A kind of gradient rotary seal structure and wind power generation equipment

Abstract

The application discloses a gradually-changing rotary sealing structure and a wind power generation device, and relates to the technical field of rotary sealing, which comprises a base, the base comprising a first sealing part and a second sealing part, the second sealing part being gradually reduced in pitch along the direction close to the bearing, and a spiral pumping effect being formed in the bearing direction, which is gradually enhanced. When the main shaft rotates, the variable-pitch structure can generate directional fluid dynamic pressure oil return capacity, pump the lubricating medium with a leakage tendency back to the bearing, and significantly reduce the risk of leakage. Meanwhile, the first sealing part is located on the side of the second sealing part away from the bearing, plays an auxiliary sealing role, can block dust or foreign matters from the outside, and further blocks the outward leakage of the lubricating medium. Further, the gradually-reduced structure of the pitch can also make the sealing contact pressure be distributed in a gradient along the axial direction, improve the sealing effect of the side close to the bearing, reduce the leakage, and the gradually-changing pitch can avoid stress concentration, reduce local overheating and abrasion of the lip, and improve the sealing life.

Description

Technical Field

[0001] This invention relates to the field of rotary sealing technology, and in particular to a gradient rotary sealing structure and a wind power generation device. Background Technology

[0002] In existing rotary mechanical seal technologies, especially in equipment with long-term unidirectional rotation such as wind turbine gearboxes, lubrication methods are gradually shifting from grease to low-viscosity thin oils. Traditional single-lip oil seals mainly rely on contact stress to achieve sealing, lacking active oil return capability and making them unsuitable for the high fluidity of thin oils, thus prone to leakage. Although ordinary spiral oil seals have a uniform pitch spiral structure on the lip surface, which can generate a certain oil return effect during rotation, their simple spiral structure cannot form a stable fluid pressure gradient, resulting in a significant decrease in sealing performance under shaft eccentricity and vibration conditions. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a gradual rotary sealing structure and a wind power generation device, which can improve oil return capacity and enhance sealing reliability.

[0004] A gradient rotary sealing structure according to a first aspect embodiment of the present invention includes: The base has a first sealing part and a second sealing part on its inner side wall that can abut against the outer peripheral wall of the main shaft. The second sealing part extends circumferentially spirally around the base. The first sealing part is located on the side of the second sealing part away from the bearing. Along the direction close to the bearing, the pitch of the second sealing part gradually decreases.

[0005] According to a first aspect embodiment of the present invention, a gradient rotary sealing structure has at least the following beneficial effects: This embodiment includes a base comprising a first sealing part and a second sealing part. By setting the pitch of the second sealing part to gradually decrease along the direction close to the bearing, a gradually enhanced helical pumping effect is formed in the bearing direction. When the spindle rotates, the variable pitch structure can generate directional hydrodynamic pressure return oil capability, pumping the lubricating medium with leakage tendency back to the bearing, significantly reducing the risk of leakage. Simultaneously, the first sealing part is located on the side of the second sealing part away from the bearing, playing an auxiliary sealing role, blocking external dust or foreign matter, and further preventing lubricating medium leakage, improving the sealing effect. Furthermore, the gradually decreasing pitch structure allows the sealing contact pressure to be distributed in a gradient along the axial direction, improving the sealing effect on the side close to the bearing, reducing leakage, and the gradual pitch change avoids stress concentration, reducing local overheating and wear at the lip, and improving seal life.

[0006] According to an embodiment of the first aspect of the present invention, the second sealing portion has a plurality of spiral portions spaced apart along the axial direction of the main shaft, an oil guide channel is defined between two adjacent spiral portions, and the width of the oil guide channel gradually decreases along the axial direction of the main shaft in the direction close to the bearing.

[0007] According to an embodiment of the first aspect of the present invention, the depth of the oil guide channel in the radial direction of the bearing gradually decreases along the direction close to the bearing.

[0008] According to an embodiment of the first aspect of the present invention, both the first sealing portion and the second sealing portion are capable of bending when their ends contact the spindle, and the first sealing portion and the second sealing portion are inclined toward the bearing.

[0009] According to an embodiment of the first aspect of the present invention, both the first sealing portion and the second sealing portion are inclined toward the bearing in a radial direction toward the spindle.

[0010] According to an embodiment of the first aspect of the present invention, the second sealing portion includes an inlet region and a return region, wherein the helical lead of the inlet region is greater than the helical lead of the return region.

[0011] According to an embodiment of the first aspect of the present invention, the helix angle of the inlet region is α, requiring 15°≤α≤35°, and the helix angle of the return region is β, requiring 5°≤β≤15°.

[0012] According to an embodiment of the first aspect of the present invention, a skeleton is embedded in the base, the skeleton being used to improve the structural strength of the base.

[0013] According to an embodiment of the first aspect of the present invention, the length of the first sealing portion is greater than the length of the second sealing portion along the radial direction of the main shaft, and the interference fit between the first sealing portion and the main shaft is less than the interference fit between the second sealing portion and the main shaft.

[0014] According to an embodiment of a second aspect of the present invention, a wind power generation device is provided, comprising the gradient rotary sealing structure of any of the above embodiments.

