A kind of wind power gear box high-speed shaft non-contact zero leakage combined sealing device

Abstract

The present application relates to the technical field of high-speed shaft sealing of wind power gear box, and particularly relates to a wind power gear box high-speed shaft non-contact zero-leakage combined sealing device for sealing the gap between the high-speed shaft in the wind power gear box and the high-speed shaft end cover of the gear box. The sealing device comprises a sealing sleeve assembly, a centrifugal switch assembly, a magnetic fluid sealing assembly, an overflow valve assembly and a gas guide pressure maintaining assembly. The sealing sleeve assembly and the centrifugal switch assembly form a gap seal, the sealing sleeve assembly, the gas guide pressure maintaining assembly and the magnetic fluid sealing assembly jointly form an air pressure seal, the magnetic fluid sealing assembly forms a magnetic fluid seal, and the gap seal, the air pressure seal and the magnetic fluid seal jointly seal the high-speed shaft in the wind power gear box and the outer end cover through the synergistic effect. Meanwhile, the overflow valve assembly maintains the pressure of the pressure maintaining ring cavity in the gas guide pressure maintaining assembly, and the lubricating oil leaked into the pressure maintaining ring cavity is discharged into the gear box through the overflow valve assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-speed shaft sealing of wind turbine gearboxes, in particular to a non-contact zero-leakage combined sealing device for high-speed shafts of wind turbine gearboxes. BACKGROUND

[0002] Wind power generation is an important way for China to achieve "carbon peak and carbon neutral" and green transformation of energy structure. The sealing of the high-speed shaft of the wind turbine gearbox is a key component to ensure the stable operation of the gearbox lubrication system, and its sealing reliability is directly related to the power generation safety, system operation efficiency and environmental friendliness of the wind turbine generator. At present, the high-speed shaft sealing of the wind turbine gearbox often adopts the structure forms of skeleton oil seal, mechanical seal and labyrinth seal. However, the skeleton oil seal is prone to wear and aging of the rubber material under complex working conditions such as high speed and large temperature difference, which leads to rapid deterioration of the sealing performance and frequent replacement, seriously affecting the operation efficiency and economy of the equipment. Although the mechanical seal has certain sealing performance, it has high requirements for installation precision, shaft concentricity and lubrication conditions, and in the operation environment of frequent start-stop, variable speed, shaft vibration and severe temperature difference fluctuation of the wind turbine, dry friction, thermal deformation and even sealing failure are easy to occur, making it difficult to achieve long-term stable operation. The labyrinth seal is widely used due to its simple structure and high-speed resistance, but its sealing ability for the lubricating oil and oil mist splashed in the gearbox is limited, and it is difficult to achieve zero leakage, which has a high risk of leakage. Therefore, the sealing reliability of the high-speed shaft of the wind turbine gearbox has become a key problem restricting the high-quality development of wind turbine generators. SUMMARY

[0003] The purpose of the present application is to provide a non-contact zero-leakage combined sealing device for high-speed shafts of wind turbine gearboxes, which can avoid oil mist leakage in the gearbox.

[0004] The technical solution of the present application is: a non-contact zero-leakage combined sealing device for high-speed shafts of wind turbine gearboxes, which is arranged at the high-speed shaft of the wind turbine gearbox. The high-speed shaft is arranged in the high-speed shaft end cover of the gearbox through the high-speed shaft generator side bearing. An outer end cover is arranged on one side of the high-speed shaft end cover of the gearbox. The end of the high-speed shaft penetrates the outer end cover and extends to the outside of the outer end cover. The sealing device is used to seal the gap between the high-speed shaft and the high-speed shaft end cover of the gearbox. The sealing device includes a sealing sleeve assembly, a centrifugal switch assembly, a magnetic fluid sealing assembly and a gas guiding and pressure maintaining assembly. The gap is sealed by the sealing sleeve assembly and the centrifugal switch assembly. The gas pressure seal is formed by the sealing sleeve assembly, the gas guiding and pressure maintaining assembly and the magnetic fluid sealing assembly. The magnetic fluid seal is formed by the magnetic fluid sealing assembly. The high-speed shaft and the outer end cover of the wind turbine gearbox are sealed by the cooperation of the gap seal, the gas pressure seal and the magnetic fluid seal.

[0005] The sealing sleeve assembly is arranged outside the high-speed shaft generator side bearing, and comprises an oil guide ring and a conically arranged dynamic sealing sleeve; the oil guide ring is arranged outside the high-speed shaft generator side bearing, is mounted on the inner wall of the high-speed shaft end cover of the gear box, and is provided with an oil guide gap between the oil guide ring and the high-speed shaft; a plurality of oil guide holes are provided through the oil guide ring, each of the oil guide holes is communicated with the outside through an oil injection channel provided on the high-speed shaft end cover of the gear box and an oil injection hole provided on the outer end cover, and an oil discharge groove is provided on the inner wall of the oil guide ring and communicated with the plurality of oil guide holes; the dynamic sealing sleeve is sleeved on the first shaft shoulder of the high-speed shaft, and the large diameter end of the dynamic sealing sleeve is located on one side of the oil guide ring; an oil guide ring gland is sleeved on the outer part of the dynamic sealing sleeve, the oil guide ring gland is connected with the inner wall of the high-speed shaft end cover of the gear box, one side wall of the oil guide ring gland is abutted with the side wall of the oil guide ring, the inner wall of one side of the oil guide ring gland is provided with a conical structure matched with the dynamic sealing sleeve, the other side wall of the oil guide ring gland is connected with the side wall of the outer end cover, and the centrifugal gap is provided between the inner wall of the oil guide ring gland and the dynamic sealing sleeve.

[0006] The centrifugal switch assembly is sleeved on the second shaft shoulder of the high-speed shaft, and is arranged between the high-speed shaft generator side bearing and the dynamic sealing sleeve; the centrifugal switch assembly comprises a hollow centrifugal sleeve, a T-shaped sealing ring is arranged in the centrifugal sleeve, the T-shaped sealing ring comprises a sealing part and an abutment part, the sealing part is slidably connected with the side wall of the centrifugal sleeve through a sliding opening, and one end of the sealing part is abutted with the inner wall of the oil guide ring gland; a pre-tightening spring is arranged on the inner diameter side of the abutment part and connected with the inner wall of the centrifugal sleeve, and a centrifugal rotating mechanism is arranged on the abutment part, so that the sealing part of the T-shaped sealing ring is pressed into the inside of the centrifugal sleeve under the action of centrifugal force through the centrifugal rotating mechanism.

[0007] The magnetic fluid sealing assembly is arranged on one side of the dynamic sealing sleeve, and comprises an inner pole shoe and an outer pole shoe with the same structure; the inner wall of the inner pole shoe and the outer pole shoe is provided with a pole tooth, and the pole tooth of the inner pole shoe and the outer pole shoe is provided with a magnetic fluid; the inner pole shoe, the outer pole shoe and the permanent magnet ring are connected with the inner wall of the oil guide ring gland, and one side of the outer pole shoe is connected with the side wall of the outer end cover.

