High-rotating-speed labyrinth contact type air seal

Abstract

The high-rotating-speed labyrinth contact type air seal is used for sealing the low-pressure side and the high-pressure side of a pivoting assembly, and the pivoting assembly comprises a box body, a transmission shaft and a rotating part; vent holes communicated with an inner cavity of the box body are formed in the outer wall of the box body, the transmission shaft is rotationally installed in the box body, and the rotating piece is fixed to the end, extending out of the box body, of the rotating shaft; in the pivoting assembly, the two sides of the vent hole are the low-pressure side and the high-pressure side respectively; wherein one side provided with the rotating piece is a low-voltage side, and the other side is a high-voltage side; an axial sealing assembly is arranged between the box body and the transmission shaft, a radial sealing assembly is arranged between the box body and the rotating piece, and the axial sealing assembly and the radial sealing assembly are both arranged on the low-pressure side of the pivoting assembly. According to the scheme, the axial sealing assembly is used for sealing the pivoting assembly in the axial direction, the axial sealing assembly is used for sealing the rotating part and the transmission shaft in the radial direction, then the sealing effect of the air seal is better, and the efficiency of the whole machine is improved.

Description

Technical Field

[0001] The invention relates to the field of high-speed sealing structures, and in particular to a high-speed labyrinth contact type air seal. Background Art

[0002] When a gearbox equipped with an impeller runs at high speed, a high-pressure environment will be formed inside the box, and a low-pressure environment will be formed when the impeller side rotates at high speed; the air vents on the gearbox are connected to the atmospheric pressure, which in turn forms various pressure differences on the pivot assembly, causing the lubricating oil on the gearbox side to be at risk of leakage, and the atmospheric pressure gas to be at risk of running to the impeller side.

[0003] The prior art with publication number CN217582569U discloses an integrated gas seal and oil seal structure for a centrifugal fan, the integrated gas seal and oil seal structure comprising an oil seal part and a gas seal part, the outer wall of the oil seal part is provided with an O-ring retaining groove 1, the inner wall of the oil seal part is provided with an oil seal groove 1, the main shaft is provided with an oil unloading groove 1, the inner wall of the gas seal part is provided with an gas seal groove, the middle part of the gas seal groove is provided with an air release groove, the left end face of the oil seal part cooperates with the right outer ring of the bearing, the outside of the gas seal part is provided with an inner cavity of the fan, the left side of the bearing seat and the bearing is provided with a bearing pressure cover, one side of the bearing pressure cover is provided with an O-ring retaining groove 2, the main shaft is provided with an oil unloading groove 2, the bottom of the oil seal part is provided with an oil path connecting groove 1, and the bottom of the bearing pressure cover is provided with an oil path connecting groove 2.

[0004] The structure in the prior art can only seal from the axial direction of the main shaft, and the gas seal part and the main shaft are matched only through the end faces, so that the air tightness of the gas seal and oil seal set is poor. Summary of the invention

[0005] In order to solve the problem of poor air tightness on the high-pressure side and the low-pressure side of the pivot assembly under high-speed operation in the prior art, an object of the present invention is to provide a high-speed labyrinth contact air seal having better sealing effect.

[0006] In order to achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a high-speed labyrinth contact gas seal is used to seal the low-pressure side and the high-pressure side of the pivot assembly, the pivot assembly includes a housing, a transmission shaft and a rotating part; a vent hole connected to its inner cavity is arranged on the outer wall of the housing, the transmission shaft is rotatably installed in the housing, and the rotating part is fixed to one end of the rotating shaft extending out of the housing; in the pivot assembly, the two sides of the vent hole are respectively the low-pressure side and the high-pressure side; the side on which the rotating part is installed is the low-pressure side, and the other side is the high-pressure side; an axial sealing assembly is arranged between the housing and the transmission shaft, and a radial sealing assembly is arranged between the housing and the rotating part, and both the axial sealing assembly and the radial sealing assembly are arranged on the low-pressure side of the pivot assembly.

