Self-pressure-stabilizing gas storage and supply bottle for satellite electric propulsion

Abstract

The invention relates to a self-pressure-stabilizing gas storage and supply cylinder for satellite electric propulsion, which comprises a gas cylinder body configured to provide a containing space for gas, the gas cylinder body is a hollow cavity with one end closed and the other end provided with a gas inlet and outlet, and the gas is conveyed to a satellite propeller through the gas inlet and outlet as a propellant; the piston assembly is configured to separate the inner cavity of the gas cylinder and move towards one end, close to the gas inlet and outlet, in the inner cavity of the gas cylinder along with consumption of the propellant so as to compensate volume change caused by consumption of the propellant and maintain stable pressure of the inner cavity of the gas cylinder; the spring assembly is configured to provide constant return thrust for the piston assembly so as to drive the piston assembly to move towards one end of the air inlet and outlet; and the sealing assembly is configured to guarantee the sealing performance of the separation of the piston assembly. Through the structure of built-in piston sealing and constant force spring volume compensation, the internal pressure of the gas cylinder is directly maintained to be 30 MPa all the time, and adjustment of an external pressure reducing valve is not needed.

Description

Technical Field

[0001] This invention relates to the field of satellite propulsion system technology, and specifically to a self-stabilizing gas storage cylinder for satellite electric propulsion. Background Technology

[0002] Satellite electric propulsion (such as xenon thrusters in electric propulsion) is a core actuator for satellite operation in orbit, and its performance directly determines the satellite's attitude control accuracy, orbit maintenance capability, and on-orbit lifespan. These types of thrusters typically require extremely low operating currents (on the order of 10⁻⁶). 6 (~10-³g / s), but it places extremely high demands on the stability of the inlet pressure, generally requiring pressure fluctuations to be less than ±0.5%.

[0003] Currently, satellite thruster storage and supply systems generally adopt the traditional scheme of "rigid gas cylinder + high-pressure reducing valve + pressure regulating valve". The reducing valve throttles and reduces the high-pressure gas in the cylinder to the target operating pressure, and the pressure regulating valve maintains a stable output pressure. However, this traditional scheme has the following inherent drawbacks: First, the pressure inside the cylinder continuously decreases as gas is consumed. While a system of "rigid gas cylinder + high-pressure reducing valve + pressure regulating valve" is commonly used, this system requires multiple components such as the reducing valve, pressure regulating valve, and filter to be connected in series, leading to an increase in pipeline joints and a significant increase in the risk of high-pressure gas leakage. Satellites in orbit have stringent requirements for leakage rate (≤1×10⁻⁶). -6 Pa·m 3 The first problem is that the pressure-reducing valve's throttling and stabilizing method is highly susceptible to flow fluctuations. Even under extremely low flow conditions, the throttling effect can easily cause pressure lag, leading to output pressure fluctuations exceeding the allowable range. Furthermore, wear of the valve core under high pressure will further reduce the stabilizing accuracy, resulting in significant accuracy degradation after long-term on-orbit operation. The second problem is that the variable volume scheme in ground industrial scenarios cannot be directly adapted to the special operating conditions of satellite thrusters with extremely low flow and long life due to problems such as dynamic response lag and thermodynamic interference. The "rigid high-pressure gas cylinder + multi-stage pressure reducing valve" architecture has two key technical shortcomings: 1) The internal pressure of the gas cylinder continuously decreases as gas is consumed, and the pressure reducing valve needs to dynamically adjust its opening to maintain the output pressure. During the adjustment process, pressure drift is easily caused by response lag and flow fluctuation, which cannot meet the high-precision pressure stabilization requirements of the thruster within ±0.5%; 2) The pressure reducing valve has pressure loss due to its throttling effect, and the wear of the valve core under high pressure will further reduce the pressure stabilization accuracy. The accuracy decays significantly after long-term operation in orbit.

[0004] To solve the above problems, the industry has tried to maintain the internal pressure stable by changing the volume of the gas cylinder, but in high pressure working condition, due to sealing, driving, thermodynamic effect and other problems, it cannot adapt to the satellite working condition, and the traditional variable volume structure has many technical bottlenecks: on the one hand, the high pressure seal slides fast, the leakage rate is high, and it cannot meet the long life requirement of 5-15 years of satellite, and high pressure sealing is difficult to realize, conventional sealing materials are prone to creep and cold flow failure under 30MPa high pressure, metal sealing requires high machining precision, and the wear of the sealing surface caused by reciprocating motion further aggravates the leakage risk; on the other hand, the power components or driving mechanisms that drive the volume change are difficult to meet the application requirements of aerospace, for example, the weight of the conventional ordinary spring is large, the constant force precision is low, the thrust fluctuation is >±5%, it is difficult to provide large thrust while considering lightweight, and the precision and fatigue life cannot match the long life operation requirements of the satellite. In addition, the variable volume scheme in the ground industrial scene cannot directly adapt to the special working condition of the satellite thruster with extremely low flow and long life due to problems such as dynamic response lag and thermodynamic effect interference.

