipeline. A shaftless electric fuel pump is installed at the outlet of the fuel tank and connected to the second main engine circuit. Engine main pipe one and engine main pipe two are used to deliver the pressurized propellant to the combustion chamber respectively; The control system is electrically connected to the liquid oxygen shaftless electric pump and the fuel shaftless electric pump. Both the liquid oxygen shaftless electric pump and the fuel shaftless electric pump adopt an embedded high-speed brushless motor structure, in which the rotor directly drives the impeller to rotate, eliminating the traditional bearing mechanism and forming a compact integrated pump body structure. The control system is used to control the liquid oxygen shaftless electric pump and the fuel shaftless electric pump to start in advance for pre-pressurization before rocket launch and to run continuously during engine operation, so as to maintain the liquid oxygen tank and the fuel tank in a low-pressure operating state.

[0009] As a preferred technical solution of this application, the liquid oxygen storage tank and the fuel storage tank are made of high-strength aluminum-lithium alloy, and the working pressure is stably maintained at 0.1–0.15 MPa. The tank wall thickness is 60%–70% of the wall thickness of a traditional self-pressurized storage tank.

[0010] As a preferred technical solution of this application, the liquid oxygen shaftless electric pump and the fuel shaftless electric pump are powered by a dedicated lithium battery pack for the second stage of the rocket, and both are equipped with redundant motor controllers and cryogenic thermal control protection systems, enabling them to operate stably under extreme conditions of high altitude and low temperature.

[0011] As a preferred technical solution of this application, the control system independently controls the liquid oxygen shaftless electric pump and the fuel shaftless electric pump through PWM regulation, so as to realize adaptive flow regulation and anti-cavitation protection.

[0012] As a preferred technical solution of this application, the housing packaging material of the liquid oxygen shaftless electric pump and the fuel shaftless electric pump is a lightweight titanium alloy or carbon fiber composite material.

[0013] As a preferred technical solution of this application, both the liquid oxygen shaftless electric pump and the fuel shaftless electric pump adopt a modular design and are detachably integrated into the pipeline system between the liquid oxygen storage tank and the engine main pipeline one, and the fuel storage tank and the engine main pipeline two.

[0014] A method for reducing rocket structural weight using a shaftless electric pump for pre-pressurization, comprising the following steps: S1: During the rocket launch preparation phase, the control system receives control signals and controls the liquid oxygen shaftless electric pump and the fuel shaftless electric pump to start in advance, respectively pre-pressurizing the liquid oxygen output from the liquid oxygen tank and the fuel output from the fuel tank, so that the engine inlet pressure meets the starting requirements. S2: After the engine starts, the liquid oxygen shaftless electric pump and the fuel shaftless electric pump continue to operate, dynamically adapting the boost output according to the propellant consumption rate and thrust changes, so that the internal pressure of the liquid oxygen tank and the fuel tank is always maintained within the set low pressure range. S3: During the operation of the liquid oxygen storage tank and the fuel storage tank in a low-pressure state, the control system adjusts the operating status of the liquid oxygen shaftless electric pump and the fuel shaftless electric pump through independent PWM signals to adapt to different flow requirements and suppress cavitation. By reducing the structural pressure requirements of the liquid oxygen tank and fuel tank through the above steps, it is possible to reduce the thickness of the tank walls and the number of supporting pressurization cylinders, thereby achieving an overall weight reduction of the rocket's second-stage structure.

