阅读说明：本技术 一种用于液体火箭发动机的轴封装置 (Shaft seal device for liquid rocket engine ) 是由 周磊 李健 陈巍 钟明磊 王小雨 方欢 王涛峰 黄峰 张方 陈泽 刘洋 徐亚兴 于 2021-01-07 设计创作，主要内容包括：本申请涉及一种用于液体火箭发动机的轴封装置,涉及发动机轴封技术领域。本轴封装置包括安装座、第一密封模块和第二密封模块,安装座内设有一用于套设电机转子的通孔,第一密封模块嵌设于通孔内,第一密封模块用于在电机转子与通孔之间形成密封,以阻止推进剂进入电机腔室,第二密封模块设于安装座上且位于第一密封模块的下游,第二密封模块用于在电机转子与通孔之间形成气动密封,同时用于将进入第二密封模块内的推进剂引流至安装座外,以辅助第一密封模块共同阻止推进剂进入电机腔室。本申请提供的轴封装置,能够满足火箭发动机电动泵低泄漏甚至零泄漏的要求,防漏性能好,且结构简单、空间紧凑、造价成本低。(The application relates to a shaft seal device for a liquid rocket engine, and relates to the technical field of engine shaft seals. This shaft seal device includes the mount pad, first sealing module and second sealing module, be equipped with a through-hole that is used for the cover to establish electric motor rotor in the mount pad, first sealing module inlays and locates in the through-hole, first sealing module is used for forming sealedly between electric motor rotor and through-hole, in order to prevent the propellant to get into the motor cavity, second sealing module locates on the mount pad and is located first sealing module's low reaches, second sealing module is used for forming pneumatic seal between electric motor rotor and through-hole, be used for simultaneously with getting into outside the propellant drainage in the second sealing module to the mount pad, in order to assist first sealing module to prevent the propellant to get into the motor cavity jointly. The shaft seal device provided by the application can meet the requirements of low leakage and even zero leakage of the electric pump of the rocket engine, has good leakage-proof performance, and has the advantages of simple structure, compact space and low manufacturing cost.)

1. A shaft seal arrangement for a liquid rocket engine, comprising:

the mounting seat (1) is internally provided with a through hole (10) for sleeving the motor rotor (2);

a first sealing module embedded in the through hole (10) for forming a seal between the motor rotor (2) and the through hole (10) to prevent propellant from entering the motor chamber;

a second sealing module located on the mounting (1) and downstream of the first sealing module, the second sealing module being configured to form a pneumatic seal between the motor rotor (2) and the through-hole (10) and, at the same time, to direct propellant entering the second sealing module out of the mounting (1) to assist the first sealing module in preventing the propellant from entering the motor chamber.

2. The shaft seal apparatus for a liquid rocket engine according to claim 1 wherein said first sealing module comprises:

the first sealing assembly (30) is embedded in the inner wall of the through hole (10), the first sealing assembly (30) is used for forming a seal between the motor rotor (2) and the through hole (10) and depressurizing the propellant entering the through hole (10) so as to gasify part of the propellant entering the through hole (10);

and the second sealing assembly comprises at least one second sealing element (31), the second sealing element (31) is embedded in the inner wall of the through hole (10) and is arranged at the downstream of the first sealing assembly (30), and the second sealing assembly is used for forming sealing between the motor rotor (2) and the through hole (10) and depressurizing the propellant entering the through hole (10) again.

3. A shaft seal arrangement for a liquid rocket engine according to claim 2, wherein: first seal assembly (30) are the annular, and are close to the interval is equipped with two at least decompression groove (32) on the medial surface of motor rotor (2), decompression groove (32) are used for the process the propellant steps down.

4. A shaft seal arrangement for a liquid rocket engine according to claim 2, wherein: the second sealing element (31) is close to the inner side face of the motor rotor (2) and is provided with at least one elastic sheet (33), and the elastic sheet (33) is used for being in interference fit with the motor rotor (2) and bending towards the direction of the first sealing assembly (30) so as to form sealing between the motor rotor (2) and the through hole (10).

5. A shaft seal arrangement for a liquid rocket engine according to claim 4, wherein: the number of the elastic pieces (33) on each second sealing piece (31) is 2, the two elastic pieces (33) are arranged at intervals, and the interference is 0.1-0.2 mm, so that sealing is formed between the motor rotor (2) and the through hole (10), and the propellant entering the through hole (10) is depressurized again.

