Hydrogen pressurization equipment applied to low-altitude flight field

Abstract

The utility model relates to hydrogen pressurization technical field especially, more specifically relates to a kind of hydrogen pressurization equipment applied to low altitude flight field, including, planet outer rotor motor, cam box, cam and cylinder.The utility model realizes radial transmission by adopting planet outer rotor motor cooperation cam, and planet outer rotor motor volume is smaller compared to traditional motor, while there is no crankshaft and connecting rod component, reduce the space of hydrogen pressurization equipment whole occupancy, and reduce the equipment whole weight, while integrating first-stage compression cavity and secondary compression cavity in a cylinder, reduce intermediate connecting piece, improve the anti-vibration performance of hydrogen pressurization equipment, and make the operation of cylinder more reliable and stable, it is connected through standardization bolt between cam box, planet outer rotor motor and cylinder, there is no welding structure, disassembly is easy, it is convenient to maintain;And adopt hierarchical pressurization structure, compared to traditional single-stage compression energy consumption reduction;More suitable for low altitude flight field equipment.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen pressurization technology, and in particular to a hydrogen pressurization device for use in low-altitude flight. Background Technology

[0002] In the field of low-altitude flight, the triangular demand for "lightweight, long endurance, and high stability" in power assistance systems for small drones and light manned aircraft is becoming increasingly prominent. Hydrogen, as a zero-carbon clean energy source, has a much higher energy density than lithium batteries, making it one of the core energy solutions for addressing the short endurance limitations of low-altitude aircraft. However, the storage and use of hydrogen requires specific pressure conditions: existing hydrogen storage tanks for low-altitude aircraft typically use a low pressure of 22MPa to balance weight and safety, while power systems such as hydrogen fuel cells require a high pressure of 35MPa hydrogen input. Therefore, hydrogen-powered low-altitude aircraft need to be equipped with corresponding hydrogen pressurization equipment for power replenishment during use. To ensure the flexible use of low-altitude aircraft, they usually need to be transported by vehicle, but hydrogen pressurization equipment is large and heavy, making it unsuitable for transporting along with the aircraft.

[0003] Traditional booster equipment typically employs a combination of motor, crankshaft, and single-stage piston, resulting in dispersed components and numerous connections, making it unsuitable for vehicle transport. Furthermore, traditional booster equipment uses a constant-speed asynchronous motor, operating at full power regardless of the required pressure. Additionally, traditional booster equipment contains easily damaged components such as crankshafts, connecting rods, and flywheels, requiring high assembly precision and disassembling more than 10 connecting parts for maintenance. Moreover, the crankshaft and connecting rod connections are prone to loosening under vibration during transport, posing a safety hazard. Therefore, a hydrogen booster equipment specifically designed for low-altitude flight that is "small in size, low in energy consumption, simple in structure, and vibration-resistant" has become a key technological bottleneck in promoting the industrialization of hydrogen-powered low-altitude aircraft. Utility Model Content

[0004] Therefore, this utility model provides a hydrogen booster device for use in low-altitude flight, in order to solve the problems of existing booster devices being large in size, high in energy consumption, and difficult to adapt to the low-altitude flight field.

[0005] To achieve the above objectives, this utility model provides a hydrogen pressurization device for low-altitude flight, comprising a planetary external rotor motor, a cam box, a cam, and a cylinder; The cam is located inside the cam box. The cam includes a shaft and two round wheels eccentrically mounted on the shaft. The phase angle between the two round wheels is 180°. The planetary external rotor motor is located on one side of the cam box, and its output shaft extends into the cam box and is connected to the shaft with a key. The cylinder is connected to a protruding guide on the top surface of the cam box. The cylinder is equipped with a primary compression chamber and a secondary compression chamber. One end of the primary piston rod is inserted into the primary compression chamber, and the other end of the primary piston rod passes through the guide and contacts one of the round wheels in the cam box. One end of the secondary piston rod is inserted into the secondary compression chamber, and the other end of the secondary piston rod passes through the guide and contacts another round wheel in the cam box. The planetary external rotor motor is used to drive the cam to rotate, so that the two wheels respectively drive the first-stage piston rod and the second-stage piston rod to perform alternating reciprocating linear motion.

