Bidirectional swing ball type gimbals for liquid rocket engines

Abstract

The application belongs to the field of gimbal devices, and specifically discloses a bidirectional swing ball-type gimbal for a liquid rocket engine, which comprises an upper ball seat, a lower ball seat and a center block, the upper ball seat is arranged at the upper end of the lower ball seat, a passage is horizontally arranged through the lower ball seat, the center block is in the shape of a cuboid, the center block is arranged in the passage, the height of the passage is greater than the height of the center block, the upper ball seat is rotationally connected with the center block, the lower end of the upper ball seat is provided with a first concave curved surface, the upper end of the lower ball seat is provided with a second curved surface which is attached to the first curved surface, the top of the passage is provided with a third concave curved surface, and the upper end of the center block is provided with a fourth curved surface which is attached to the third curved surface, the gimbal has good flexibility and motion characteristics, can adapt to complex working environments and load changes, can reduce contact stress, improve the stability and durability of the system, can also disperse impact and vibration forces, and has good impact resistance and vibration resistance.

Description

Technical Field

[0001] This invention belongs to the field of constant-level seat devices, specifically relating to a bidirectional spherical constant-level seat for liquid rocket engines. Background Technology

[0002] Liquid rocket engines are crucial components of launch vehicles, providing propulsion for flight and enabling thrust vectoring control. During flight, servo mechanisms glide the engine to control the rocket's pitch, yaw, and roll attitude. The thrust mount is a key component in liquid rocket engines, responsible for transmitting thrust and enabling the glide function; it typically connects the engine mount to the thrust chamber. High-thrust liquid rocket engines use various types of dual-pendulum thrust mounts, including cross-axis, ring, and spherical mounts.

[0003] The constant-mount mount used in domestically deployed conventional high-thrust liquid rocket engines is the cross-axis constant-mount mount. The cross-axis constant-mount mount typically has the following drawbacks:

[0004] (1) The cross shaft transmits force through the lugs on both sides. Under the action of thrust, the cross shaft deflects, which is prone to jamming, resulting in large frictional torque and poor reliability and maintainability. The cross shaft has lugs on both the upper and lower sides of the constant-pressure seat. The cross shaft is mounted on the lugs. When the constant-pressure seat bears the thrust of the engine, the cross shaft will deflect. Excessive deflection may cause changes in the clearance fit between the shaft and the bearing. When the shaft end deflection is greater than the bearing clearance, there will be a "jamming" problem, which will affect the lubrication and movement between the two, affect the engine oscillation, and thus affect the attitude control of the rocket. In order to avoid this situation, the bearing clearance is usually increased to accommodate the deflection change. However, excessive bearing clearance will reduce the contact angle, which will lead to an increase in the maximum contact stress, resulting in a series of strength problems, and may even damage the lubrication, causing the bearing to "stick", resulting in poor lubrication and increased friction, thus affecting the performance and reliability of the constant-pressure seat.

[0005] (2) High assembly precision is required, making quality control during production difficult. Traditional cross shaft mounting typically consists of multiple components, such as the cross shaft, multiple bearing housings, and flange seats. These components require precise alignment and connection during assembly. Due to the involvement of multiple parts in the fit and connection, it is necessary to ensure that their positions and angles are correctly matched to avoid assembly errors. Simultaneously, the assembly of the bearing housings requires alignment checks and adjustments. This includes using measuring tools and equipment to check the relative positions and angles of the shaft holes to ensure the centering of the shaft holes at both ends. Mechanical loosening and eccentricity are difficult to avoid during manufacturing and assembly, leading to a decrease in the accuracy and stability of engine sway.

[0006] The domestic high-pressure staged combustion cycle dual pendulum engine adopts an annular constant level seat. The annular constant level seat consists of a constant level ring and a frame beam force transmission frame. The constant level ring is located in the thrust chamber body. Compared with the cross shaft constant level seat, the two pairs of shafts of the annular constant level seat are orthogonally distributed but not integrated. The stress conditions of the ring are more severe, its structure is more complex, its radial dimension is larger, and its structure is heavier.

[0007] The spherical constant level seat's swing pair consists of a sphere and a bearing housing. The thrust is transmitted through the center of the sphere, while the load on the two side lugs is relatively small. There are reports of its application abroad, but the specific structure is unclear. There is no such constant level seat in China yet. Summary of the Invention

[0008] The purpose of this invention is to provide a bidirectional spherical constant-pressure seat for liquid rocket engines, which has good flexibility and motion characteristics, can adapt to complex working environments and load changes; at the same time, it can reduce contact stress, improve the stability and durability of the system, and can also disperse impact and vibration forces, thus having good impact and vibration resistance.

