Compressor

Abstract

The embodiment of the invention discloses a compressor, and belongs to the technical field of marine compressors, the compressor is provided with at least two sealing rings, gaps exist between the sealing rings and a rotating shaft, the size of the gap away from the medium side is smaller than that of the gap adjacent to the medium side, evaporation gas is subjected to step-by-step throttling and pressure reduction, and recycling of the evaporation gas is achieved. The first movable ring is arranged on the shaft sleeve in a sleeved mode, the first static ring abuts against the first movable ring, the first movable ring is provided with a first movable pressure groove, the second movable ring is arranged on the shaft sleeve in a sleeved mode, the second static ring abuts against the second movable ring, the second movable ring is provided with a second movable pressure groove, the first movable pressure groove can suck sealing gas, and the second movable pressure groove can suck sealing gas. A non-contact gas film type sealing structure is formed, the service life is prolonged, and the compressor adapts to the situations of swinging, deflection, up-down floating and the like in the sailing process of the LNG ship.

Description

Technical Field

[0001] The present application relates to the technical field of marine compressors, and in particular to a compressor. Background Art

[0002] During the transportation of liquefied natural gas (LNG), boil-off gas (BOG) is generated. This gas increases the pressure in the LNG storage tanks, causing LNG evaporation to intensify. BOG compressors are used to process this gas and maintain a constant pressure within the LNG tanks. However, traditional BOG compressors carry the risk of BOG leakage. Summary of the Invention

[0003] The embodiments of the present application provide a compressor that can solve the problem of boil-off gas leakage in traditional BOG compressors.

[0004] The embodiment of the present application provides a compressor comprising: a casing with an accommodating chamber provided therein, the casing comprising a medium side and an atmosphere side arranged opposite to each other along a first direction and respectively connected to the accommodating chamber; a rotating shaft arranged in the accommodating chamber and extending along the first direction; a first sealing assembly comprising at least two sealing rings spaced apart along the first direction, the sealing ring being arranged on one end of the rotating shaft adjacent to the medium side, a gap being present between the sealing ring and the rotating shaft, and a size of the gap away from the medium side being smaller than a size of the gap adjacent to the medium side along the first direction; a shaft sleeve being sleeved on one end of the rotating shaft adjacent to the atmosphere side; a second sealing assembly comprising a first dynamic ring and a first static ring, the first dynamic ring being sleeved on the shaft sleeve adjacent to the medium side One end, the first static ring abuts against the end of the first dynamic ring toward the sealing ring, and the first dynamic ring is provided with a first dynamic pressure groove on a side facing the first static ring; the third sealing assembly includes a second dynamic ring and a second static ring, the second dynamic ring is sleeved on an end of the shaft sleeve adjacent to the atmosphere side, the second static ring abuts against the end of the second dynamic ring away from the first dynamic ring, and the second dynamic pressure groove is provided on a side facing the second static ring; the rotating shaft can drive the first dynamic ring and the second dynamic ring to rotate through the shaft sleeve, the first dynamic pressure groove can suck in sealing gas to form an air film between the first dynamic ring and the first static ring, and the second dynamic pressure groove can suck in sealing gas to form an air film between the second dynamic ring and the second static ring.

[0005] Optionally, the first sealing assembly further includes a base and at least two supports; the base is in the shape of a tube, the base is inscribed in the inner wall of the casing, and the base is arranged at one end of the accommodating chamber adjacent to the medium side; the support is in the shape of a ring, the support is inscribed in the base, the at least two supports are spaced apart along the first direction on the inner side of the base, and the sealing ring is arranged between two adjacent supports; along the first direction, one of the opposite ends of the sealing ring arranged between two adjacent supports is elastically connected to one support, and the other end is abutted against the other support.

[0006] Optionally, the first sealing assembly further includes a pressure plate; the pressure plate is annular in shape, the pressure plate cover is provided at one end of the base away from the medium side along the first direction, and the pressure plate is detachably connected to the base; along the first direction, a sealing ring is provided between the pressure plate and the adjacent support, one end of the sealing ring is elastically connected to the support, and the other end abuts against the pressure plate.

[0007] Optionally, a connecting portion is protruding from the outer wall of the sleeve, and the connecting portion surrounds the sleeve along the circumferential direction of the sleeve; the end of the first moving ring facing away from the first stationary ring is connected to the connecting portion, and the end of the second moving ring facing away from the second stationary ring is connected to the connecting portion; the rotating shaft drives the sleeve to rotate, and the sleeve drives the first moving ring and the second moving ring to rotate through the connecting portion.

[0008] Optionally, the second sealing assembly further includes a first stationary ring seat, and the third sealing assembly further includes a second stationary ring seat; the first stationary ring seat is annular in shape, surrounds the shaft sleeve along the circumferential direction of the shaft sleeve, abuts against the inner wall of the housing, and is detachably connected to the housing; the first stationary ring is elastically connected to the first stationary ring seat; the second stationary ring seat is annular in shape, the second stationary ring seat is arranged at one end of the shaft sleeve adjacent to the atmosphere side, the second stationary ring is arranged on the inner side of the second stationary ring seat and is elastically connected to the second stationary ring seat; the second stationary ring seat is detachably connected to the first stationary ring seat.

[0009] Optionally, the first stationary ring seat includes a first base and a first ring wall, and the second stationary ring seat includes a second base and a second ring wall; the first base is annular in shape, and the first base is arranged around the end of the sleeve adjacent to the medium side, the first stationary ring is elastically abutted against the first base, the first ring wall is shaped like a tube, and the first ring wall is connected to the first base at one end along the first direction, and at least part of the first ring wall is sealingly abutted against the inner wall of the casing; the second base is annular in shape, and the second base is arranged around the end of the sleeve adjacent to the atmosphere side, the second stationary ring is elastically abutted against the second base, and the second ring wall is protruding on the side of the second base facing the second stationary ring; the second ring wall abuts against the inner wall of the first ring wall, and the end of the first ring wall away from the first base along the first direction is detachably connected to the second base.

[0010] Optionally, the compressor further includes a drive ring, which is sleeved on one end of the shaft sleeve adjacent to the atmosphere side; a locking piece is inserted into the drive ring, and along the radial direction of the rotating shaft, the locking piece passes through the shaft sleeve and abuts against the rotating shaft.

[0011] Optionally, the compressor further includes a positioning block; the positioning block is detachably connected to an end of the second stationary ring seat facing away from the second stationary ring; the drive ring is connected to the positioning block, and the drive ring can rotate relative to the positioning block.

[0012] Optionally, a slot is provided on the side wall of the positioning block, and the slot surrounds the positioning block along the circumferential direction of the positioning block; a plug-in portion is protruding from the side wall of the driving ring, and the plug-in portion is embedded in the slot; the rotating shaft drives the driving ring to rotate through the shaft sleeve, and the plug-in portion moves in the slot along the circumferential direction of the positioning block.

[0013] Optionally, the compressor further comprises a first compression sleeve, which is disposed on one end of the shaft sleeve adjacent to the medium side, and abuts against one end of the first movable ring facing away from the second movable ring; the first compression sleeve is threadedly connected to the shaft sleeve; and / or, the compressor further comprises a second compression sleeve, which is disposed on one end of the shaft sleeve adjacent to the atmosphere side, and abuts against one end of the second movable ring facing away from the first movable ring; the second compression sleeve is threadedly connected to the shaft sleeve.

[0014] Optionally, the second sealing assembly further includes a first elastic member and a first push ring; along the first direction, a first ridge is protruding from one side of the first base toward the first moving ring, the first ridge is annular in shape, and a first accommodating cavity is defined between the first ridge and the first ring wall; the first push ring is arranged in the first accommodating cavity, the first push ring is elastically connected to the first base through the first elastic member, and the end of the first push ring facing away from the first base abuts against the first static ring; and / or, the third sealing assembly further includes a second elastic member and a second push ring; along the first direction, a second ridge is protruding from one side of the second base toward the second moving ring, the second ridge is annular in shape, and a second accommodating cavity is defined between the second ridge and the second ring wall; the second push ring is arranged in the second accommodating cavity, the second push ring is elastically connected to the second base through the second elastic member, and the end of the second push ring facing away from the second base abuts against the second static ring.

[0015] Optionally, the first push ring includes a first bearing ring, a first abutment ring and a first connecting ring; the first bearing ring surrounds the first ridge along the circumferential direction of the first ridge, and three first ring grooves are provided on the inner circumferential wall of the first bearing ring, and the inner diameters of the three first ring grooves decrease from the end close to the first base to the end away from the first base, forming a three-step structure; the first abutment ring is embedded in the first ring groove with the largest inner diameter among the three first ring grooves, and the first abutment ring abuts against the first stationary ring; the first connecting ring is embedded in the first ring groove with the second largest inner diameter among the three first ring grooves; along the first direction, the first connecting ring is adjacent to the first stationary ring and is clamped with the first abutment ring, and the first connecting ring is away from the first stationary ring. The end is provided with a first protrusion, and the first protrusion is inserted into the first ring groove with the smallest inner diameter among the three first ring grooves; the first protrusion abuts against the first ridge.