[0005] Therefore, it has become a technical problem to be solved in the current satellite propulsion system field to develop a self-stable constant pressure output device for a gas storage and supply cylinder that can adapt to the working condition of a satellite thruster, has high stable pressure precision, high reliability and is lightweight. SUMMARY

[0006] The present application provides a self-stable pressure storage and supply cylinder for satellite electric propulsion, which directly maintains the internal pressure of the cylinder at 30MPa through the structure of built-in piston sealing and constant force spring volume compensation, and realizes the following innovations: 1) without external pressure reducing valve adjustment, the pressure fluctuation caused by internal pressure decay and dynamic adjustment is eliminated from the root, and the satellite propulsion cylinder realizes on-orbit constant pressure self-stabilization without increasing external pressure regulating components and without significantly increasing weight / volume; 2) solves the problems of pressure fluctuation and insufficient precision of the existing pressure reducing valve pressure stabilizing scheme, high complexity of the traditional system, high leakage risk, and insufficient engineering adaptability of the variable volume pressure stabilizing scheme in the aerospace scene.

[0007] The present application provides a self-stable pressure storage and supply cylinder for satellite electric propulsion, which directly maintains the internal pressure of the cylinder at 30MPa through the structure of built-in piston sealing and constant force spring volume compensation, and realizes the following innovations: 1) without external pressure reducing valve adjustment, the pressure fluctuation caused by internal pressure decay and dynamic adjustment is eliminated from the root, and the satellite propulsion cylinder realizes on-orbit constant pressure self-stabilization without increasing external pressure regulating components and without significantly increasing weight / volume; 2) solves the problems of pressure fluctuation and insufficient precision of the existing pressure reducing valve pressure stabilizing scheme, high complexity of the traditional system, high leakage risk, and insufficient engineering adaptability of the variable volume pressure stabilizing scheme in the aerospace scene. The cylinder body is configured to provide a gas containing space, the cylinder body is a hollow cavity with one end closed and the other end provided with a gas inlet and outlet, and the gas as propellant (such as xenon gas) is delivered to the satellite thruster through the gas inlet and outlet; The piston assembly is configured to separate the cylinder cavity and move towards the end close to the gas inlet and outlet in the cylinder cavity as the propellant is consumed, to compensate for the volume change caused by the consumption of the propellant and maintain the pressure stability of the cylinder cavity; The spring assembly is configured to provide a constant restoring force for the piston assembly to drive the piston assembly to move towards the end of the gas inlet and outlet; and A sealing assembly configured to ensure the sealing of the piston assembly.

[0008] Further, the piston assembly is coaxially arranged in the inner cavity of the gas cylinder body, so as to divide the inner cavity of the gas cylinder into: a first inner cavity configured to store the propellant, the first inner cavity being located at one side close to the gas inlet / outlet port; and a second inner cavity configured to provide a supplementary space for the installation and movement of the spring assembly, the second inner cavity being located at one side close to the closed end of the gas cylinder body.

[0009] Further, the piston assembly comprises: a piston body having a hollow structure, an inner cavity of the piston body being a third inner cavity configured to install the spring assembly, the third inner cavity being in communication with the second inner cavity; and a central shaft configured to provide an installation reference and rotational support for the spring assembly.

[0010] Further, the spring assembly comprises: a spring body configured to provide a constant return thrust for the piston assembly, the spring body being a volute spring, and the output constant elastic force of the spring body being matched with the pressure maintaining pressure of the gas cylinder, the volute spring structure being adopted, and the stress distribution of the volute spring being more uniform than that of a spiral spring, so as to avoid local stress overload; a passive wheel being a fixed fulcrum of the spring body and passively rotating with the spring body; a winding wheel configured to transmit the torque of the spring body, the winding wheel being a winding or releasing execution member of the spring body; an output wheel configured to convert the torque into a pulling force for driving the movement of the piston assembly; and a steel cable configured to pull the piston assembly to move in the inner cavity of the gas cylinder; the passive wheel, the winding wheel and the output wheel are collectively arranged in the third inner cavity in the form of a counter-wound constant force spring, and the counter-wound arrangement reduces the friction loss in the winding / releasing process of the spring and reduces the fatigue damage. The spring body provides a constant force, the passive wheel fixes the inner end of the spring body, the winding wheel winds or releases the spring, the output wheel converts the torque into a pulling force, and the steel cable pulls the piston assembly to move.