6. A shaft seal arrangement for a liquid rocket engine according to claim 2, wherein: the quantity of second sealing member (31) is 2, two be equipped with between second sealing member (31) one with mount pad (1) and first seal assembly (30) all link to each other retaining ring (34), retaining ring (34) are close to one side of motor rotor (2) is used for the subsides to be located on motor rotor (2) to cut off two second sealing member (31).

7. A shaft seal arrangement for a liquid rocket engine according to claim 6, wherein: and a leakage-proof gasket (34) is arranged between the check ring (34) and the mounting seat (1), and the check ring (34), the mounting seat (1) and the first sealing assembly (30) are connected through bolts.

8. A shaft seal arrangement for a liquid rocket engine according to claim 2, wherein said second sealing module comprises:

an air inlet channel (40) comprising a first air inlet and a first air outlet, wherein the first air inlet is used for being connected with air blowing equipment;

an outlet channel (41) comprising a second inlet and a second outlet;

seal channel, it includes along the direction interval of keeping away from second sealing member (31) locate first seal groove (42) and second seal groove (43) of through-hole (10) inner wall, first seal groove (42) and second seal groove (43) and the equal UNICOM of second air inlet, second seal groove (43) and first gas outlet UNICOM for be used for form pneumatic seal between motor rotor (2) and through-hole (10), will get into simultaneously in the first seal groove (42) the propellant drainage extremely outside the second gas outlet.

9. A shaft seal arrangement for a liquid rocket engine according to claim 8, wherein: the second sealing groove (43) is located at the downstream of the first sealing groove (42), and the first sealing groove (42) and the second sealing groove (43) are both annular or rectangular.

10. A shaft seal arrangement for a liquid rocket engine according to claim 8, wherein: and the gas introduced into the first air inlet is inert gas, and the pressure of the inert gas is 0.2-0.5 MPa.

Technical Field

The application relates to the technical field of engine shaft seals, in particular to a shaft seal device for a liquid rocket engine.

Background

At present, a propellant conveying mode is an important component of a spacecraft propulsion system, the type of the propellant conveying mode determines the structure and parameters of the spacecraft and the whole propulsion system of the spacecraft to a great extent, and the traditional propellant supply modes of a liquid two-component propulsion system generally comprise a pumping mode and a squeezing mode. Compared with a propulsion system with large thrust and high specific impulse, a propellant storage tank and a pressurized gas cylinder in the extrusion type supply system need to bear high pressure, so that the structural mass of the extrusion type supply system is larger; the pump-type system relies on a pump to pressurize the propellant, thus greatly reducing the structural mass and design cost of the propellant storage tank and pressurized gas cylinder.

In the correlation technique, the pumping pressure formula system can be divided into turbopump supply system and electric pump supply system, and wherein, the turbopump structure is relatively more complicated, and it is great to make the assembly degree of difficulty, and the development cost is high, the cycle length, and under the comparison, the electric pump supply system has with low costs, and system architecture is simple, and the operation is reliable, easily adjusts advantages such as control, the modularization of being convenient for. Particularly, with the high-speed development of motor and battery technologies, the propellant is supplied by the electric pump, so that the motor-driven high-speed propellant supply device has more and more obvious advantages and has wide application prospects in the field of commercial aerospace.

In the electric pump supply system, the electric pump drives the pump through high speed motor and carries out the pressurization to the propellant, and high speed motor carries out work under the coexistent condition of propellant and high-tension electricity, and still involve high-speed and microthermal operating condition, and operational environment is abominable, if the propellant leaks to the cavity of motor, then produces the accident of burning explosion very easily, consequently, the reliability of electric pump axial seal structure is the important factor that restricts the safe and stable operation of electric pump system. At present, an axial dynamic sealing structure commonly used in a liquid rocket engine is a mechanical sealing device, the sealing effect is good, however, the problems of complex structure, large size, high cost and difficult later maintenance exist, and the further popularization and use of the axial dynamic sealing structure are limited to a great extent.

Disclosure of Invention

The embodiment of the application provides a shaft seal device for a liquid rocket engine, and aims to solve the problems of complex structure, large size and high cost of the shaft seal device for the liquid rocket engine in the related technology.