[0016] Optionally, the second push ring includes a second bearing ring, a second abutment ring and a second connecting ring; the second bearing ring surrounds the second ridge along the circumferential direction of the second ridge, and three second ring grooves are provided on the inner circumferential wall of the second bearing ring, and the inner diameters of the three second ring grooves decrease from the end close to the second base to the end away from the second base, forming a three-step structure; the second abutment ring is embedded in the second ring groove with the largest inner diameter among the three second ring grooves, and the second abutment ring abuts against the second stationary ring; the second connecting ring is embedded in the second ring groove with the second largest inner diameter among the three second ring grooves; along the first direction, the second connecting ring is clamped with the second abutment ring at one end adjacent to the second stationary ring, and the second connecting ring is protruding from the end away from the second stationary ring with a second protrusion, and the second protrusion is inserted into the second ring groove with the smallest inner diameter among the three second ring grooves; the second protrusion abuts against the second ridge.

[0017] Optionally, the casing is provided with a first through hole and a second through hole respectively connected to the accommodating cavity, and the first through hole and the second through hole are spaced apart along the first direction; the evaporated gas entering the accommodating cavity through the medium side passes through the gap in sequence along the first direction and is discharged from the casing through the first through hole; the first annular wall is provided with a third through hole passing through the first annular wall, and the third through hole is connected to the second through hole.

[0018] The beneficial effect of the present application is that a compressor is provided, which is provided with at least two sealing rings in the accommodating cavity of the casing. The sealing ring is arranged at one end of the rotating shaft adjacent to the medium side, and there is a gap between the sealing ring and the rotating shaft. The size of the gap away from the medium side is smaller than the size of the gap adjacent to the medium side. Therefore, through the design of gradually decreasing gap size, the evaporated gas introduced from the medium side is throttled and reduced in pressure step by step. The evaporated gas after throttling and pressure reduction can flow back to the LNG storage tank to achieve the recovery and utilization of the evaporated gas. A shaft sleeve is sleeved on the rotating shaft, the first moving ring is sleeved on the end of the shaft sleeve adjacent to the medium side of the casing, the first static ring is in contact with the end of the first moving ring facing the sealing ring, a first dynamic pressure groove is provided on the side of the first moving ring facing the first static ring, the second moving ring is sleeved on the end of the shaft sleeve adjacent to the atmosphere side of the casing, the second static ring is in contact with the end of the second moving ring away from the first moving ring, a second dynamic pressure groove is provided on the side of the second moving ring facing the second static ring, the rotating shaft can drive the first moving ring and the second moving ring to rotate through the shaft sleeve, the first dynamic pressure groove can absorb sealing gas to form an air film between the first moving ring and the second moving ring, and the second dynamic pressure groove can absorb Sealing gas is introduced to form an air film between the second dynamic ring and the second static ring, thereby forming a non-contact air film sealing structure between the medium side and the atmosphere side to prevent evaporative gas from leaking from the atmosphere side. Moreover, the air film sealing form can effectively reduce the wear caused by friction between the dynamic ring and the static ring while ensuring the sealing performance, thereby increasing the service life of the dynamic ring and the static ring, and achieving long-term sealing of leaked evaporative gas. Moreover, the step-by-step throttling and pressure reduction combined with the non-contact air film sealing can enable the compressor to adapt to the swaying, yaw and up and down floating of LNG ships during navigation, thereby ensuring the stability of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 is a schematic cross-sectional structural diagram of a compressor provided in an embodiment of the present application;

[0021] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure at point A;

[0022] Figure 3 yes Figure 2 A schematic diagram of the enlarged structure at point B;

[0023] Figure 4 yes Figure 1 Schematic diagram of the enlarged structure at C;

[0024] Figure 5 yes Figure 1 A schematic diagram of the enlarged structure at D;

[0025] Figure 6 yes Figure 1 A schematic diagram of the structure at E is enlarged;

[0026] Figure 7 yes Figure 1 The enlarged structural diagram of F;

[0027] Figure 8a This is a schematic diagram of a first structural example of a first moving ring in a compressor provided in an embodiment of the present application;

[0028] Figure 8b This is a schematic diagram of the first structure of the second dynamic ring in the compressor provided in an embodiment of the present application;

[0029] Figure 9a This is a schematic diagram of a second structure of the first moving ring in the compressor provided in an embodiment of the present application;

[0030] Figure 9b This is a second structural diagram of the second dynamic ring in the compressor provided in an embodiment of the present application;

[0031] Figure 10 is a partial cross-sectional structural schematic diagram of a first push ring in a compressor provided in an embodiment of the present application;

[0032] Figure 11 1 is a schematic cross-sectional structural diagram of a first bearing ring in a first push ring of a compressor provided in an embodiment of the present application;

[0033] Figure 12 yes Figure 11 Schematic diagram of the enlarged structure at G;

[0034] Figure 13 1 is a schematic cross-sectional structural diagram of a first abutting ring in a first push ring of a compressor provided in an embodiment of the present application;

[0035] Figure 14 yes Figure 13 A schematic diagram of the structure at H is enlarged;

[0036] Figure 15 1 is a schematic cross-sectional structural diagram of a first connecting ring in a first push ring of a compressor provided in an embodiment of the present application;

[0037] Figure 16 is a partial cross-sectional structural diagram of a second push ring in a compressor provided in an embodiment of the present application;

[0038] Figure 17 1 is a schematic cross-sectional structural diagram of a second bearing ring in a second push ring of a compressor provided in an embodiment of the present application;

[0039] Figure 18 yes Figure 17 A schematic diagram of the enlarged structure at position I;

[0040] Figure 19 1 is a schematic cross-sectional structural diagram of a second abutting ring in a second push ring of a compressor provided in an embodiment of the present application;

[0041] Figure 20 yes Figure 19 A schematic diagram of the enlarged structure at J;

[0042] Figure 21 This is a schematic cross-sectional structural diagram of the second connecting ring in the second push ring of the compressor provided in an embodiment of the present application.

[0043] Description of reference numerals:

[0044] 1. Compressor;

[0045] 10. Housing, 101. Accommodating chamber, 102. Medium side, 103. Atmosphere side, 11. First through hole, 12. Second through hole;

[0046] 20, rotating shaft, 21, first section, 22, second section;

[0047] 30. First sealing assembly, 31. Sealing ring, 310. Gap, 311. Spring, 32. Base, 321. Protrusion, 33. Support, 331. Abutment, 332. Support, 34. Press plate;

[0048] 40. Shaft sleeve, 41. Connecting portion, 42. First compression sleeve, 43. Second compression sleeve, 44. Transmission pin;

[0049] 50. Second sealing assembly, 51. First dynamic ring, 510. First dynamic pressure groove, 52. First stationary ring, 53. First stationary ring seat, 531. First base, 5310. First accommodating cavity, 5311. First ridge, 5312. Anti-rotation pin, 532. First ring wall, 5320. Third through hole, 5321. Bend, 54. First elastic member, 55. First push ring, 551. First bearing ring, 5510. First ring groove, 552. First abutting ring, 5521. First protrusion, 553. First connecting ring, 5531. First protrusion, 5532. First clamping portion;

[0050] 60. Third sealing assembly, 61. Second dynamic ring, 610. Second dynamic pressure groove, 62. Second stationary ring, 63. Second stationary ring seat, 631. Second base, 6310. Second accommodating cavity, 6311. Second ridge, 632. Second ring wall, 6320. Third through hole, 64. Second elastic member, 65. Second push ring, 651. Second bearing ring, 6510. Second ring groove, 652. Second abutting ring, 6521. Second protrusion, 653. Second connecting ring, 6531. Second protrusion, 6532. Second clamping portion;

[0051] 70. Drive ring, 701. Connecting portion, 71. Locking member, 72. Positioning block, 720. Slot;

[0052] 80. Sealing ring, 81. Tension spring, 82. Screw;

[0053] X, first direction, Y, second direction. DETAILED DESCRIPTION

[0054] The technical solutions 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 those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; and "inside" and "outside" refer to the outline of the device.

[0055] Reference Figure 1 In some embodiments of the present application, a compressor 1 is provided, which includes: a casing 10, a rotating shaft 20, a first sealing assembly 30, a sleeve 40, a second sealing assembly 50 and a third sealing assembly 60.

[0056] A accommodating chamber 101 is provided inside the casing 10. The casing 10 includes a medium side 102 and an atmospheric side 103 arranged opposite to each other along a first direction X. The medium side 102 and the atmospheric side 103 are respectively connected to the accommodating chamber 101. The medium side 102 is used to receive evaporated gas leaked from the LNG storage tank, and the atmospheric side 103 of the casing 10 is used to connect to the bearing box of the compressor 1 (not shown in the figure).

