A dynamic pressure sealing device for an air compressor impeller

Abstract

The present invention discloses a dynamic pressure sealing device for an air compressor impeller, which is arranged between an end plate and an impeller, and relates to the technical field of air compressors. The dynamic pressure sealing device includes a dynamic pressure groove, a positioning ring, a movable pressure ring, a reset spring and a cylinder, wherein the first plane is provided with the dynamic pressure groove, and the dynamic pressure groove includes an annular negative pressure groove and an arc-shaped positive pressure groove uniformly arranged outside the annular negative pressure groove in the circumferential direction, and one end of the arc-shaped positive pressure groove is connected to the annular negative pressure groove. The present invention arranges a dynamic pressure groove on the back of the impeller so that the fluid flows in the dynamic pressure groove when the impeller rotates, and the cylinder pushes the movable pressure ring toward the dynamic pressure groove through the gas in the exhaust pipe of the air compressor, so that a boundary layer air film is formed between the movable pressure ring and the annular sealing area. The boundary layer air film is used as a seal. Compared with the conventional labyrinth seal, the boundary layer gap size is at the micron level, which is much smaller than the minimum gap of the labyrinth seal, and the leakage can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of air compressors, and in particular to a dynamic pressure sealing device for an impeller of an air compressor. Background Art

[0002] During the operation of the air compressor, the air is often worked with the help of an impeller. It is essential to prevent unnecessary leakage during the air compression process, and the internal seal of the air compressor is a widely used method. At present, the internal seal of the air compressor is basically a labyrinth seal structure with comb teeth evenly arranged and distributed. This kind of sealing structure needs to strictly control the gap between the comb teeth to ensure its sealing performance. Therefore, it has high requirements on processing accuracy and assembly. At the same time, the sealing effect of this sealing structure needs to be improved. Summary of the invention

[0003] The object of the present invention is to provide a dynamic pressure sealing device for an air compressor impeller to solve the problems raised in the above background technology.

[0004] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0005] The present invention provides a dynamic pressure sealing device for an air compressor impeller, which is arranged between an end plate and an impeller, wherein opposite sides of the impeller and the end plate are respectively a first plane and a second plane, and the dynamic pressure sealing device comprises a dynamic pressure groove, a positioning ring, a movable pressure ring, a return spring and a cylinder, wherein the dynamic pressure groove is opened on the first plane, and the dynamic pressure groove comprises an annular negative pressure groove and an arc-shaped positive pressure groove evenly arranged outside the annular negative pressure groove along the circumferential direction, one end of the arc-shaped positive pressure groove is connected with the annular negative pressure groove, and the dynamic pressure groove forms an annular sealing area on the first plane; the positioning ring is coaxial with the annular sealing area and is fixed on the second plane, the movable pressure ring is sealingly slidably arranged on the outside of the positioning ring, and the movable pressure ring corresponds to the annular sealing area, the cylinder and the return spring are both assembled between the movable pressure ring and the second plane, and the cylinder is connected to the exhaust pipeline of the air compressor through a pipeline.

[0006] Furthermore, the arc-shaped positive pressure groove includes an outer arc edge, an inner arc edge and an end straight edge, and the distance between the outer arc edge and the inner arc edge increases continuously from one end to the other end of the annular negative pressure groove.

[0007] Furthermore, a sealing ring is embedded on the outer wall of the positioning ring, and the sealing ring is within the sliding stroke of the movable pressure ring.

[0008] Furthermore, there are multiple return springs, and the multiple return springs are evenly arranged between the movable pressure ring and the second plane along the circumferential direction.

[0009] Furthermore, mounting holes are evenly arranged on the end plate in the annular sealing area along the circumferential direction, and the cylinder is installed in each mounting hole;

[0010] The cylinder includes a cylinder body fixedly assembled in a mounting hole, a piston sealingly and slidably arranged in the cylinder body, and a movable rod coaxially fixed on the side of the piston close to a movable pressure ring. The movable rod extends at one end away from the piston and is fixedly connected to the movable pressure ring. An air inlet is provided at one end of the cylinder body away from the movable pressure ring, and the air inlet is connected to an exhaust pipeline of an air compressor through a pipeline.