[0007] Preferably, the axial sealing assembly includes an air sealing ring and an axial air seal; the air sealing ring sleeve is arranged on the transmission shaft, the air sealing ring is tightly fitted with the transmission shaft, the axial air sealing sleeve is arranged on the air sealing ring, the axial air seal is fixedly connected to the casing, and a labyrinth sealing structure is arranged between the axial air seal and the air sealing ring.

[0008] Preferably, the labyrinth sealing structure includes a first sealing portion, a second sealing portion and a third sealing portion arranged on the axial air seal, and the first sealing portion, the second sealing portion and the third sealing portion all protrude from the inner wall of the axial air seal; the second sealing portion is located between the two first sealing portions, and the first sealing portion cooperates with the outer wall of the air seal ring; a plurality of axially arranged first grooves are arranged on the outer wall of the air seal ring, and the plurality of second sealing portions correspond one-to-one to the plurality of first grooves, and the second sealing portions extend into the first grooves; the plurality of third sealing portions correspond one-to-one to the plurality of second sealing portions, the plurality of second sealing portions and the plurality of third sealing portions are alternately arranged, and the third sealing portions cooperate with the outer wall of the air seal ring.

[0009] Preferably, the third sealing portion comprises third sealing teeth, fourth sealing teeth and fifth sealing teeth, which are arranged in sequence and axially, and have different heights.

[0010] Preferably, the fourth sealing teeth, the fifth sealing teeth and the third sealing teeth are arranged in sequence from the low-pressure side to the high-pressure side.

[0011] Preferably, the fourth sealing tooth and the fifth sealing tooth are clearance-fitted, and the fifth sealing tooth and the third sealing tooth are tight-fitted.

[0012] Preferably, the height of the fourth sealing tooth is lower than that of the third sealing tooth, and the height of the third sealing tooth is lower than that of the fifth sealing tooth.

[0013] Preferably, the end surface of the rotating member facing the transmission shaft is a radial sealing surface, a third groove is arranged on the radial sealing surface, one end of the air sealing ring extends into the third groove, and the air sealing ring cooperates with the third groove to form a sealing structure.

[0014] Preferably, the radial sealing assembly includes a radial air seal, which is fixed on the axial air seal. The radial air seal is provided with a sixth sealing tooth and a seventh sealing tooth, which are alternately arranged. The sixth sealing tooth cooperates with the radial sealing surface of the rotating part to form a sealing structure. A fourth groove is also provided on the radial sealing surface. One end of the seventh sealing tooth extends into the fourth groove. The seventh sealing tooth cooperates with the inner wall of the fourth groove to form a sealing gap.

[0015] Preferably, the length of the sixth sealing tooth is shorter than that of the seventh sealing tooth.

[0016] The beneficial effects of the technical solution of the present invention are: the axial direction of the pivot assembly is sealed by the axial sealing assembly, and the radial direction of the rotating part and the transmission shaft is sealed by the axial sealing assembly, thereby making the air seal effect better and improving the efficiency of the whole machine; the above-mentioned sealing structure is simpler to manufacture, easy to install and replace, which not only reduces maintenance costs, but also has a wider and safer application environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a high-speed labyrinth contact gas seal; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 It is a schematic diagram of the connection structure of the gas seal ring, radial gas seal and axial gas seal; Figure 4 for Figure 3 Enlarged view of point B in the middle; Figure 5 It is a schematic diagram of the structure of the gas sealing ring; Figure 6 It is a schematic diagram of the structure of the axial gas seal; Figure 7 It is a schematic diagram of the structure of the impeller and the transmission shaft.