[0008] The guide gas pressure maintaining assembly comprises a pressure maintaining ring cavity formed by the inner wall of the oil guide ring cover, the side wall of the dynamic sealing sleeve, the high speed shaft and the side wall of the inner pole shoe, the pressure maintaining ring cavity is communicated with the pressure maintaining guide gas channel and the leakage liquid collecting cavity formed on the oil guide ring cover, the pressure maintaining guide gas channel is communicated with the external gas source through the pressurizing hole formed on the outer end cover, one end of the leakage liquid collecting cavity is communicated with the overflow channel, the overflow channel is located below the high speed shaft, the inner part of the overflow channel is provided with the overflow valve assembly, one end of the overflow channel is communicated with the inside of the gear box through the high speed shaft generator side bearing and the gear box through the pressure releasing hole formed on the oil guide ring, the pressure of the pressure maintaining ring cavity is maintained through the overflow valve assembly, and the lubricating oil leaked into the pressure maintaining ring cavity is discharged into the inside of the gear box through the overflow valve assembly.

[0009] Preferably, the sleeve sealing ring is arranged between the dynamic sealing sleeve and the high speed shaft, the large diameter end of the dynamic sealing sleeve is connected with the first shaft shoulder of the high speed shaft, and the small diameter end of the dynamic sealing sleeve is provided with a sleeve blocking ring; a plurality of spiral grooves are uniformly formed on the side wall of the dynamic sealing sleeve.

[0010] Further, the bearing blocking ring is arranged on one side of the high speed shaft generator side bearing and located between the high speed shaft generator side bearing and the oil guide ring, and the oil storage groove is formed on the outer wall of the oil guide ring and communicated with the plurality of oil guide holes.

[0011] Preferably, the oil guide ring cover sealing ring is arranged between the oil guide ring cover and the oil guide ring and between the oil guide ring cover and the gear box high speed shaft end cover.

[0012] Further, the centrifugal sleeve comprises a mounting ring, left and right sleeve rings are symmetrically arranged on two sides of the mounting ring, the T-shaped sealing ring is buckled in the inside of the centrifugal sleeve through the left and right sleeve rings, the left sleeve ring abuts against the second shaft shoulder of the high speed shaft, and the left sleeve ring sealing ring is arranged between the left sleeve ring and the second shaft shoulder, the right sleeve ring abuts against the side wall of the dynamic sealing sleeve, and the right sleeve ring sealing ring is arranged between the right sleeve ring and the dynamic sealing sleeve, the sliding opening is arranged between the left and right sleeve rings, and the sealing part of the T-shaped sealing ring extends to the outside of the centrifugal sleeve through the sliding opening; the T-shaped sealing ring is composed of a plurality of sealing ring petals connected in series, the clamping parts are arranged at two ends of each sealing ring petal, and the clamping parts at the two ends of each sealing ring petal are staggered.

[0013] Further, the centrifugal rotating mechanism comprises left and right bearing rings symmetrically arranged on two sides of the T-shaped sealing ring, a plurality of mounting bases are arranged on the left and right bearing rings, a centrifugal block is rotatably connected to each mounting base through a pin shaft, the centrifugal block is provided with a centrifugal part and a contact part at two ends thereof, the weight of the centrifugal part is greater than that of the contact part, and the contact part is matched with the clamping groove on the abutting part.

[0014] Preferably, the inner pole shoe and the outer pole shoe are respectively provided with an inner pole shoe sealing ring and an outer pole shoe sealing ring.

[0015] Preferably, the stable pressure gas guiding channel is provided with a gas guiding sealing ring at the pressurizing hole, and the gas guiding sealing ring is arranged on the side wall of the oil guiding ring cover.

[0016] Further, the overflow valve assembly comprises a valve core, the valve core abuts against the inner wall of one side of the overflow channel to form a tapered sealing surface, the valve core is provided with a valve core oil guiding hole, one end of the valve core is connected with a pressure regulating spring, one end of the pressure regulating spring is connected with a pressure adjusting screw, the side wall of the pressure adjusting screw abuts against the inner wall of the overflow channel, the compression amount of the pressure regulating spring is adjusted by the pressure adjusting screw, the overflow pressure is formed at the tapered sealing surface formed by the valve core and the overflow channel, the middle part of the pressure adjusting screw is provided with an overflow pressure relief hole; when the pressure in the pressure maintaining ring cavity is not higher than the overflow pressure of the overflow valve assembly, the overflow valve assembly is in a closed state, the valve core is abutted against the inner wall of the overflow channel under the action of the pressure regulating spring, the leakage liquid collecting cavity is separated from the overflow channel by the valve core to play a pressure maintaining role; when the pressure in the pressure maintaining ring cavity reaches the overflow pressure of the overflow valve assembly, the pressure regulating spring in the overflow channel starts to compress, the valve core is separated from the inner wall of the overflow channel, and the leakage liquid collecting cavity is communicated with the pressure relief hole through the overflow channel, the valve core oil guiding hole and the overflow pressure relief hole.

[0017] The beneficial effects of the present application are as follows:

[0018] The cross section of the dynamic sealing sleeve from inside to outside is formed in a conical shape from large to small, which forms pressure reduction effect, so that the lubricating oil in the centrifugal gap gradually decreases in pressure in the leakage direction from left to right. At the same time, the conical spiral groove generates a pressure difference from right to left during high-speed rotation of the high-speed shaft, which generates pumping pressure of the lubricating oil in the centrifugal gap from right to left, further sealing the lubricating oil in the centrifugal gap; in addition, the conical cross section of the dynamic sealing sleeve gradually increases from right to left, so that the lubricating oil in the centrifugal gap is subjected to a great centrifugal force during high-speed rotation of the conical spiral groove, so that the lubricating oil forms an opposite centrifugal force in the leakage direction of the centrifugal gap, which plays a centrifugal sealing effect; again, the gas pressure in the pressure maintaining ring cavity seals the lubricating oil in the centrifugal gap; the four kinds of comprehensive effects of the throttling effect of the conical cross section, the pumping effect of the spiral groove, the centrifugal effect of the combination of the conical cross section and the spiral groove, and the gas pressure effect of the pressure maintaining ring cavity achieve pressure balance on the right side of the oil drain groove, so that the lubricating oil from the inside of the oil drain groove can only enter the gear box from the left side to play a supplementary cooling and lubricating effect on the bearings and gears inside the gear box; the magnetic fluid sealing assembly plays a pressure maintaining sealing effect on the pressure maintaining cavity formed by the pressure maintaining ring cavity, the pressure stabilizing gas guide channel and the leakage liquid collection cavity, which fully utilizes the advantage that the magnetic fluid can reliably seal the gas. Finally, the overflow valve assembly automatically discharges the possible leaked lubricating oil into the gear box, so that the lubricating oil is gap sealed when flowing through the oil guide gap, the passage gap and the centrifugal gap during the power generation process of the wind turbine generator, there is no mechanical physical contact, and the entire sealing system forms a non-contact, zero leakage and super long life sealing scheme. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0020] Figure 1 is a sectional view of the installation position of the present application in the wind turbine gearbox;