[0009] To achieve the above objectives, the present invention provides a bidirectional spherical constant-level seat for a liquid rocket engine, comprising an upper spherical seat, a lower spherical seat, and a central block. The upper spherical seat is located at the upper end of the lower spherical seat, and a channel is horizontally provided through the lower spherical seat. The central block is rectangular in shape and is located within the channel. The height of the channel is greater than the height of the central block. The upper spherical seat is rotatably connected to the central block. The lower end of the upper spherical seat has a concave first curved surface, the upper end of the lower spherical seat has a convex second curved surface that conforms to the first curved surface, the top of the channel has a concave third curved surface, and the upper end of the central block has a convex fourth curved surface that conforms to the third curved surface.

[0010] Furthermore, the top of both ends of the channel is provided with cutouts to accommodate the rotational stroke of the central block.

[0011] Furthermore, the lower end of the central block is located away from the bottom of the channel.

[0012] Furthermore, the center block is provided with a threaded hole, and the lower end of the upper ball seat is provided with a rotating hole. The rotating hole and the threaded hole are connected together by a pin assembly so that the upper ball seat is rotatably connected to the center block.

[0013] Furthermore, there are two threaded holes, which are coaxially arranged; there are two rotating holes, which are coaxially arranged; and there are two pin assemblies.

[0014] Furthermore, the pin assembly includes a bushing fitted inside the rotating hole and a threaded pin passing through the bushing and threadedly connected to the threaded hole.

[0015] Furthermore, both the first and second surfaces are spheres.

[0016] Furthermore, both the third and fourth surfaces are spherical.

[0017] Furthermore, both the second and third curved surfaces are coated with lubricant.

[0018] Furthermore, the upper ball seat is provided with a plurality of first mounting holes, and the lower ball seat is provided with a plurality of second mounting holes.

[0019] The present invention has the following beneficial effects:

[0020] In this embodiment of the invention, the upper spherical mount of the bidirectional rocking spherical constant-level seat for a liquid rocket engine is mounted on the engine frame, and the lower spherical mount is mounted on the thrust chamber. The first curved surface on the upper spherical mount and the second curved surface on the lower spherical mount are in surface contact, ensuring that the upper and lower spherical mounts do not interfere with each other when they rotate relative to the center block. Furthermore, since the height of the channel is greater than the height of the center block, it can meet the rotational margin of the center block within the channel. At the same time, the third curved surface on the lower spherical mount and the fourth curved surface on the center block are in surface contact. Therefore, when the lower spherical mount rotates relative to the center block, the third and fourth curved surfaces rotate, realizing the rocking function of the bidirectional rocking spherical constant-level seat for liquid rocket engines. This provides better flexibility and motion characteristics, enabling it to adapt to complex working environments and load changes. Moreover, the curved surface connection increases the contact area, providing a larger contact area to distribute the load. This design can effectively reduce stress concentration at the connection point, reduce contact stress, thereby improving the stability and durability of the system. It can also disperse impact and vibration forces, exhibiting good impact and vibration resistance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a bidirectional spherical constant-pressure seat for a liquid rocket engine provided in an embodiment of the present invention;

[0023] Figure 2 A cross-sectional view of a bidirectional spherical spherical mount for a liquid rocket engine provided in an embodiment of the present invention;

[0024] Figure 3 An exploded view of a bidirectional spherical buoyancy gauge for a liquid rocket engine provided in an embodiment of the present invention;

[0025] Figure 4 This is an exploded view from another perspective of the bidirectional spherical buoyancy plate for liquid rocket engines provided in an embodiment of the present invention.

[0026] Explanation of the markings in the image:

[0027] 1. Upper ball seat; 2. Lower ball seat; 3. Center block; 4. Pin assembly; 11. First curved surface; 12. Rotating hole; 13. First mounting hole; 21. Channel; 22. Second curved surface; 23. Third curved surface; 24. Cutout; 25. Second mounting hole; 31. Fourth curved surface; 32. Threaded hole; 41. Bushing; 42. Threaded pin. Detailed Implementation

[0028] 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.

[0029] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0030] 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.

[0031] 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.