[0011] Furthermore, the movable pressure ring is hollow inside to form an annular air pressure chamber open to one side of the annular sealing area, a high-strength elastic membrane is provided at the opening of the annular air pressure chamber, and an air inlet passage connected to the annular air pressure chamber is axially penetrated on the piston and the movable rod.

[0012] Furthermore, an exhaust pipe is provided on the movable pressure ring, and an exhaust valve is provided on the exhaust pipe.

[0013] Furthermore, the positioning ring is evenly provided with through grooves along the circumferential direction, and the inner side of the movable pressure ring is provided with a sliding member slidably fitted in the through groove.

[0014] Furthermore, an annular exhaust pipe is coaxially provided on the inner side of the positioning ring, and one end of each sliding member away from the movable pressure ring is fixedly connected to the annular exhaust pipe, one of the sliding members is an exhaust pipe, and one end of the exhaust pipe away from the movable pressure ring is connected to the inside of the annular exhaust pipe; the side of the annular exhaust pipe close to the impeller is evenly provided with exhaust grooves inclined toward the annular sealing area along the circumferential direction.

[0015] Compared with the prior art, one or more of the above technical solutions have the following beneficial effects:

[0016] The present invention arranges a dynamic pressure groove on the back side of the impeller so that the fluid flows in the dynamic pressure groove when the impeller rotates, and the gas in the exhaust pipe of the air compressor causes the cylinder to push the movable pressure ring toward the dynamic pressure groove, thereby forming a boundary layer air film between the movable pressure ring and the annular sealing area. The boundary layer air film is used as a seal. Compared with a conventional labyrinth seal, the boundary layer gap size is at the micron level, which is much smaller than the minimum gap of the labyrinth seal, and can greatly reduce leakage.

[0017] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 It is a schematic diagram of the end cover and impeller structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the impeller of the present invention from a first perspective;

[0021] Figure 3 This is a schematic diagram of the structure of the impeller of the present invention from a second viewing angle;

[0022] Figure 4 This is a schematic structural diagram of the end cover of the present invention from a first viewing angle;

[0023] Figure 5 is a schematic structural diagram of the end cover of the present invention from a second viewing angle;

[0024] Figure 6 It is a schematic diagram of the back structure of the end cover of the present invention;

[0025] Figure 7 yes Figure 6 Schematic diagram of CC structure;

[0026] Figure 8 yes Figure 7 Schematic diagram of the local structure at A;

[0027] Fig. 9 It is a schematic diagram of the cutaway three-dimensional structure of the end cover and the impeller of the present invention;

[0028] Fig.10 yes Fig. 9 Schematic diagram of the structure at B;

[0029] Fig.11 It is a schematic diagram of the air pressure distribution in the dynamic pressure groove during the rotation of the impeller of the present invention.

[0030] In the figure:

[0031] 1-impeller; 11-first plane; 12-annular sealing area; 2-end plate; 21-second plane; 22-mounting hole; 3-dynamic pressure groove; 31-annular negative pressure groove; 32-arc-shaped positive pressure groove; 321-outer arc edge; 322-inner arc edge; 323-end straight edge; 4-positioning ring; 41-sealing ring; 42-through groove; 5-movable pressure ring; 51-annular air pressure chamber; 52-high-strength elastic membrane; 53-exhaust pipe; 531-exhaust valve; 55-annular exhaust pipe; 551-exhaust groove; 6-reset spring; 7-cylinder; 71-cylinder body; 72-piston; 73-movable rod; 74-inlet. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0033] See also Figure 1-Figure 11 The present invention provides a dynamic pressure sealing device for an air compressor impeller 1, which is arranged between the impeller 1 and the end plate 2 and the impeller 1, wherein the opposite sides of the impeller 1 and the end plate 2 are respectively a first plane 11 and a second plane 21, and the dynamic pressure sealing device comprises a dynamic pressure groove 3, a positioning ring 4, a movable pressure ring 5, a return spring 6 and a cylinder 7, wherein the first plane 11 is provided with the dynamic pressure groove 3, and the dynamic pressure groove 3 comprises an annular negative pressure groove 31 and an arc-shaped positive pressure groove 32 uniformly arranged outside the annular negative pressure groove 31 in the circumferential direction, and the arc-shaped positive pressure groove 32 is provided outside the annular negative pressure groove 31. One end of the groove 32 is connected to the annular negative pressure groove 31, and the dynamic pressure groove 3 forms an annular sealing area 12 on the first plane 11; the positioning ring 4 is coaxial with the annular sealing area 12 and is fixed on the second plane 21, and the movable pressure ring 5 is sealingly slidably arranged on the outside of the positioning ring 4, and the movable pressure ring 5 corresponds to the annular sealing area 12, the cylinder 7 and the return spring 6 are both assembled between the movable pressure ring 5 and the second plane 21, and the cylinder 7 is connected to the exhaust pipe 53 (not shown) of the air compressor through a pipeline (not shown).