[0021] Figure 2 is a sectional view of the use state of the present application;

[0022] Figure 3 is Figure 2 is a local enlarged view of B in the middle;

[0023] Figure 4 is another side sectional view of the use state of the present application;

[0024] Figure 5 A cross-sectional view of the oil guide ring of the present application;

[0025] Figure 6 A schematic view of the structure of the sealing sleeve assembly of the present application;

[0026] Figure 7 A partial three-dimensional view of the assembly of the centrifugal switch assembly;

[0027] Figure 8 A partial cross-sectional view of the centrifugal switch assembly when the high speed shaft is stationary;

[0028] Figure 9 A partial cross-sectional view of the centrifugal switch assembly when the high speed shaft is in motion;

[0029] Figure 10 A schematic view of the T-shaped sealing ring joint;

[0030] Figure 11 A schematic view of the structure of the magnetic fluid assembly of the present application;

[0031] Figure 12 A Figure 4 A partial enlarged view at C.

[0032] In the figure: high-speed shaft 1, high-speed shaft generator side bearing 11, first shaft shoulder 12, bearing retainer 13, gear box oil inlet nozzle 14, gear box oil outlet nozzle 15, second shaft shoulder 16, left collar seal ring 16-1; gear box high-speed shaft end cover 2, oil injection channel 2-1; outer end cover 3, oil injection hole 3-1; seal sleeve assembly 4, oil guide ring 41, oil guide hole 41-1, oil discharge groove 41-2, oil storage groove 41-3, oil guide gap 41-4, dynamic seal sleeve 42, centrifugal gap 42-1, oil guide ring gland 43, oil guide ring gland seal ring 43-1, horizontal inner circular surface 43-2, passage gap 43-3, sleeve retainer 44, helical groove 45; magnetic fluid seal assembly 5, inner pole shoe 51, inner pole shoe seal ring 51-1, outer pole shoe 52, outer pole shoe seal ring 52-1, pole tooth 53, permanent magnet ring 54; air guide pressure maintaining assembly 6, pressure maintaining ring cavity 61, pressure maintaining cavity 61-1, pressure stabilizing air guide channel 62, pressurizing hole 62-1, leakage liquid collection cavity 63, pressure relief hole 63-1, overflow channel 63-2, overflow valve assembly 64, valve core 64-1, valve core oil guide hole 64-2, pressure regulating spring 64-3, pressure adjusting screw 64-4, overflow pressure relief hole 64-5, air guide seal ring 65; centrifugal switch assembly 7, centrifugal sleeve 71, mounting ring 71-1, left collar 71-2, right collar 71-3, right collar seal ring 71-4, T-shaped seal ring 72, sealing part 72-1, abutting part 72-2, seal ring ring petal 72-3, clamping part 72-4, clamping groove 72-5, pre-tightening spring 73, centrifugal rotating mechanism 74, left receiving ring 74-1, right receiving ring 74-2, mounting base 74-3, centrifugal block 75, centrifugal part 75-1, contact part 75-2. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0034] In the description of the present application, it should be noted that the terms "middle", "upper", "lower", "one side", "one end", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application; in addition, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] As Figures 1-12 shown, a kind of wind power gear box high-speed shaft non-contact zero leakage combined sealing device is arranged at the high-speed shaft 1 of wind power gear box, high-speed shaft 1 is rotatably connected in the high-speed shaft end cover 2 of gear box by high-speed shaft generator side bearing 11, outer end cover 3 is provided on the side of high-speed shaft end cover 2, the end of high-speed shaft 1 penetrates outer end cover 3 and extends to the outside of outer end cover 3, sealing device is used to seal the gap between high-speed shaft 1 and high-speed shaft end cover 2 in wind power gear box, the sealing device includes: sealing sleeve assembly 4, magnetic fluid sealing assembly 5 and air guide pressure maintaining assembly 6, centrifugal switch assembly 7, overflow valve assembly 64; Figure 1 Position A is the installation position of the sealing device described in the embodiment; wherein the gap sealing is formed by sealing sleeve assembly 4 and centrifugal switch assembly 7, the air pressure sealing is formed by sealing sleeve assembly 4, air guide pressure maintaining assembly 6 and magnetic fluid sealing assembly 5, the magnetic fluid sealing is formed by magnetic fluid sealing assembly 5, and the overflow valve assembly 64 is used to maintain pressure and discharge the possible leaked lubricating oil into the gear box; the high-speed shaft and the outer end cover of wind power gear box are sealed by the synergistic effect of gap sealing, air pressure sealing and magnetic fluid sealing, and the possible leaked lubricating oil is discharged into the gear box by overflow valve assembly 64.

[0036] Specifically in the present embodiment, the zero-leakage combined seal is formed by the sealing sleeve assembly 4, the magnetic fluid sealing assembly 5, the air guide and pressure maintaining assembly 6, the centrifugal switch assembly 7, and the overflow valve assembly 64. When the wind turbine control system detects that the ambient wind speed reaches the wind turbine cut-in wind speed, the wind turbine control system will perform self-checking on the electrical system, the mechanical system, the sensing system, and the lubricating system. The present patent takes the wind turbine gearbox lubricating system as the research object, and therefore only the gearbox lubricating system and related factors are described. Other electrical and mechanical systems are common technologies in the technical field of wind turbine gearboxes, and are not described again. When the wind turbine control system detects that the ambient wind speed reaches the wind turbine cut-in wind speed, the gearbox lubricating oil pump is started, the lubricating oil provided by the lubricating oil pump is filtered and cooled by the filtering system and the cooling system, and then two pressure oil paths are formed through the three-way joint, which are the gearbox lubricating oil path and the gearbox sealing oil path. The lubricating oil of the gearbox lubricating oil path reaches the set pressure and flow rate through pressure and flow control, and then enters the gearbox through the gearbox oil inlet nozzle 14 to cool and lubricate the gears and bearings inside the gearbox, avoid part wear caused by dry friction during starting, and finally flows out through the gearbox oil outlet nozzle 15 to return to the oil supply tank of the gearbox lubricating oil pump to realize the circulation of the lubricating oil path. At the same time, the lubricating oil of the gearbox sealing oil path reaches the set pressure and flow rate through control, and then enters the oil injection channel 2-1 through the oil injection hole 3-1 in the outer end cover 3, and then enters the oil discharge groove 41-2 through the oil storage groove 41-3 and the oil guide hole 41-1. At this time, since the T-shaped sealing ring 72 on the centrifugal switch assembly 7 is pressed against the horizontal inner circular surface 43-2 of the oil guide ring pressure cover 43 to play a static sealing role, the lubricating oil in the oil discharge groove 41-2 can only flow into the gearbox through the oil guide gap 41-4 on the left side of the oil discharge groove 41-2 to play an auxiliary cooling and lubricating role on the high-speed shaft generator side bearing 11.