[0006] Furthermore, a first-stage intake valve, a first-stage exhaust valve, a second-stage intake valve, and a second-stage exhaust valve are provided on the outside of the cylinder. The first-stage intake valve and the first-stage exhaust valve are connected to the first-stage compression chamber, the second-stage intake valve and the second-stage exhaust valve are connected to the second-stage compression chamber, and the first-stage exhaust valve and the second-stage intake valve are located on the same side and connected to each other through an external air pipe.

[0007] Furthermore, the guide section is provided with a primary guide cavity and a secondary guide cavity. The primary guide cavity and the secondary guide cavity are used to accommodate the primary piston rod and the secondary piston rod respectively and to provide radial limiting guidance. Both the primary guide cavity and the secondary guide cavity are cylindrical chambers and are connected to the interior of the cam box.

[0008] Furthermore, both the primary and secondary compression chambers are cylindrical chambers, with the volume of the primary compression chamber being larger than that of the secondary compression chamber.

[0009] Furthermore, one end of the first-stage piston rod is configured as a rod body, and the other end is configured as a rod head. The end face of the rod body is a plane, and the end face of the rod head is a curved surface. The curved surface contacts the eccentrically positioned circular wheel on the cam.

[0010] Furthermore, the end of the first-stage piston rod is provided with several grooves, and a Ster seal ring is fitted inside the grooves.

[0011] Furthermore, the secondary piston rod is configured in the same way as the primary piston rod.

[0012] Furthermore, a primary return spring is fitted onto the rod body of the primary piston rod. One end of the primary return spring abuts against the rod head of the primary piston rod, and the other end abuts against the cylinder end face. The primary return spring is used to reset the primary piston rod. A secondary return spring is fitted onto the rod body of the secondary piston rod, and the secondary return spring is set in the same way as the primary return spring.

[0013] Furthermore, a first bearing and a second bearing are respectively sleeved at both ends of the shaft, and the cam is fixed in the cam box through the first bearing and the second bearing; The first bearing is fixed in the bearing groove of the first small end cover, which is bolted to one side wall of the cam box; the second bearing is fixed in the bearing groove of the second small end cover, which is bolted to the large end cover, which is bolted to the other side wall of the cam box.

[0014] Furthermore, one side wall of the cam box is configured as a side end cover, which is bolted to the cam box.

[0015] Compared with existing technologies, the advantages of this invention are as follows: by using a planetary external rotor motor in conjunction with a cam to achieve radial transmission, the planetary external rotor motor is smaller in size than traditional motors, and it eliminates crankshaft and connecting rod components, reducing the overall space occupied by the hydrogen booster equipment and lowering its overall weight. Furthermore, by integrating the primary and secondary compression chambers into a single cylinder, it reduces intermediate connecting parts, improves the vibration resistance of the hydrogen booster equipment, and makes the cylinder operation more reliable and stable. The cam box, planetary external rotor motor, and cylinder are all connected by standardized bolts, eliminating welding structures and facilitating disassembly and maintenance. Moreover, the staged booster structure reduces energy consumption compared to traditional single-stage compression, making it more suitable for use in low-altitude flight applications. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural diagram of the hydrogen booster device in this embodiment; Figure 2 This is a three-dimensional structural schematic diagram of the hydrogen booster device in this embodiment; Figure 3 This is a front view schematic diagram of the hydrogen booster device in this embodiment; Figure 4 This is a right-side structural schematic diagram of the hydrogen booster device in this embodiment; Figure 5 This is a schematic diagram of the left-hand structure of the hydrogen booster device in this embodiment; Figure 6 This is an exploded structural diagram of the cam box in this embodiment.