[0015] As a preferred technical solution of this application, in step S2, the set low pressure range is specifically 0.1~0.15MPa or 0.2 MPa. By reducing the tank pressure from 0.4~0.5 MPa of the traditional self-pressurizing system to the low pressure range, the tank wall thickness is reduced to 60%~70% of the original system wall thickness.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: In the scheme of this application: 1. By reducing the working pressure of the propellant tank from 0.4~0.5 MPa to 0.1~0.15 MPa, the tank wall thickness can be reduced by 30%-40%. Simultaneously, the complex high-pressure self-pressurization system can be eliminated or the carrying capacity of high-pressure helium cylinders can be significantly reduced, thereby achieving overall weight reduction of the rocket's second-stage structure in both the propellant tank and pressurization system aspects, effectively improving launch efficiency. The shaftless electric pump is directly driven by a motor, resulting in a fast response speed. The PWM-controlled electric pump can adjust the output pressure and flow rate in real time and precisely, quickly following changes in engine thrust, achieving active and adaptive matching of propellant supply pressure and flow rate.

[0017] 2. The shaftless electric pump eliminates the need for easily damaged mechanical bearings and dynamic seals, resulting in a simple and compact structure. It avoids the challenges of low-temperature lubrication and has inherently higher reliability. The use of redundant controllers and low-temperature thermal control design further enhances its robustness in extreme rocket environments. The "electric pump + control system" replaces traditional complex components such as gas pressurization pipelines, pressure reducing valves, and gas generators, simplifying the propulsion system architecture. Attached Figure Description

[0018] Figure 1 A cross-sectional structural schematic diagram of a device for reducing rocket structure weight by pre-pressurizing with a shaftless electric pump, provided for this application; Figure 2 This application provides a schematic diagram of a device system for reducing the weight of a rocket structure by pre-pressurizing with a shaftless electric pump.

[0019] The image shows: 1. Second stage rocket body; 11. Liquid oxygen tank; 12. Fuel tank; 13. Liquid oxygen shaftless electric pump; 14. Fuel shaftless electric pump; 15. Engine main pipeline one; 16. Combustion chamber; 17. Engine main pipeline two; 2. Control system; 21. Redundant motor controller; 22. Low temperature thermal protection system. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely illustrates some embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. These terms are only for the convenience of describing this invention and simplifying the description, and do not 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 invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Please see Figures 1 to 2 The present invention provides a technical solution: a device and method for reducing the weight of a rocket structure by pre-pressurizing with a shaftless electric pump, comprising a second-stage rocket body 1, which includes a liquid oxygen tank 11, a fuel tank 12, a liquid oxygen shaftless electric pump 13, a fuel shaftless electric pump 14, an engine main pipeline 15, an engine main pipeline 2 17, and a combustion chamber 16. Liquid oxygen tank 11 is located at the front of the second-stage rocket body 1 and is used to store liquid oxygen propellant; Fuel tank 12, located after liquid oxygen tank 11, is used to store liquid fuel; The liquid oxygen shaftless electric pump 13 is located at the outlet of the liquid oxygen storage tank 11 and connected to the engine main pipeline 15. A shaftless electric fuel pump 14 is installed at the outlet of the fuel tank 12 and connected to the engine main pipeline 17. Engine main pipe 15 and engine main pipe 217 are used to deliver the pressurized propellant to the combustion chamber 16 respectively. Control system 2 is electrically connected to liquid oxygen shaftless electric pump 13 and fuel shaftless electric pump 14; Both the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 adopt an embedded high-speed brushless motor structure, which directly drives the impeller to rotate by the rotor, omitting the traditional bearing mechanism and forming a compact integrated pump body structure. The control system 2 is used to control the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 to start in advance for pre-pressurization before rocket launch and to run continuously during engine operation, so as to maintain the liquid oxygen tank 11 and the fuel tank 12 in a low-pressure working state.

[0026] As a preferred embodiment, based on the above method, the liquid oxygen storage tank 11 and the fuel storage tank 12 are further made of high-strength aluminum-lithium alloy, the working pressure is stably maintained at 0.1–0.15 MPa, and the tank wall thickness is 60%–70% of the wall thickness of a traditional self-pressurized storage tank.

[0027] The liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 are powered by a dedicated lithium battery pack for the second stage of the rocket. Both are equipped with a redundant motor controller 21 and a cryogenic thermal control protection system 22, enabling them to operate stably under extreme conditions of high altitude and low temperature.