[0034] When the air compressor is not running, no pressure is formed in the exhaust pipe 53 of the air compressor, that is, no pressure is formed in the cylinder 7, and the cylinder 7 has no thrust. Under the elastic force of the return spring 6, the movable pressure ring 5 moves away from the annular sealing area 12 to avoid dry grinding between the movable pressure ring 5 and the first plane 11 of the impeller 1 when the air film with sufficient rigidity has not been formed in the annular sealing area 12 during the initial startup of the air compressor;

[0035] After the air compressor has been running for a period of time, pressure is formed in the exhaust pipe 53 of the air compressor, and the gas in the exhaust pipe 53 enters the cylinder 7, so that air pressure is formed in the cylinder 7, and the cylinder 7 generates thrust and pushes the movable pressure ring 5 to move toward the annular sealing area 12. In this process, due to the design of the dynamic pressure groove 3, the fluid flows in the annular sealing area 12, and a boundary layer air film is formed between the movable pressure ring 5 and the annular sealing area 12. As the movable pressure ring 5 continues to move toward the annular sealing area 12, the thickness of the boundary layer air film gradually decreases. Correspondingly, the stiffness of the air film becomes higher and higher until the thrust of the cylinder 7 and the reverse thrust of the air film reach a balance. At this time, the thickness of the air film is only a few microns, and the air film forms a sealing layer between the movable pressure ring 5 and the annular sealing area 12, thereby achieving sealing. Compared with conventional labyrinth seals, the boundary layer gap size of the present invention is at the micron level, which is much smaller than the minimum gap of the labyrinth seal, which can greatly reduce the leakage and improve the sealing effect.

[0036] like Figure 3 As shown, in a specific embodiment of the present invention, the arc-shaped positive pressure groove 32 includes an outer arc edge 321, an inner arc edge 322 and an end straight edge 333, and the distance between the outer arc edge 321 and the inner arc edge 322 increases continuously from one end to the other end of the annular negative pressure groove 31, and the length of the inner arc edge 322 is greater than the length of the inner arc edge 322. Based on the above design, during the rotation of the impeller 1, the gas in the annular negative pressure groove 31 will continuously move toward the arc-shaped positive pressure groove 32, so that the annular sealing area 12 forms a boundary layer gas film, and in the dynamic pressure groove 3, the pressure increases continuously from the inside to the outside.

[0037] like Figure 8 As shown, in a specific embodiment of the present invention, a sealing ring 41 is embedded on the outer wall of the positioning ring 4, and the sealing ring 41 is within the sliding stroke of the movable pressing ring 5. Based on the above design, the sealing ring 41 can achieve sliding sealing between the positioning ring 4 and the movable pressing ring 5.

[0038] Combination Figure 7 and Figure 8 As shown, in a specific embodiment of the present invention, there are multiple return springs 6, and the multiple return springs 6 are evenly arranged between the movable pressure ring 5 and the second plane 21 along the circumferential direction. Based on the above design, when the air compressor is not running, the elastic force of the multiple return springs 6 can evenly act on the movable pressure ring 5 to pull the movable pressure ring 5 to move smoothly away from the annular sealing area 12.