[0018] Reference numerals: 1, rotating member; 11, radial sealing surface; 12, third groove; 13, fourth groove; 2. transmission shaft; 21. first mounting portion; 22. second mounting portion; 23. third mounting portion; 24. first positioning portion; 25. second positioning portion; 3. Box body; 31. Ventilation hole; 32. First clamping protrusion; 33. Second clamping protrusion; 34. Third clamping protrusion; 35. Oil inlet; 4. Sliding bearing; 41. Lubricating oil channel; 5. gas sealing ring; 51. first groove; 52. fifth groove; 6. Axial gas seal; 61. First sealing part; 62. Second groove; 63. First clamping part; 64. Second sealing part; 65. Third sealing part; 651. Third sealing tooth; 652. First sealing member; 6521. Second clamping part; 6522. Fourth sealing tooth; 653. Second sealing member; 6531. Fifth sealing tooth; 66. Step through hole; 7. Oil seal; 8. radial air seal; 81. sixth sealing tooth; 82. seventh sealing tooth; 83. fourth sealing portion; 9. Bolts; 10. Sealing ring. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0022] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. Example

[0024] like Figures 1 to 7A high-speed labyrinth contact gas seal is shown, which is used to seal the low-pressure side and the high-pressure side of the pivot assembly. The pivot assembly includes a housing 3, a transmission shaft 2 and a rotating member 1. The housing 3 is provided with a vent hole 31 connected to its inner cavity on the outer wall. The transmission shaft 2 is rotatably installed in the housing 3. The rotating member 1 is fixed to one end of the rotating shaft extending out of the housing 3. In the pivot assembly, the two sides of the vent hole 31 are respectively a low-pressure side and a high-pressure side; the side where the rotating member 1 is installed is the low-pressure side, and the other side is the high-pressure side; An axial sealing assembly is provided between the housing 3 and the transmission shaft 2, and a radial sealing assembly is provided between the housing 3 and the rotating member 1. Both the axial sealing assembly and the radial sealing assembly are provided on the low-pressure side of the pivot assembly.

[0025] The high-speed operation of the pivot assembly will form a high-pressure environment in the casing, and the high-speed rotation of the impeller side will form a low-pressure environment; the vents on the casing are connected to the atmospheric pressure, which in turn forms various pressure differences on the pivot assembly, thereby causing the lubricating oil on the gearbox side to leak; the atmospheric pressure gas is at risk of running to the impeller side; the above scheme is adopted to seal the axial direction of the pivot assembly through the axial sealing assembly, and to seal the radial direction of the rotating part 1 and the transmission shaft 2 through the axial sealing assembly, thereby making the air seal effect better and improving the efficiency of the whole machine; the above sealing structure is simpler to manufacture, easy to install and replace, which not only reduces maintenance costs, but also has a wider and safer application environment.

[0026] In this embodiment, Figure 1 and Figure 2 As shown, the axial sealing assembly includes an air seal ring 5 and an axial air seal 6; the air seal ring 5 is sleeved on the transmission shaft 2, the air seal ring 5 is tightly fitted with the transmission shaft 2, the axial air seal 6 is sleeved on the air seal ring 5, the axial air seal 6 is fixedly connected to the housing 3, and a labyrinth sealing structure is arranged between the axial air seal 6 and the air seal ring 5.

[0027] Further preferably, Figure 2 As shown, a first clamping groove is provided on the outer wall of the axial gas seal 6, and a first clamping protrusion 32 is protruded on the inner wall of the box body 3, and the first clamping protrusion 32 is embedded in the first clamping groove.

[0028] In this embodiment, Figure 3 and Figure 4 As shown, the labyrinth seal structure includes a first sealing portion 61, a second sealing portion 64 and a third sealing portion arranged on the axial gas seal 6, and the first sealing portion 61, the second sealing portion 64 and the third sealing portion 65 all protrude from the inner wall of the axial gas seal 6; The second sealing portion 64 is located between the two first sealing portions 61, and the first sealing portion 61 cooperates with the outer wall of the gas sealing ring 5; a plurality of axially arranged first grooves 51 are provided on the outer wall of the gas sealing ring 5, and the plurality of second sealing portions 64 correspond one-to-one to the plurality of first grooves 51, and the second sealing portions 64 extend into the first grooves 51; the plurality of third sealing portions 65 correspond one-to-one to the plurality of second sealing portions 64, and the plurality of second sealing portions 64 and the plurality of third sealing portions 65 are alternately arranged, and the third sealing portions 65 cooperate with the outer wall of the gas sealing ring 5.