[0057] Reference Figures 1 to 6The rotating shaft 20 is arranged in the accommodating cavity 101, and the rotating shaft 20 extends along the first direction X. The axial direction of the rotating shaft 20 is parallel to the first direction X. The rotating shaft 20 includes a first section 21 and a second section 22 connected along the first direction X. The first section 21 is adjacent to the medium side 102, and the inner diameter of the first section 21 is larger than the inner diameter of the second section 22. The second section 22 of the rotating shaft 20 is connected to the bearing in the bearing box, and the bearing box is used to drive the rotating shaft 20 to rotate.

[0058] Reference Figures 1 to 3 The first sealing assembly 30 is disposed in the accommodating cavity 101. The first sealing assembly 30 includes at least two sealing rings 31 spaced apart along the first direction X. The sealing ring 31 is disposed on one end of the rotating shaft 20 adjacent to the medium side 102. Figures 1 to 3 In the embodiment described above, the sealing ring 31 is disposed on the first section 21 of the rotating shaft 20. Figure 3 There is a gap 310 between the sealing ring 31 and the rotating shaft 20. There is a gap 310 between each sealing ring 31 and the rotating shaft 20. Along the second direction Y, the gap 310 has a size L mm. Along the first direction X, the size L of the gap 310 away from the medium side 102 is smaller than the size L of the gap 310 adjacent to the medium side 102. Figure 1 and Figure 2 In the illustrated embodiment, there are three sealing rings 31 , spaced apart along a first direction X. The three sealing rings 31 are respectively disposed around the first section 21 of the rotating shaft 20 . The gaps 310 between the three sealing rings 31 and the rotating shaft 20 decrease in value along the first direction X. The second direction Y is parallel to the radial direction of the rotating shaft 20 .

[0059] Reference Figure 1 、 Figure 5 and Figure 6 The shaft sleeve 40 is sleeved on one end of the rotating shaft 20 adjacent to the atmosphere side 103 . Specifically, the shaft sleeve 40 is sleeved on the second section 22 of the rotating shaft 20 .

[0060] Reference Figure 1 、 Figure 4 and Figure 5 The second sealing assembly 50 is disposed in the accommodating cavity 101. The second sealing assembly 50 includes a first dynamic ring 51 and a first static ring 52. The first dynamic ring 51 is sleeved on one end of the sleeve 40 adjacent to the medium side 102. The first static ring 52 abuts against one end of the first dynamic ring 51 toward the sealing ring 31 along the first direction X. Figure 8a and Figure 9a A first dynamic pressure groove 510 is opened on one side of the first dynamic ring 51 facing the first static ring 52 along the first direction X. There are multiple first dynamic pressure grooves 510 , which are spaced apart along the circumferential direction of the first dynamic ring 51 .

[0061] Reference Figure 1、 Figure 5 and Figure 6 The third sealing assembly 60 is disposed in the accommodating cavity 101. The third sealing assembly 60 includes a second dynamic ring 61 and a second static ring 62. The second dynamic ring 61 is sleeved on one end of the sleeve 40 adjacent to the atmospheric side 103. The second static ring 62 abuts against one end of the second dynamic ring 61 away from the first dynamic ring 51 along the first direction X. Figure 8b and Figure 9b A second dynamic pressure groove 610 is opened on one side of the second dynamic ring 61 facing the second static ring 62 along the first direction X. There are multiple second dynamic pressure grooves 610, and the multiple second dynamic pressure grooves 610 are arranged at intervals along the circumferential direction of the second dynamic ring 61.

[0062] During transportation, liquefied natural gas (LNG) partially evaporates, producing boil-off gas (BOG). This BOG increases the pressure in the LNG storage tanks, and as external heat continues to enter, the evaporation of LNG intensifies. For large LNG carriers, it's uneconomical to drain or burn the BOG. The BOG needs to be reliquefied and recondensed before being returned to the LNG tanks to ensure the temperature and pressure of the LNG in the tanks are within the appropriate range. The BOG compressor is used to process the boil-off gas to maintain a constant LNG pressure in the tanks. To maintain the normal operation of the BOG compressor, it needs to be equipped with a corresponding sealing device to ensure stable internal pressure and prevent leakage of the hazardous BOG medium.

[0063] Traditional BOG compressors primarily utilize a carbon ring structure, also known as a packing seal, as a common shaft seal for pump shafts. This seal prevents leakage by surrounding the pump shaft with a soft material (such as graphite or asbestos). While packing seals offer advantages such as simple structure and easy maintenance, they also offer disadvantages such as poor sealing effectiveness, easy wear, and the need for regular packing replacement. Contact mechanical seals primarily consist of a rotating ring and a stationary ring. Springs are used to ensure a tight fit between the opposing end faces of the rotating and stationary rings, achieving a good seal. However, the contact seal faces of the rotating and stationary rings contact each other during operation, increasing overall equipment power consumption. Furthermore, these contact seals require coolant to cool the seal faces. If the mechanical seal fails, BOG can leak into the pump, compromising the lubricating oil in the bearing housing and damaging components such as bearings and synchronous gears, contaminating the process media conveyed by the BOG compressor.

[0064] The compressor 1 provided in the embodiment of the present application has a first sealing assembly 30 disposed within the accommodating chamber 101 of the casing 10. The first sealing assembly 30 includes at least two sealing rings 31 spaced apart along a first direction X. The sealing rings 31 are disposed around the first section 21 of the rotating shaft 20 adjacent to the medium side 102. A gap 310 exists between the sealing ring 31 and the rotating shaft 20. The gap 310 has a dimension L along a second direction Y. The gap 310 allows boil-off gas (BOG) entering the accommodating chamber 101 from the medium side 102 to enter the gap 310. Along the first direction X, the dimension L of the gap 310 away from the medium side 102 is smaller than the dimension L of the gap 310 adjacent to the medium side 102. As a result, the boil-off gas entering the accommodating chamber 101 can sequentially pass through different gaps 310 with decreasing L values along the first direction X. Consequently, the boil-off gas is throttled and depressurized step by step through the respective gaps 310 by the at least two sealing rings 31 spaced apart along the first direction X, thereby recondensing the boil-off gas (BOG) into LNG, thereby achieving BOG recovery and utilization.

[0065] A shaft sleeve 40 is sleeved on the second section 22 of the rotating shaft 20, and a second sealing assembly 50 and a third sealing assembly 60 are arranged in the accommodating cavity 101. The second sealing assembly 50 includes a first dynamic ring 51 and a first static ring 52. The first dynamic ring 51 is sleeved on one end of the shaft sleeve 40 adjacent to the medium side 102 of the housing 10 along the first direction X, and the first static ring 52 abuts against one end of the first dynamic ring 51 facing the sealing ring 31. A first dynamic pressure groove 510 is provided on a side of the first dynamic ring 51 facing the first static ring 52. The second dynamic ring 61 is sleeved on one end of the shaft sleeve 40 adjacent to the atmosphere side 103 of the housing 10, and the second static ring 62 abuts against one end of the second dynamic ring 61 away from the first dynamic ring 51 along the first direction X. A second dynamic pressure groove 610 is provided on a side of the second dynamic ring 61 facing the second static ring 62. The rotating shaft 20 can drive the first dynamic ring 51 and the second dynamic ring 61 through the shaft sleeve 40. 1 rotates, the first dynamic ring 51 drives the first dynamic pressure groove 510 to rotate to inhale sealing gas, thereby forming an air film between the first dynamic ring 51 and the first static ring 52. The second dynamic ring 61 drives the second dynamic pressure groove 610 to rotate to inhale sealing gas, thereby forming an air film between the second dynamic ring 61 and the second static ring 62. Therefore, the second sealing assembly 50 and the third sealing assembly 60 are combined in the accommodating chamber 101 to form a dry gas seal, thereby forming a non-contact air film sealing structure between the medium side 102 and the atmosphere side 103, thereby preventing LNG formed after step-by-step throttling and pressure reduction from leaking from the atmosphere side 103 into the bearing box and contaminating the bearing lubricant. In addition, while ensuring sealing performance, the wear between the dynamic ring and the static ring caused by the contact mechanical seal can be effectively reduced, thereby extending the service life of the dynamic ring and the static ring, reducing the power consumption of the compressor 1, and ensuring the quality of the bearing lubricant in the bearing box.

[0066] Furthermore, to address the rocking, yaw, and up-and-down motion of LNG vessels during navigation, the gap 310 between the sealing ring 31 in the first sealing assembly 30 and the first section 21 of the rotating shaft 20 enables the sealing ring 31 to provide a secondary seal against boil-off gas (BOG). The sealing structure of the sealing ring 31 is located in front of the dry gas seal structure, forming a forward-mounted secondary seal that gradually throttles and reduces the pressure of the boil-off gas introduced into the accommodating chamber 101. The throttled and reduced-pressure boil-off gas then flows back to the LNG tank's inlet, maintaining a stable pressure differential between the dry gas seal and the accommodating chamber 101 of the casing 10, thereby ensuring stable and reliable operation of the dry gas seal formed by the second sealing assembly 50 and the third sealing assembly 60.

