O-ring type drum-shaped flow guide extrusion oil film damper

Abstract

The present application relates to a kind of O-ring type drum flow guide extrusion oil film damper, including damper outer ring and damper inner ring, the end of the damper inner ring is connected to elastic support, the outer ring of the damper inner ring is equipped with annular spherical projection, the inner ring of damper outer ring is equipped with annular concave spherical surface adapted to annular spherical projection, annular concave spherical surface and annular spherical projection are filled with oil film, O-shaped rubber ring between the damper outer ring and the damper inner ring is loaded in oil film both ends, oil supply hole and oil leakage hole are opened in the damper outer ring, and oil supply hole and oil leakage hole are communicated with oil film, the oil film gap shape is changed from flat plate to arch structure in the present application, the oil film journal and the oil film outer ring are prevented from colliding and rubbing, and the oil film thickness is sharply changed in axial direction, so that the oil film thickness between the damper inner ring and the damper outer ring tends to be uniform, pressure distribution is symmetrical, the normal work of rotor system is guaranteed, it is favorable to increase oil film damping, enhance damper damping effect, and reduce the formation of vapor cavity.

Description

Technical Field

[0001] This invention relates to the field of extrusion oil film dampers, specifically to an O-ring type drum-shaped flow-guiding extrusion oil film damper. Background Technology

[0002] The rotor is a crucial component of an aero-engine, and rotor vibration is one of the main obstacles to improving aero-engine performance. When the rotor operates at high speed, the rotor system is prone to problems such as large-amplitude vibration, uncoordinated precession, and power system instability, and even rotor shaft breakage, seriously affecting the performance and lifespan of the aero-engine. To suppress rotor vibration, the installation of squeeze film dampers (SFD) between the support and the casing has been proven to be a simple and effective method.

[0003] Currently, commonly used extrusion film dampers fall into two main categories: open extrusion film dampers without seals and closed extrusion film dampers with seals. To reduce two-phase flow problems such as air intake and increase oil film damping, seals are added to both ends of the damper to form a closed extrusion film damper. Commonly used seals include piston rings and O-rings. Due to the better sealing effect and the elastic damping characteristics of the O-ring rubber itself, O-ring sealing structures are often used in military aero engines.

[0004] Traditional extrusion film dampers produce annular oil films when the rotor shaft is stationary or at low operating speeds. However, at higher speeds, the rotor shaft undergoes deflection, causing significant axial changes in oil film thickness. This can easily lead to rubbing between the oil film journal and the outer ring of the oil film. Furthermore, the calculation of the dynamic characteristics of extrusion film dampers is based on the assumption that the axial thickness of the oil film remains constant. However, actual engines generally do not meet these assumptions, making it impossible to accurately obtain the dynamic characteristics of SFDs through calculation.

[0005] During the operation of the squeeze oil film damper, the pressure in the negative pressure zone caused by the oil film compression is lower than the saturated vapor pressure of the lubricating oil. This causes the lubricating oil to evaporate and form a large amount of vapor, resulting in vapor cavitation. The generation of vapor cavitation leads to a reduction in the volume occupied by the working lubricating oil, which in turn causes a decrease in damping.

[0006] For closed-loop compression film dampers with O-rings, excessive stiffness of the O-rings can cause significant nonlinearity in the damper's dynamic characteristics under harsh operating conditions, leading to damper vibration reduction failure. When the rotor shaft speed is high, the radial amplitude of the damper journal is large, which often causes the O-ring to be compressed far beyond its maximum compression ratio, resulting in O-ring damage and seal failure. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an O-ring type drum-shaped flow guide extrusion oil film damper.

[0008] This invention is achieved through the following technical solution: providing an O-ring type drum-shaped flow guide extrusion oil film damper, including an outer ring and an inner ring. The inner ring is connected to the end of an elastic support. The outer ring of the inner ring has an annular spherical protrusion, and the inner ring of the outer ring has an annular concave spherical surface adapted to the annular spherical protrusion. The space between the annular concave spherical surface and the annular spherical protrusion is filled with an oil film. O-ring rubber rings located at both ends of the oil film are installed between the outer ring and the inner ring. The outer ring has an oil supply hole and an oil leakage hole that are both connected to the oil film.

[0009] This design, by changing the oil film gap shape from a flat plate to an arched structure, prevents rubbing between the oil film journal and the outer ring caused by adjusting the rotor's attitude angle during deflection, and also reduces drastic changes in oil film thickness along the axial direction. This results in a more uniform oil film thickness and symmetrical pressure distribution between the inner and outer rings of the damper, ensuring the normal operation of the rotor system. Changing the oil film gap shape to an arched structure increases the effective compression area of ​​the oil film without increasing the axial length, which is beneficial for increasing oil film damping and enhancing the damper's vibration reduction effect.

