Graphite sealing ring dynamic pressure groove and graphite sealing ring

Abstract

The utility model discloses a graphite sealing ring dynamic pressure groove and a graphite sealing ring, the surface of the graphite sealing ring dynamic pressure groove is provided with a scale-imitating micro-texture structure, the scale-imitating micro-texture structure is composed of scale-imitating sheet units which are arranged layer by layer and stacked in a staggered mode, and the scale-imitating sheet units are arranged along the flowing direction of fluid. The thickness of each imitated fish scale unit is gradually increased, every two adjacent imitated fish scale units located on the same layer are arranged in a spaced mode and form a step structure with the imitated fish scale units located on the lower layer, and the graphite sealing ring dynamic pressure groove is formed in the sealing face of the graphite sealing ring. According to the graphite sealing ring dynamic pressure groove and the graphite sealing ring, the airflow speed can be increased, the airflow flow can be increased, the dynamic pressure effect can be improved, the opening force of graphite sealing can be increased, the sealing ring and a sealing runway tend to be non-contact, and therefore the friction abrasion degree of the graphite sealing is reduced, and the service life of a sealing piece is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of graphite sealing, and particularly provides a hydrodynamic groove of a graphite sealing ring and a graphite sealing ring. Background Art

[0002] Due to its advantages such as low leakage, high pressure difference, and high temperature resistance, graphite sealing has developed into an ideal sealing for the bearing cavity of aero-engines. Classified according to the sealing principle, the circumferential graphite sealing belongs to a contact sealing structure. Various grooves with different depths are machined on the ring petals of the graphite sealing ring, which can balance the pressure (deep grooves) or generate a hydrodynamic effect (shallow grooves), enabling the sealing ring to operate stably with low friction or even no friction at high speeds. However, due to fluid viscosity, a boundary layer will form on the hydrodynamic groove, indirectly reducing the thickness of the hydrodynamic groove. At the same time, due to high temperature, high speed, and the frictional resistance of the air flow, the air flow is prone to become turbulent, thereby weakening the hydrodynamic effect, resulting in a decrease in the opening force of the graphite seal, difficulty in floating up the ring petals of the graphite sealing ring, an increase in the degree of friction and wear of the sealing surface, a decline in the sealing performance, and a shortening of the service life of the seal.

[0003] Therefore, how to improve the existing graphite sealing ring structure to increase the opening force of the graphite seal, reduce the wear of the sealing surface, improve the sealing performance, and extend the service life of the seal has become an urgent problem to be solved. Summary of the Utility Model

[0004] In view of this, the purpose of the present utility model is to provide a hydrodynamic groove of a graphite sealing ring and a graphite sealing ring to at least solve the problems existing in the existing graphite sealing structure.

[0005] On the one hand, the present utility model provides a hydrodynamic groove of a graphite sealing ring. The surface of the hydrodynamic groove of the graphite sealing ring is provided with an anti-fish-scale micro-texture structure. The anti-fish-scale micro-texture structure is composed of anti-fish-scale units arranged in layers and staggered and stacked. Among them, along the flow direction of the fluid, the thickness of each anti-fish-scale unit gradually increases. Adjacent two anti-fish-scale units in the same layer are spaced apart and respectively form a step structure with the anti-fish-scale units located in the lower layer.

[0006] Preferably, the anti-fish-scale unit includes 1 upper surface and 3 side surfaces. Among them, the upper surface is an inclined surface. The upper surface includes a leading edge, a trailing edge, and two side edges. The leading edge intersects with the wall surface of the hydrodynamic groove, and the trailing edge and the two side edges are respectively connected to the wall surface of the hydrodynamic groove through the 3 side surfaces.