[0067] Furthermore, to address the rocking, yaw, and up-and-down buoyancy characteristics of LNG ships during navigation, the first sealing assembly 30 is employed as a supplementary seal. This provides excellent centering compensation in the radial direction (i.e., second direction Y) of the rotating shaft 20. The gap 310 between the sealing ring 31 and the rotating shaft 20 forms an elastic air film between the sealing ring 31 and the rotating shaft 20. As the gap 310 between the sealing ring 31 and the rotating shaft 20 fluctuates with the ship's pitch, the elastic air film in gap 310 is squeezed, generating a centering compensation force along the radial direction of the rotating shaft 20. This realigns the axis of the sealing ring 31 with that of the rotating shaft 20, restoring the gap 310 between the sealing ring 31 and the rotating shaft 20 to a normal value. The gap 310 between the sealing ring 31 and the rotating shaft 20 is crucial for the first sealing assembly 30's progressive throttling and pressure reduction of the boil-off gas. Therefore, employing the sealing ring 31 as a supplementary seal for the dry gas seal improves the floatability and stability of the dry gas seal in conditions of rocking, yaw, and up-and-down buoyancy.

[0068] In some embodiments, the sealing ring 31 is a carbon ring.

[0069] In some embodiments, the sealing ring 31 is a combined structure formed by a carbon ring with a metal ring embedded outside.

[0070] In some embodiments, the first dynamic ring 51 is made of silicon carbide, silicon nitride, or cemented carbide.

[0071] In some embodiments, the first dynamic ring 51 is made of cemented carbide.

[0072] In some embodiments, the second dynamic ring 61 is made of silicon carbide, silicon nitride, or cemented carbide.

[0073] In some embodiments, the second dynamic ring 61 is made of cemented carbide.

[0074] Cemented carbide has the characteristics of high hardness, strong wear resistance, high temperature resistance, small linear expansion coefficient, low friction coefficient, and good impact toughness. It can reduce the contact friction between the second dynamic ring 61 and the second static ring 62 and improve the service life.

[0075] In some embodiments, the first stationary ring 52 is made of graphite.

[0076] In some embodiments, the second stationary ring 62 is made of graphite.

[0077] Graphite has the advantages of good self-lubricating properties, low friction coefficient, good corrosion resistance, good thermal conductivity, low linear expansion coefficient, and good temperature resistance.

[0078] In some embodiments, reference Figures 1 to 3 The first sealing assembly 30 further includes a base 32 and at least two supports 33. The base 32 is in the shape of a tube and extends along the first direction X. The base 32 is inscribed in the inner wall of the housing 10 and is disposed at one end of the accommodating chamber 101 adjacent to the medium side 102 along the first direction X. The support 33 is in the shape of a ring and is inscribed in the base 32. At least two supports 33 are spaced apart on the inner side of the base 32 along the first direction X. Figure 1 and Figure 2 The sealing ring 31 is arranged between two adjacent supports 33. Along the first direction X, one end of the opposite ends of the sealing ring 31 arranged between the two adjacent supports 33 is elastically connected to one support 33, and the other end abuts against the other support.

[0079] The base 32 is internally connected to the housing 10, so that a sealed contact is formed between the base 32 and the housing 10, so that the evaporated gas entering the accommodating chamber 101 through the medium side 102 can only be transmitted along the first direction X through the gap 310, ensuring the stability of the first sealing component 30 in the step-by-step throttling and pressure reduction of the evaporated gas. In some embodiments, refer to Figure 2 A sealing ring 80 is provided between the outer wall of the base 32 and the inner wall of the housing 10. Specifically, the outer wall of the base 32 defines an annular groove extending along the circumference of the base 32. The sealing ring 80 is embedded in the annular groove to form a seal, thereby ensuring the sealing between the base 32 and the housing 10. The sealing ring 80 is an O-ring.

[0080] The structural design of the sealing ring 31 arranged between two adjacent supports 33, with one end elastically connected to one support 33 and the other end abutting against the other support 33, enables the sealing ring 31 to adapt to the swaying, yaw and up and down floating situations that occur during the navigation of the LNG ship, ensuring the step-by-step throttling and pressure reduction treatment of the boil-off gas.

[0081] In some embodiments, reference Figure 2The support 33 includes an abutment portion 331 and a support portion 332. The abutment portion 331 is annular and inscribed within the inner wall of the base 32. The support portion 332 is annular and inscribed within the inner wall of the abutment portion 331. The abutment portion 331 and the support portion 332 have an L-shaped cross-section. One end of the sealing ring 31, located between two adjacent supports 33, is elastically connected to the support portion 332 of one support 33 via a spring 311, while the other end abuts the abutment portion 331 of the other support 33. The coordinated design of the abutment portion 331 and the support portion 332 in the supports 33 ensures a tight seal between the abutment portion 331 and the base 32, while also ensuring elastic support for the sealing ring 31 by the support portion 332. This improves the adaptability and stability of the sealing ring 31 in the event of sway, yaw, and up-and-down movement of the LNG ship during navigation, ensuring gradual throttling and pressure reduction of the boil-off gas.

[0082] In some embodiments, reference Figure 2 and Figure 3 A protrusion 321 is provided at one end of the base 32 adjacent to the medium side 102 along the first direction X. The protrusion 321 is annular in shape and is inscribed in the base 32. Along the first direction X, a sealing ring 31 is provided between the protrusion 321 and the adjacent support 33. One end of the sealing ring 31 is elastically connected to the protrusion 321 through a spring 311, and the other end abuts against the support portion 332 of the support 33.

[0083] In some embodiments, reference Figure 1 and Figure 2 The first sealing assembly 30 further includes a pressure plate 34, which is annular in shape and covers the end of the base 32 away from the medium side 102 along the first direction X. The pressure plate 34 is detachably connected to the base 32. Specifically, referring to Figure 1 The pressing plate 34 is detachably connected to the base 32 by screws 82 to ensure the connection stability between the pressing plate 34 and the base 32. The screws 82 are hexagon socket screws.

[0084] Reference Figure 1 and Figure 2 Along the first direction X, a sealing ring 31 is disposed between the pressure plate 34 and the adjacent support 33. One end of the sealing ring 31 is elastically connected to the support 33. Specifically, one end of the sealing ring 31 is elastically connected to the support portion 332 of the support 33 via a spring 311, while the other end of the sealing ring 31 abuts the pressure plate 34. The design of the pressure plate 34 forms an end-face seal against the base 32 and the adjacent support 33, thereby allowing evaporated gas entering the accommodating chamber 101 via the medium side 102 to flow only through the gaps 310 between the multiple sealing rings 31 and the rotating shaft 20. This ensures the stability of the throttling and pressure reduction of the evaporated gas and ensures its recovery and utilization.

[0085] In some embodiments, reference Figure 1 and Figure 2 A first through hole 11 communicating with the accommodating chamber 101 is provided on the casing 10. The first through hole 11 can be connected to the LNG storage tank. The evaporated gas is throttled and depressurized step by step through multiple sealing rings 31 to re-form LNG. The LNG can re-enter the LNG storage tank through the first through hole 11, thereby realizing the recycling of the leaked evaporated gas and ensuring the pressure stability in the LNG storage tank.

[0086] In some embodiments, reference Figure 1 and Figure 5 A connecting portion 41 protrudes from the outer wall of the sleeve 40 and surrounds the sleeve 40 along its circumferential direction. Along the first direction X, the end of the first movable ring 51 facing away from the first stationary ring 52 is connected to the connecting portion 41, and the end of the second movable ring 61 facing away from the second stationary ring 62 is connected to the connecting portion 41. Specifically, the first movable ring 51 and the second movable ring 61 are disposed on either side of the connecting portion 41 along the first direction X and are respectively connected to the connecting portion 41, so that the rotating shaft 20 drives the first and second movable rings 51, 61 to rotate synchronously through the connecting portion 41 of the sleeve 40, thereby synchronously generating air films between the first movable ring 51 and the first stationary ring 52, and between the second movable ring 61 and the second stationary ring 62, thereby ensuring sealing against the atmospheric side 103 and preventing evaporated gas, which has undergone step-by-step throttling and pressure reduction, from leaking into the bearing housing on the atmospheric side and contaminating the lubricating fluid.

[0087] In some embodiments, reference Figure 5 The sleeve 40 is sealingly mounted on the second section 22 of the rotating shaft 20. Specifically, the inner wall of the sleeve 40 defines an annular groove extending circumferentially of the sleeve 40. A sealing ring 80 is disposed within the annular groove. The sealing ring 80 surrounds the second section 22 circumferentially of the rotating shaft 20 to ensure sealing between the sleeve 40 and the second section 22 of the rotating shaft 20. The sealing ring 80 is an O-ring.