[0017] Reference numerals: 1. Planetary external rotor motor; 2. Cam box; 201. Guide section; 202. First-stage guide cavity; 203. Second-stage guide cavity; 204. First bearing; 205. Second bearing; 206. First small end cover; 207. Second small end cover; 208. Large end cover; 209. Side end cover; 3. Cam; 301. Shaft; 302. Gear; 4. Cylinder; 401. First-stage compression cavity; 402. Second-stage compression cavity; 403. First-stage intake valve; 404. First-stage exhaust valve; 405. Second-stage intake valve; 406. Second-stage exhaust valve; 501. First-stage piston rod; 502. Second-stage piston rod; 601. First-stage return spring; 602. Second-stage return spring. Detailed Implementation

[0018] To make the objectives and advantages of this utility model clearer, the utility model will be further described below with reference to the embodiments; it should be understood that the specific embodiments described herein are only for explaining this utility model and are not intended to limit this utility model.

[0019] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0020] It should be noted that in the description of this utility model, the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this utility model.

[0021] Furthermore, it should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] Please see Figure 1 As shown, this embodiment provides a hydrogen pressurization device for use in low-altitude flight. Includes a planetary external rotor motor 1, a cam box 2, a cam 3, and a cylinder 4; The planetary external rotor motor 1 serves as the power drive core of the hydrogen pressurization equipment. It is located on one side of the cam box 2 and fixed by bolts. The output shaft of the planetary external rotor motor 1 extends into the cam box 2. A cam 3 is horizontally arranged inside the cam box 2. The cam 3 includes a shaft 301 and two round wheels 302 eccentrically arranged on the shaft 301. A first bearing 204 and a second bearing 205 are respectively sleeved at both ends of the shaft 301. The cam 3 is fixed inside the cam box 2 by the first bearing 204 and the second bearing 205. Both the first small end cover 206 and the second small end cover 207 have bearing grooves on their inner walls. The first bearing 204 is fixed in the bearing groove of the first small end cover 206, and the first small end cover 206 is bolted to one side wall of the cam box 2. The second bearing 205 is fixed in the bearing groove of the second small end cover 207, and the second small end cover 207 is bolted to the large end cover 208, and the large end cover 208 is bolted to the other side wall of the cam box 2.

[0023] A side end cover 209 is also provided on the front side of the cam box 2. The side end cover 209 is connected to the cam box 2 by bolts. The side end cover 209 can be removed by removing the bolts, which facilitates the internal maintenance and repair of the equipment.

[0024] The output shaft of the planetary external rotor motor 1 is connected to one end of the shaft 301 by a key, enabling the planetary external rotor motor 1 to drive the cam 3 to rotate; A protruding guide portion 201 is provided on the top surface of the cam box 2, and the guide portion 201 is connected to the cylinder 4; The guide section 201 is provided with a primary guide cavity 202 and a secondary guide cavity 203. Both the primary guide cavity 202 and the secondary guide cavity 203 are cylindrical chambers, and the cylindrical chambers are connected to the interior of the cam box 2. The cylinder 4 is provided with a primary compression chamber 401 and a secondary compression chamber 402. Both the primary compression chamber 401 and the secondary compression chamber 402 are cylindrical chambers, and the chamber volume of the primary compression chamber 401 is larger than the chamber volume of the secondary compression chamber 402. The primary guide cavity 202 corresponds to the primary compression cavity 401, and the cross-sectional area of ​​the primary guide cavity 202 is greater than that of the primary compression cavity 401. The secondary guide cavity 203 corresponds to the secondary compression cavity 402, and the cross-sectional area of ​​the secondary guide cavity 203 is greater than that of the secondary compression cavity 402. A primary piston rod 501 is provided in the primary compression chamber 401. One end of the primary piston rod 501 is a rod body, and the other end is a rod head. The end face of the rod body is a plane, and the end face of the rod head is a curved surface. One end of the rod body of the primary piston rod 501 extends into the primary compression chamber 401, and one end of the rod head of the primary piston rod 501 passes through the primary guide chamber 202 and contacts the eccentrically arranged circular wheel 302 on the cam 3. A secondary piston rod 502 is provided in the secondary compression chamber 402, and the arrangement of the secondary piston rod 502 is the same as that of the primary piston rod 501. The two eccentrically mounted circular wheels 302 on the cam 3 have a phase angle of 180°. When the cam 3 rotates, the two circular wheels 302 respectively push the first-stage piston rod 501 and the second-stage piston rod 502 to perform alternating reciprocating linear motion. A primary intake valve 403, a primary exhaust valve 404, a secondary intake valve 405, and a secondary exhaust valve 406 are provided on the outside of cylinder 4. The primary intake valve 403 and the primary exhaust valve 404 are connected to the primary compression chamber 401, the secondary intake valve 405 and the secondary exhaust valve 406 are connected to the secondary compression chamber 402, and the primary exhaust valve 404 and the secondary intake valve 405 are located on the same side and are connected by an external air pipe.