[0011] Further, the spring body is made of TC4 titanium alloy or stainless steel, the surface of the spring body is subjected to electrochemical polishing and passivation treatment, and the fatigue life of the spring body is ≥10 5The secondary cycle is used to meet the working requirement of the satellite in orbit for 5-15 years. The spring body is made of TC4 titanium alloy or stainless steel, which has high strength, high toughness and excellent fatigue resistance. The surface is electrochemically polished (to reduce the stress concentration of surface defects) and passivated (to form a dense oxide film and improve corrosion resistance), which significantly prolongs the fatigue life. The sealing groove is arranged on the outer circumferential surface of the piston body near the air inlet and outlet.

[0012] Further, the inner end of the spring body is welded to the passive wheel and wrapped outside the passive wheel, and the outer end of the spring body is welded to the winding wheel. The welding process (welding of the inner end and the passive wheel, and the outer end and the winding wheel) adopts laser welding, which has high weld strength and few defects, avoiding the welded part from becoming a weak point of fatigue failure.

[0013] Further, the piston assembly further comprises: The passive shaft is configured to provide a rotating support shaft for the passive wheel; the passive wheel is arranged on the passive shaft in the same plane as the winding wheel; and The winding output shaft is configured to provide a rotating support shaft for the winding wheel and the output wheel; the passive shaft and the winding output shaft are both fixed in the third inner cavity; and the winding wheel and the output wheel are coaxially arranged on the winding output shaft.

[0014] Further, the gas cylinder inner cavity is provided with a steel cable connecting support at one end near the air inlet and outlet; one end of the steel cable is fixed to the steel cable connecting support, and the other end is fixed to the output wheel.

[0015] Further, the sealing assembly comprises: The metal skeleton is configured to bear high-pressure radial load; and The rubber coating layer is wrapped outside the metal skeleton and forms a sealing lip, which is attached to the inner wall of the gas cylinder body to form a sealing surface; and / or The metal skeleton is made of titanium alloy TC4 to prevent the rubber coating layer from being squeezed into the gap under high pressure; the rubber coating layer is an irradiation-stable rubber coating layer, which can maintain its performance under a total irradiation dose of ≤1×10 5The mechanical property attenuation is less than or equal to 5% in the orbit environment of Gy, and the problems such as hardening, embrittlement, cracking and sealing failure caused by irradiation do not occur. The sealing assembly separates the first inner cavity (propellant cavity) and the third inner cavity (spring receiving cavity), avoids the leakage of propellant (such as xenon) from the propellant cavity to the spring receiving cavity, prevents the impurities in the spring receiving cavity from affecting the purity of the propellant, and ensures the normal supply of the propellant; the high-pressure radial load is borne by the metal framework to prevent the rubber coating layer from being extruded into the gap under high pressure, so that the sealing surface is always tightly fitted in the high-pressure working environment of the satellite propulsion system, and the strict requirements of long service life (5-15 years) and low leakage rate of the satellite are met.

[0016] Further, the cross section of the metal framework is in a U-shaped structure, the rubber coating layer is filled in the U-shaped structure and extends outward to form a sealing lip, and the sealing lip is in interference fit with the inner wall of the gas cylinder body.

[0017] Further, the rubber coating layer is a perfluoroether rubber coating layer. The perfluoroether rubber has excellent radiation resistance, high and low temperature resistance, and high pressure resistance, and is a special material for aerospace high pressure sealing scenes.

[0018] Further, the gas cylinder body is further wrapped with: A multi-layer insulation assembly (MLI, Multi-Layer Insulation) configured to control the temperature fluctuation of the inner cavity of the gas cylinder, limit the fluctuation range to within ±5℃, reduce the influence of the temperature change of the external orbit environment on the propellant in the cavity, and ensure the stability of the propellant state, so as to realize accurate self-stabilization of pressure in cooperation with the spring assembly and the piston assembly, and adapt to the temperature environment requirement of the satellite in orbit operation. The multi-layer insulation assembly is a core insulation structure for spacecraft / satellite in vacuum, high and low temperature alternating orbit environment, which is used to greatly reduce the radiation heat exchange and control the temperature of the equipment. The typical structure of the multi-layer insulation assembly includes an outer protective layer (Kapton film (aluminum / gold plated)), a heat insulation core layer (N layers), and an inner protective / adhesion layer (thin polyimide or polyester film), wherein the heat insulation core layer includes a reflective layer (aluminum / gold plated polyester / polyimide film (reflectivity > 90%), responsible for reflecting infrared radiation) and a spacer layer (polyester net, glass fiber paper, aerogel felt, etc., low thermal conductivity, low density, separating the reflective layer, reducing interlayer solid thermal conductivity).