[0010] As an optimization, an annular circumferential oil supply groove is formed on the annular concave spherical surface, and multiple oil supply holes are provided, all of which are connected to the annular circumferential oil supply groove. In this design, the multiple oil supply holes are all connected to the annular circumferential oil supply groove, maintaining the lubricating oil pressure in the damper at a relatively high level. This ensures that the high-pressure lubricating oil is evenly distributed to all positions of the damper, making the oil film pressure in most areas of the damper higher than the saturated vapor pressure of the lubricating oil, thus reducing the formation of vapor cavitation.

[0011] As an optimization, the annular circumferential oil supply groove is provided with two grooves, and the oil supply holes on the two grooves are staggered circumferentially. In this design, the staggered arrangement of the oil supply holes on the two grooves facilitates the supply of high-pressure lubricating oil.

[0012] As an optimization, inclined guide channels are connected to both sides of the annular circumferential oil supply groove. The ends of the guide channels between the two annular circumferential oil supply grooves are connected, and the oil leakage hole is connected to the connection point. The guide channels in this design introduce the high-pressure lubricating oil from the annular circumferential oil supply groove into the oil film region, thereby significantly reducing the area of ​​the negative pressure zone below the saturated vapor pressure of the lubricating oil during the damper's operation, and reducing the generation of lubricating oil vapor. To ensure the damping characteristics of the damper during long-term operation and to promptly drain the lubricating oil at high temperatures caused by friction, the oil leakage hole is installed at the connection point where the two guide channels intersect.

[0013] As an optimization, multiple circumferentially distributed guide channels are provided on both sides of the annular circumferential oil supply groove, and the guide channels on both sides are symmetrically arranged. The multiple circumferentially distributed guide channels in this design facilitate the rapid introduction of high-pressure lubricating oil into the oil film area.

[0014] As an optimization, the angle between the guide channel and the annular circumferential oil supply channel is 30-60 degrees. In this design, the angle between the guide channel and the annular circumferential oil supply channel is 30-60 degrees, thereby enabling the rapid introduction of high-pressure lubricating oil through the inclined guide channel.

[0015] As an optimization, the annular spherical protrusion is concentric with the annular concave spherical surface.

[0016] As an optimization, the outer ring of the inner ring of the damper has a mounting groove for installing an O-ring, and the inner ring of the outer ring of the damper has an arc-shaped groove adapted to the O-ring. The mounting groove in this design is used to install the O-ring, and the arc-shaped groove on the inner ring of the outer ring of the damper improves the sealing effect, reduces the deformation of the O-ring, and lowers the stiffness of the O-ring during operation.

[0017] As an optimization, a limiting ring located outside the O-ring is fixed to the inner ring of the damper. The limiting ring in this design prevents the O-ring from being damaged by compression, ensuring a tight seal.

[0018] The beneficial effects of this invention are as follows: The O-ring type drum-shaped flow guide extrusion oil film damper of this invention changes the shape of the oil film gap from a flat plate to an arched structure, which prevents the oil film journal and the outer ring of the oil film from rubbing against each other when the rotor is flexing and deforming, and also prevents the drastic change in the oil film thickness in the axial direction. This makes the oil film thickness between the inner and outer rings of the damper more uniform and the pressure distribution symmetrical, ensuring the normal operation of the rotor system. Without increasing the axial length, it increases the effective extrusion area of ​​the oil film, which is beneficial to increase the oil film damping and enhance the damper's vibration reduction effect. At the same time, this invention can also distribute high-pressure lubricating oil evenly to all positions of the damper, so that the oil film pressure in most areas of the damper is higher than the saturated vapor pressure of the lubricating oil, reducing the formation of vapor cavitation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the inner side of the annular concave spherical surface of the present invention;

[0021] Figure 3 For the present invention Figure 2 Sectional view of plane AA;

[0022] Figure 4 For the present invention Figure 3 Sectional view of the middle BB plane;

[0023] Figure 5 For the present invention Figure 3 Sectional view of the C-plane;

[0024] Figure 6 This is a schematic diagram of the oil film state in the prior art;

[0025] Figure 7 This is a schematic diagram of the oil film state according to the present invention;

[0026] Figure 8 This is a schematic diagram of the structure of the oil film of the present invention;

[0027] Figure 9 This is a frontal schematic diagram of the oil film of the present invention;

[0028] As shown in the figure:

[0029] 1. Elastic support; 2. O-ring; 3. Arc-shaped groove; 4. Limiting ring; 5. Outer ring of damper; 6. Rotor; 7. Annular spherical protrusion; 8. Annular concave spherical surface; 9. Oil film; 10. Annular circumferential oil supply groove; 11. Guide groove; 12. Oil supply hole; 13. Oil leakage hole; 14. Bearing; 15. Inner ring of damper. Detailed Implementation

[0030] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0031] like Figures 1-9 As shown, the O-ring type drum-shaped flow guide extrusion oil film damper of the present invention includes an outer ring 5 and an inner ring 15. The inner ring 15 is connected to the end of the elastic support 1, which is fixed to the casing with bolts. The rotor 6 is mounted on the inner ring of the inner ring 15 of the damper through a bearing 14, thereby supporting the rotor 6 through the inner ring 15 of the damper.

[0032] O-rings 2 are installed between the outer ring 5 and the inner ring 15 of the damper, located at both ends of the oil film 9. The outer ring of the inner ring 15 of the damper has a mounting groove for installing the O-rings 2. The inner ring of the outer ring 5 of the damper has an arc-shaped groove 3 that fits the O-ring 2. The arc-shaped groove 3 fits the outer ring of the O-ring 2 to improve the sealing effect, reduce the deformation of the O-ring, and reduce the stiffness of the O-ring during operation.

[0033] A limiting ring 4 is fixed to the inner ring 15 of the damper, located outside the O-ring 2. This prevents excessive rotor vibration and protects the O-ring 2.

[0034] Fluororubber is oil-resistant and high-temperature resistant, meeting the requirements of aero-engines. Therefore, fluororubber was chosen as the material for the O-ring 2. The O-ring 2 is a standard part, and a suitable specification can be selected by consulting the O-ring 2 specification table. The compression ratio Y is a parameter for evaluating the deformation of the O-ring 2. To ensure a good seal for the O-ring 2, based on experience and national standards, the O-ring seal SFD generally uses an internal moving seal, with a compression ratio Y ranging from 15% to 17%. This allows for the calculation of the minimum thickness of the limiting ring 4 installed to protect the O-ring.

[0035] The outer ring of the inner ring 15 of the damper is provided with an annular spherical protrusion 7, and the inner ring of the outer ring 5 of the damper is provided with an annular concave spherical surface 8 that is adapted to the annular spherical protrusion 7. The annular spherical protrusion 7 and the annular concave spherical surface 8 are concentric, and the space between the annular concave spherical surface 8 and the annular spherical protrusion 7 is filled with an oil film 9.

[0036] The outer ring 5 of the damper has an oil supply hole 12 and an oil leakage hole 13, both of which are connected to the oil film 9.

[0037] To improve the oil supply effect, an annular circumferential oil supply groove 10 is formed on the annular concave spherical surface 8, and multiple oil supply holes 12 are provided, all of which are connected to the annular circumferential oil supply groove 10. In this embodiment, the annular circumferential oil supply groove 10 is machined with three oil supply holes 12 spaced circumferentially at 120° intervals.

[0038] The annular circumferential oil supply groove 10 is provided in two rows, and the oil supply holes 12 on the two annular circumferential oil supply grooves 10 are arranged alternately in the circumferential direction, so a total of six oil supply holes 12 are provided.

[0039] like Figure 2 , 8 As shown in Figures 9 and 1, inclined guide channels 11 are connected to both sides of the annular circumferential oil supply groove 10, and the angle between the guide channels 11 and the annular circumferential oil supply groove 10 is 30 degrees to 60 degrees. In this embodiment, multiple circumferentially distributed guide channels 11 are provided on each side of the annular circumferential oil supply groove 10, and the guide channels 11 on both sides are symmetrically arranged.

[0040] The ends of the guide grooves 11 between the two annular circumferential oil supply grooves 10 are connected, and the oil leakage hole 13 is connected to the connection point. In this embodiment, the oil leakage hole 13 is installed at the connection point where the two guide grooves 11 intersect, which can promptly discharge lubricating oil with a high temperature caused by friction.

[0041] Figure 8 and Figure 9 This is a schematic diagram of the oil film. The numbers in the diagram represent the corresponding positions of that part of the oil film on the damper.

[0042] Method of using this invention:

[0043] The vibration load of rotor 6 is transmitted from elastic support 1 to the oil film 9 between the inner surface of the outer ring 5 of the damper and the inner ring 15 of the damper. Under the action of the lateral load of rotor 6, the outer surface of the inner ring 15 of the damper generates radial displacement to squeeze the oil film 9. The squeezed oil film 9 generates oil film reaction force to play a vibration reduction role.