[0037] In the present embodiment, as Figures 1-6As shown, the sealing sleeve assembly 4 is arranged outside the high-speed shaft generator side bearing 11, and the sealing sleeve assembly 4 comprises an oil guide ring 41 and a conically arranged dynamic sealing sleeve 42. The oil guide ring 41 is arranged outside the high-speed shaft generator side bearing 11, and is mounted on the inner wall of the gear box high-speed shaft end cover 2. An oil guide gap 41-4 is arranged between the oil guide ring 41 and the high-speed shaft 1. A plurality of oil guide holes 41-1 are arranged through the oil guide ring 41. Each oil guide hole 41-1 is in communication with the outside through an oil injection channel 2-1 arranged on the gear box high-speed shaft end cover 2 and an oil injection hole 3-1 arranged on the outer end cover 3. An oil discharge groove 41-2 is arranged on the inner wall of the oil guide ring 41, and the oil discharge groove 41-2 is in communication with the plurality of oil guide holes 41-1. The dynamic sealing sleeve 42 is sleeved on the first shaft shoulder 12 of the high-speed shaft 1, and the large diameter end of the dynamic sealing sleeve 42 is located on one side of the oil guide ring 41. An oil guide ring gland 43 is sleeved on the outside of the dynamic sealing sleeve 42. The oil guide ring gland 43 is connected with the inner wall of the gear box high-speed shaft end cover 2. One side of the oil guide ring gland 43 abuts against the side wall of the oil guide ring 41. The inner wall of one side of the oil guide ring gland 43 is provided with a conical structure matched with the dynamic sealing sleeve 42. The other side of the oil guide ring gland 43 is connected with the side wall of the outer end cover 3. A centrifugal gap 42-1 is arranged between the inner wall of the oil guide ring gland 43 and the dynamic sealing sleeve 42.

[0038] As shown, Figures 1-4 The dynamic sealing sleeve 42 and the high-speed shaft 1 are provided with a sleeve sealing ring. The large diameter end of the dynamic sealing sleeve 42 is connected with the first shaft shoulder 12 of the high-speed shaft 1, and the small diameter end of the dynamic sealing sleeve 42 is provided with a sleeve blocking ring 44. A plurality of spiral grooves 45 are uniformly arranged on the side wall of the dynamic sealing sleeve 42.

[0039] Based on the above embodiment, the oil is injected into the inside of the oil discharge groove 41-2 through the oil injection hole 3-1, the oil injection channel 2-1 and the oil guide hole 41-1, and the oil in the inside of the oil discharge groove 41-2 flows to the centrifugal gap 42-1 between the dynamic sealing sleeve 42 and the oil guide ring cover 43; when the high-speed shaft 1 drives the dynamic sealing sleeve 42 to rotate at high speed, the oil in the centrifugal gap 42-1 between the dynamic sealing sleeve 42 and the oil guide ring cover 43 forms a sealing pressure opposite to the leakage direction at the centrifugal gap 42-1 under the action of centrifugal force, pumping effect and throttling resistance; since the dynamic sealing sleeve 42 is a conical shape with a cross section decreasing from inside to outside, the conical cross section of the dynamic sealing sleeve 42 gradually decreases in the process of the lubricating oil flowing to the right in the centrifugal gap 42-1, forming a throttling pressure reduction effect, so that the lubricating oil pressure in the centrifugal gap 42-1 gradually decreases in the leakage direction from left to right, and at the same time, the lubricating oil has a tendency to gradually fill the entire centrifugal gap 42-1 from left to right under the action of pressure; secondly, the conical spiral groove 45 generates a pressure difference from right to left with the high-speed rotation of the high-speed shaft 1, which generates a pumping pressure from right to left on the lubricating oil in the centrifugal gap 42-1, further sealing the lubricating oil in the centrifugal gap 42-1. In addition, since the conical cross section of the dynamic sealing sleeve 42 gradually increases from right to left, the lubricating oil in the centrifugal gap 42-1 will also be subjected to a great centrifugal force during the high-speed rotation of the conical spiral groove 45 with the high-speed shaft 1, and due to the blocking of the oil guide ring cover 43, the centrifugal action of the lubricating oil is manifested as a centrifugal force opposite to the leakage direction of the centrifugal gap 42-1, playing a centrifugal sealing role.

[0040] Wherein, one side of the high-speed shaft generator side bearing 11 is provided with a bearing check ring 13, and the bearing check ring 13 is located between the high-speed self-aligning roller bearing 11 and the oil guide ring 41, the outer wall of the oil guide ring 41 is provided with an oil storage groove 41-3, and the oil storage groove 41-3 is communicated with a plurality of oil guide holes 41-1; the oil guide ring cover 43 is provided with an oil guide ring cover sealing ring 43-1 between the oil guide ring 41 and the oil guide ring cover 43 and between the oil guide ring cover 43 and the gear box high-speed shaft end cover 2.

[0041] Based on the above embodiment, the high-speed shaft 1 is arranged in the gear box, the gear box outer cover 2 is installed on the gear box, and the gear box is provided with lubricating oil for ensuring the normal operation of the high-speed shaft 1, the lubricating oil in the gear box splashes into the gear box outer cover 2 and leaks through the connection between the high-speed shaft 1 and the outer end cover 3, and the sealing assembly seals between the high-speed shaft 1 and the outer end cover 3 to prevent the lubricating oil from leaking from the inside of the gear box.

[0042] In this embodiment, as Figure 3 And Figures 7-10As shown, the centrifugal switch assembly 7 is sleeved on the second shaft shoulder 16 of the high-speed shaft 1, and is arranged between the high-speed shaft generator side bearing 11 and the dynamic seal sleeve 4. The centrifugal switch assembly 7 comprises a hollow centrifugal sleeve 71, and the inside of the centrifugal sleeve 71 is provided with a T-shaped sealing ring 72. The T-shaped sealing ring 72 comprises a sealing part 72-1 and an abutting part 72-2. The sealing part 72-1 is connected with the side wall of the centrifugal sleeve 71 through a sliding port, and one end of the sealing part 72-1 abuts against the inner wall of the oil guide ring gland 43. The inner diameter side of the abutting part 72-2 is provided with a pre-tightening spring 73 connected with the inner wall of the centrifugal sleeve 71. The centrifugal sleeve 71 is provided with a centrifugal rotating mechanism 74. The centrifugal rotating mechanism 74 presses the sealing part 72-1 of the T-shaped sealing ring 72 into the inside of the centrifugal sleeve 71 under the action of centrifugal force.