The present application provides a shaft seal arrangement for a liquid rocket engine, comprising:

the mounting seat is internally provided with a through hole for sleeving the motor rotor;

the first sealing module is embedded in the through hole and is used for forming sealing between the motor rotor and the through hole so as to prevent propellant from entering a motor cavity;

and the second sealing module is arranged on the mounting seat and positioned at the downstream of the first sealing module, is used for forming pneumatic sealing between the motor rotor and the through hole and is simultaneously used for guiding the propellant entering the second sealing module to the outside of the mounting seat so as to assist the first sealing module in preventing the propellant from entering the motor cavity.

In some embodiments, the first sealing module comprises:

the first sealing assembly is embedded in the inner wall of the through hole and is used for forming sealing between the motor rotor and the through hole and depressurizing the propellant entering the through hole so as to gasify part of the propellant entering the through hole;

and the second sealing assembly comprises at least one second sealing element, the second sealing element is embedded in the inner wall of the through hole and arranged at the downstream of the first sealing assembly, and the second sealing assembly is used for forming sealing between the motor rotor and the through hole and reducing the pressure of the propellant entering the through hole again.

In some embodiments, the first sealing assembly is annular, and at least two pressure reduction grooves are arranged on the inner side surface close to the motor rotor at intervals and used for reducing the pressure of the propellant passing through the pressure reduction grooves.

In some embodiments, at least one elastic sheet is disposed on an inner side surface of the second sealing member close to the motor rotor, and the elastic sheet is configured to be in interference fit with the motor rotor and bend towards the first sealing assembly, so as to form a seal between the motor rotor and the through hole.

In some embodiments, the number of the elastic pieces on each second sealing element is 2, the two elastic pieces are arranged at intervals, and the interference is 0.1-0.2 mm, so that the sealing is formed between the motor rotor and the through hole, and the propellant entering the through hole is depressurized again.

In some embodiments, the number of the second sealing elements is 2, a retainer ring connected to both the mounting seat and the first sealing assembly is disposed between the two second sealing elements, and one side of the retainer ring, which is close to the motor rotor, is used for being attached to the motor rotor to separate the two second sealing elements.

In some embodiments, a leak-proof gasket is arranged between the retainer ring and the mounting seat, and the retainer ring, the mounting seat and the first sealing assembly are connected through bolts.

In some embodiments, the second sealing module comprises:

the air inlet channel comprises a first air inlet and a first air outlet, and the first air inlet is used for being connected with air blowing equipment;

an air outlet channel comprising a second air inlet and a second air outlet;

and the sealing channel comprises a first sealing groove and a second sealing groove which are arranged at intervals along the direction far away from the second sealing element, the first sealing groove is communicated with the second sealing groove and the second air inlet, the second sealing groove is communicated with the first air outlet so as to be used for forming pneumatic sealing between the motor rotor and the through hole, and simultaneously, the propellant in the first sealing groove is drained to the outside of the second air outlet.

In some embodiments, the second seal groove is located downstream of the first seal groove, and the first and second seal grooves are both annular or rectangular.

In some embodiments, the gas introduced into the first gas inlet is an inert gas, and the pressure of the inert gas is 0.2-0.5 MPa.

The beneficial effect that technical scheme that this application provided brought includes:

the embodiment of the application provides a shaft seal device for a liquid rocket engine, because be provided with a through-hole that is used for the cover to establish electric motor rotor on the mount pad to interval sets up first sealing module and second sealing module in proper order on the through-hole, wherein, first sealing module is used for forming sealedly between electric motor rotor and through-hole, and second sealing module is used for forming pneumatic seal between electric motor rotor and through-hole, is used for simultaneously leading the propellant that gets into in the second sealing module outside the mount pad, prevents propellant entering motor cavity jointly with supplementary first sealing module. This shaft seal device adopts the sealed form of first sealed module and the sealed module combination of second, plays sealed effect and prevents that propellant from getting into the basis of motor cavity, can also form pneumatic seal simultaneously through the air current with propellant drainage to the mount pad outside, sealed leak protection is effectual, and simple structure, space are compact, the cost is with low costs.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic cross-sectional view of a shaft seal arrangement for a liquid rocket engine provided in an embodiment of the present application;

fig. 2 is a schematic diagram of the leakage flow trend of the propellant for the shaft seal device of the liquid rocket engine provided by the embodiment of the application.