[0032] Example

[0033] Please see Figure 1-4As shown, the bidirectional spherical constant-level seat for liquid rocket engines provided in this embodiment includes an upper spherical seat 1, a lower spherical seat 2, and a central block 3. The upper spherical seat 1 is located at the upper end of the lower spherical seat 2. A channel 21 is horizontally provided through the lower spherical seat 2. The central block 3 is rectangular in shape and is located inside the channel 21. The height of the channel 21 is greater than the height of the central block 3. The upper spherical seat 1 and the central block 3 are rotatably connected. The lower end of the upper spherical seat 1 is provided with a concave first curved surface 11. The upper end of the lower spherical seat 2 is provided with a convex second curved surface 22 that fits with the first curved surface 11. The top of the channel 21 is provided with a concave third curved surface 23. The upper end of the central block 3 is provided with a convex fourth curved surface 31 that fits with the third curved surface 23.

[0034] With the above structure, in practical applications, the bidirectional spherical constant-level seat for liquid rocket engines implemented in this invention has an upper ball seat 1 connected to the engine frame (not shown in the figure) via a flange, allowing relative movement between the engine (not shown in the figure) and the engine frame (not shown in the figure), and transmitting the engine's thrust to the engine frame to propel the rocket. The lower ball seat 2 is connected to the thrust chamber (not shown in the figure), bearing and transmitting the engine's thrust load, and transferring it to other components of the constant-level seat. The upper ball seat 1 is rotatably connected to the center block 3, allowing relative rotational movement between the upper ball seat 1 and the center block 3 to bear and transmit torsional and lateral loads. Simultaneously, the first curved surface 11 on the upper ball seat 1 and the second curved surface 22 on the lower ball seat 2 are in surface contact, ensuring that when the upper ball seat 1 and the center block 3 rotate relative to each other, the first curved surface 11 and the second curved surface 22 rotate, allowing the upper ball seat 1 and the lower ball seat 2 to... Without interference, and because the height of channel 21 is greater than the height of center block 3, it can meet the rotational margin of center block 3 within channel 21. At the same time, the third curved surface 23 on the lower ball seat 2 and the fourth curved surface 31 on center block 3 are in curved contact. Therefore, when the lower ball seat 2 rotates relative to center block 3, the third curved surface 23 and the fourth curved surface 31 rotate, realizing the swing function of the bidirectional swing ball seat for liquid rocket engines. It has better flexibility and motion characteristics and can adapt to complex working environments and load changes. Furthermore, due to the curved surface rotation of the first curved surface 11 and the second curved surface 22, as well as the curved surface rotation of the third curved surface 23 and the fourth curved surface 31, the curved surface connection increases the contact area, which can provide a larger contact area to distribute the load. This design can effectively reduce stress concentration at the connection point, reduce contact stress, thereby improving the stability and durability of the system. It can also disperse impact and vibration forces, and has good impact and vibration resistance.

[0035] Specifically, each end of the channel 21 has a cutout 24 at the top to accommodate the rotational stroke of the center block 3. When the lower ball seat 2 rotates relative to the center block 3, the cutout 24 can accommodate the rotational stroke of the center block 3 to satisfy the relative rotation of the lower ball seat 2 and the center block 3. At the same time, it can also play a limiting role to prevent the relative rotation of the lower ball seat 2 and the center block 3 from being excessive.

[0036] Specifically, when the upper ball seat 1 is rotatably connected to the center block 3, the lower end of the center block 3 is far away from the bottom of the channel 21, thereby ensuring that the bottom of the channel 21 also has enough space to accommodate the rotation stroke of the center block 3, so as to satisfy the relative rotation of the lower ball seat 2 and the center block 3.

[0037] Specifically, a threaded hole 32 is provided on the center block 3, and a rotating hole 12 is provided at the lower end of the upper ball seat 1. The rotating hole 12 and the threaded hole 32 are connected together by a pin assembly 4 so that the upper ball seat 1 and the center block 3 are rotatably connected. After the pin assembly 4 passes through the rotating hole 12, it is threadedly connected to the threaded hole 32, so that the upper ball seat 1 and the center block 3 are rotatably connected, thereby enabling the upper ball seat 1 and the center block 3 to rotate relative to the pin assembly 4.

[0038] Specifically, there are two threaded holes 32, which are coaxially arranged; there are two rotating holes 12, which are coaxially arranged; and there are two pin assemblies 4. The two pin assemblies 4 pass through the two rotating holes 12 from both ends of the upper ball seat 1 and are threadedly connected to the two threaded holes 32 respectively. The threaded holes 32, rotating holes 12 and pin assemblies 4 are all coaxially arranged to satisfy the relative rotation between the upper ball seat 1 and the center block 3.