[0007] Further preferably, the anti-fish-scale unit is an axisymmetric structure. The projection of the anti-fish-scale unit on the plane is approximately a fan-shaped ring. The fan-shaped ring is composed of 4 arcs connected in sequence. Among them, the curve equation of the first arc is: x 2 + y 2 = R2 , the curve equation of the second arc is: The curve equation of the third arc is: x 2 +(y - R) 2 = R 2 , the curve equation of the fourth arc is: In the formula, R is the radius of the arc, R = h / tanα, h is the height of the trailing edge of the upper surface of the fish-scale-like unit, and α is the angle between the upper surface of the fish-scale-like unit and the wall surface of the dynamic pressure groove.

[0008] Further preferably, the angle α between the upper surface of the fish-scale-like unit and the wall surface of the dynamic pressure groove is 2° to 5°.

[0009] Further preferably, the height h of the trailing edge of the upper surface of the fish-scale-like unit = 0.2δ, where δ is the boundary layer thickness.

[0010] Further preferably, in the fish-scale-like micro-texture structure, the fish-scale-like unit includes a first fish-scale-like unit, a second fish-scale-like unit, a third fish-scale-like unit, and a fourth fish-scale-like unit. The second fish-scale-like unit and the third fish-scale-like unit are both located on the lower layer of the first fish-scale-like unit and are respectively located on both sides of the first fish-scale-like unit. The fourth fish-scale-like unit is located on the lower layer of the second fish-scale-like unit and the third fish-scale-like unit and is located between the second fish-scale-like unit and the third fish-scale-like unit. The third arc of the first fish-scale-like unit coincides with the fourth arc of the second fish-scale-like unit, the first arc of the third fish-scale-like unit, and the second arc of the fourth fish-scale-like unit.

[0011] The present invention also provides a graphite sealing ring, and the above-mentioned dynamic pressure groove of the graphite sealing ring is arranged on the sealing surface of the graphite sealing ring.

[0012] The dynamic pressure groove of the graphite sealing ring and the graphite sealing ring provided by the present invention can improve the boundary layer state through the fish-scale-like micro-texture structure, increase the flow velocity and flow rate of the fluid in the dynamic pressure groove, improve the dynamic pressure effect, increase the opening force, make the sealing ring easier to float, reduce the friction and wear degree of the graphite seal, improve the sealing performance, and extend the working life of the sealing element. Description of the Drawings

[0013] The following further describes the present invention in detail in conjunction with the drawings and embodiments:

[0014] Figure 1 is the inner unfolded view of the graphite sealing ring provided by the present invention;

[0015] Figure 2 is the three-dimensional view of the fish-scale-like micro-texture structure;

[0016] Figure 3 It is an enlarged view of the fish-scale-like micro-texture structure;

[0017] Figure 4 It is a diagram of the fluid flow state in the central area of the fish-scale-like unit;

[0018] Figure 5 It is a planar projection view of the fish-scale-like unit;

[0019] Figure 6 It is a schematic diagram of the planar projection of multiple fish-scale-like units. Specific embodiments

[0020] The following will further explain the present utility model in combination with specific implementation schemes, but it is not limited to the present utility model.

[0021] As Figures 1 to 6 shown, the present utility model provides a hydrodynamic groove for a graphite sealing ring, including: a fish-scale-like micro-texture structure 5 is arranged on the surface of the hydrodynamic groove of the graphite sealing ring, and the fish-scale-like micro-texture structure 5 is composed of fish-scale-like units 1 arranged in layers and staggered and stacked. Among them, along the flow direction of the fluid, the thickness of each fish-scale-like unit 1 gradually increases. Adjacent two fish-scale-like units 1 in the same layer are arranged at intervals and respectively form a stepped structure with the fish-scale-like units 1 in the lower layer.