[0028] As a preferred embodiment, based on the above method, the control system further controls the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 independently through PWM regulation to achieve adaptive flow regulation and anti-cavitation protection. The outer casing of the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 is made of lightweight titanium alloy or carbon fiber composite material.

[0029] Both the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 adopt a modular design and are detachably integrated into the piping system between the liquid oxygen tank 11 and the engine main line 15, and between the fuel tank 12 and the engine main line 2 17.

[0030] After liquid oxygen flows out from the bottom of the liquid oxygen storage tank 11, it directly enters the inlet of the shaftless electric pump. The motor stator is energized to generate a rotating magnetic field, which drives the rotor with impeller to suspend and rotate in the liquid oxygen. Under the action of centrifugal force, the liquid oxygen is thrown out of the impeller. After being pressurized, it flows to the combustion chamber 16 through the engine main pipeline 15. This integrated "rotor + impeller" bearingless design eliminates mechanical friction loss and complex shaft seal structure, making the pump body volume more than 50% smaller than that of traditional electric pumps, significantly reducing weight, and fundamentally eliminating the risk of propellant leakage, greatly improving the system's compactness and layout flexibility.

[0031] During rocket flight, there is no need to fill the propellant tank with a large amount of high-pressure gas to push the propellant, as is the case with traditional rockets. Only a very small amount of helium is needed to maintain a positive pressure of 0.1 MPa to prevent the propellant from boiling or cavitation. The main pressure increase of the propellant is completed entirely by the shaftless electric pump. Because the tank pressure requirement drops sharply from the traditional 0.4~0.5 MPa to 0.1~0.2 MPa, the shell thickness of the tank can be designed according to the low-pressure vessel standard. The wall thickness can be safely reduced to 60%-70% of the original system, which greatly reduces the structural weight of the tank. At the same time, the number of supporting high-pressure helium cylinders can be reduced by more than 4 times, achieving the "ultimate slimming" of the rocket's second-stage structure.

[0032] A method for reducing rocket structural weight using a shaftless electric pump for pre-pressurization, comprising the following steps: S1: During the rocket launch preparation phase, the control system receives a control signal and controls the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 to start in advance, respectively pre-pressurizing the liquid oxygen output from the liquid oxygen tank 11 and the fuel output from the fuel tank 12, so that the engine inlet pressure meets the starting requirements. S2: After the engine starts, the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 continue to operate, dynamically adapting the boost output according to the propellant consumption rate and thrust changes, so that the internal pressure of the liquid oxygen tank 11 and the fuel tank 12 is always maintained within the set low pressure range. S3: During the operation of the liquid oxygen storage tank 11 and the fuel storage tank 12 under low pressure, the control system 2 adjusts the operating status of the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 through independent PWM signals to adapt to different flow requirements and suppress cavitation. By reducing the structural pressure requirements of the liquid oxygen tank 11 and the fuel tank 12 through the above steps, the tank wall thickness can be reduced and the number of supporting pressurization cylinders can be reduced, thereby achieving an overall weight reduction of the rocket's second-stage structure.

[0033] As a preferred embodiment, based on the above method, in step S2, the set low pressure range is specifically 0.1~0.15 MPa or 0.2 MPa. By reducing the tank pressure from 0.4~0.5 MPa of the conventional self-pressurizing system to the low pressure range, the tank wall thickness is reduced to 60%~70% of the original system wall thickness.

[0034] Operating steps: a. When the engine is operating with variable thrust, the control system 2 collects engine thrust commands and flow meter feedback data in real time; b. Control system 2 calculates and outputs two independent PWM signals to dynamically adjust the speed of the two shaftless electric pumps; c. When a sudden increase in propellant flow or an inlet pressure close to saturated vapor pressure is detected, the control system rapidly increases the PWM duty cycle and pump speed to increase head and suppress cavitation.