[0019] Further, the gas cylinder body is made of any one of carbon fiber winding composite material, titanium alloy or stainless steel; the gas cylinder body is lined with an aluminum alloy lining, and the aluminum alloy lining is subjected to hard anodizing treatment, and the surface roughness Ra is less than or equal to 0.05μm, so as to meet the requirement of maximum stress x 1.5 ≤ yield strength of the inner wall of the gas cylinder body.

[0020] Further, the carbon fiber winding composite material is a structural material made of carbon fiber filaments and a resin matrix by a winding process, and the resin matrix is a high-temperature resistant epoxy resin.

[0021] The working principle of the present application is as follows: Based on the ideal gas state equation pV=nRT, when the satellite thruster works, the propellant (krypton / xenon) in the propellant cavity is slowly consumed, the amount of substance n of the gas decreases, and the pressure in the cavity decreases slightly; at this time, the restoring force of the constant force spring is greater than the reverse thrust of the propellant on the piston assembly, which drives the piston assembly to move slowly towards the gas cylinder port, reducing the volume V of the gas; through the precise thrust matching of the constant force spring, the volume V of the gas and the amount of substance n of the gas change synchronously in proportion, thereby maintaining the propellant cavity pressure stable at 30Mpa.

[0022] When the propellant enters the first inner cavity from the gas inlet and outlet, the pressure in the first inner cavity rapidly rises, generating a leftward thrust on the right side of the piston body, which overcomes the pre-tightening force of the spring body and moves leftward as a whole (away from the end of the gas inlet and outlet), at this time, the second inner cavity is compressed, the steel cable is lengthened, the output wheel is rotated clockwise by the steel cable, the output wheel is coaxially fixedly connected with the winding wheel, the winding wheel is synchronously rotated clockwise, the spring body is wound onto the winding wheel from the outside of the driven wheel, the spring body is wound and stored, a constant restoring force is generated, the driven wheel is passively rotated with the spring inner ring, and the sealing assembly on the outer periphery of the piston moves leftward and is always tightly attached to the inner wall of the gas cylinder, strictly isolating the propellant cavity and the spring storage cavity and preventing gas leakage; when the satellite thruster works, the propellant gas flows out from the gas inlet and outlet, the pressure in the first inner cavity decreases, the gas thrust in the first inner cavity is less than the constant force of the spring assembly, the constant restoring force of the spiral spring is released, the spring body is released from the winding wheel to the outside of the driven wheel, driving the winding wheel / output wheel to reverse, the steel cable moves the piston towards the gas inlet and outlet, and the volume of the first inner cavity is reduced to compensate for the volume of the first inner cavity, realizing self-stabilization of the pressure.

[0023] The present application cancels the series components such as pressure reducing valve, pressure stabilizing valve and filter of the traditional storage and supply system, directly realizes self-stabilization of the pressure by integrating the piston assembly and the spiral constant force spring assembly in the gas cylinder body, and realizes the energy storage when the ground is filled with high-pressure xenon gas, and the spring drives the piston to move to compensate for the gas consumption in the on-orbit working, the whole process does not need additional power components, realizes the integration of filling and pressure stabilization, simplifies the system control logic, has high self-stabilization precision of the pressure, and is suitable for extremely low flow conditions: through the precise thrust matching of the spiral constant force spring, the volume is self-adaptively adjusted in the propellant consumption process, the pressure fluctuation is ≤±0.3MPa, and the supply precision requirement of the satellite thruster mg / s level extremely low flow is completely met.