In the figure: 1-a mounting seat, 10-a through hole, 2-a motor rotor, 30-a first sealing assembly, 31-a second sealing element, 32-a decompression groove, 33-an elastic sheet, 34-a retainer ring, 40-an air inlet channel, 41-an air outlet channel, 42-a first sealing groove and 43-a second sealing groove.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a shaft seal device for a liquid rocket engine, which can solve the problems of complex structure, large size and high cost of the shaft seal device for the liquid rocket engine in the related technology.

Referring to fig. 1, the shaft sealing device comprises a mounting base 1, a first sealing module and a second sealing module, a through hole 10 used for sleeving a motor rotor 2 is formed in the mounting base 1, the first sealing module is embedded in the through hole 10 and used for forming sealing between the motor rotor 2 and the through hole 10 so as to prevent propellant from entering a motor cavity, the second sealing module is arranged on the mounting base 1 and located at the downstream of the first sealing module, the second sealing module is used for forming pneumatic sealing between the motor rotor 2 and the through hole 10 and simultaneously used for guiding the propellant entering the second sealing module to the outside of the mounting base 1 so as to assist the first sealing module to prevent the propellant from entering the motor cavity, the propellant and the motor cavity are isolated, and safe operation of a motor is guaranteed.

Further, the first sealing module specifically comprises a first sealing assembly 30 and a second sealing assembly, wherein the first sealing assembly 30 is embedded in the inner wall of the through hole 10, the first sealing assembly 30 is mainly used for forming sealing between the motor rotor 2 and the through hole 10, and depressurizing propellant entering the through hole 10 to gasify part of propellant entering the through hole 10; the second sealing assembly comprises at least one second sealing element 31, the second sealing element 31 is also embedded in the inner wall of the through hole 10 and is arranged at the downstream of the first sealing assembly 30, namely, if the propellant enters the shaft sealing device, the propellant passes through the first sealing assembly 30 and then passes through the second sealing element 31, the second sealing assembly is mainly used for forming sealing between the motor rotor 2 and the through hole 10, if the propellant leaks, the propellant entering the through hole 10 can be depressurized again by the second sealing assembly, and the rest propellant is further gasified.

Further, from structural design's angle, first seal assembly 30 is the annular, and is close to motor rotor 2's medial surface on the interval be equipped with two at least decompression grooves 32, and decompression groove 32 sets up along the direction interval distribution of the flow direction of propellant, mainly used steps down the propellant that passes through, is clearance fit between first seal assembly 30, mount pad 1 and the motor rotor 2, and the clearance is at 0.1mm ~ 0.3 mm. The sealing and pressure reducing principle of the first sealing assembly 30 is as follows: the first sealing assembly 30 comprises a plurality of pressure reduction grooves 32, the first sealing assembly 30 is in clearance fit with the motor rotor, the pressure reduction grooves 32 and the motor rotor 2 form a series of throttling clearances and expansion spaces, and propellant fluid generates large resistance through multiple throttling and expansion, so that the sealing purpose is achieved.

Furthermore, at least one elastic sheet 33 is disposed on an inner side surface of the second sealing member 31 close to the motor rotor 2, and the elastic sheet 33 is configured to be in interference fit with the motor rotor 2 and bend towards the first sealing assembly 30, so as to form a seal between the motor rotor 2 and the through hole 10. There is a certain clearance space between each second seal 31 and the rotor 2 of the motor, and when the propellant flows through, the propellant is further depressurized in the same way.

Furthermore, the number of the elastic pieces 33 on each second sealing element 31 is 2, the two elastic pieces 33 are arranged at intervals, and the interference is 0.1-0.2 mm, so that a seal is formed between the motor rotor 2 and the through hole 10, and the propellant entering the through hole 10 is depressurized again through the gap. The second sealing member 31 is made of tetrafluoroethylene and a metal sheet by a die pressing process.

Furthermore, from the perspective of structural design, the number of the second sealing members 31 is 2, a retaining ring 34 connected to the mounting base 1 and the first sealing assembly 30 is disposed between the two second sealing members 31, and one side of the retaining ring 34 close to the motor rotor 2 is used for being attached to the motor rotor 2 to separate the two second sealing members 31, thereby further ensuring the sealing effect of the shaft sealing device.