[0022] The hydrodynamic groove of the graphite sealing ring can improve the boundary layer state by arranging a fish-scale-like micro-texture structure on its surface. As Figure 1 shown, when the fluid enters the sealing ring 2, the axial groove 3 plays a role in guiding the flow and will introduce the fluid into the circumferential groove 4 for balancing the pressure. At the same time, the fluid will enter the hydrodynamic groove. When the fluid passes through the fish-scale-like micro-texture structure on the surface of the hydrodynamic groove, as Figure 3 shown, most of the fluid will flow along the Figure 3 arrow direction in, that is, along the stepped areas on both sides of the fish-scale-like unit. And the fluid in the central area of the fish-scale-like unit will also flow towards the stepped areas on both sides of the fish-scale-like unit under the action of pressure. Due to the action of pressure, the flow velocity of this part of the fluid will increase, thereby increasing the overall flow velocity of the stepped area. In addition, as Figure 4 shown, when the fluid enters the lower fish-scale-like unit from the upper fish-scale-like unit, a recirculation area will appear behind the step. The fluid flows along the SR direction, and then the fluid adheres to the wall surface, continues to flow and enters the next layer of fish-scale-like unit. In this way, during the airflow flow process, the direct contact with the wall surface is weakened, the lubricity near the wall surface is improved, the friction is reduced, the airflow velocity is increased, the boundary layer is made thinner, the airflow flow rate is increased, the hydrodynamic effect is increased, the opening force of the graphite seal is increased, the sealing ring and the sealing runway can tend to be non-contact, thereby reducing the friction and wear degree of the graphite seal and prolonging the working life of the seal.

[0023] As an improvement to the technical solution, as Figure 2 shown, the fish-scale-like unit 1 includes one upper surface and three side surfaces. Among them, the upper surface is an inclined surface, and the upper surface includes a leading edge, a trailing edge and two side edges. The leading edge intersects with the wall surface of the dynamic pressure groove, and the trailing edge and the two side edges are respectively connected to the wall surface of the dynamic pressure groove through the three side surfaces.

[0024] As an improvement to the technical solution, as Figure 5 shown, the fish-scale-like unit 1 has an axisymmetric structure. The projection of the fish-scale-like unit 1 on the plane is approximately fan-shaped, and the fan shape is composed of four arcs connected in sequence. Among them, the curve equation of the first arc A is: x 2 +y 2 =R 2 . The curve equation of the second arc B is: The curve equation of the third arc C is: x 2 +(y - R) 2 =R 2 . The curve equation of the fourth arc D is: In the formula, R is the radius of the arc, R = h / tanα, h is the height of the trailing edge of the upper surface of the fish-scale-like unit 1, and α is the included angle between the upper surface of the fish-scale-like unit 1 and the wall surface of the dynamic pressure groove (as Figure 2 , Figure 4 shown).

[0025] As an improvement to the technical solution, the included angle α between the upper surface of the fish-scale-like unit 1 and the wall surface of the dynamic pressure groove is 2° to 5°.

[0026] As an improvement to the technical solution, the height h of the trailing edge of the upper surface of the fish-scale-like unit 1 = 0.2δ, where δ is the boundary layer thickness.

[0027] As an improvement to the technical solution, as Figure 6 shown, in the fish-scale-like micro-texture structure, the fish-scale-like unit 1 includes a first fish-scale-like unit 11, a second fish-scale-like unit 12, a third fish-scale-like unit 13 and a fourth fish-scale-like unit 14. The second fish-scale-like unit 12 and the third fish-scale-like unit 13 are both located on the lower layer of the first fish-scale-like unit 11 and are respectively located on both sides of the first fish-scale-like unit 11. The fourth fish-scale-like unit 14 is located on the lower layer of the second fish-scale-like unit 12 and the third fish-scale-like unit 13 and is located between the second fish-scale-like unit 12 and the third fish-scale-like unit 13. The third arc of the first fish-scale-like unit 11 coincides with the fourth arc of the second fish-scale-like unit 12, the first arc of the third fish-scale-like unit 13, and the second arc of the fourth fish-scale-like unit 14.

[0028] The present utility model also provides a graphite sealing ring, wherein a dynamic pressure groove of the above-mentioned graphite sealing ring is arranged on the sealing surface of the graphite sealing ring.

