Internal reflux structure for propellant of turbine pump of liquid rocket engine

Abstract

The invention discloses an internal reflux structure for a propellant of a turbopump of a liquid rocket engine, and relates to the technical field of liquid rocket engines. The internal reflux structure for the propellant of the turbopump of the liquid rocket engine comprises a first internal reflux structure and a second internal reflux structure. The first inner backflow structure comprises a gap formed by a centrifugal wheel rear cover plate and a pump cavity, a gap formed by a first resistance element and a centrifugal wheel rear protruding shoulder, a centrifugal wheel rear cavity, a centrifugal wheel rear hub radial groove, a main shaft inner backflow hole, a shaft sleeve channel, a movable ring front cavity channel, a bearing channel, a bearing rear radial gap and a movable ring rear backflow hole. The second internal backflow structure comprises a gap formed by the centrifugal wheel front cover plate and the pump cavity, a gap formed by the second resistance element and the centrifugal wheel front protruding shoulder, and a gap formed by the centrifugal wheel rear protruding shoulder and the pump cavity static part. According to the internal reflux structure for the propellant of the turbopump of the liquid rocket engine, the structural compactness, the assembly manufacturability and the working reliability of the turbopump are improved, and the internal reflux structure is widely applied to the field of rocket engines.

Description

Technical Field

[0001] This invention relates to the field of liquid rocket engine technology, and in particular to a propellant internal recirculation structure for a liquid rocket engine turbopump. Background Technology

[0002] The turbopump in a liquid rocket engine plays a crucial role in pressurizing and delivering propellant to the thrust chamber. After entering the pump chamber and being pressurized by the centrifugal impeller, most of the propellant enters the pressurized water chamber for further deceleration and pressurization. The remaining small portion enters the internal flow path formed by the gap between the pump chamber and the centrifugal impeller, bearings, and external return pipes, ultimately converging into the main propellant flow. The existence of the internal flow path in the turbopump creates an uneven pressure distribution on the inner and outer surfaces of the turbopump rotor components, ultimately leading to axial force on the turbopump rotor. Simultaneously, the internal flow path plays a critical role in cooling and lubricating the bearings. Therefore, designing a compact and rational internal return structure for the turbopump propulsion system is essential for the development of liquid rocket engines. Currently, there is a lack of a clearly defined, clear, and complete internal return structure for turbopumps, posing significant difficulties and challenges to the development of liquid rocket engines. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an internal propellant recirculation structure for a liquid rocket engine turbopump, thereby improving the stability and reliability of the liquid rocket engine turbopump operation.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows:

[0005] An internal propellant recirculation structure for a liquid rocket engine turbopump includes a first internal recirculation structure and a second internal recirculation structure.

[0006] The first internal reflux structure includes the gap formed between the centrifugal wheel rear cover plate and the pump cavity, the gap formed between the first resistance element and the centrifugal wheel rear shoulder, the centrifugal wheel rear cavity, the centrifugal wheel rear hub radial groove, the main shaft internal reflux hole, the bushing channel, the moving ring front cavity channel, the bearing channel, the bearing rear radial clearance, and the moving ring rear reflux hole.

[0007] The second internal reflux structure includes the gap formed between the centrifugal wheel front cover plate and the pump chamber, the gap formed between the second resistance element and the centrifugal wheel front shoulder, and the gap between the centrifugal wheel front shoulder and the stationary part of the pump chamber.

[0008] Preferably, the first resistance element is a hard, wear-resistant metal or graphite, and the surface characteristics of the first resistance element or the rear shoulder of the centrifugal wheel are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the first internal return structure, improve the pump volumetric efficiency, and reduce the downstream propellant pressure of the internal flow path.

[0009] Preferably, the first resistance element is a floating ring structure, in order to reduce the flow rate of the first internal recirculation structure, improve the pump volumetric efficiency, and reduce the propellant pressure downstream of the internal flow path.

[0010] Preferably, the radial grooves of the rear hub of the centrifugal wheel are evenly distributed in the circumference, and the ungrooved position of the rear hub of the centrifugal wheel can play a role in axial and radial positioning.

[0011] Preferably, the internal reflux hole of the spindle includes an inlet hole, a center hole, and an outlet hole, and the inlet hole and the outlet hole are uniformly distributed in the circumferential direction.

[0012] Preferably, the bushing channel includes a circumferential annular cavity and circumferentially distributed perforated channels.

[0013] Preferably, the number of backflow holes in the moving ring is two or more, which serves to reduce the propellant pressure downstream of the internal flow path and cool the surface of the moving ring friction pair.