[0043] As shown in the drawings, Figure 2 , Figures 7-10 the centrifugal sleeve 71 comprises a mounting ring 71-1. The left sleeve ring 71-2 and the right sleeve ring 71-3 are symmetrically arranged on both sides of the mounting ring 71-1. The T-shaped sealing ring 72 is buckled in the inside of the centrifugal sleeve 71 through the left sleeve ring 71-2 and the right sleeve ring 71-3. The left sleeve ring 71-2 abuts against the second shaft shoulder 16 of the high-speed shaft 1, and the left sleeve ring 71-2 and the second shaft shoulder 16 are provided with a left sleeve ring sealing ring 16-1. The right sleeve ring 71-3 abuts against the side wall of the dynamic seal sleeve 42, and the right sleeve ring 71-3 and the dynamic seal sleeve 42 are provided with a right sleeve ring sealing ring 71-4. The left sleeve ring 71-2 and the right sleeve ring 71-3 are provided with a sliding port. The sealing part 72-1 of the T-shaped sealing ring 72 extends to the outside of the centrifugal sleeve 71 through the sliding port. The T-shaped sealing ring 72 is composed of a plurality of sealing ring petals 72-3 connected in sequence. The two ends of each sealing ring petal 72-3 are provided with a clamping part 72-4, and the clamping parts 72-4 at the two ends of each sealing ring petal 72-3 are staggered. In this embodiment, the clamping parts 72-4 of the two adjacent sealing ring petals 72-3 are connected in sliding mode. When the end of the sealing part 72-1 abuts against the oil guide ring gland 43, there is a gap between the clamping part 72-4 of any sealing ring petal 72-3 and the adjacent sealing ring petal 72-3. The centrifugal rotating mechanism 74 presses all the sealing ring petals 72-3 into the inside of the centrifugal sleeve 71 through the gap. The position of the gap is shown in Figure 10 .

[0044] Specifically, as shown in the drawings, Figures 7-9As shown, the centrifugal rotating mechanism 74 includes a left receiving ring 74-1 and a right receiving ring 74-2 symmetrically arranged on both sides of the T-shaped sealing ring 72, and a plurality of mounting bases 74-3 are arranged on the left receiving ring 74-1 and the right receiving ring 74-2. A centrifugal block 75 is rotatably connected to each mounting base 74-3 through a pin shaft, and the centrifugal block 75 is provided with a centrifugal portion 75-1 and a contact portion 75-2 at two ends thereof respectively, the weight of the centrifugal portion 75-1 is greater than the weight of the contact portion 75-2, and the contact portion 75-2 is matched with the clamping groove 72-5 on the abutting portion 72-2.

[0045] Based on the above embodiment, when the wind turbine self-checking system passes, the wind turbine starts the blade operation to generate electricity, the high-speed shaft 1 starts to rotate, the T-shaped sealing ring 72 on the centrifugal switch assembly 7 is separated from the horizontal inner circular surface 43-2 of the oil guide ring gland 43 under the action of centrifugal force to form a passage gap 43-3, at this time, the lubricating oil in the oil discharge groove 41-2 can flow into the inside of the gearbox through the oil guide gap 41-4 to assist the cooling and lubrication of the high-speed shaft generator side bearing 11, and can also flow into the centrifugal gap 42-1 formed by the oil guide ring gland 43 and the dynamic sealing sleeve 42 through the passage gap 43-3; when the wind turbine is converted from the power generation state to the shutdown state, the high-speed shaft 1 stops rotating, and the sealing ring 72 on the centrifugal switch assembly 7 on the right side of the oil discharge groove 41-2 is pressed tightly to the horizontal inner circular surface 43-2 of the oil guide ring gland 43 again to play a static sealing role, and also plays a good sealing role on the oil mist in the gearbox.

[0046] In the embodiment, as shown in Figure 2 、 Figure 4 and Figure 11 , the magnetic fluid sealing assembly 5 is arranged on one side of the dynamic sealing sleeve 42, the magnetic fluid sealing assembly 5 includes an inner pole shoe 51 and an outer pole shoe 52 with the same structure, the inner walls of the inner pole shoe 51 and the outer pole shoe 52 are provided with pole teeth 53, the pole teeth 53 of the inner pole shoe 51 and the outer pole shoe 52 are provided with magnetic fluids, and the inner pole shoe 51 and the outer pole shoe 52 are connected with a permanent magnet ring 54, the outer walls of the inner pole shoe 51, the permanent magnet ring 54 and the outer pole shoe 52 are connected with the inner wall of the oil guide ring gland 43, and one side of the outer pole shoe 52 is connected with the side wall of the outer end cover 3.

[0047] Based on the above embodiment, the inner pole shoe 51, the permanent magnet 54, the outer pole shoe 52 and the magnetic fluid form a magnetic fluid sealing at the connection between the high-speed shaft 1 and the outer end cover 3, which plays a pressure maintaining role on the pressure maintaining ring cavity 61; when the high-speed shaft 1 stops running for a long time, the magnetic fluid sealing plays a sealing role on the external dust to prevent the external dust from entering the inside of the gearbox; in addition, the magnetic fluid in the embodiment is an oil-repellent type magnetic fluid.

[0048] Specifically, the inner shoe 51 and the outer shoe 52 are respectively provided with an inner shoe sealing ring 51-1 and an outer shoe sealing ring 52-1 between the inner shoe 51 and the outer shoe 52 and the oil guide ring cover 43.

[0049] Based on the above embodiment, the gas in the pressure maintaining ring cavity 61 is prevented from leaking between the inner shoe 51 and the outer shoe 52 and the inner wall of the oil guide ring cover 43 by the inner shoe sealing ring 51-1 and the outer shoe sealing ring 52-1, so as to ensure the constant pressure in the pressure maintaining ring cavity 61. It should be noted that the oil in the present application is the lubricating oil used in the gearbox.

[0050] In the present embodiment, as shown in Figure 2 , Figure 4 and Figure 12 , the gas guiding and pressure maintaining assembly 6 includes a pressure maintaining ring cavity 61 formed by the inner wall of the oil guide ring cover 43, the side wall of the dynamic sealing sleeve 42, the high-speed shaft 1 and the side wall of the inner shoe 51, the pressure maintaining ring cavity 61 is in communication with a pressure stabilizing gas guiding channel 62 and a leakage liquid collecting cavity 63 formed in the oil guide ring cover 43; the pressure stabilizing gas guiding channel 62 is in communication with an external gas source through a pressurizing hole 62-1 formed in the outer end cover 3; one end of the leakage liquid collecting cavity 63 is in communication with an overflow channel 63-2, the overflow channel 63-2 is located below the high-speed shaft 1, the overflow channel 63-2 is internally provided with an overflow valve assembly 64, and one end of the overflow channel 63-2 is in communication with the inside of the gearbox through a pressure relief hole 63-1 formed in the oil guide ring 41 and the high-speed shaft generator side bearing.

[0051] The pressure stabilizing gas guiding channel 62 and the pressurizing hole 62-1 are provided with a gas guiding sealing ring 65, and the gas guiding sealing ring 65 is arranged on the side wall of the oil guide ring cover 43; the gas guiding sealing ring 65 ensures that the gas does not escape between the outer end cover 3 and the oil guide ring cover 43, so as to ensure the constant pressure in the pressure maintaining ring cavity 61.