[0088] In some embodiments, reference Figure 5 The first movable ring 51 is connected to the connecting portion 41 through a transmission pin 44, and the second movable ring 61 is connected to the connecting portion 41 through a transmission pin 44. The provision of the transmission pin 44 ensures the stability of the connection portion 41 driving the first movable ring 51 and the second movable ring 61 to rotate.

[0089] In some embodiments, reference Figure 5 Tension springs 81 are provided on two opposite side surfaces of the connecting portion 41 along the first direction X. This ensures the connection stability and floatability between the connecting portion 41 and the first and second movable rings 51 and 61 to accommodate the swaying, yaw, and up-and-down floating conditions that may occur on LNG ships during navigation.

[0090] In some embodiments, reference Figure 5 A sealing ring 80 is provided at the location where the outer wall of the sleeve 40 contacts the first dynamic ring 51, and a sealing ring 80 is provided at the location where the outer wall of the sleeve 40 contacts the second dynamic ring 61. Specifically, an annular groove is formed on the outer wall of the sleeve 40 and surrounds the sleeve 40 along the circumferential direction of the sleeve 40. The sealing ring 80 is embedded in the annular groove to ensure sealing between the first dynamic ring 51, the second dynamic ring 61, and the sleeve 40. The sealing ring 80 is an O-ring.

[0091] In some embodiments, reference Figure 1 and Figure 4 The second sealing assembly 50 further includes a first stationary ring seat 53. The first stationary ring seat 53 is annular in shape. The first stationary ring seat 53 surrounds the sleeve 40 along the circumferential direction of the sleeve 40. The first stationary ring seat 53 abuts against the inner side wall of the housing 10, and with reference to Figure 1 The first stationary ring seat 53 is detachably connected to the housing 10, and the first stationary ring 52 is elastically connected to the first stationary ring seat 53. Figure 1 、 Figure 6 and Figure 7 The third sealing assembly 60 further includes a second stationary ring seat 63, which is annular in shape. The second stationary ring seat 63 is arranged around the first end of the sleeve 40 adjacent to the atmosphere side 103, and the second stationary ring 62 is arranged inside the second stationary ring seat 63 and elastically connected to the second stationary ring seat 63. Figure 6 The second stationary ring seat 63 is detachably connected to the first stationary ring seat 53 .

[0092] The setting of the first stationary ring seat 53 can form an elastic support for the first stationary ring 52 along the first direction X, ensuring the floatability of the first stationary ring 52 along the first direction X, thereby ensuring the stability of the air film formed between the first stationary ring 52 and the first dynamic ring 51; the setting of the second stationary ring seat 63 can form an elastic support for the second stationary ring 62 along the first direction X, ensuring the floatability of the second stationary ring 62 along the first direction X, thereby ensuring the stability of the air film formed between the second stationary ring 62 and the second dynamic ring 61.

[0093] The structural design of the detachable connection between the second stationary ring seat 63 and the first stationary ring seat 53 enables the first stationary ring seat 53 and the second stationary ring seat 63 to form an integrated structure, thereby ensuring the stability of the second sealing assembly 50 and the third sealing assembly 60 in the casing 10 when the LNG ship sways, yaws, and floats up and down during navigation, and preventing the evaporated gas after the step-by-step throttling and pressure reduction from leaking into the bearing box on the atmosphere side and contaminating the lubricating fluid.

[0094] In some embodiments, reference Figure 1 and Figure 4The first stationary ring seat 53 includes a first base 531 and a first ring wall 532. The first base 531 is annular in shape and is disposed around one end of the sleeve 40 adjacent to the medium side 102. The first stationary ring 52 elastically abuts against the first base 531. The first ring wall 532 is tubular in shape and extends along the first direction X. One end of the first ring wall 532 is connected to the first base 531, and the other end of the first ring wall 532 is adjacent to the atmosphere side 103. At least a portion of the first ring wall 532 is sealed against the inner wall of the housing 10. Figure 1 、 Figure 6 and Figure 7 The second stationary ring seat 63 includes a second base 631 and a second ring wall 632. The second base 631 is annular in shape and is arranged around one end of the sleeve 40 adjacent to the atmospheric side 103. The second stationary ring 62 is elastically abutted against the second base 631. The second ring wall 632 protrudes from the second base 631 on the side facing the second stationary ring 62.

[0095] The second ring wall 632 abuts against the inner side wall of the first ring wall 532. Specifically, the second ring wall 632 is disposed inside the first ring wall 532, and the second ring wall 632 abuts against the first ring wall 532. Figure 6 The first annular wall 532 is detachably connected to the second base 631 at one end thereof facing away from the first base 531 along the first direction X. The structural design of the first annular wall 532 extending along the first direction X and the detachable connection to the second base 631 at one end thereof facing away from the first base 531 enables the first stationary ring seat 53 and the second stationary ring seat 63 to form an integral structure. This ensures the stability of the second sealing assembly 50 and the third sealing assembly 60 within the casing 10 when the LNG ship experiences swaying, yaw, and up-and-down floating during navigation, and prevents boil-off gas, which has undergone step-by-step throttling and pressure reduction, from leaking into the atmosphere-side bearing housing and contaminating the lubricating fluid.

[0096] In some embodiments, reference Figure 6 The first annular wall 532 is bent along the first direction X at one end thereof, away from the first base 531, to form a bent portion 5321. The bent portion 5321 abuts against the inner wall of the housing 10 along the first direction X. The bent portion 5321 is detachably connected to the second base 631 via a screw 82, thereby achieving a detachable connection between the first annular wall 532 and the second base 631. The screw 82 is a hexagon socket head screw.

[0097] In some embodiments, reference Figure 4 A first elastic member 54 is provided on a side of the first base 531 facing the first static ring 52 . The first base 531 is elastically connected to the first static ring 52 through the first elastic member 54 to ensure the floatability of the first static ring 52 .

[0098] In some embodiments, the first elastic member 54 is a spring.

[0099] In some embodiments, reference Figure 1 An anti-rotation pin 5312 is inserted into the side of the first base 531 away from the first stationary ring 52 along the first direction X. The anti-rotation pin 5312 extends along the first direction X. The anti-rotation pin 5312 can prevent the first stationary ring seat 53 from rotating, thereby ensuring the stability of the integrated structure between the first stationary ring seat 53 and the second stationary ring seat 63.

[0100] In some embodiments, reference Figure 7 A second elastic member 64 is provided on a side of the second base 631 facing the second static ring 62 . The second base 631 is elastically connected to the second static ring 62 through the second elastic member 64 to ensure the floatability of the second static ring 62 .

[0101] In some embodiments, the second elastic member 64 is a spring.

[0102] In some embodiments, reference Figure 1 and Figure 5 The housing 10 is provided with a second through hole 12 communicating with the accommodating cavity 101. Figure 5 A third through hole 5320 is provided on the first annular wall 532 and passes through the first annular wall 532. The third through hole 5320 is connected to the second through hole 12. The second through hole 12 is used to introduce sealing gas into the accommodating cavity 101. The sealing gas can enter the inner side of the first annular wall 532 through the third through hole 5320.

[0103] In the process of the rotating shaft 20 driving the first movable ring 51 and the second movable ring 61 to rotate through the connecting part 41 of the sleeve 40, the first dynamic pressure groove 510 on the first movable ring 51 sucks in the sealing gas for pressurization during high-speed rotation, and the higher-pressure gas flows into the sealing end face between the first movable ring 51 and the first static ring 52, which will generate an opening force to disengage the sealing end face. When the opening force overcomes the elastic force of the first elastic member 54 and the sealing gas pressure, the sealing end face is completely disengaged, so that the first movable ring 51 and the first static ring 52 are separated along the first direction X, and an air film is formed between the first movable ring 51 and the first static ring 52. At this time, the sealing end face of the air film seal is in a non-contact operation state, and the thickness of the air film between the first movable ring 51 and the first static ring 52 is 2μm~5μm. Similarly, the second dynamic pressure groove 610 on the second dynamic ring 61 draws in the sealing gas for pressurization during high-speed rotation. The higher-pressure gas flowing into the sealing end face between the second dynamic ring 61 and the second static ring 62 will generate an opening force to disengage the sealing end face. When the opening force overcomes the elastic force of the second elastic member 64 and the sealing gas pressure, the sealing end face is completely disengaged, so that the second dynamic ring 61 and the second static ring 62 are separated along the first direction X, and an air film is formed between the second dynamic ring 61 and the second static ring 62. At this time, the sealing end face of the air film seal is in a non-contact operation state, and the thickness of the air film between the second dynamic ring 61 and the second static ring 62 is 2μm to 5μm.

[0104] The friction pair consisting of the dynamic and static rings of the dry gas seal has no wear during normal operation due to the existence of the air film, and only has slight wear during start-up and shutdown. Therefore, the dry gas seal has low power consumption, which is about 5% of the power consumption of the contact mechanical seal. At the same time, it can ensure stable and reliable operation of the seal and a long service life.