[0029] For this graphite sealing ring, by arranging a dynamic pressure groove with a fish-scale-like micro-texture structure, the friction between the fluid and the wall surface of the dynamic pressure groove can be reduced, the fluid flow rate can be increased, the fluid flow rate can be increased, the dynamic pressure effect can be enhanced, the opening force of the graphite seal can be increased, and the sealing ring and the sealing runway tend to be non-contact, thereby reducing the friction and wear degree of the graphite seal and extending the working life of the seal.

[0030] The specific embodiments of the present utility model are written in a progressive manner, emphasizing the differences between the various embodiments, and the similar parts can be referred to each other.

[0031] The above has described in detail the embodiments of the present utility model in conjunction with the drawings. However, the present utility model is not limited to the above embodiments, and various changes can be made without departing from the gist of the present utility model within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A hydrodynamic groove of a graphite sealing ring, characterized in that: The surface of the hydrodynamic groove of the graphite sealing ring is provided with a fish-scale-like micro-texture structure, and the fish-scale-like micro-texture structure is composed of fish-scale-like units (1) arranged layer by layer and staggered and stacked. Among them, along the flow direction of the fluid, the thickness of each fish-scale-like unit (1) gradually increases, and adjacent two fish-scale-like units (1) in the same layer are arranged at intervals and respectively form a stepped structure with the fish-scale-like unit (1) in the lower layer.

2. The hydrodynamic groove of the graphite sealing ring according to claim 1, wherein: The fish-scale-like unit (1) includes 1 upper surface and 3 side surfaces. Among them, the upper surface is an inclined surface, and the upper surface includes a leading edge, a trailing edge and two side edges. The leading edge intersects with the wall surface of the hydrodynamic groove, and the trailing edge and the two side edges are respectively connected to the wall surface of the hydrodynamic groove through the 3 side surfaces.

3. The hydrodynamic groove of the graphite sealing ring according to claim 2, wherein: The fish-scale-like unit (1) is an axisymmetric structure. The projection of the fish-scale-like unit (1) on a plane is approximately a fan-shaped ring, and the fan-shaped ring is composed of 4 arcs connected in sequence. Among them, the curve equation of the first arc is: x 2 +y 2 =R 2 , and the curve equation of the second arc is: The curve equation of the third arc is: x 2 +(y - R) 2 =R 2 , and the curve equation of the fourth arc is: In the formula, R is the radius of the arc, R = h / tanα, h is the height of the trailing edge of the upper surface of the fish-scale-like unit (1), and α is the angle between the upper surface of the fish-scale-like unit (1) and the wall surface of the dynamic pressure groove.

4. The hydrodynamic groove of the graphite sealing ring according to claim 3, characterized in that: The included angle α between the upper surface of the fish-scale-like unit (1) and the wall surface of the hydrodynamic groove is 2° to 5°.

5. The hydrodynamic groove of the graphite sealing ring according to claim 3, wherein: The height h of the trailing edge of the upper surface of the fish-scale-like unit (1) is h = 0.2δ, where δ is the boundary layer thickness.

6. The hydrodynamic groove of the graphite sealing ring according to claim 3, wherein: In the fish-scale-like micro-texture structure, the fish-scale-like unit (1) includes a first fish-scale-like unit (11), a second fish-scale-like unit (12), a third fish-scale-like unit (13) and a fourth fish-scale-like unit (14). The second fish-scale-like unit (12) and the third fish-scale-like unit (13) are both located in the lower layer of the first fish-scale-like unit (11) and are respectively located on both sides of the first fish-scale-like unit (11). The fourth fish-scale-like unit (14) is located in the lower layer of the second fish-scale-like unit (12) and the third fish-scale-like unit (13) and is located between the second fish-scale-like unit (12) and the third fish-scale-like unit (13). The third arc of the first fish-scale-like unit (11) coincides with the fourth arc of the second fish-scale-like unit (12), the first arc of the third fish-scale-like unit (13), and the second arc of the fourth fish-scale-like unit (14).

7. A graphite sealing ring, characterized in that: The sealing surface of the graphite sealing ring is provided with the hydrodynamic groove of the graphite sealing ring according to any one of claims 1 to 6.

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