[0039] Specifically, the pin assembly 4 includes a bushing 41 fitted inside the rotating hole 12 and a threaded pin 42 passing through the bushing 41 and threadedly connected to the threaded hole 32. The bushing 41 is located between the rotating hole 12 and the threaded pin 42, which can prevent the rotating hole 12 and the threaded pin 42 from rotating and rubbing against each other. After the threaded pin 42 is threadedly connected to the threaded hole 32, the upper ball seat 1 and the center block 3 can be connected together.

[0040] Specifically, the first surface 11 and the second surface 22 are both spherical surfaces, as are the third surface 23 and the fourth surface 31. The surface rotation of the first surface 11 and the second surface 22 is spherical rotation, and the surface rotation of the third surface 23 and the fourth surface 31 is spherical rotation. The installation method of the spherical plain bearing can provide better positioning and assembly capabilities, which not only simplifies the assembly process but also ensures the stable operation of the constant level seat during operation. Furthermore, the spherical bearing can freely adjust for shaft deviation and alignment issues. When the engine is assembled and operating, there may be some minor deviations or deformations, and the spherical bearing can adapt to these changes through free adjustment. It can adapt to deviations and deformations during engine assembly and operation to a certain extent, and also avoids deflection changes and jamming problems.

[0041] Specifically, lubricant is sprayed on both the second curved surface 22 and the third curved surface 23. This can improve the performance and life of the upper ball seat 1, the lower ball seat 2 and the center block 3, and reduce friction between moving parts, ensuring the precise movement and service life of the constant level seat.

[0042] Specifically, the upper ball seat 1 is provided with multiple first mounting holes 13, and the lower ball seat 2 is provided with multiple second mounting holes 25. The first mounting holes 13 are used for mounting and fixing the upper ball seat 1 to the engine frame, and the second mounting holes 25 are used for mounting and fixing the lower ball seat 2 to the thrust chamber.

[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.

Claims

1. A bidirectional spherical constant-pressure seat for a liquid rocket engine, characterized in that, The device includes an upper ball seat, a lower ball seat, and a center block. The upper ball seat is located above the lower ball seat, and a horizontal channel is provided through the lower ball seat. The center block is rectangular in shape and is located within the channel. The height of the channel is greater than the height of the center block. The upper ball seat and the center block are rotatably connected. The lower end of the upper ball seat has a concave first curved surface, the upper end of the lower ball seat has a convex second curved surface that fits with the first curved surface, the top of the channel has a concave third curved surface, and the upper end of the center block has a convex fourth curved surface that fits with the third curved surface. The top of both ends of the channel is provided with cutouts to accommodate the rotational stroke of the central block and to limit its movement. The lower end of the central block is away from the bottom of the channel; The center block is provided with a threaded hole, and the lower end of the upper ball seat is provided with a rotating hole. The rotating hole and the threaded hole are connected together by a pin assembly so that the upper ball seat is rotatably connected to the center block.

2. The bidirectional oscillating spherical constant-pressure seat for a liquid rocket engine according to claim 1, characterized in that, The number of threaded holes is two, and the two threaded holes are coaxially arranged; the number of rotating holes is two, and the two rotating holes are coaxially arranged; the number of pin assemblies is two.

3. The bidirectional oscillating spherical constant-pressure seat for a liquid rocket engine according to claim 2, characterized in that, The pin assembly includes a bushing fitted inside the rotating hole and a threaded pin passing through the bushing and threadedly connected to the threaded hole.

4. The bidirectional oscillating spherical constant-pressure seat for a liquid rocket engine according to claim 1, characterized in that, Both the first and second surfaces are spheres.

5. The bidirectional spherical constant-pressure seat for a liquid rocket engine according to claim 1, characterized in that, Both the third and fourth surfaces are spheres.

6. The bidirectional oscillating spherical constant-pressure seat for a liquid rocket engine according to claim 1, characterized in that, Lubricant is sprayed onto both the second and third curved surfaces.

7. The bidirectional oscillating spherical constant-pressure seat for a liquid rocket engine according to claim 1, characterized in that, The upper ball seat is provided with a plurality of first mounting holes, and the lower ball seat is provided with a plurality of second mounting holes.

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