[0105] In some embodiments, the sealing gas is an inert gas that does not contaminate the boil-off gas after throttling and depressurization by the first sealing assembly 30 , thereby ensuring the purity and quality of the boil-off gas after throttling and depressurization that flows back into the LNG storage tank.

[0106] In some embodiments, the sealing gas is nitrogen or the like.

[0107] In some embodiments, reference Figure 8a The cross-sectional shape of the first dynamic pressure groove 510 is a dry-shaped shape, and the first dynamic pressure groove 510 is a bidirectionally rotating container-type double-end face dry gas seal. Figure 8b The cross-sectional shape of the second dynamic pressure groove 610 is a dry-shaped shape, and the second dynamic pressure groove 610 is a bidirectionally rotating container-type double-end face dry gas seal.

[0108] In some embodiments, reference Figure 9a The first dynamic pressure groove 510 is a unidirectional rotating cartridge double-end dry gas seal, refer to Figure 9bThe second dynamic pressure groove 610 is a unidirectionally rotating, cartridge-type, double-end dry gas seal. Specifically, the first dynamic pressure groove 510 and the second dynamic pressure groove 610 are each a unidirectional Archimedean spiral groove. The cross-sectional areas of the first and second dynamic pressure grooves 510 and 610 gradually increase along the spiral extension direction. The unidirectional Archimedean spiral groove not only fully utilizes a groove structure with a large fluid dynamic pressure effect, but also provides a large fluid dynamic pressure effect and gas film stability for the unidirectional Archimedean spiral groove dry gas seal.

[0109] In some embodiments, reference Figure 1 and Figure 6 The compressor 1 further includes a drive ring 70, which is sleeved on one end of the shaft sleeve 40 adjacent to the atmospheric side 103. Figure 1 A locking member 71 is inserted into the drive ring 70. The locking member 71 extends through the sleeve 40 in the radial direction of the rotating shaft 20 (i.e., the second direction Y) and abuts against the rotating shaft 20. The provision of the locking member 71 allows the sleeve 40 to tightly embrace the second section 22 of the rotating shaft 20 and restrict the axial movement of the sleeve 40 in the first direction X, thereby ensuring the installation stability of the sleeve 40 on the rotating shaft 20 and the stability of the rotation of the first and second rotating rings 51 and 61 driven by the sleeve 40.

[0110] In some embodiments, the locking member 71 is a set screw.

[0111] In some embodiments, reference Figure 1 and Figure 6 The compressor 1 further includes a positioning block 72, which is detachably connected to an end of the second stationary ring seat 63 that faces away from the second stationary ring 62. Specifically, the positioning block 72 is detachably connected to an end of the second base 631 that faces away from the second stationary ring 62 along the first direction X. The drive ring 70 is connected to the positioning block 72, and the drive ring 70 is rotatable relative to the positioning block 72. The coordinated design of the positioning block 72 and the drive ring 70 enables the drive ring 70 to form an integrated drive ring with the second stationary ring seat 63 through the positioning block 72. The integrated structure of the drive ring 70 and the positioning block 72 can provide stronger radial pressure, allowing the locking member 71 to ensure stronger speed synchronization between the shaft sleeve 40 and the rotating shaft 20 under the conditions of rocking, yaw, and up-and-down floating of the LNG ship.

[0112] In some embodiments, reference Figure 6A slot 720 is defined on the side wall of the positioning block 72, which surrounds the positioning block 72 along its circumferential direction. A plug-in portion 701 protrudes from the side wall of the drive ring 70 and is embedded in the slot 720. The rotating shaft 20 drives the drive ring 70 to rotate via the sleeve 40, and the plug-in portion 701 moves within the slot 720 along the circumferential direction of the positioning block 72. The mating design of the plug-in portion 701 and the slot 720 allows the slot 720 to limit the plug-in portion 701, ensuring the rotational stability of the drive ring 70 and thus ensuring that the drive ring 70 provides stable radial pressure. This allows the locking member 71 to ensure stronger speed synchronization between the sleeve 40 and the rotating shaft 20 under the rocking, yaw, and up-and-down floating conditions of the LNG ship.

[0113] Furthermore, to address the swaying, yaw, and up-and-down floating characteristics of LNG vessels during navigation, the locking element 71 is secured using an integrated drive ring 70 and positioning block 72, rather than a split drive ring or lock nut. The locking element 71 synchronizes the rotational speed of the shaft 20 with that of the sleeve 40, ensuring sufficient rotational speed between the first dynamic ring 51 and the first static ring 52, and between the second dynamic ring 61 and the second static ring 62 to maintain the formation of a dynamic pressure film, thereby preventing seal failure caused by dry wear of the sealing end faces. The integrated drive ring 70 and positioning block 72 structure used to secure the locking element 71 provides excellent radial pressure while simplifying assembly and disassembly. This higher radial pressure significantly increases the upper limit of static friction between the locking element 71 and the shaft 20, further improving the speed synchronization capability between the sleeve 40 and the shaft 20. The ease of assembly and disassembly also provides enhanced support for subsequent maintenance of the dry gas seal.

[0114] In some embodiments, reference Figure 1 and Figure 5 The compressor 1 further includes a first compression sleeve 42, which is mounted on the end of the shaft sleeve 40 adjacent to the medium side 102. The first compression sleeve 42 abuts against the end of the first movable ring 51 facing away from the second movable ring 61. The provision of the first compression sleeve 42 restricts movement of the first movable ring 51 in the first direction X, ensuring accurate positioning of the first movable ring 51 with the shaft sleeve 40 in the first direction X (i.e., along the axial direction of the rotating shaft 20), thereby ensuring the formation of an air film between the first movable ring 51 and the first stationary ring 52 to achieve stable end-face sealing.

[0115] In some embodiments, an internal thread is provided on the inner wall of the first compression sleeve 42, and correspondingly, an external thread is provided on the outer wall of the sleeve 40. The first compression sleeve 42 and the sleeve 40 are threadedly connected. Compared with the screw connection, the threaded connection is used as the connection method between the first compression sleeve 42 and the sleeve 40, so that the first compression sleeve 42 has better axial force bearing capacity and occupies less space. In the bumpy environment of LNG ships, the threaded connection can withstand axial stress for a longer time than the screw connection, which is beneficial to extending the service life of the dry gas seal in the bumpy environment of LNG ships.

[0116] In some embodiments, reference Figure 1 、 Figure 5 and Figure 6 The compressor 1 further includes a second compression sleeve 43, which is mounted on the end of the shaft sleeve 40 adjacent to the atmosphere side 103. The second compression sleeve 43 abuts against the end of the second dynamic ring 61 facing away from the first dynamic ring 51. The provision of the second compression sleeve 43 restricts movement of the second dynamic ring 61 along the first direction X, thereby ensuring accurate positioning of the second dynamic ring 61 with the shaft sleeve 40 along the first direction X (i.e., along the axial direction of the rotating shaft 20). This further ensures that an air film is formed between the second dynamic ring 61 and the second stationary ring 62, thereby achieving stability in the end face seal.

[0117] In some embodiments, an internal thread is provided on the inner wall of the second compression sleeve 43, and correspondingly, an external thread is provided on the outer wall of the sleeve 40. The second compression sleeve 43 and the sleeve 40 are threadedly connected. Compared with the screw connection, the threaded connection is used as the connection method between the second compression sleeve 43 and the sleeve 40, so that the second compression sleeve 43 has better axial force bearing capacity and occupies less space. In the bumpy environment of LNG ships, the threaded connection can withstand axial stress for a longer time than the screw connection, which is beneficial to extending the service life of the dry gas seal in the bumpy environment of LNG ships.

[0118] In some embodiments, reference Figure 1 and Figure 4 The second sealing assembly 50 further includes a first elastic member 54 and a first push ring 55. Along the first direction X, the first base 531 is provided with a first ridge 5311 protruding toward the first movable ring 51. The shape of the first ridge 5311 is annular. Figure 4 A first accommodating cavity 5310 is defined between the first ridge 5311 and the first annular wall 532. A first push ring 55 is disposed in the first accommodating cavity 5310. The first push ring 55 is elastically connected to the first base 531 via a first elastic member 54. The end of the first push ring 55 facing away from the first base 531 abuts against the first stationary ring 52. The provision of the first push ring 55 enables a bidirectional static seal to be formed between the first stationary ring 52 and the first stationary ring seat 53 in a first direction X (i.e., the axial direction of the rotating shaft 20) and a second direction Y (i.e., the radial direction of the rotating shaft 20).