[0039] Combination Figure 7 and Figure 8 As shown, in a specific embodiment of the present invention, mounting holes 22 are evenly arranged on the end plate 2 in the annular sealing area 12 along the circumferential direction, and the cylinder 7 is installed in each mounting hole 22;

[0040] like Fig.10 As shown, the cylinder 7 includes a cylinder body 71 fixedly assembled in the mounting hole 22, a piston 72 sealingly and slidably arranged in the cylinder body 71, and a movable rod 73 coaxially fixed on the side of the piston 72 close to the movable pressure ring 5, the movable rod 73 extends from one end away from the piston 72 and is fixedly connected to the movable pressure ring 5, and an air inlet 74 is provided at one end of the cylinder body 71 away from the movable pressure ring 5, and the air inlet 74 is connected to the exhaust pipe 53 of the air compressor through a pipeline.

[0041] Based on the above design, when pressure is formed in the exhaust pipe 53 of the air machine, gas can enter the cylinder body 71 from the air inlet 74 through the pipeline, pushing the piston 72 to move toward the side of the annular sealing area 12, thereby pushing the movable pressure ring 5 to move toward the side of the annular sealing area 12 through the movable rod 73.

[0042] like Fig.10 As shown, in a specific embodiment of the present invention, the interior of the movable pressure ring 5 is hollow to form an annular air pressure chamber 51 which is open to the annular sealing area 12, and a high-strength elastic membrane 52 is provided at the opening of the annular air pressure chamber 51, and an air inlet passage which is connected to the annular air pressure chamber 51 is axially penetrated on the piston 72 and the movable rod 73.

[0043] Based on the above design, the present invention can introduce the gas in the cylinder 7 into the annular air pressure chamber 51 through the air intake channel, so that the high-strength elastic membrane 52 undergoes different deformations corresponding to different annular sealing areas. It can be understood that the high-strength elastic membrane 52 in the high-pressure area of ​​the annular sealing area has a smaller deformation, and the high-strength elastic membrane 52 in the low-pressure area of ​​the annular sealing area has a larger deformation, thereby increasing the stiffness of the air film between the annular sealing area and the movable pressure ring 5 as much as possible to further improve the sealing effect.

[0044] It is additionally noted that if Fig.11 As shown, the closer to the outside of the annular sealing area 12, the greater the air pressure. If the movable pressure ring 5 is a hard structure, when the thrust of the cylinder 7 and the reverse thrust of the air film reach a balance, at this time, the air film stiffness of the low-pressure area in the annular sealing area 12 will be smaller than the air film stiffness of the high-pressure area. The present invention allows the high-strength elastic film 52 to deform differently in different corresponding annular sealing areas, so that the air film stiffness area of ​​each part in the annular sealing area 12 can reach the maximum in a consistent manner, thereby further improving the sealing effect.

[0045] like Fig.10 As shown, in a specific embodiment of the present invention, the movable pressure ring 5 is provided with an exhaust pipe 53, and the exhaust pipe 53 is provided with an exhaust valve 531. Based on the above design, the present invention can adjust the air pressure in the annular air pressure chamber 51 through the exhaust valve 531, so that the annular air pressure chamber 51 maintains a suitable air pressure.

[0046] like Fig.10 As shown, in a specific embodiment of the present invention, the positioning ring 4 is evenly provided with through grooves 42 along the circumferential direction, and the inner side of the movable pressure ring 5 is provided with a sliding member that is slidably fitted in the through groove 42. Based on the above design, the present invention can lock the circumferential rotation of the sliding member through the sliding member, so that it can only slide along the axial direction of the positioning ring 4, thereby preventing the sliding member from rotating relative to each other during the sealing process.