[0029] Further preferably, the first sealing portion 61 includes at least two first sealing teeth protruding from the inner wall of the axial gas seal 6 .

[0030] Further preferably, the second sealing portion 64 includes at least one second sealing tooth protruding from the inner wall of the axial gas seal 6 .

[0031] In order to further improve the sealing performance of the air-sealing structure, in this embodiment, the third sealing portion 65 includes a third sealing tooth 651, a fourth sealing tooth 6522 and a fifth sealing tooth 6531. The fourth sealing tooth 6522, the fifth sealing tooth 6531 and the third sealing tooth 651 are sequentially arranged and axially arranged, and the third sealing tooth 651, the fourth sealing tooth 6522 and the fifth sealing tooth 6531 have different heights. Such an arrangement can effectively change the sealing path in the air seal, thereby further improving the sealing performance of the air-sealing structure.

[0032] Further preferably, the fourth sealing teeth 6522 , the fifth sealing teeth 6531 and the third sealing teeth 651 are sequentially arranged in a direction from the low-pressure side to the high-pressure side.

[0033] Further preferably, the fourth sealing tooth 6522 and the fifth sealing tooth 6531 are clearance-fitted, and the fifth sealing tooth 6531 and the third sealing tooth 651 are tight-fitted.

[0034] Further preferably, the height of the fourth sealing tooth 6522 is lower than that of the third sealing tooth 651 , and the height of the third sealing tooth 651 is lower than that of the fifth sealing tooth 6531 .

[0035] Further preferably, Figure 4As shown, the fourth sealing tooth 6522 is arranged on the first sealing member 652, the fifth sealing tooth 6531 is arranged on the second sealing member 653, and the first sealing member 652 and the second sealing member 653 are both clamped with the axial gas seal 6. Specifically, a second groove 62 is arranged on the inner wall of the axial gas seal 6, a first clamping portion 63 is protruded on the inner wall of the second groove 62, a second clamping portion 6521 is protruded on the first sealing member 652, and the second sealing member 653 is bent to form a fifth sealing tooth 6531 and a locking portion, the second clamping portion 6521 and the locking portion are located in the second groove 62, and the second clamping portion 6521 is located between the first clamping portion 63 and the positioning portion; the positioning portion and the fifth sealing tooth 6531 are respectively pressed against the inner wall of the second groove 62 which is arranged opposite to each other, thereby fixing the first sealing member 652 on the axial gas seal 6.

[0036] Further preferably, the second sealing tooth is arranged on the first clamping portion 63 .

[0037] In this embodiment, Figure 4 As shown, in the cross section of the first sealing tooth, the end surface of the first sealing tooth facing away from the rotating member 1 is a straight surface, and the end surface of the first sealing tooth facing the rotating member 1 includes a first inclined surface, a first curved surface and a first straight surface arranged in sequence from the inside to the outside; in the cross section of the second sealing tooth, the end surface of the first sealing tooth facing away from the rotating member 1 is vertical, and the end surface of the second sealing tooth facing the rotating member 1 includes a second inclined surface, a second curved surface and a second straight surface arranged in sequence from the inside to the outside; in the cross section of the third sealing tooth 651, the end surface of the third sealing tooth facing away from the rotating member 1 is vertical, and the end surface of the third sealing tooth facing the rotating member 1 includes a third inclined surface, a third curved surface and a third straight surface arranged in sequence from the inside to the outside; in the cross section of the fourth sealing tooth 6522, the end surface of the fourth sealing tooth facing away from the rotating member 1 includes a fourth inclined surface, a fourth curved surface and a fourth straight surface arranged in sequence from the inside to the outside, and the end surface of the fourth sealing tooth facing the rotating member 1 is vertical; the cross section of the fifth sealing tooth 6531 is rectangular. Such an arrangement can change the air passage of the labyrinth sealing structure, thereby improving the air tightness of the labyrinth sealing structure.