[0035] Dual-pump independent PWM regulation enables precise control of the liquid oxygen and fuel mixture ratio; combined with the thermal control protection system, it ensures that the electric pump will not fail due to overcooling under extreme high-altitude conditions such as vacuum and extremely low temperatures; the anti-cavitation control strategy with early intervention ensures absolute stability during engine start-up and all-time operation.

[0036] Specifically, the device and method for reducing rocket structural weight by pre-pressurizing with a shaftless electric pump includes the following complete operating procedure: Phase 1 (Pre-launch pressurization): The control system receives the pre-ignition command, and the liquid oxygen shaftless electric pump 13 and the fuel shaftless electric pump 14 start a few seconds in advance. The rotation of the shaftless pumps pressurizes the propellant in the pipeline, causing the pressure of liquid oxygen and fuel at the inlet of combustion chamber 16 to rise rapidly, exceeding the engine start-up pressure threshold, and achieving smooth engine ignition.

[0037] Phase Two (Low-Pressure Maintenance in Main Stage Operation): After successful engine ignition, the main thrust phase begins. At this time, the shaftless electric pump operates continuously at full speed or as needed, acting as an "active source of propellant suction." Because the pump's suction effect is far greater than the thrust effect of the small air pressure inside the tanks, the liquid oxygen tank 11 and fuel tank 12 are maintained at a low pressure of 0.1–0.15 MPa. Propellant is continuously pumped into the combustion chamber.

[0038] The third stage (coasting and shutdown): Upon receiving the shutdown command, the control system cuts off the power supply to the electric pump, the pump stops working, the pipeline valves are closed, and the second-level working cycle is completed.

[0039] Taking a small liquid-fueled launch vehicle as an example, its second-stage oxygen tank has a volume of 12.54 cubic meters, and its fuel tank has a volume of 7.95 cubic meters.

[0040] In the traditional approach: if the tank pressure is 0.5 MPa, 20 standard 40L, 25°C, 13.0 MPa helium cylinders are required, each weighing approximately 15KG, with the accompanying piping weighing approximately 5KG, for a total cylinder system weight of approximately 400KG; the rocket tank itself weighs 660KG.

[0041] After adopting the solution of this invention: the tank pressure is reduced to 0.2 MPa, the demand for helium cylinders is reduced sharply to 8, and the cylinder system weight is reduced by 160KG; due to the reduced pressure, the tank wall thickness is reduced by 30%, and the tank weight is reduced to 440KG, a weight reduction of 220KG. These two items alone directly reduce the weight by 380KG.

[0042] Reducing the weight of the rocket's second stage by 380 kg can be directly converted into an increase in payload capacity of approximately 280 kg. Based on current commercial space launch market prices, the service fee for each kilogram of low Earth orbit payload capacity is approximately 35,000 to 40,000 yuan. The increase of 280 kg in payload capacity directly generates a single-launch economic benefit of approximately 10 million yuan, demonstrating extremely high engineering application value.

[0043] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described herein. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the specific embodiments described above. Therefore, any modifications or equivalent substitutions to the present invention, as well as all technical solutions and improvements that do not depart from the spirit and scope of the invention, are covered within the scope of the claims of the present invention.