[0052] Based on the above embodiment, the gas source provides gas pressure to the pressure maintaining ring cavity 61 through the pressurizing hole 62-1 and the pressure maintaining gas guiding channel 62. In this process, oil is injected into the interior of the oil discharge groove 41-2 through the oil injection hole 3-1, the oil injection channel 2-1, and the oil guiding hole 41-1. The oil inevitably leaks to the pressure maintaining ring cavity 61 after being sealed by the centrifugal gap 42-1. At this time, the interior of the pressure maintaining ring cavity 61 is sealed by the oil in the dynamic sealing gap 42-1. The gas pressure in the pressure maintaining ring cavity 61 also plays a sealing role on the lubricating oil in the centrifugal gap 42-1. Therefore, the throttling effect of the conical section, the pumping effect of the helical groove, the centrifugal effect of the combination of the conical section and the helical groove, and the gas pressure effect of the pressure maintaining ring cavity 61 all play a synergistic sealing effect on the lubricating oil in the centrifugal gap 42-1. The four comprehensive effects reach pressure balance on the right side of the oil discharge groove 41-2, so that the lubricating oil from the interior of the oil discharge groove 41-2 can only enter the gear box from the left side to play a role in auxiliary cooling and lubrication for the bearings and gears inside the gear box.

[0053] In the present embodiment, as shown in Figure 12 The overflow valve assembly 64 includes a valve core 64-1 that abuts against the inner wall of one side of the overflow channel 63-2 to form a conical sealing surface. The valve core 64-1 is provided with a valve core oil guiding hole 64-2. One end of the valve core 64-1 is connected with a pressure regulating spring 64-3. One end of the pressure regulating spring 64-3 is connected with a pressure adjusting screw 64-4. The side wall of the pressure adjusting screw 64-4 abuts against the inner wall of the overflow channel 63-2. The compression amount of the pressure regulating spring 64-3 is adjusted by the pressure adjusting screw 64-4 to adjust the overflow pressure formed at the conical sealing surface between the valve core 64-1 and the overflow channel 63-2. The middle part of the pressure adjusting screw 64-4 is provided with an overflow pressure relief hole 64-5. When the pressure in the pressure maintaining ring cavity 61 is not higher than the overflow pressure of the overflow valve assembly 64, the overflow valve assembly 64 is in a closed state. The valve core 64-1 is abutted against the inner wall of the overflow channel 63-2 under the action of the pressure regulating spring 64-3 to separate the leakage liquid collecting cavity 63 from the overflow channel 63-2 to play a pressure maintaining role. When the pressure in the pressure maintaining ring cavity 61 reaches the overflow pressure of the overflow valve assembly, the pressure regulating spring 64-3 in the overflow channel 63-2 starts to compress. The valve core 64-1 is separated from the inner wall of the overflow channel 63-2 to make the leakage liquid collecting cavity 63 communicate with the pressure relief hole 63-1 through the overflow channel 63-2, the valve core oil guiding hole 64-2, and the overflow pressure relief hole 64-5.

[0054] Based on the above embodiments, through the throttling effect of the tapered cross section, the pumping effect of the helical groove, the centrifugal effect of the combination of the tapered cross section and the helical groove, and the gas pressure effect of the pressure maintaining ring cavity 61, the four comprehensive effects have a synergistic sealing effect on the lubricating oil in the centrifugal gap 42-1. In this process, a small part of the lubricating oil inevitably leaks into the pressure maintaining ring cavity 61 through the centrifugal gap 42-1, and under the action of gravity and the pressure of the pressure maintaining ring cavity 61, this part of the leaked lubricating oil will collect in the leakage liquid collecting cavity 63. Since the volume of the pressure maintaining cavity 61-1 formed by the leakage liquid collecting cavity 63, the pressure maintaining ring cavity 61 and the pressure stabilizing gas guiding channel 62 is constant, as the amount of lubricating oil leaked into the leakage liquid collecting cavity 63 through the centrifugal gap 42-1 gradually increases, the gas inside the pressure maintaining cavity 61-1 is compressed, and the gas pressure inside the pressure maintaining cavity 61-1 gradually increases. When the gas pressure inside the pressure maintaining cavity 61-1 reaches the overflow pressure of the overflow valve assembly, the valve core 64-1 of the overflow valve assembly moves to the left to open, so that the lubricating oil in the leakage liquid collecting cavity 63 enters the gear box under the action of the gas pressure, and the liquid level of the lubricating oil leaked through the centrifugal gap 42-1 is always lower than the contact position of the pole tooth 53 of the magnetic fluid seal and the high-speed shaft 1.

[0055] The working principle of the application is as follows: the lubricating oil of the gear box sealing oil circuit is introduced into the oil injection channel 2-1 through the oil injection hole 3-1 on the outer end cover 3, and then enters the oil discharge groove 41-2 through the oil storage groove 41-3 and the oil guide hole 41-1; after the self-checking system of the wind turbine passes, the wind turbine starts the blade operation to generate electricity, the high-speed shaft 1 starts to rotate, the T-shaped sealing ring 72 on the centrifugal switch assembly 7 is separated from the horizontal inner circular surface 43-2 of the oil guide ring gland 43 under the action of centrifugal force to form a passage gap 43-3, at this time, the lubricating oil in the oil discharge groove 41-2 can flow into the gear box to assist the cooling and lubrication of the high-speed shaft generator side bearing 11 through the oil guide gap 41-4, and can also flow into the centrifugal gap 42-1 formed by the oil guide ring gland 43 and the dynamic sealing sleeve 42 through the passage gap 43-3. At this time, since the dynamic sealing sleeve 42 is a conical shape with the cross section gradually decreasing from inside to outside, the lubricating oil in the centrifugal gap 42-1 gradually fills the entire centrifugal gap 42-1 from left to right under the action of pressure due to the gradually decreasing conical cross section of the dynamic sealing sleeve 42 in the right-to-left flow process. At the same time, the conical spiral groove 45 generates a pressure difference from right to left due to the high-speed rotation of the high-speed shaft 1, which generates a pumping pressure from right to left on the lubricating oil in the centrifugal gap 42-1, further sealing the lubricating oil in the centrifugal gap 42-1. In addition, since the conical cross section of the dynamic sealing sleeve 42 gradually increases from right to left, the lubricating oil in the centrifugal gap 42-1 will also be subjected to a great centrifugal force during the high-speed rotation of the conical spiral groove 45 with the high-speed shaft 1, and the centrifugal action of the lubricating oil is opposite to the leakage direction of the centrifugal gap 42-1 due to the blockage of the oil guide ring gland 43, which plays a centrifugal sealing role. In addition, the gas pressure in the pressure maintaining ring cavity 61 also plays a sealing role on the lubricating oil in the centrifugal gap 42-1. Therefore, the throttling effect of the conical cross section, the pumping effect of the spiral groove, the centrifugal effect of the combination of the conical cross section and the spiral groove, and the gas pressure effect of the pressure maintaining ring cavity 61 all play a synergistic sealing effect on the lubricating oil in the centrifugal gap 42-1, and the four comprehensive effects reach pressure balance on the right side of the oil discharge groove 41-2, so that the lubricating oil from the inside of the oil discharge groove 41-2 can only enter the gear box from the left side to assist the cooling and lubrication of the bearings and gears in the gear box.In this process, a small amount of lubricating oil inevitably leaks into the pressure- maintaining ring cavity 61 through the centrifugal gap 42-1, but under the action of gravity and the pressure of the pressure-maintaining ring cavity, the leaked lubricating oil collects in the leakage collection cavity 63. Since the volume of the pressure-maintaining cavity 61-1 formed by the leakage collection cavity 63, the pressure-maintaining ring cavity 61, and the pressure-stabilizing gas guide channel 62 is constant, as the amount of lubricating oil leaked into the pressure relief channel 63 through the centrifugal gap 42-1 gradually increases, the gas inside the pressure-maintaining cavity 61-1 is compressed, and the gas pressure inside the pressure-maintaining cavity 61-1 gradually increases. When the gas pressure inside the pressure-maintaining cavity 61-1 reaches the overflow pressure of the overflow valve assembly, the spool 64-1 of the overflow valve assembly moves to the left to open, allowing the lubricating oil leaked into the pressure relief channel 63 to enter the gearbox under the action of gas pressure, thereby allowing the pressure relief channel 63 to continue to collect the lubricating oil leaked through the centrifugal gap 42-1. When a certain amount is collected, it is discharged into the gearbox through the overflow valve assembly 64. This reciprocation ensures that the liquid level of the lubricating oil leaked through the centrifugal gap 42-1 is always below the contact position of the pole teeth 53 of the magnetic fluid seal and the rotating shaft. In the running process, the medium that needs to be sealed by the magnetic fluid seal is always pressurized air, which has a pressure-maintaining sealing effect on the pressure-maintaining cavity 61-1, fully utilizing the advantage of magnetic fluid that can reliably seal gas. The lubricating oil in the wind turbine generator during the power generation process is sealed by gap sealing when flowing through the oil guide gap 41-4, the passage gap 43-3, and the centrifugal gap 42-1, and there is no mechanical and physical contact, making the entire sealing system a non-contact, zero-leakage, and ultra-long-life sealing solution.