[0014] Preferably, the reflux hole of the moving ring is manufactured by casting or 3D printing.

[0015] Preferably, the second resistance element is a hard, wear-resistant metal or graphite, and the surface characteristics of the second resistance element or the front shoulder of the centrifugal wheel are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the second internal backflow structure and improve the pump volumetric efficiency.

[0016] Preferably, the second resistance element is a floating ring structure, in order to reduce the flow rate of the second internal recirculation structure and improve the pump volumetric efficiency.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) This invention proposes a complete internal propellant reflux structure for liquid rocket engine turbopumps. Through the arrangement of the internal reflux structure in the turbopump, the combined effects of turbopump axial force control, bearing cooling and lubrication, dynamic ring friction pair surface cooling, and improved pump volumetric efficiency can be achieved.

[0019] (2) In the internal propellant reflux structure of the liquid rocket engine turbopump of the present invention, the traditional external reflux pipe is changed to the internal reflux hole of the main shaft, which improves the compactness, assembly processability and working reliability of the turbopump. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of an internal propellant reflux structure in a liquid rocket engine turbopump according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the composition of the internal reflux hole of the main spindle.

[0023] Explanation of the markings in the image:

[0024] 1- Gap formed between the centrifugal impeller rear cover plate and the pump chamber; 2- Gap formed between the first resistance element and the rear shoulder of the centrifugal impeller; 3- Rear cavity of the centrifugal impeller; 4- Radial groove of the rear hub of the centrifugal impeller; 5- Internal return hole of the main shaft; 6- Bushing channel; 7- Front cavity channel of the moving ring; 8- Bearing channel; 9- Rear radial clearance of the bearing; 10- Rear return hole of the moving ring; 11- Gap formed between the centrifugal impeller front cover plate and the pump chamber; 12- Gap formed between the second resistance element and the front shoulder of the centrifugal impeller; 13- Gap between the front shoulder of the centrifugal impeller and the stationary part of the pump chamber; 51- Inlet hole; 52- Center hole; 53- Outlet hole. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] Example

[0029] See Figure 1 The liquid rocket engine turbopump propellant internal recirculation structure shown includes a first internal recirculation structure and a second internal recirculation structure.

[0030] The first internal reflux structure includes a gap 1 formed by the rear cover plate of the centrifugal wheel and the pump chamber, a gap 2 formed by the first resistance element and the rear shoulder of the centrifugal wheel, a rear cavity of the centrifugal wheel, a radial groove of the rear hub of the centrifugal wheel, an internal reflux hole of the main shaft, a bushing channel, a front cavity of the moving ring, a bearing channel, a rear radial clearance of the bearing, and a rear reflux hole of the moving ring.

[0031] The second internal reflux structure includes a gap 11 formed between the centrifugal wheel front cover plate and the pump chamber, a gap 12 formed between the second resistance element and the centrifugal wheel front shoulder, and a gap 13 between the centrifugal wheel front shoulder and the stationary part of the pump chamber.

[0032] In one embodiment, the first resistance element is a hard, wear-resistant metal or graphite, and the surface characteristics of the first resistance element or the rear shoulder of the centrifugal wheel are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the first internal backflow structure, improve the pump volumetric efficiency, and reduce the downstream propellant pressure of the internal flow path.

[0033] In another embodiment, the first resistance element is a floating ring structure, which aims to reduce the flow rate of the first internal recirculation structure, improve the pump volumetric efficiency, and reduce the propellant pressure downstream of the internal flow path.

[0034] The radial grooves 4 of the rear hub of the centrifugal wheel are evenly distributed in the circumference, and the ungrooved position of the rear hub of the centrifugal wheel can play a role in axial and radial positioning.

[0035] See Figure 2 The spindle internal reflux hole 5 shown includes an inlet hole 51, a center hole 52, and an outlet hole 53. The inlet hole 51 and the outlet hole 53 are evenly distributed in the circumferential direction.

[0036] The bushing channel 6 includes a circumferential annular cavity and circumferentially distributed perforated channels.

[0037] The number of backflow holes 10 on the moving ring is two or more, which serves to reduce the propellant pressure downstream of the internal flow path and cool the friction pair surface of the moving ring.

[0038] The reflux hole 10 of the moving ring is manufactured by casting or 3D printing.

[0039] In one embodiment, the second resistance element is a hard, wear-resistant metal or graphite, and the surface characteristics of the second resistance element or the front shoulder of the centrifugal wheel are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the second internal backflow structure and improve the pump volumetric efficiency.