[0038] In this embodiment, Figure 2 , Figure 3 , Figure 5 and Figure 7 As shown, the end surface of the rotating member 1 facing the transmission shaft 2 is a radial sealing surface 11, and a third groove 12 is provided on the radial sealing surface 11. One end of the gas sealing ring 5 extends into the third groove 12, and the gas sealing ring 5 cooperates with the third groove 12 to form a sealing structure. In this way, it is possible to seal between the transmission shaft 2 and the rotating member 1, further improving the sealing performance of the pivot assembly.

[0039] In this embodiment, Figure 4 and Figure 6As shown, the radial sealing assembly includes a radial gas seal 8, which is fixed on the axial gas seal 6, and is provided with a sixth sealing tooth 81 and a seventh sealing tooth 82, which are alternately arranged, and the sixth sealing tooth 81 cooperates with the radial sealing surface 11 of the rotating member 1 to form a sealing structure, and the radial sealing surface 11 is also provided with a fourth groove 13, one end of the seventh sealing tooth 82 extends into the fourth groove 13, and the seventh sealing tooth 82 cooperates with the inner wall of the fourth groove 13 to form a sealing gap. Such an arrangement can further improve the sealing performance of the pivot assembly.

[0040] Further preferably, Figure 6 As shown, a fifth inclined surface is provided on the end of the sixth sealing tooth 81 that cooperates with the rotating member 1, and the fifth inclined surface is provided on the end surface of the sixth sealing tooth 81 that faces away from the transmission shaft 2; a sixth inclined surface is provided on the end of the seventh sealing tooth 82 that cooperates with the rotating member 1, and the sixth inclined surface is provided on the end surface of the seventh sealing tooth 82 that faces away from the transmission shaft 2.

[0041] Further preferably, Figure 6 As shown, the length of the sixth sealing tooth 81 is shorter than that of the seventh sealing tooth 82 .

[0042] Further preferably, Figure 2 As shown, there is at least one fourth groove 13, and at least one seventh sealing tooth 82 is disposed in any fourth groove 13; at least one seventh sealing tooth 82 extends into the third groove. In this way, the radial gas seal 8 can seal the portion between the gas seal ring 5 and the rotating member 1, thereby further improving the airtightness of the sealing structure.

[0043] In order to fix the radial gas seal 8 on the axial gas seal 6, in this embodiment, as shown in FIG. Figure 2 and Figure 6 As shown, a threaded hole 64 is provided on the end face of the radial gas seal 8 facing away from the rotating member 1, and a stepped through hole 66 is provided on the end face of the axial gas seal 6 facing away from the rotating member 1. The threaded portion of the bolt 9 passes through the stepped through hole 66 and is threadedly connected with the threaded hole 64 of the radial gas seal 8, and the head of the bolt 9 is restricted in the stepped through hole 66 by the step surface in the stepped through hole 66.

[0044] In order to facilitate the positioning between the radial gas seal 8 and the axial gas seal 6, in this embodiment, as shown in FIG. Figure 3 As shown, a second groove is arranged on the end surface of the axial gas seal 6 facing the rotating member 1 , and a radial gas seal 8 is arranged in the second groove. A sealing ring 10 is arranged between the second groove and the radial gas seal 8 .

[0045] Further preferably, a first sealing groove is arranged on the inner wall of the second slot, and a sealing ring is arranged in the first sealing groove.

[0046] Further preferably, the second groove is communicated with the inner cavity of the axial gas seal 6, such as Figure 5 As shown, a fifth groove 52 is provided on the outer wall of the gas sealing ring 5. Figure 6 As shown, a fourth sealing portion 83 is protruded on the inner wall of the radial gas seal 8 , and the fourth sealing portion 83 cooperates with the inner wall of the fifth groove 52 to form a sealing structure.