[0056] When the wind turbine generator is switched from the power generation state to the shutdown state, the high-speed shaft 1 stops rotating, and the sealing ring 72 on the centrifugal switch assembly 7 on the right side of the oil drain groove 41-2 is re-compressed to the horizontal inner circular surface 43-2 of the oil guide ring gland 43 to play a static sealing role. The wind turbine control system then closes the gearbox seal oil circuit. When the wind turbine generator is switched from the power generation state to the shutdown state, the pressure-maintaining cavity 61-1 remains a closed cavity due to the static sealing effect of the sealing ring 72.

[0057] It is worth mentioning that the rotation speed of the high-speed shaft 1 plays an important role in the formation of the passage gap 43-3 between the T-shaped sealing ring 72 and the horizontal inner circular surface 43-2 of the oil guide ring cover 43, the pumping effect of the spiral groove, and the centrifugal sealing effect of the sealing structure. Under different rotation speeds of the wind turbine, the higher the rotation speed of the high-speed shaft, the larger the passage gap 43-3 formed by the centrifugal effect, the more lubricating oil flowing out of the oil discharge groove 41-2 flows into the centrifugal gap 42-1 through the passage gap 43-3, however, the higher the rotation speed of the high-speed shaft, the greater the pumping pressure and centrifugal pressure in the centrifugal gap 42-1 to inhibit leakage. On the contrary, the lower the rotation speed of the high-speed shaft, the smaller the passage gap 43-3 formed by the centrifugal effect, the less lubricating oil flowing out of the oil discharge groove 41-2 flows into the centrifugal gap 42-1 through the passage gap 43-3, and the lower the rotation speed of the high-speed shaft, the smaller the pumping pressure and centrifugal pressure in the centrifugal gap 42-1 to inhibit leakage. This feature of self-adaptive adjustment of leakage flow and sealing effect with rotation speed makes the sealing device always meet the zero leakage requirement under the complex working conditions of frequent start-stop and variable speed of the wind turbine.

[0058] Finally, it should be pointed out that the above description is only the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A wind turbine gearbox high speed shaft non-contact zero leakage combined sealing device, which is arranged at the high speed shaft of a wind turbine gearbox, the high speed shaft is arranged in the high speed shaft end cover of the gearbox through the high speed shaft generator side bearing, an outer end cover is arranged on one side of the high speed shaft end cover, the end of the high speed shaft penetrates the outer end cover and extends to the outside of the outer end cover, the sealing device is used for sealing the gap between the high speed shaft and the high speed shaft end cover of the gearbox, characterized in that, The sealing device comprises a sealing sleeve assembly, a centrifugal switch assembly, a magnetic fluid sealing assembly and an air guide and pressure maintaining assembly, the sealing sleeve assembly and the centrifugal switch assembly form a gap seal, the sealing sleeve assembly, the air guide and pressure maintaining assembly and the magnetic fluid sealing assembly jointly form an air pressure seal, and the magnetic fluid sealing assembly forms a magnetic fluid seal, and the gap seal, the air pressure seal and the magnetic fluid seal jointly seal the high-speed shaft and the outer end cover of the wind turbine gearbox through the synergistic effect of the gap seal, the air pressure seal and the magnetic fluid seal; The sealing sleeve assembly is arranged outside the high-speed shaft generator side bearing, the sealing sleeve assembly comprises an oil guide ring and a conical dynamic sealing sleeve, the oil guide ring is arranged outside the high-speed shaft generator side bearing, the oil guide ring is mounted on the inner wall of the high-speed shaft end cover of the gearbox, and an oil guide gap is arranged between the oil guide ring and the high-speed shaft, a plurality of oil guide holes are arranged through the oil guide ring, each oil guide hole is communicated with the outside through an oil injection channel arranged on the high-speed shaft end cover of the gearbox and an oil injection hole arranged on the outer end cover, an oil discharge groove is arranged on the inner wall of the oil guide ring, and the oil discharge groove is communicated with the plurality of oil guide holes; the dynamic sealing sleeve is arranged on the first shaft shoulder of the high-speed shaft, and the large diameter end of the dynamic sealing sleeve is located on one side of the oil guide ring; an oil guide ring gland is arranged outside the dynamic sealing sleeve, the oil guide ring gland is connected with the inner wall of the high-speed shaft end cover of the gearbox, one side wall of the oil guide ring is abutted with one side wall of the oil guide ring gland, a conical structure matched with the dynamic sealing sleeve is arranged on the inner wall of one side of the oil guide ring gland, the other side wall of the oil guide ring gland is connected with the side wall of the outer end cover, and the inner wall of the oil guide ring gland is arranged between the dynamic sealing sleeve and the centrifugal gap; The centrifugal switch assembly is arranged on the second shaft shoulder of the high-speed shaft, and the centrifugal switch assembly is arranged between the high-speed shaft generator side bearing and the dynamic sealing sleeve, the centrifugal switch assembly comprises a hollow centrifugal sleeve, a T-shaped sealing ring is arranged in the centrifugal sleeve, the T-shaped sealing ring comprises a sealing part and an abutting part, the sealing part is slidably connected with the side wall of the centrifugal sleeve through a sliding hole, and one end of the sealing part is abutted with the inner wall of the oil guide ring gland; a pre-tightening spring is arranged on the inner diameter side of the abutting part and connected with the inner wall of the centrifugal sleeve, and a centrifugal rotating mechanism is arranged on the abutting part, and the sealing part of the T-shaped sealing ring is pressed into the centrifugal sleeve under the action of centrifugal force through the centrifugal rotating mechanism; The magnetic fluid sealing assembly is arranged on one side of the dynamic sealing sleeve, the magnetic fluid sealing assembly comprises an inner pole shoe and an outer pole shoe with the same structure, the inner wall of the inner pole shoe and the outer pole shoe is provided with a pole tooth, the pole tooth of the inner pole shoe and the outer pole shoe is provided with a magnetic fluid, the inner pole shoe and the outer pole shoe are connected with a permanent magnet ring, the outer wall of the inner pole shoe, the permanent magnet ring and the outer pole shoe is connected with the inner wall of the oil guide ring gland, and one side of the outer pole shoe is connected with the side wall of the outer end cover. The guide gas pressure maintaining assembly comprises a pressure maintaining ring cavity formed by the inner wall of the oil guide ring pressure cover, the side wall of the dynamic sealing sleeve, the high speed shaft and the side wall of the inner pole shoe, the pressure maintaining ring cavity is communicated with a pressure stabilizing guide gas passage and a leakage liquid collecting cavity formed on the oil guide ring pressure cover; the pressure stabilizing guide gas passage is communicated with an external gas source through a pressurizing hole formed on the outer end cover; one end of the leakage liquid collecting cavity is communicated with an overflow passage, the overflow passage is located below the high speed shaft, the overflow passage is internally provided with an overflow valve assembly, one end of the overflow passage is communicated with the inside of the gear box through a pressure relief hole formed on the oil guide ring and a high speed shaft generator side bearing; the pressure maintaining ring cavity is pressure maintained by the overflow valve assembly, and the lubricating oil leaked into the pressure maintaining ring cavity is discharged into the inside of the gear box through the overflow valve assembly.