[0040] In another embodiment, the second resistance element is a floating ring structure, in order to reduce the flow rate of the second internal recirculation structure and improve the pump volumetric efficiency.

[0041] The internal propellant reflux structure of this liquid rocket engine turbopump works as follows: After the propellant flows out of the centrifugal impeller outlet, most of it enters the pressurization chamber for further deceleration and pressurization. A small portion of the propellant enters the gap 1 formed between the centrifugal impeller rear cover plate and the pump chamber. After being throttled by the gap 2 formed by the first resistance element and the rear shoulder of the centrifugal impeller, the pressure is significantly reduced. It then flows further through the rear cavity 3 of the centrifugal impeller, the radial groove 4 of the rear hub of the centrifugal impeller, the internal reflux hole 5 of the main shaft, the bushing channel 6, and the front cavity 7 of the moving ring, where it is split. The first part flows through the bearing channel 8 and the rear radial gap 9 of the bearing to the main flow of the pump inlet, where it cools and lubricates the bearing. The second part flows through the rear reflux hole 10 of the moving ring to the main flow of the pump inlet, where it cools the friction pair surface of the moving ring. The remaining small portion of the propellant flowing out of the centrifugal impeller outlet enters the gap 11 formed between the centrifugal impeller front cover plate and the pump chamber. After being throttled by the gap 12 formed by the second resistance element and the front shoulder of the centrifugal impeller, the pressure is significantly reduced. Finally, it flows through the gap 13 between the front shoulder of the centrifugal impeller and the stationary part of the pump chamber to the main flow of the inducer channel.

[0042] The internal propellant reflux structure of the liquid rocket engine turbopump of the present invention can achieve the comprehensive functions of turbopump axial force control, bearing cooling and lubrication, dynamic ring friction pair surface cooling, and improved pump volumetric efficiency. It replaces the traditional external reflux pipe with an internal reflux hole in the main shaft, which improves the turbopump's structural compactness, assembly processability, and operational reliability, and has a wide range of applications in the field of rocket engines.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0044] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A propellant internal recirculation structure for a liquid rocket engine turbopump, characterized in that, It includes a first internal reflux structure and a second internal reflux structure; The first internal reflux structure includes the gap formed between the centrifugal wheel rear cover plate and the pump chamber, the gap formed between the first resistance element and the centrifugal wheel rear shoulder, the centrifugal wheel rear chamber, the centrifugal wheel rear hub radial groove, the main shaft internal reflux hole, the bushing channel, the moving ring front cavity channel, the bearing channel, the bearing rear radial gap, and the moving ring rear reflux hole. The second internal reflux structure includes the gap formed between the centrifugal wheel front cover plate and the pump chamber, the gap formed between the second resistance element and the centrifugal wheel front shoulder, and the gap between the centrifugal wheel front shoulder and the stationary part of the pump chamber.

2. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The first resistance element is made of hard, wear-resistant metal or graphite. The surface characteristics of the first resistance element or the rear shoulder of the centrifugal wheel are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the first internal backflow structure, improve the pump volumetric efficiency, and reduce the downstream propellant pressure in the internal flow path.

3. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The first resistance element is a floating ring structure, which aims to reduce the flow rate of the first internal recirculation structure, improve the pump volumetric efficiency, and reduce the propellant pressure downstream of the internal flow path.

4. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The radial grooves of the rear hub of the centrifugal wheel are evenly distributed in the circumference, and the ungrooved position of the rear hub of the centrifugal wheel can play a role in axial and radial positioning.

5. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The spindle internal reflux hole includes an inlet hole, a center hole, and an outlet hole, and the inlet hole and outlet hole are uniformly distributed in the circumferential direction.

6. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The bushing channel includes a circumferential annular cavity and circumferentially distributed perforated channels.

7. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The number of backflow holes in the moving ring is two or more, which serves to reduce the propellant pressure downstream of the internal flow path and cool the surface of the moving ring friction pair.

8. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The aforementioned reflux hole in the moving ring is manufactured using casting or 3D printing processes.

9. The internal propellant recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The second resistance element is made of hard, wear-resistant metal or graphite. The surface characteristics of the second resistance element or the front shoulder of the centrifugal impeller are smooth or have a labyrinth seal throttling structure, so as to reduce the flow rate of the second internal backflow structure and improve the pump volumetric efficiency.

10. The propellant internal recirculation structure of the liquid rocket engine turbopump according to claim 1, characterized in that, The second resistance element is a floating ring structure, which aims to reduce the flow rate of the second internal backflow structure and improve the pump volumetric efficiency.

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