[0047] like Fig.10 As shown, in a specific embodiment of the present invention, an annular exhaust pipe 5553 is coaxially provided on the inner side of the positioning ring 4, and one end of each sliding member away from the movable pressure ring 5 is fixedly connected to the annular exhaust pipe 5553, one of the sliding members is an exhaust pipe 53, and one end of the exhaust pipe 53 away from the movable pressure ring 5 is connected to the inside of the annular exhaust pipe 5553; the annular exhaust pipe 5553 is evenly provided with exhaust grooves 551 inclined toward the annular sealing area 12 along the circumferential direction on one side close to the impeller 1. Based on the above design, the present invention can collect the gas in the exhaust pipe 53 and introduce it into the annular exhaust pipe 5553, and then evenly discharge it through the exhaust groove 551, so that the discharged gas is slowly replenished into the annular negative pressure groove 31, thereby reducing the negative pressure value in the annular negative pressure groove 31, thereby improving the sealing effect.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A dynamic pressure sealing device for an air compressor impeller, arranged between an end plate and an impeller, wherein the side of the impeller close to the end plate is a first plane, and the side of the end plate close to the impeller is a second plane, characterized in that: The dynamic pressure sealing device comprises a dynamic pressure groove, a positioning ring, a movable pressure ring, a return spring and a cylinder, wherein the dynamic pressure groove is opened on the first plane, the dynamic pressure groove comprises an annular negative pressure groove and an arc-shaped positive pressure groove uniformly arranged outside the annular negative pressure groove in the circumferential direction, one end of the arc-shaped positive pressure groove is connected with the annular negative pressure groove, and the dynamic pressure groove forms an annular sealing area on the first plane; the positioning ring is coaxial with the annular sealing area and fixed on the second plane, the movable pressure ring is sealingly slidably arranged on the outside of the positioning ring, and the movable pressure ring corresponds to the annular sealing area, the return spring is assembled between the movable pressure ring and the second plane, the cylinder is embedded in the end plate, and the cylinder is connected to the exhaust pipeline of the air compressor through a pipeline; A sealing ring is embedded on the outer wall of the positioning ring, and the sealing ring is within the sliding stroke of the movable pressure ring; The end plate in the annular sealing area is evenly provided with mounting holes along the circumferential direction, and the cylinder is installed in each mounting hole; The cylinder includes a cylinder body fixedly assembled in a mounting hole, a piston sealingly and slidably arranged in the cylinder body, and a movable rod coaxially fixed on the side of the piston close to a movable pressure ring. The movable rod extends at one end away from the piston and is fixedly connected to the movable pressure ring. An air inlet is provided at one end of the cylinder body away from the movable pressure ring, and the air inlet is connected to an exhaust pipeline of an air compressor through a pipeline.

2. The dynamic pressure sealing device for an air compressor impeller according to claim 1, characterized in that: The arc-shaped positive pressure groove comprises an outer arc edge, an inner arc edge and an end straight edge, and the distance between the outer arc edge and the inner arc edge increases continuously from one end to the other end of the annular negative pressure groove.

3. The dynamic pressure sealing device for an air compressor impeller according to claim 1, characterized in that: There are multiple return springs, and the multiple return springs are evenly arranged between the movable pressure ring and the second plane along the circumferential direction.

4. The dynamic pressure sealing device for an air compressor impeller according to claim 1, characterized in that: The movable pressure ring is hollow inside to form an annular air pressure chamber open to one side of the annular sealing area, a high-strength elastic membrane is arranged at the opening of the annular air pressure chamber, and an air inlet passage connected to the annular air pressure chamber is axially penetrated on the piston and the movable rod.

5. The dynamic pressure sealing device for an air compressor impeller according to claim 4, characterized in that: The movable pressure ring is provided with an exhaust pipe, and the exhaust pipe is provided with an exhaust valve.

6. The dynamic pressure sealing device for an air compressor impeller according to claim 5, characterized in that: The positioning ring is evenly provided with through grooves along the circumferential direction, and the inner side of the movable pressure ring is provided with a sliding piece slidably fitted in the through grooves.

7. The dynamic pressure sealing device for an air compressor impeller according to claim 6, characterized in that: An annular exhaust pipe is coaxially provided on the inner side of the positioning ring, and one end of each sliding member away from the movable pressure ring is fixedly connected to the annular exhaust pipe, one of the sliding members is an exhaust pipe, and the end of the exhaust pipe away from the movable pressure ring is connected to the inside of the annular exhaust pipe; the side of the annular exhaust pipe close to the impeller is evenly provided with exhaust grooves inclined toward the annular sealing area along the circumferential direction.

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