[0044] The high-speed rotating rotor 6 undergoes deflection deformation due to manufacturing errors, assembly errors, and material inhomogeneity. This deformation causes changes in the size of the oil film gap at both ends, resulting in uneven distribution of the oil film 9. Consequently, this uneven distribution of the oil film pressure field generates an additional torque. Traditional extrusion oil film damper designs often neglect the impact of the high-speed deflection deformation of the rotor 6 on the damper's operation.

[0045] This invention features an annular spherical protrusion 7 on the outer ring of the inner ring 15 of the damper, and an annular concave spherical surface 8 on the inner ring of the outer ring 5. When the rotor 6 undergoes flexural deformation, the annular spherical protrusion 7 and the annular concave spherical surface 8 are concentric, and under the action of the O-ring 2, the head of the elastic support 1 continuously adjusts its angle, making the oil film thickness between the inner and outer rings of the damper tend to be uniform and the pressure distribution symmetrical. This also prevents rubbing between the oil film journal and the outer ring of the oil film caused by the flexural deformation of the rotor 6, ensuring the normal operation of the rotor system. During rotor flexural deformation, the oil film state of a conventional SFD is as follows: Figure 6 As shown, the SFD oil film state of the present invention is as follows: Figure 7 , Figure 6 and Figure 7 The upper and middle parts are images of the oil film state before deformation, and the lower part is an image of the oil film state after deformation.

[0046] The circumferentially staggered oil supply holes 12 are spaced at 120° intervals, which keeps the lubricating oil pressure in the damper at a relatively high level. The high-pressure lubricating oil is evenly distributed to various positions of the damper by the oblique guide grooves that are periodically distributed in the circumferential direction, so that the oil film pressure in most areas of the damper is higher than the saturated vapor pressure of the lubricating oil, reducing the formation of vapor cavitation.

[0047] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. An O-ring type drum-shaped flow guide extrusion oil film damper, comprising an outer damper ring (5) and an inner damper ring (15), wherein the inner damper ring (15) is connected to the end of an elastic support (1), characterized in that: The outer ring of the inner ring (15) of the damper is provided with an annular spherical protrusion (7), and the inner ring of the outer ring (5) of the damper is provided with an annular concave spherical surface (8) adapted to the annular spherical protrusion (7). The space between the annular concave spherical surface (8) and the annular spherical protrusion (7) is filled with an oil film (9). O-rings (2) located at both ends of the oil film (9) are installed between the outer ring (5) of the damper and the inner ring (15) of the damper. The outer ring (5) of the damper is provided with an oil supply hole (12) and an oil leakage hole (13) that are both connected to the oil film (9).

2. The O-ring type drum-shaped flow guide extrusion oil film damper according to claim 1, characterized in that: The annular concave spherical surface (8) has an annular circumferential oil supply groove (10), and the oil supply hole (12) is provided in multiple ways and is connected to the annular circumferential oil supply groove (10).

3. The O-ring type drum-shaped flow guide extrusion oil film damper according to claim 2, characterized in that: The annular circumferential oil supply groove (10) is provided with two grooves, and the oil supply holes (12) on the two annular circumferential oil supply grooves (10) are arranged alternately in the circumferential direction.

4. The O-ring type drum-shaped flow guide extrusion oil film damper according to claim 3, characterized in that: The two sides of the annular circumferential oil supply groove (10) are connected to inclined guide grooves (11), and the ends of the guide grooves (11) between the two annular circumferential oil supply grooves (10) are connected and the oil leakage hole (13) is connected to the connection point.

5. The O-ring type drum-shaped flow guide extrusion oil film damper according to claim 4, characterized in that: The annular circumferential oil supply groove (10) has multiple circumferentially distributed guide grooves (11) on both sides, and the guide grooves (11) on both sides are symmetrically arranged.

6. The O-ring type drum-shaped flow guide extrusion oil film damper according to claim 4, characterized in that: The angle between the guide groove (11) and the annular circumferential oil supply groove (10) is 30 degrees to 60 degrees.

7. The O-ring type drum-shaped flow guide extrusion oil film damper according to any one of claims 1-6, characterized in that: The annular spherical protrusion (7) is concentric with the annular concave spherical surface (8).

8. The O-ring type drum-shaped flow guide extrusion oil film damper according to any one of claims 1-6, characterized in that: The outer ring of the inner ring (15) of the damper has an installation groove for installing the O-ring (2), and the inner ring of the outer ring (5) of the damper has an arc-shaped groove (3) that is adapted to the O-ring (2).

9. The O-ring type drum-shaped flow guide extrusion oil film damper according to any one of claims 1-6, characterized in that: A limiting ring (4) located outside the O-ring (2) is fixed to the inner ring (15) of the damper.

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