Claims

1. A device for reducing the weight of a rocket structure by pre-pressurizing with a shaftless electric pump, characterized in that, include: The second-stage rocket body (1) includes a liquid oxygen tank (11), a fuel tank (12), a liquid oxygen shaftless electric pump (13), a fuel shaftless electric pump (14), an engine main line one (15), an engine main line two (17), and a combustion chamber (16). A liquid oxygen storage tank (11) is located at the front of the second-stage rocket body (1) and is used to store liquid oxygen propellant; A fuel storage tank (12) is disposed after the liquid oxygen storage tank (11) and is used to store liquid fuel; A liquid oxygen shaftless electric pump (13) is installed at the outlet of the liquid oxygen storage tank (11) and connected to the engine main pipeline (15); A shaftless fuel pump (14) is installed at the outlet of the fuel tank (12) and connected to the engine main pipeline (17); Engine main line one (15) and engine main line two (17) are used to deliver the pressurized propellant to the combustion chamber (16) respectively. The control system (2) is electrically connected to the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14); Both the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) adopt an embedded high-speed brushless motor structure, which directly drives the impeller to rotate by the rotor, omitting the traditional bearing mechanism and forming a compact integrated pump body structure. The control system (2) is used to control the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) to start in advance for pre-pressurization before rocket launch and to run continuously during engine operation so that the liquid oxygen tank (11) and the fuel tank (12) are kept in a low-pressure working state.

2. The device for reducing rocket structural weight using a shaftless electric pump pre-pressurization according to claim 1, characterized in that, The liquid oxygen tank (11) and the fuel tank (12) are made of high-strength aluminum-lithium alloy, and the working pressure is stably maintained at 0.1–0.15 MPa. The tank wall thickness is 60%–70% of the wall thickness of a traditional self-pressurized tank.

3. The device for reducing rocket structural weight using a shaftless electric pump pre-pressurization according to claim 1, characterized in that, The liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) are powered by a dedicated lithium battery pack for the second stage of the rocket. Both are equipped with a redundant motor controller (21) and a cryogenic thermal control protection system (22), enabling them to operate stably under extreme conditions of high altitude and low temperature.

4. The device for reducing rocket structural weight by pre-pressurizing with a shaftless electric pump according to claim 3, characterized in that, The control system independently controls the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) through PWM regulation, so as to realize adaptive flow regulation and anti-cavitation protection.

5. The device for reducing rocket structural weight using a shaftless electric pump pre-pressurization according to claim 1, characterized in that, The housing of the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) is made of lightweight titanium alloy or carbon fiber composite material.

6. The device for reducing rocket structural weight using a shaftless electric pump pre-pressurization according to claim 1, characterized in that, Both the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) adopt a modular design and are detachably integrated into the pipeline system between the liquid oxygen tank (11) and the engine main pipeline one (15), and the fuel tank (12) and the engine main pipeline two (17).

7. A method for reducing rocket structural weight using a shaftless electric pump pre-pressurization, based on the device for reducing rocket structural weight using a shaftless electric pump pre-pressurization as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: During the rocket launch preparation phase, the control system receives control signals and controls the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) to start in advance, respectively pre-pressurizing the liquid oxygen output from the liquid oxygen tank (11) and the fuel output from the fuel tank (12) so that the engine inlet pressure meets the starting requirements. S2: After the engine is started, the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) continue to operate, dynamically adapting the boost output according to the propellant consumption rate and thrust change, so that the internal pressure of the liquid oxygen tank (11) and the fuel tank (12) is always maintained within the set low pressure range. S3: During the operation of the liquid oxygen tank (11) and the fuel tank (12) under low pressure, the control system (2) adjusts the operating status of the liquid oxygen shaftless electric pump (13) and the fuel shaftless electric pump (14) through independent PWM signals to adapt to different flow requirements and suppress cavitation. By reducing the structural pressure requirements of the liquid oxygen tank (11) and fuel tank (12) through the above steps, the tank wall thickness can be reduced and the number of supporting pressurized gas cylinders can be reduced, thereby achieving an overall weight reduction of the rocket's second-stage structure.

8. A method for reducing rocket structural weight using a shaftless electric pump pre-pressurization according to claim 7, characterized in that, In step S2, the set low pressure range is specifically 0.1~0.15 MPa or 0.2 MPa. By reducing the tank pressure from 0.4~0.5 MPa in the traditional self-pressurizing system to the low pressure range, the tank wall thickness is reduced to 60%~70% of the original system wall thickness.

Images