[0024] The present application has at least the following advantages: 1) the system has high integration degree and light quality: the constant force spring is arranged in an integrated structure with the propellant in the same cavity, the spring is coaxially accommodated in the hollow inner cavity of the piston, no external transmission mechanism and separate cavity structure are needed, compared with the external spring scheme, the quality is reduced by 20% to 30%, the satellite launch cost is significantly reduced, in addition, the volute constant force spring is selected as the driving mechanism, the weight is only 1 / 5 of that of the ordinary spring with the same thrust, the constant force accuracy is < ± 1%; 2) the sealing reliability is high, and the leakage risk is extremely low: the metal framework + rubber composite sealing assembly is adopted, the metal framework provides rigid support to avoid rubber extrusion failure under high pressure of 30 MPa, the rubber adopts a low-emission and radiation-resistant formula to realize high-reliability sealing with a leakage rate of ≤1*10 ⁻7 Pa·m³ / s, while ensuring smooth movement of the piston at ultra-low speed, achieving ultra-low leakage rate and wear-free sealing at micron-level slow speed; 3) the pressure self-stabilization accuracy is high, and the system is suitable for extremely low flow conditions: through precise thrust matching of the volute constant force spring, the volume is self-adaptively adjusted during propellant consumption, the pressure fluctuation is ≤±0.3 MPa, which fully meets the gas supply accuracy requirements of the satellite thruster with mg / s level extremely low flow; 4) the system has strong adaptability in orbit and long service life: the gas cylinder is wrapped with multiple thermal insulation components, and the materials are selected to be radiation-resistant and low outgassing, which can adapt to the orbital temperature fluctuation of-50℃ to +100℃ and the space radiation environment, and the in-orbit service life can reach 5 to 15 years, especially suitable for deep space exploration and other tasks that cannot be maintained in orbit; 5) the system has simple structure and high reliability: the passive pressure self-stabilization design is adopted, without complex active control and pressurization system, so that the failure points are few, and the in-orbit operation reliability can be greatly improved; 6) all downstream pressure reduction and stabilization components are cancelled, the constant pressure output is realized through the structure of the gas cylinder itself, the number of components is reduced by more than 40%, and the leakage points and system complexity are greatly reduced; through the structure of the built-in piston sealing + constant force spring volume compensation, the internal pressure of the gas cylinder is always maintained at 30 MPa without external pressure reduction valve adjustment, and the pressure fluctuation caused by internal pressure decay and dynamic adjustment is eliminated from the root. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to further illustrate the above and other advantages and features of the embodiments of the present application, more specific descriptions of the embodiments of the present application will be presented with reference to the accompanying drawings. It can be understood that these drawings only depict typical embodiments of the present application, and therefore should not be considered as limiting the scope thereof. In the drawings, the same or corresponding parts will be denoted by the same or similar reference numerals for the sake of clarity.

[0026] Figure 1 A cross-sectional schematic view of the gas cylinder after inflation in some embodiments of the present application is shown; Figure 2 A cross-sectional schematic view of the gas cylinder when there is no gas in some embodiments of the present application is shown; Figure 3 shows a cross-sectional view of a gas cylinder in some embodiments of the present application; Figure 4 shows a cross-sectional view of a gas cylinder body in some embodiments of the present application; Figure 5 shows a cross-sectional view of a piston assembly in some embodiments of the present application; Figure 6 shows a schematic view of a spring assembly in some embodiments of the present application; Figure 7 shows a schematic view of a sealing assembly in some embodiments of the present application; Reference signs: 1-gas cylinder body, 101-inlet / outlet port, 102-first inner cavity, 103-second inner cavity, 104-cable connecting support, 105-heat insulation assembly, 106-gas cylinder body inner liner, 2-piston assembly, 201-piston body, 202-passive shaft, 203-winding output shaft, 204-third inner cavity, 3-spring assembly, 301-spring body, 302-passive wheel, 303-winding wheel, 304-output wheel, 305-cable, 4-sealing assembly, 401-metal framework, 402-rubber coating layer. DETAILED DESCRIPTION

[0027] It should be noted that each component in each drawing can be exaggerated for illustration and is not necessarily to scale.

[0028] In the present application, each embodiment is merely intended to illustrate the scheme of the present application and should not be understood as limiting.

[0029] In the present application, unless specifically indicated, the quantifier "one" does not exclude the scenario of multiple elements.

[0030] It should also be noted herein that, for the sake of clarity and simplicity, only a part of components or assemblies can be shown in the embodiments of the present application, but a person of ordinary skill in the art can understand that, under the teaching of the present application, the required components or assemblies can be added according to the specific scenario as needed.

[0031] It should also be noted herein that, within the scope of the present application, the phrases "same", "equal", "equal to" and the like do not mean that the two values are absolutely equal, but allow a certain reasonable error, that is, the phrases also cover "substantially the same", "substantially equal", "substantially equal to".

[0032] It should also be noted that in the description of the present application, the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0033] In addition, the embodiments of the present application describe the process steps in a specific order, however, this is only for the convenience of distinguishing between steps, and is not limited to the order of the steps, and in different embodiments of the present application, the order of the steps can be adjusted according to the adjustment of the process.