[0025] The first-stage intake valve 403, the first-stage exhaust valve 404, the second-stage intake valve 405, and the second-stage exhaust valve 406 are all equipped with valve copper gaskets at the connection points with the cylinder 4. The copper gaskets have good plasticity and can produce slight deformation when the valves are tightened, thus achieving a gapless seal.

[0026] A primary return spring 601 is fitted on the rod body of the primary piston rod 501. One end of the primary return spring 601 abuts against the rod head of the primary piston rod 501, and the other end abuts against the end face of the cylinder 4. It is used to reset the primary piston rod 501. When the cam 3 rotates to the non-pushing end, the primary return spring 601 pushes the primary piston rod 501 to reset with the rotation of the cam 3. Several grooves are also provided at the end of the rod body of the primary piston rod 501, and a Ster seal ring is fitted in the groove.

[0027] A secondary return spring 602 is sleeved on the rod body of the secondary piston rod 502. The secondary return spring 602 is set in the same way as the primary return spring 601.

[0028] In this embodiment, the hydrogen booster equipment adopts a modular design with an overall rectangular structure. It is connected by standardized bolts, eliminating redundant connecting parts. A planetary external rotor motor 1, coupled with a cam 3, drives the system, replacing the crankshaft and connecting rod method of traditional asynchronous motors, reducing vulnerable parts by 50%. The booster unit is the core component for compressing hydrogen from 22 MPa to 35 MPa. It employs a "two-stage series booster chamber" structure to reduce the single-stage compression ratio. The first-stage compression ratio is 1.27:1, and the second-stage compression ratio is 1.25:1, reducing energy consumption and component wear. The specific structure and component parameter relationships are as follows. Cylinder 4 is the carrier of the booster chamber. It is made of 316L stainless steel, which is resistant to hydrogen corrosion. The surface is electrolytically polished and the roughness Ra≤0.8μm. It has two independent chambers along the axial direction: primary compression chamber 401 and secondary compression chamber 402.

[0029] The first-stage piston rod 501 and the second-stage piston rod 502 are slidably disposed in the first-stage compression chamber 401 and the second-stage compression chamber 402, respectively. The piston rods are made of lightweight high-strength alloy with a density of 7.75 g / cm³, a tensile strength ≥735 MPa, and a weight of 1.2 kg each. The piston head diameter of the first-stage piston rod 501 is 30 mm, and the piston head diameter of the second-stage piston rod 502 is 28 mm. The clearance between the piston rod and the inner wall of the cylinder 4 is 0.02-0.03 mm.

[0030] A Sterling seal is provided between the first-stage piston rod 501, the second-stage piston rod 502 and the inner wall of the cylinder 4. The seal is made of polytetrafluoroethylene modified material with a hydrogen permeability resistance ≤1×10⁻⁶. -11 cm 3 / (cm s Pa), and wear resistance life ≥ 5000 hours.

[0031] The top of cylinder 4 has four valve ports.

[0032] Furthermore, the hydrogen booster device in this embodiment can be equipped with a gas passage control component during use to achieve directional flow of hydrogen, pressure stabilization, and on-demand speed adjustment. Combined with sensors and a processor, it forms a closed-loop control. The specific structure and component relationships are as follows: The vehicle-mounted hydrogen storage tank interface is connected to the first-stage intake valve 403 through the input gas guide channel, and the aircraft's power system interface is connected to the second-stage exhaust valve 406 through the output gas guide channel. The pressure sensor is installed on the inner wall of the power system interface to collect the output pressure in real time and transmit the data to the processor through a shielded wire; A flow sensor is installed in the output gas guide channel to collect hydrogen flow rate, with a range of 0-50 L / min, to help determine the power system requirements.