[0119] In some embodiments, reference Figure 4 and Figures 10 to 12 The first push ring 55 includes a first bearing ring 551, a first abutting ring 552 and a first connecting ring 553. Figure 4 The first supporting ring 551 surrounds the first ridge 5311 along the circumferential direction of the first ridge 5311, referring to Figures 10 to 12 The inner wall of the first supporting ring 551 is provided with three first annular grooves 5510. The inner diameters of the three first annular grooves 5510 decrease from the end close to the first base 531 to the end away from the first base 531, forming a three-step structure. Figure 10 The first abutting ring 552 is embedded in the first annular groove 5510 with the largest inner diameter among the three first annular grooves 5510 , and the first abutting ring 552 abuts against the first stationary ring 52 . Figure 10 and Figures 13 and 14 A first protrusion 5521 is protruding from the side wall of the first abutment ring 552. The first protrusion 5521 surrounds the first abutment ring 552 along the circumferential direction of the first abutment ring 552. The first protrusion 5521 is inserted into the first annular groove 5510 with the largest inner diameter among the three first annular grooves 5510 to ensure the assembly stability between the first abutment ring 552 and the first bearing ring 551, and to ensure that the first push ring 55 performs axial static sealing on the first static ring 52 in the first direction X.

[0120] Reference Figure 10 The first connecting ring 553 is embedded in the first ring groove 5510 with the second largest inner diameter among the three first ring grooves 5510. Figure 4 and Figure 10 , along the first direction X, one end of the first connecting ring 553 adjacent to the first stationary ring 52 is engaged with the first abutting ring 552, referring to Figure 10 and Figure 15 The first connecting ring 553 is provided with a first clamping portion 5532 protruding from one end thereof adjacent to the first stationary ring 52 along the first direction X. Figure 10 The first connecting ring 553 is engaged with the first abutting ring 552 via the first engaging portion 5532. Figure 10 and Figure 15 A first protrusion 5531 is protruded from one end of the first connecting ring 553 away from the first stationary ring 52 , and the first protrusion 5531 is inserted into the first ring groove 5510 with the smallest inner diameter among the three first ring grooves 5510 .

[0121] Reference Figure 4The first connecting ring 553 surrounds the first ridge 5311 along the circumferential direction of the first ridge 5311, and along the second direction Y, the first protrusion 5531 of the first connecting ring 553 abuts against the first ridge 5311, and the first connecting ring 553 cooperates with the first bearing ring 551 and the first abutting ring 552 to ensure that the first push ring 55 performs radial static sealing on the first stationary ring seat 53 and the first stationary ring 52 in the second direction Y.

[0122] Reference Figure 4 The end of the first bearing ring 551 away from the first static ring 52 along the first direction X is elastically connected to the first base 531 through the first elastic member 54, ensuring that the first push ring 55 statically seals the first static ring seat 53 axially in the first direction X.

[0123] In some embodiments, reference Figure 4 and Figure 10 A tension spring 81 is provided between the first protrusion 5531 of the first connecting ring 553 and the first supporting ring 551 to ensure a floating connection between the first connecting ring 553 and the first supporting ring 551, and to ensure the stability of the first push ring 55 in the environment where the LNG ship sways, deflects, and floats up and down.

[0124] In some embodiments, reference Figure 7 and Figures 16 to 20 The second push ring 65 includes a second bearing ring 651, a second abutting ring 652 and a second connecting ring 653. Figure 7 The second supporting ring 651 surrounds the second ridge 6311 along the circumferential direction of the second ridge 6311, referring to Figures 16 to 18 The inner wall of the second supporting ring 651 is provided with three second annular grooves 6510. The inner diameters of the three second annular grooves 6510 decrease from the end close to the second base 631 to the end away from the second base 631, forming a three-step structure. Figure 16 The second abutting ring 652 is embedded in the second annular groove 6510 with the largest inner diameter among the three second annular grooves 6510, and the second abutting ring 652 abuts against the second stationary ring 62. Figure 16 and Figures 19 and 20 A second protrusion 6521 is protruding from the side wall of the second abutment ring 652, and the second protrusion 6521 surrounds the second abutment ring 652 along the circumferential direction of the second abutment ring 652. The second protrusion 6521 is inserted into the second annular groove 6510 with the largest inner diameter among the three second annular grooves 6510 to ensure the assembly stability between the second abutment ring 652 and the second bearing ring 651, and to ensure that the second push ring 65 performs axial static sealing on the second static ring 62 in the first direction X.

[0125] Reference Figure 16 The second connecting ring 653 is embedded in the second ring groove 6510 with the second largest inner diameter among the three second ring grooves 6510. Figure 7 and Figure 16 , along the first direction X, the end of the second connecting ring 653 adjacent to the second stationary ring 62 is engaged with the second abutting ring 652, referring to Figure 16 and Figure 21 The second connecting ring 653 is provided with a second clamping portion 6532 protruding from one end thereof adjacent to the second stationary ring 62 along the first direction X. Figure 16 The second connecting ring 653 is engaged with the second abutting ring 652 via the second engaging portion 6532. Figure 16 and Figure 21 A second protrusion 6531 is protruded from one end of the second connecting ring 653 away from the second stationary ring 62 , and the second protrusion 6531 is inserted into the second ring groove 6510 with the smallest inner diameter among the three second ring grooves 6510 .

[0126] Reference Figure 7 The second connecting ring 653 surrounds the second ridge 6311 along the circumferential direction of the second ridge 6311, and along the second direction Y, the second protrusion 6531 of the second connecting ring 653 abuts against the second ridge 6311, and the second connecting ring 653 cooperates with the second bearing ring 651 and the second abutment ring 652 to ensure that the second push ring 65 performs radial static sealing on the second stationary ring seat 63 and the second stationary ring 62 in the second direction Y.

[0127] Reference Figure 7 The end of the second bearing ring 651 away from the second static ring 62 along the first direction X is elastically connected to the second base 631 through the first elastic member 54, ensuring that the second push ring 65 statically seals the second static ring seat 63 axially in the first direction X.

[0128] In some embodiments, reference Figure 7 and Figure 16 A tension spring 81 is provided between the second protrusion 6531 of the second connecting ring 653 and the second supporting ring 651 to ensure a floating connection between the second connecting ring 653 and the second supporting ring 651, and to ensure the stability of the second push ring 65 in the environment where the LNG ship sways, deflects, and floats up and down.

[0129] The above is a detailed introduction to a compressor provided in an embodiment of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, based on the idea of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A compressor, characterized in that: include: A housing (10) is provided with a receiving cavity (101) therein, the housing (10) comprising a medium side (102) and an atmosphere side (103) which are arranged opposite to each other along a first direction (X) and are respectively in communication with the receiving cavity (101); a rotating shaft (20) disposed in the accommodating cavity (101) and extending along the first direction (X); A first sealing assembly (30) comprises at least two sealing rings (31) spaced apart along the first direction (X), the sealing rings (31) being arranged around one end of the rotating shaft (20) adjacent to the medium side (102), a gap (310) existing between the sealing ring (31) and the rotating shaft (20), and a size of the gap (310) away from the medium side (102) along the first direction (X) being smaller than a size of the gap (310) adjacent to the medium side (102); a shaft sleeve (40) sleeved on one end of the rotating shaft (20) adjacent to the atmosphere side (103); A second sealing assembly (50) includes a first dynamic ring (51) and a first static ring (52), wherein the first dynamic ring (51) is sleeved on an end of the shaft sleeve (40) adjacent to the medium side (102), the first static ring (52) abuts against an end of the first dynamic ring (51) facing the sealing ring (31), and a first dynamic pressure groove (510) is formed on a surface of the first dynamic ring (51) facing the first static ring (52); A third sealing assembly (60) includes a second dynamic ring (61) and a second static ring (62), wherein the second dynamic ring (61) is sleeved on an end of the shaft sleeve (40) adjacent to the atmosphere side (103), the second static ring (62) abuts against an end of the second dynamic ring (61) facing away from the first dynamic ring (51), and a second dynamic pressure groove (610) is formed on a surface of the second dynamic ring (61) facing the second static ring (62); The rotating shaft (20) can drive the first moving ring (51) and the second moving ring (61) to rotate through the shaft sleeve (40); the first dynamic pressure groove (510) can absorb sealing gas to form an air film between the first moving ring (51) and the first static ring (52); and the second dynamic pressure groove (610) can absorb sealing gas to form an air film between the second moving ring (61) and the second static ring (62).

2. The compressor according to claim 1, wherein The first sealing assembly (30) further includes a base (32) and at least two supports (33); The base (32) is in the shape of a tube, the base (32) is connected to the inner wall of the housing (10), and the base (32) is arranged at one end of the accommodating cavity (101) adjacent to the medium side (102); The support (33) is annular in shape, the support (33) is inscribed in the base (32), the at least two supports (33) are spaced apart and arranged inside the base (32) along the first direction (X), and the sealing ring (31) is arranged between two adjacent supports (33); Along the first direction (X), one of the two opposite ends of the sealing ring (31) disposed between two adjacent supports (33) is elastically connected to one support (33), and the other end abuts against the other support (33).