[0034] In the following embodiments, the rubber coating layer 402 is a perfluoroether rubber coating layer 402; the carbon fiber wound composite material is a structural material made of carbon fiber filaments and a resin matrix by a "winding" process, and the resin matrix is a high-temperature resistant epoxy resin.

[0035] The following embodiments provide a self-stabilized pressure storage gas cylinder for satellite electric propulsion, comprising: The cylinder body 1 is configured to provide a gas containing space, the cylinder body 1 is a hollow cavity with one end closed and the other end provided with a gas inlet and outlet port 101, and the gas as propellant (such as xenon gas) is delivered to the satellite thruster through the gas inlet and outlet port 101; the cylinder body 1 is made of any one of carbon fiber wound composite material, titanium alloy or stainless steel; the cylinder body liner 106 is an aluminum alloy liner, which is treated by hard anodizing, and the surface roughness Ra≤0.05μm to meet the requirement that the maximum stress of the inner wall of the cylinder body 1×1.5≤yield strength; The piston assembly 2 is configured to separate the cylinder cavity and move towards the end close to the gas inlet and outlet port 101 in the cylinder cavity as the propellant is consumed, so as to compensate for the volume change caused by the consumption of the propellant and maintain the stability of the pressure in the cylinder cavity; the piston assembly 2 is coaxial with the cylinder body 1 in the cylinder cavity, so that the cylinder cavity is separated into: The first inner cavity 102 is configured to store the propellant, and the first inner cavity 102 is located close to the gas inlet and outlet port 101; and The second inner cavity 103 is configured to provide a supplementary space for the installation and action of the spring assembly 3, and the second inner cavity 103 is located close to the closed end of the gas body; the piston assembly 2 comprises: a piston body 201, which is a hollow structure, an inner cavity of the piston body 201 being a third inner cavity 204, the third inner cavity 204 being configured to mount a spring assembly 3, the third inner cavity 204 being in communication with the second inner cavity 103; and a central shaft, which is configured to provide a mounting reference and rotational support for the spring assembly 3 the spring assembly 3, which is configured to provide a constant return thrust for the piston assembly 2 to drive the piston assembly 2 to move towards one end of the gas inlet and outlet port 101; the spring assembly 3 comprises: a spring body 301, which is configured to provide a constant return thrust for the piston assembly 2, the spring body 301 being a volute spring, and outputting a constant spring force matching the pressure of the gas cylinder; the fatigue life of the spring body 301 is ≥10 5 secondary cycles to meet the working requirements of the satellite in orbit for 5-15 years; the spring body 301 is made of TC4 titanium alloy or stainless steel, and the surface of the spring body 301 is subjected to electrochemical polishing and passivation treatment; a passive wheel 302, which is a fixed fulcrum of the spring body 301 and passively rotates with the spring body 301; a winding wheel 303, which is configured to transmit the torque of the spring body 301, and is a winding or releasing executive element of the spring body 301; an output wheel 304, which is configured to convert the torque into a pulling force to drive the piston assembly 2 to move; and a steel cable 305, which is configured to pull the piston assembly 2 to move in the inner cavity of the gas cylinder; the passive wheel 302, the winding wheel 303 and the output wheel 304 are collectively arranged in the third inner cavity 204 in the form of a counter-wound constant force spring. The spring body 301 provides a constant force, the passive wheel 302 fixes the inner end of the spring body 301, the winding wheel 303 winds or releases the spring, the output wheel 304 converts the torque into a pulling force, and the steel cable 305 pulls the piston assembly 2 to move; the inner end of the spring body 301 is welded to the passive wheel 302 and is sleeved outside the passive wheel 302, and the outer end of the spring body 301 is welded to the winding wheel 303; and a sealing assembly 4, which is configured to ensure the sealing separation of the piston assembly 2, a sealing groove being formed on the outer circumferential surface of the piston body 201 close to one side of the gas inlet and outlet port 101, and the sealing assembly 4 being nested in the sealing groove; the sealing assembly 4 comprises: a metal framework 401, which is configured to bear high-pressure radial load, and the cross section of the metal framework 401 is in a U-shaped structure; and A rubber coating layer 402 is filled in the U-shaped structure and extends outward to form a sealing lip, which is in interference fit with the inner wall (inner liner 106) of the cylinder body 1 to form a sealing surface; the metal skeleton 401 is made of titanium alloy TC4 to prevent the rubber coating layer 402 from being squeezed into the gap under high pressure; the rubber coating layer 402 is a radiation-stable rubber coating layer 402, which has a mechanical property decay of ≤5% under a total radiation dose of ≤1×10 5 Gy, and does not have problems such as hardening, embrittlement, cracking, and sealing failure due to radiation. The sealing assembly 4 separates the first inner cavity 102 (propellant cavity) and the third inner cavity 204 (spring receiving cavity) to prevent propellant (such as xenon gas) from leaking from the propellant cavity to the spring receiving cavity, and to prevent impurities or environmental factors in the spring receiving cavity from affecting the purity of the propellant, thereby ensuring normal supply of the propellant; the metal skeleton 401 bears the high-pressure radial load to prevent the rubber coating layer 402 from being squeezed into the gap, thereby ensuring that the sealing surface is always tightly attached under the high-pressure working environment of the satellite propulsion system, and meeting the stringent requirements of long life (5-15 years) and low leakage rate of the satellite.