[0033] In this embodiment, the processor has a built-in "pressure-speed control matrix", as shown in Table 1. Based on the feedback value of the pressure sensor, the speed of the planetary external rotor motor 1 is adjusted with an adjustment accuracy of ±5 r / min. A pressure regulating valve is connected in series in the output gas guide channel and electrically connected to the processor. When the output pressure exceeds 35.1MPa, the valve automatically opens to release pressure; when it is below 34.9MPa, the valve closes to increase pressure, ensuring that the pressure is stable at 35±0.1MPa.

[0034] Table 1: Pressure-Speed ​​Control Matrix

[0035] In addition, appropriate mounting brackets should be set up according to the actual situation for stable connection between the hydrogen pressurization equipment and the transport equipment. Rubber vibration damping pads should be installed between the mounting brackets and the hydrogen pressurization equipment and the transport equipment to absorb vibration energy and reduce the overall vibration of the hydrogen pressurization equipment during transport.

[0036] The working process of the hydrogen booster equipment in this embodiment is divided into five stages: start-up, primary compression, secondary compression, output pressure stabilization, and shutdown. The entire process is automated and closed-loop controlled. After the hydrogen booster is powered on, the external power system or hydrogen fuel cell sends a "boost demand signal" (requiring 35MPa hydrogen) to the processor. The processor initializes the pressure sensor and flow sensor, acquires the initial pressure (usually atmospheric pressure, 0.1MPa), and determines whether full-load startup is required. The processor sends a speed command of "200 r / min" to start the planetary external rotor motor 1. The motor output shaft drives the cam 3 to rotate at a speed of "200 r / min".

[0037] The rotation of cam 3 pushes the first-stage piston rod 501 to move linearly in the axial direction of the first-stage compression chamber 401. The first-stage intake valve 403 opens automatically under the pressure difference between the hydrogen storage bottle and the first-stage compression chamber 401, and the low-pressure hydrogen in the hydrogen storage bottle enters the first-stage compression chamber 401. When the first-stage piston rod 501 reaches the end of its stroke, the pressure in the first-stage compression chamber 401 rises to 28 MPa (compression ratio 1.27:1). At this time, the first-stage intake valve 403 closes under high pressure, and the first-stage exhaust valve 404 opens under pressure difference. Hydrogen gas at 28 MPa enters the inlet of the second-stage intake valve 405 through the first-stage exhaust valve 404, completing the first-stage compression.

[0038] At the same time, the rotation of cam 3 pushes the secondary piston rod 502 to move axially towards the primary compression chamber 401, and the secondary intake valve 405 automatically opens under the action of pressure difference; When the secondary piston rod 502 reaches the end of its stroke, the pressure in the secondary compression chamber 402 rises to 35 MPa (compression ratio 1.25:1). At this time, the secondary intake valve 405 closes and the secondary exhaust valve 406 opens. The 35 MPa high-pressure hydrogen enters the output gas guide channel through the secondary exhaust valve 406. The pressure sensor collects the pressure signal and feeds it back to the processor.

[0039] The processor receives the pressure signal from the pressure sensor, queries the speed control matrix, adjusts the motor speed accordingly, and enters a stable operating state.

[0040] The pressure regulating valve adjusts its opening degree according to the real-time pressure and ensures pressure stability by controlling the resistance in the passage.

[0041] After the aircraft has completed pressurization, it sends a stop pressurization signal to the processor; The processor reduces the motor speed to 100 r / min and maintains it for 30 seconds to purge the hydrogen from the passage, and then shuts off the motor.

[0042] The hydrogen booster device in this embodiment uses a planetary external rotor motor 1 + cam 3 for transmission, with a volume only 60% of that of a traditional motor. It also eliminates the crankshaft and connecting rod, reducing the component volume by 30%. The primary compression chamber 401 and the secondary compression chamber 402 are integrated into a single cylinder 4, reducing intermediate connecting parts. All components are connected by standardized bolts, with no welding structure, making disassembly convenient and maintenance easy. Furthermore, the staged booster structure reduces energy consumption by 40% compared to traditional single-stage compression (1.59:1). With its advantages of small size, low energy consumption, simple structure, and low maintenance difficulty, the hydrogen booster device in this embodiment is suitable for low-altitude flight, enabling it to be specially equipped with aircraft, carried and transported, and providing hydrogen booster power supplementation to aircraft anytime and anywhere.