2. A non-contact zero-leakage combined seal for high speed shaft of a wind turbine gearbox as claimed in claim 1, wherein, The dynamic sealing sleeve and the high speed shaft are provided with a sleeve sealing ring, the large diameter end of the dynamic sealing sleeve is connected with the first shaft shoulder of the high speed shaft, and the small diameter end of the dynamic sealing sleeve is provided with a sleeve blocking ring; a plurality of spiral grooves are uniformly formed on the side wall of the dynamic sealing sleeve.

3. A non-contact zero-leakage combined seal for high speed shaft of a wind turbine gearbox as claimed in claim 2, wherein, One side of the high speed shaft generator side bearing is provided with a bearing blocking ring, the bearing blocking ring is located between the high speed shaft generator side bearing and the oil guide ring, and an oil storage groove is formed on the outer wall of the oil guide ring and communicated with the plurality of oil guide holes.

4. A non-contact zero-leakage combined seal for high speed shaft of a wind turbine gearbox as claimed in claim 3, wherein, The oil guide ring pressure cover and the oil guide ring, and the oil guide ring pressure cover and the gear box high speed shaft end cover are both provided with an oil guide ring pressure cover sealing ring.

5. A non-contact zero leakage combination seal for high speed shaft of a wind turbine gearbox as claimed in claim 4, wherein, The centrifugal sleeve comprises a mounting ring, left and right sleeve rings are symmetrically arranged on two sides of the mounting ring, a T-shaped sealing ring is buckled in the inside of the centrifugal sleeve through the left and right sleeve rings, the left sleeve ring abuts against the second shaft shoulder of the high speed shaft, and a left sleeve ring sealing ring is arranged between the left sleeve ring and the second shaft shoulder, the right sleeve ring abuts against the side wall of the dynamic sealing sleeve, and a right sleeve ring sealing ring is arranged between the right sleeve ring and the dynamic sealing sleeve, a sliding opening is arranged between the left and right sleeve rings, and a sealing part of the T-shaped sealing ring extends to the outside of the centrifugal sleeve through the sliding opening; the T-shaped sealing ring is composed of a plurality of sealing ring petals connected in a head-to-tail manner, each sealing ring petal is provided with a clamping part at two ends, and the clamping parts at the two ends of each sealing ring petal are arranged in an interlaced manner.

6. A non-contact zero leakage combination seal for high speed shaft of a wind turbine gearbox as claimed in claim 5, wherein, The centrifugal rotating mechanism comprises left and right bearing rings symmetrically arranged on two sides of the T-shaped sealing ring, a plurality of mounting bases are arranged on the left and right bearing rings, a centrifugal block is rotatably connected to each mounting base through a pin shaft, and a centrifugal part and a contact part are arranged at two ends of the centrifugal block respectively, the weight of the centrifugal part is greater than that of the contact part, and the contact part is matched with the clamping groove on the abutting part.

7. A non-contact zero leakage combination seal for high speed shaft of a wind turbine gearbox as claimed in claim 1, wherein, The inner pole shoe and the outer pole shoe and the oil guide ring pressure cover are respectively provided with an inner pole shoe sealing ring and an outer pole shoe sealing ring.

8. A non-contact zero leakage combination seal for high speed shaft of a wind turbine gearbox as claimed in claim 1, wherein, A guide gas sealing ring is arranged at the pressure stabilizing guide gas passage and the pressurizing hole, and the guide gas sealing ring is arranged on the side wall of the oil guide ring pressure cover.

9. A non-contact zero leakage combination seal for high speed shaft of a wind turbine gearbox as claimed in claim 6, wherein, The overflow valve assembly comprises a valve core, a conical sealing surface is formed by the abutment between the valve core and the inner wall of one side of an overflow channel, a valve core oil guide hole is formed in the valve core, one end of the valve core is connected with a pressure regulating spring, one end of the pressure regulating spring is connected with a pressure adjusting screw, the side wall of the pressure adjusting screw abuts against the inner wall of the overflow channel, the compression amount of the pressure regulating spring is adjusted by the pressure adjusting screw, the overflow pressure is formed at the conical sealing surface formed by the valve core and the overflow channel, and an overflow pressure relief hole is formed in the middle of the pressure adjusting screw; when the pressure in the pressure maintaining ring cavity is not higher than the overflow pressure of the overflow valve assembly, the overflow valve assembly is in a closed state, the valve core is abutted against the inner wall of the overflow channel under the action of the pressure regulating spring, the leakage liquid collecting cavity is separated from the overflow channel by the valve core to play a pressure maintaining role; when the pressure in the pressure maintaining ring cavity reaches the overflow pressure of the overflow valve assembly, the pressure regulating spring in the overflow channel starts to compress, the valve core is separated from the inner wall of the overflow channel, and the leakage liquid collecting cavity is communicated with the pressure relief hole through the overflow channel, the valve core oil guide hole and the overflow pressure relief hole.

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