[0047] In this embodiment, Figure 2 and Figure 3 As shown, an oil seal 7 is arranged between the transmission shaft 2 and the housing 3, and the oil seal 7 is arranged on the high-pressure side of the pivot assembly. Such an arrangement can effectively improve the sealing performance of the pivot assembly.

[0048] Further preferably, a second locking protrusion 33 is provided on the interior of the box body 3 , and a third locking groove is provided on the outer wall of the oil seal 7 .

[0049] More preferably, the oil seal 7 is a non-contact oil seal 7 .

[0050] In this embodiment, Figure 2 and Figure 3 As shown, a sliding bearing 4 is arranged between the rotating shaft and the housing 3, a lubricating oil passage 41 is arranged in the middle of the sliding bearing 4, and an oil inlet 35 connected to the lubricating oil passage 41 is arranged on the housing 3; the sliding bearing 4 is arranged on the high-pressure side of the pivot assembly. Such an arrangement can provide stability for the transmission shaft 2.

[0051] Further preferably, the box body 3 is provided with a third locking protrusion 34, the sliding bearing 4 is provided with a fourth locking groove, and the third locking protrusion 34 and the fourth locking groove are locked.

[0052] Further preferably, the oil seal 7 is disposed between the sliding bearing 4 and the vent hole 31 .

[0053] In order to facilitate the installation of the oil seal 7, the air seal and the sliding bearing 4, in this embodiment, Figure 2 and Figure 7 As shown, the transmission shaft 2 includes a first mounting portion 21, a second mounting portion 22 and a third mounting portion 23 which are arranged in sequence, and the outer diameters of the first mounting portion 21, the second mounting portion 22 and the third mounting portion 23 decrease in sequence; the gas seal ring 5 is sleeved on the first mounting portion 21, the oil seal 7 is mounted on the second mounting portion 22, and the sliding bearing 4 is mounted on the third mounting portion 23. In this way, a stepped oil passage is formed through the shape of the transmission shaft 2, thereby effectively preventing the low-pressure side of the oil tank on the side of the sliding bearing 4 from moving, thereby improving the sealing performance of the pivot assembly.

[0054] Further preferably, a first positioning portion 24 is protruded from the first mounting portion 21, the second mounting portion 22 is arranged on the second positioning portion 25, the gas seal ring 5 is arranged between the first positioning portion 24 and the rotating member 1, and the oil seal 7 is arranged between the first positioning portion 24 and the second positioning portion 25. Such an arrangement can limit the stability of the positions of the gas seal ring 5 and the oil seal 7.

[0055] In this embodiment, the rotating member 1 is an impeller. In other embodiments, the rotating member 1 can also be a fan blade, a gear or a propeller.

[0056] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0057] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A high-speed labyrinth contact gas seal, characterized in that: Used to seal the low-pressure side and the high-pressure side of a pivot assembly, the pivot assembly comprising a housing (3), a transmission shaft (2) and a rotating member (1); a vent hole (31) communicating with an inner cavity of the housing (3) is provided on an outer wall of the housing (3); the transmission shaft (2) is rotatably mounted in the housing (3); and the rotating member (1) is fixed to one end of the rotating shaft extending out of the housing (3); In the pivot assembly, the two sides of the vent hole (31) are respectively a low-pressure side and a high-pressure side; the side on which the rotating member (1) is mounted is the low-pressure side, and the other side is the high-pressure side; An axial sealing assembly is provided between the housing (3) and the transmission shaft (2), and a radial sealing assembly is provided between the housing (3) and the rotating member (1). The axial sealing assembly and the radial sealing assembly are both provided on the low-pressure side of the pivot assembly.