[0043] The technical solution of this utility model has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the protection scope of this utility model is obviously not limited to these specific embodiments. Without departing from the principle of this utility model, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this utility model.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A hydrogen pressurization device for use in low-altitude flight, characterized in that, This includes a planetary external rotor motor, a cam box, cams, and cylinders; The cam is disposed inside the cam box. The cam includes a shaft and two round wheels eccentrically disposed on the shaft. The phase angle between the two round wheels is 180°. The planetary external rotor motor is located on one side of the cam box, and its output shaft extends into the cam box and is connected to the shaft with a key. The cylinder is connected to a protruding guide portion on the top surface of the cam box. The cylinder is provided with a primary compression chamber and a secondary compression chamber. One end of a primary piston rod is inserted into the primary compression chamber, and the other end of the primary piston rod passes through the guide portion and contacts one of the round wheels in the cam box. One end of a secondary piston rod is inserted into the secondary compression chamber, and the other end of the secondary piston rod passes through the guide portion and contacts another round wheel in the cam box. The planetary external rotor motor is used to drive the cam to rotate, so that the two wheels respectively push the first-stage piston rod and the second-stage piston rod to perform alternating reciprocating linear motion.

2. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, The cylinder is provided with a first-stage intake valve, a first-stage exhaust valve, a second-stage intake valve, and a second-stage exhaust valve. The first-stage intake valve and the first-stage exhaust valve are connected to the first-stage compression chamber, and the second-stage intake valve and the second-stage exhaust valve are connected to the second-stage compression chamber. The first-stage exhaust valve and the second-stage intake valve are located on the same side and are connected by an external air pipe.

3. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, The guide section is provided with a primary guide cavity and a secondary guide cavity. The primary guide cavity and the secondary guide cavity are respectively used to accommodate the primary piston rod and the secondary piston rod and to provide radial limiting and guidance. Both the primary guide cavity and the secondary guide cavity are cylindrical chambers and are connected to the interior of the cam box.

4. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, Both the primary compression chamber and the secondary compression chamber are cylindrical chambers, wherein the volume of the primary compression chamber is larger than that of the secondary compression chamber.

5. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, One end of the first-stage piston rod is configured as a rod body, and the other end is configured as a rod head. The end face of the rod body is a plane, and the end face of the rod head is a curved surface. The curved surface contacts the eccentrically mounted circular wheel on the cam.

6. The hydrogen pressurization device for low-altitude flight as described in claim 5, characterized in that, The end of the first-stage piston rod is also provided with several grooves, and a Ster seal ring is fitted inside the grooves.

7. The hydrogen pressurization device for low-altitude flight as described in claim 6, characterized in that, The secondary piston rod is configured in the same way as the primary piston rod.

8. The hydrogen pressurization device for low-altitude flight as described in claim 5, characterized in that, A primary return spring is fitted onto the rod body of the primary piston rod. One end of the primary return spring abuts against the rod head of the primary piston rod, and the other end abuts against the cylinder end face. The primary return spring is used to reset the primary piston rod. A secondary return spring is fitted onto the rod body of the secondary piston rod. The secondary return spring is configured in the same way as the primary return spring.

9. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, The shaft is fitted with a first bearing and a second bearing at both ends, and the cam is fixed in the cam box by the first bearing and the second bearing. The first bearing is fixed in the bearing groove of the first small end cover, which is bolted to one side wall of the cam box; the second bearing is fixed in the bearing groove of the second small end cover, which is bolted to the large end cover, which is bolted to the other side wall of the cam box.

10. The hydrogen pressurization device for low-altitude flight as described in claim 1, characterized in that, One side wall of the cam box is configured as a side end cover, which is bolted to the cam box.

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