Furthermore, because spare part is more, and all belong to metal parts, consequently, in order to prevent that the propellant from taking place to leak from other positions, still be equipped with leak protection gasket 34 between retaining ring 34 and mount pad 1, then link to each other through the bolt between retaining ring 34, mount pad 1 and the first seal assembly 30, firm in connection, it is all more convenient to dismantle the installation.

Further, as shown in fig. 2, the second sealing module specifically includes an air inlet channel 40, an air outlet channel 41 and a sealing channel, where the air inlet channel 40 includes a first air inlet and a first air outlet, the first air inlet is mainly used to connect with an air blowing device, the air outlet channel 41 includes a second air inlet and a second air outlet, the sealing channel includes a first sealing groove 42 and a second sealing groove 43 that are arranged on the inner wall of the through hole 10 at intervals along a direction away from the second sealing member 31, the first sealing groove 42 is communicated with both the second sealing groove 43 and the second air inlet, and the second sealing groove 43 is communicated with the first air outlet to form a pneumatic seal between the motor rotor 2 and the through hole 10, and simultaneously, the propellant entering the first sealing groove 42 is guided out of the second air outlet.

Further, the diameter of the second sealing groove 43 is larger than that of the first sealing groove 42, the second sealing groove 43 is located at the downstream of the first sealing groove 42, so that the propellant is blown into the first sealing groove 42 while the airflow has a tendency of flowing back to form sealing, and the first sealing groove 42 and the second sealing groove 43 are both annular or rectangular. Specifically, referring to fig. 2, the first sealing groove 42 and the second sealing groove 43 are communicated with the motor rotor 2 through a small gap existing between the inner wall of the through hole 10, when the propellant passes through the first sealing assembly 30 and the two second sealing members 31 in sequence, most of the propellant is changed into a gaseous state due to continuous decompression at this time, and after entering the first sealing groove 42, because a large amount of high-pressure gas enters from the first gas inlet at this time, according to the principle that the gas flows from high pressure to low pressure, the high-pressure gas entering from the first gas inlet first enters the second sealing groove 43 from the first gas outlet, and then enters the first sealing groove 42 from the gap between the first sealing groove 42 and the second sealing groove 43 to form a backflow, and a black arrow in fig. 2 is a leakage propellant flow path. In the process, pneumatic sealing is formed between the through hole 10 and the motor rotor 2, the high-pressure airflow entering the first sealing groove 42 prevents the propellant from flowing further downstream, so that the propellant is prevented from further entering the motor cavity, in addition, the propellant enters the second air inlet along with the flowing direction of the high-pressure airflow and finally flows out of the shaft sealing device from the second air outlet, the leaked propellant is guided out, the sealing effect is achieved, the leaked propellant is discharged, the propellant is fundamentally prevented from entering the motor cavity, and white arrows in fig. 2 are used for eating a degassing flow path.

Further, the high-pressure gas introduced into the first air inlet is nitrogen, the pressure of the nitrogen is 0.2-0.5 MPa, other inert gases compatible with a propellant such as helium and the like can be selected, the propellant is liquid hydrogen, liquid oxygen, LNG and the like, the pressure before entering the shaft sealing device is 3-4 MPa, the pressure of the motor cavity is 0.1MPa, the propellant undergoes first pressure reduction after passing through the first sealing assembly 30, the pressure is reduced to 1.3MPa, the pressure is reduced to 0.3MPa when passing through the first second sealing assembly 31, the pressure is reduced to about 0.11MPa when passing through the second sealing assembly 31, the leaked propellant is blown off and discharged through the nitrogen with 0.2-0.5 MPa, the mass of the hydrogen leaked to the motor cavity is substantially 0g, and the mass flow of the propellant at the second air outlet is about 5 mg/s.

This shaft seal device adopts the mode of combination seal, combine contact seal and non-contact seal promptly, first seal assembly 30 is non-contact seal, two second sealing members 31 are contact seal, the airflow channel of the sealed module of second is non-contact seal promptly, form four sealing faces in proper order in through-hole 10, realize not only sealed while but also realizing reducing pressure step by step, turn into the gas easy to seal with difficult sealed liquid, and through the propellant of the isolated most leakage of twice second sealing member 31, blow off the discharge through blowing off the gas at last, sealed reliability has been guaranteed greatly, and overall structure is simple compact, the size is very little relatively, and is low in cost, it is sealed effectual.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.