3. The compressor according to claim 2, wherein The first sealing assembly (30) further includes a pressure plate (34); The pressing plate (34) is annular in shape and is provided on an end of the base (32) that is away from the medium side (102) along the first direction (X). The pressing plate (34) is detachably connected to the base (32). Along the first direction (X), a sealing ring (31) is provided between the pressure plate (34) and the adjacent support (33), one end of the sealing ring (31) is elastically connected to the support (33), and the other end abuts against the pressure plate (34).

4. The compressor according to claim 1, wherein A connecting portion (41) is protruding from the outer wall of the shaft sleeve (40), and the connecting portion (41) surrounds the shaft sleeve (40) along the circumferential direction of the shaft sleeve (40); One end of the first moving ring (51) facing away from the first stationary ring (52) is connected to the connecting portion (41), and one end of the second moving ring (61) facing away from the second stationary ring (62) is connected to the connecting portion (41); The rotating shaft (20) drives the shaft sleeve (40) to rotate, and the shaft sleeve (40) drives the first movable ring (51) and the second movable ring (61) to rotate through the connecting portion (41).

5. The compressor according to claim 4, wherein The second sealing assembly (50) further includes a first stationary ring seat (53), and the third sealing assembly (60) further includes a second stationary ring seat (63); The first stationary ring seat (53) is annular in shape, surrounds the shaft sleeve (40) along the circumferential direction of the shaft sleeve (40), abuts against the inner side wall of the housing (10), and is detachably connected to the housing (10); The first stationary ring (52) is elastically connected to the first stationary ring seat (53); The second stationary ring seat (63) is annular in shape and is disposed around one end of the shaft sleeve (40) adjacent to the atmosphere side (103). The second stationary ring (62) is disposed inside the second stationary ring seat (63) and is elastically connected to the second stationary ring seat (63). The second stationary ring seat (63) is detachably connected to the first stationary ring seat (53).

6. The compressor according to claim 5, characterized in that The first stationary ring seat (53) includes a first base (531) and a first ring wall (532), and the second stationary ring seat (63) includes a second base (631) and a second ring wall (632); The first base (531) is annular in shape and is disposed around one end of the shaft sleeve (40) adjacent to the medium side (102). The first stationary ring (52) elastically abuts against the first base (531). The first annular wall (532) is tubular in shape and one end of the first annular wall (532) along the first direction (X) is connected to the first base (531). At least a portion of the first annular wall (532) is in sealing contact with the inner wall of the housing (10). The second base (631) is annular in shape and is disposed around one end of the shaft sleeve (40) adjacent to the atmosphere side (103). The second stationary ring (62) elastically abuts against the second base (631). The second ring wall (632) protrudes from a side of the second base (631) facing the second stationary ring (62). The second annular wall (632) abuts against the inner side wall of the first annular wall (532), and one end of the first annular wall (532) away from the first base (531) along the first direction (X) is detachably connected to the second base (631).

7. The compressor according to claim 5, wherein The compressor further includes a drive ring (70), wherein the drive ring (70) is sleeved on an end of the shaft sleeve (40) adjacent to the atmosphere side (103); A locking piece (71) is inserted into the driving ring (70). Along the radial direction of the rotating shaft (20), the locking piece (71) passes through the shaft sleeve (40) and abuts against the rotating shaft (20).

8. The compressor according to claim 7, wherein The compressor further includes a positioning block (72); The positioning block (72) is detachably connected to an end of the second stationary ring seat (63) facing away from the second stationary ring (62); The driving ring (70) is connected to the positioning block (72), and the driving ring (70) is rotatable relative to the positioning block (72).

9. The compressor according to claim 8, wherein A slot (720) is provided on the side wall of the positioning block (72), and the slot (720) surrounds the positioning block (72) along the circumferential direction of the positioning block (72); A plug-in portion (701) is protruding from the side wall of the driving ring (70), and the plug-in portion (701) is embedded in the slot (720); The rotating shaft (20) drives the driving ring (70) to rotate via the shaft sleeve (40), and the plug-in portion (701) moves in the slot (720) along the circumferential direction of the positioning block (72).

10. The compressor according to claim 1, wherein The compressor further comprises a first compression sleeve (42), the first compression sleeve (42) being sleeved on an end of the shaft sleeve (40) adjacent to the medium side (102), and the first compression sleeve (42) being in contact with an end of the first movable ring (51) facing away from the second movable ring (61); The first compression sleeve (42) is threadedly connected to the shaft sleeve (40); And / or, the compressor further comprises a second compression sleeve (43), the second compression sleeve (43) being sleeved on an end of the shaft sleeve (40) adjacent to the atmosphere side (103), the second compression sleeve (43) being in contact with an end of the second movable ring (61) facing away from the first movable ring (51); The second compression sleeve (43) is threadedly connected to the shaft sleeve (40).

11. The compressor according to claim 6, wherein The second sealing assembly (50) further includes a first elastic member (54) and a first push ring (55); Along the first direction (X), a first ridge (5311) is provided on one side of the first base (531) facing the first movable ring (51), the first ridge (5311) being annular in shape, and a first accommodating cavity (5310) is defined between the first ridge (5311) and the first ring wall (532); The first push ring (55) is arranged in the first accommodating cavity (5310), the first push ring (55) is elastically connected to the first base (531) via the first elastic member (54), and one end of the first push ring (55) facing away from the first base (531) abuts against the first stationary ring (52); And / or, the third sealing assembly (60) further includes a second elastic member (64) and a second push ring (65); Along the first direction (X), a second ridge (6311) is provided on one side of the second base (631) facing the second movable ring (61), the second ridge (6311) being annular in shape, and a second accommodating cavity (6310) is defined between the second ridge (6311) and the second ring wall (632); The second push ring (65) is arranged in the second accommodating cavity (6310), and the second push ring (65) is elastically connected to the second base (631) through the second elastic member (64), and the end of the second push ring (65) facing away from the second base (631) abuts against the second stationary ring (62).

12. The compressor according to claim 11, wherein The first push ring (55) includes a first bearing ring (551), a first abutting ring (552) and a first connecting ring (553); The first supporting ring (551) surrounds the first convex ridge (5311) along the circumferential direction of the first convex ridge (5311), and three first annular grooves (5510) are provided on the inner peripheral wall of the first supporting ring (551), and the inner diameters of the three first annular grooves (5510) decrease from an end close to the first base (531) to an end away from the first base (531), forming a three-step structure; The first abutment ring (552) is embedded in the first annular groove (5510) having the largest inner diameter among the three first annular grooves (5510), and the first abutment ring (552) abuts against the first stationary ring (52); The first connecting ring (553) is embedded in the first ring groove (5510) with the second largest inner diameter among the three first ring grooves (5510); Along the first direction (X), one end of the first connecting ring (553) adjacent to the first stationary ring (52) is engaged with the first abutting ring (552); one end of the first connecting ring (553) facing away from the first stationary ring (52) is protrudingly provided with a first protruding portion (5531); the first protruding portion (5531) is inserted into the first ring groove (5510) with the smallest inner diameter among the three first ring grooves (5510); The first protrusion (5531) abuts against the first ridge (5311).

13. The compressor according to claim 11, wherein The second push ring (65) includes a second bearing ring (651), a second abutting ring (652) and a second connecting ring (653); The second supporting ring (651) surrounds the second convex ridge (6311) along the circumferential direction of the second convex ridge (6311), and three second annular grooves (6510) are provided on the inner peripheral wall of the second supporting ring (651). The inner diameters of the three second annular grooves (6510) decrease from one end close to the second base (631) to the end away from the second base (631), forming a three-step structure; The second abutting ring (652) is embedded in the second annular groove (6510) with the largest inner diameter among the three second annular grooves (6510), and the second abutting ring (652) abuts against the second stationary ring (62); The second connecting ring (653) is embedded in the second ring groove (6510) with the second largest inner diameter among the three second ring grooves (6510); Along the first direction (X), one end of the second connecting ring (653) adjacent to the second stationary ring (62) is engaged with the second abutting ring (652); one end of the second connecting ring (653) facing away from the second stationary ring (62) is protrudingly provided with a second protruding portion (6531); the second protruding portion (6531) is inserted into the second ring groove (6510) with the smallest inner diameter among the three second ring grooves (6510); The second protrusion (6531) abuts against the second ridge (6311).

14. The compressor according to claim 6, wherein The housing (10) is provided with a first through hole (11) and a second through hole (12) respectively connected to the accommodating cavity (101), and the first through hole (11) and the second through hole (12) are arranged at intervals along the first direction (X); The evaporated gas entering the accommodating chamber (101) through the medium side (102) passes through the gap (310) in sequence along the first direction (X) and is discharged from the housing (10) through the first through hole (11); A third through hole (5320) penetrating the first ring wall (532) is provided on the first ring wall (532), and the third through hole (5320) is communicated with the second through hole (12).

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