[0036] The piston assembly 2 further comprises: a passive shaft 202 configured to provide a rotating support shaft for the passive wheel 302; the passive wheel 302 is arranged on the passive shaft 202 in the same plane as the winding wheel 303; and a winding output shaft 203 configured to provide a rotating support shaft for the winding wheel 303 and the output wheel 304, the passive shaft 202 and the winding output shaft 203 are both fixedly arranged in the third inner cavity 204; the winding wheel 303 and the output wheel 304 are coaxially arranged on the winding output shaft 203.

[0037] A steel cable connecting bracket 104 is further arranged at one end of the cylinder inner cavity close to the gas inlet and outlet 101, one end of the steel cable 305 is fixed on the steel cable connecting bracket 104, and the other end is fixed on the output wheel 304 and wound around the outside of the output wheel 304; the inner diameter of the cylinder body 1 is 80 mm, and the reverse thrust of the gas on the piston assembly 2 under 30 MPa pressure is approximately 15.0796 kN, the output thrust of the constant force spring 3 is set to 15.0796 kN, and the thrust fluctuation is ±0.8%; The cylinder body 1 is further wrapped with: a multilayer thermal insulation assembly 105 configured to control the temperature fluctuation of the cylinder inner cavity to limit the fluctuation range within ±5°C, thereby reducing the influence of the temperature change of the external orbital environment on the propellant in the cavity, ensuring the stability of the propellant, and further cooperating with the spring assembly 3 and the piston assembly 2 to realize precise self-stabilization of pressure and adapt to the temperature environment requirements of the satellite in orbit.

[0038] The working process of the cylinder in this embodiment is as follows: When the ground xenon gas is filled, the xenon gas source higher than 30MPa enters the inside of the gas cylinder, when the propellant enters the first inner cavity 102 from the gas inlet and outlet 101, the pressure of the first inner cavity 102 rapidly increases, the right side of the piston body 201 generates the left pushing force, the piston body 201 moves left (far away from the end of the gas inlet and outlet 101) under the action of the gas pressure, overcomes the pre-tightening force of the spring body 301, at this time, the second inner cavity 103 is compressed, the steel cable 305 is lengthened under the pushing force and drives the output wheel 304 to rotate clockwise, the output wheel 304 is coaxially fixedly connected with the winding wheel 303, the winding wheel 303 synchronously rotates clockwise, the volute spring body 301 on the driven wheel is wound, at the same time, the spring body 301 forms the constant force spring force and drives the driven wheel 302 to rotate counterclockwise, until the gas filling amount of the gas cylinder reaches the specified mass, the ground gas filling is completed, the sealing assembly 4 on the outer periphery of the piston moves left, is always tightly attached to the inner wall of the gas cylinder, strictly isolates the propellant cavity and the spring storage cavity, and prevents the gas leakage; when the satellite propeller works, the xenon gas in the gas cylinder is slowly consumed, the pressure slightly decreases, that is, the propellant gas flows out from the gas inlet and outlet 101, the pressure of the first inner cavity 102 decreases, the gas pushing force of the first inner cavity 102 is less than the constant force of the spring assembly 3 (the force of the gas in the gas cylinder on the piston assembly 2 is lower than the spring force generated by the volute constant force spring body 301), the driven wheel 302 starts to tighten the volute constant force spring body 301 clockwise, drives the winding wheel 303 to rotate counterclockwise, and the coaxial output wheel 304 starts to rotate counterclockwise and winds the steel cable 305 at the same time, the steel cable 305 pulls the piston assembly 2 to move to the direction of the gas inlet and outlet 101, the piston assembly 2 moves to the steel cable connecting support 104 of the gas cylinder body 1 at the speed of μm / d, the volume of the first inner cavity 102 decreases, so as to compensate the volume of the first inner cavity 102, realizes the self-stabilization of the pressure: according to the ideal gas state equation pV=nRT, when the amount of substance n of the gas decreases, the pressure in the cavity slightly decreases, at this time, the gas volume V is reduced, the gas volume V and the amount of substance n change synchronously in proportion, so that the pressure in the gas cylinder is stably maintained at 30MPa.