2. A high-speed labyrinth contact gas seal according to claim 1, characterized in that: The axial sealing assembly comprises an air seal ring (5) and an axial air seal (6); the air seal ring (5) is sleeved on the transmission shaft (2), the air seal ring (5) and the transmission shaft (2) are tightly matched, the axial air seal (6) is sleeved on the air seal ring (5), the axial air seal (6) is fixedly connected to the housing (3), and a labyrinth seal structure is provided between the axial air seal (6) and the air seal ring (5).

3. A high-speed labyrinth contact gas seal according to claim 2, characterized in that: The labyrinth seal structure comprises a first sealing portion (61), a second sealing portion (64) and a third sealing portion (65) which are arranged on the axial gas seal (6); the first sealing portion (61), the second sealing portion (64) and the third sealing portion (65) all protrude from the inner wall of the axial gas seal (6); The second sealing portion (64) is located between the two first sealing portions (61), and the first sealing portion (61) cooperates with the outer wall of the gas sealing ring (5); a plurality of axially arranged first grooves (51) are provided on the outer wall of the gas sealing ring (5), the plurality of second sealing portions (64) correspond to the plurality of first grooves (51) one by one, and the second sealing portions (64) extend into the first grooves (51); The plurality of third sealing portions (65) correspond to the plurality of second sealing portions (64) one by one, the plurality of second sealing portions (64) and the plurality of third sealing portions (65) are arranged alternately, and the third sealing portions (65) cooperate with the outer wall of the air sealing ring (5).

4. A high-speed labyrinth contact gas seal according to claim 3, characterized in that: The third sealing portion (65) comprises a third sealing tooth (651), a fourth sealing tooth (6522) and a fifth sealing tooth (6531); the fourth sealing tooth (6522), the fifth sealing tooth (6531) and the third sealing tooth (651) are arranged in sequence and axially; the third sealing tooth (651), the fourth sealing tooth (6522) and the fifth sealing tooth (6531) have different heights.

5. A high-speed labyrinth contact gas seal according to claim 4, characterized in that: The fourth sealing tooth (6522), the fifth sealing tooth (6531) and the third sealing tooth (651) are arranged in sequence from the low-pressure side to the high-pressure side.

6. A high-speed labyrinth contact gas seal according to claim 4, characterized in that: The fourth sealing tooth (6522) and the fifth sealing tooth (6531) are clearance-fitted, and the fifth sealing tooth (6531) and the third sealing tooth (651) are tight-fitted.

7. A high-speed labyrinth contact gas seal according to claim 4, characterized in that: The height of the fourth sealing tooth (6522) is lower than that of the third sealing tooth (651), and the height of the third sealing tooth (651) is lower than that of the fifth sealing tooth (6531).

8. The high-speed labyrinth contact gas seal according to claim 1, characterized in that: The end surface of the rotating member (1) facing the transmission shaft (2) is a radial sealing surface (11), a third groove (12) is provided on the radial sealing surface (11), one end of the air sealing ring (5) extends into the third groove (12), and the air sealing ring (5) cooperates with the third groove (12) to form a sealing structure.

9. A high-speed labyrinth contact gas seal according to claim 8, characterized in that: The radial sealing assembly comprises a radial air seal (8), the radial air seal (8) being fixed on the axial air seal (6), the radial air seal (8) being provided with a sixth sealing tooth (81) and a seventh sealing tooth (82), the sixth sealing tooth (81) and the seventh sealing tooth (82) being arranged alternately, the sixth sealing tooth (81) cooperating with a radial sealing surface (11) of a rotating member (1) to form a sealing structure, the radial sealing surface (11) being further provided with a fourth groove (13), one end of the seventh sealing tooth (82) extending into the fourth groove (13), the seventh sealing tooth (82) cooperating with an inner wall of the fourth groove (13) to form a sealing gap.

10. A high-speed labyrinth contact gas seal according to claim 9, characterized in that: The length of the sixth sealing tooth (81) is shorter than that of the seventh sealing tooth (82).

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