[0039] Although some embodiments of the present application have been described in the present application, those skilled in the art can understand that these embodiments are only shown as examples. Those skilled in the art can think of numerous variants, alternatives and improvements under the teaching of the present application without going beyond the scope of the present application. The appended claims aim to limit the scope of the present application, and thereby cover the methods and structures within the scope of the claims themselves and their equivalent transformations.

Claims

1. A self-regulating pressure storage and supply gas cylinder for satellite electric propulsion, characterized in that, include: The gas cylinder body is configured to provide a space for containing gas. The gas cylinder body is a hollow cavity with one end closed and the other end provided with an inlet and outlet. The gas is used as a propellant and is delivered to the satellite thruster through the inlet and outlet. A piston assembly is configured to divide the cylinder cavity and move towards the end closer to the inlet / outlet as propellant is consumed, in order to compensate for the volume change caused by propellant consumption and maintain stable pressure in the cylinder cavity. A spring assembly configured to provide a constant restoring thrust to the piston assembly to drive the piston assembly toward one end of the inlet / outlet port; and A sealing assembly configured to ensure the sealing of the piston assembly partition.

2. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 1, characterized in that, The piston assembly is coaxially disposed within the gas cylinder cavity with the gas cylinder body, thereby dividing the gas cylinder cavity into: A first inner cavity, configured to store the propellant, is located on the side near the air inlet / outlet. as well as The second inner cavity, configured to provide supplemental space for the installation and operation of the spring assembly, is located on the side near the closed end of the gas body.

3. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 1, characterized in that, The piston assembly includes: A piston body, which is a hollow structure, has an inner cavity that is a third inner cavity configured to mount the spring assembly; and A central shaft is configured to provide a mounting reference and rotational support for the spring assembly.

4. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 3, characterized in that, The spring assembly includes: A spring body, configured to provide a constant restoring thrust to the piston assembly, wherein the spring body is a spiral spring and outputs a constant elastic force matching the cylinder's stabilizing pressure; The passive wheel is a fixed fulcrum of the spring body and rotates passively with the spring body. A take-up reel is configured to transmit the torque of the spring body; An output wheel, configured to convert the torque into a pulling force that drives the piston assembly to move; and A steel cable is configured to pull the piston assembly to move within the cylinder cavity; the driven wheel, winding wheel, and output wheel are arranged together in the third cavity in the form of a reverse-winding constant force spring.

5. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 4, characterized in that, The spring body is made of TC4 titanium alloy or stainless steel, and the surface of the spring body is electrochemically polished and passivated; and / or A sealing groove is provided on the outer peripheral surface of the piston body, near the air inlet and outlet, and the sealing assembly is nested in the sealing groove.

6. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 4, characterized in that, The piston assembly also includes: A passive shaft configured to provide a rotational support shaft for the passive wheel; the passive wheel is arranged on the passive shaft and remains in the same plane as the take-up reel; and A take-up output shaft is configured to provide rotational support for the take-up reel and the output reel, both the passive shaft and the take-up output shaft being fixed within the third inner cavity; the take-up reel and the output reel are coaxially arranged on the take-up output shaft.

7. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 4, characterized in that, A steel cable connecting bracket is also provided at one end of the inner cavity of the gas cylinder, near the inlet and outlet. One end of the steel cable is fixed to the steel cable connecting bracket, and the other end is fixed to the output wheel.

8. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 1, characterized in that, The sealing assembly includes: A metal frame, configured to withstand radial loads; and A rubber overlay layer, which covers the outside of the metal frame and forms a sealing lip, adheres to the inner wall of the gas cylinder body to form a sealing surface; and / or The metal skeleton is made of titanium alloy TC4; the rubber coating is an irradiation-stable rubber coating.

9. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 1, characterized in that, The gas cylinder body is also encased in: Multi-layer insulation components are configured to control temperature fluctuations within the gas cylinder cavity.

10. The self-regulating pressure storage and supply gas cylinder for satellite electric propulsion according to claim 1, characterized in that, The gas cylinder body is made of any one of carbon fiber wound composite material, titanium alloy or stainless steel; the inner lining of the gas cylinder body is an aluminum alloy lining, which is hard anodized and has a surface roughness Ra≤0.05μm to meet the requirement that the maximum stress on the inner wall of the gas cylinder body ×1.5≤yield strength.

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