[0015] The wind power generation equipment according to the second aspect of the present invention has at least the following beneficial effects: The wind power generation equipment of this embodiment features a gradually decreasing rotary seal structure. By incorporating a second sealing portion with a pitch that gradually decreases towards the bearing, a gradually enhanced helical pumping effect is created in the bearing direction. When the main shaft rotates, the variable pitch structure generates directional hydrodynamic pressure return, pumping the leak-prone lubricating medium back to the bearing, significantly reducing the risk of leakage. Simultaneously, the first sealing portion, located on the side of the second sealing portion away from the bearing, acts as an auxiliary seal, blocking external dust or foreign matter and further preventing lubricating medium leakage, thus improving the sealing effect. Furthermore, the gradually decreasing pitch structure allows for a gradient distribution of sealing contact pressure along the axial direction, improving the sealing effect near the bearing and reducing leakage. The gradual pitch also avoids stress concentration, reducing localized overheating and wear at the lip, and extending the seal life.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a first cross-sectional view of a gradient rotary sealing structure in an embodiment of the present invention; Figure 2 This is a second cross-sectional view of a gradient rotary sealing structure according to an embodiment of the present invention; Figure 3 This is a third cross-sectional view of a gradient rotary sealing structure in an embodiment of the present invention; Figure 4 This is a fourth cross-sectional view of a gradient rotary sealing structure in an embodiment of the present invention; Figure 5 This is a cross-sectional view of the connection between a gradient rotary seal structure and a bearing in an embodiment of the present invention.

[0018] Figure label: Main spindle 100; end cap 101; bearing 102; pressure plate 103; mounting groove 104; Base 110; First sealing part 111; Second sealing part 112; Spiral part 113; Oil guide channel 114; Inlet area 115; Return area 116; Skeleton 117. Detailed Implementation

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

[0020] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0021] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0023] Reference Figures 1 to 5 In an embodiment of the present invention, a gradient rotary seal structure is fitted onto the outer periphery of a main shaft 100. The gradient rotary seal structure includes a base 110, which is annular in shape. Its inner sidewall is provided with a first sealing portion 111 and a second sealing portion 112 capable of abutting against the outer peripheral wall of the main shaft 100. The second sealing portion 112 extends helically around the base 110, and the first sealing portion 111 is located on the side of the second sealing portion 112 facing away from the bearing 102. Along the direction close to the bearing 102, the pitch of the second sealing portion 112 gradually decreases.

[0024] During installation, the gradual rotary seal structure is installed between the main shaft 100 and the end cover 101 of the wind power generator, and fixed in the mounting groove 104 of the end cover 101 by a pressure plate 103. When the main shaft 100 rotates, the pitch of the second sealing part 112 gradually decreases along the direction close to the bearing 102, forming a spiral pumping effect that gradually increases from the side away from the bearing to the side close to the bearing. This generates a directional hydrodynamic pressure return oil capability, actively pumping the lubricating medium (such as thin oil or grease) that originally had a tendency to leak outward back to the side where the bearing 102 is located, ensuring the lubrication effect of the bearing 102 while preventing the lubricating medium leakage. At the same time, the first sealing part 111 is located on the outside of the second sealing part 112 away from the bearing 102, playing an auxiliary sealing and dustproof role. It can prevent external dust, moisture or foreign objects from entering the seal and further block the leakage of a small amount of lubricating medium that may cross the second sealing part 112, thus forming a double sealing protection.

[0025] The second sealing portion 112 has a plurality of spiral portions 113 spaced axially along the main shaft 100, defining an oil guide channel 114 between adjacent spiral portions 113. The oil guide channel 114 gradually narrows in width along the axial direction of the main shaft 100, closer to the bearing 102. In other words, the spacing between the spiral portions 113 near the bearing 102 is smaller, while the spacing further away from the bearing 102 is larger. This gradual width design makes the oil guide channel 114 narrower near the bearing 102, increasing the fluid velocity and pressure as it flows through this area, thereby enhancing the ability to pump the lubricating medium towards the bearing 102.

[0026] Along the direction close to bearing 102, the depth of the oil guide channel 114 gradually decreases radially from bearing 102. That is, the oil guide channel 114 is deeper on the side away from bearing 102 and shallower on the side closer to bearing 102. This gradual depth design has two important functions. First, when the spindle 100 rotates, the deeper channel inlet can more effectively capture and contain the lubricating medium overflowing from the bearing side, while the gradually shallower channel outlet exerts a compression effect on the fluid, causing the fluid pressure to gradually increase along the flow direction, forming a stable positive pressure gradient, thereby driving the lubricating medium to flow back towards bearing 102. Second, the gradually decreasing depth means that the length of the helical portion 113 near bearing 102 is shorter, resulting in lower structural flexibility. With the same interference fit, the ratio of deformation to length of the shorter helical portion 113 is larger, leading to a greater elastic pressure contact force between the helical portion 113 and the spindle 100 at that location. This results in more stable contact with the spindle 100 and facilitates the formation of a higher and more uniform sealing pressure. Furthermore, it enables a gradient distribution of sealing contact pressure along the axial direction of the main shaft 100, gradually increasing towards the bearing 102: the side closer to the bearing 102 (where the oil guide channel 114 has a shallower depth) experiences higher contact pressure, resulting in a stronger sealing effect and effectively reducing leakage; while the side farther from the bearing 102 (where the oil guide channel 114 has a deeper depth) experiences relatively lower contact pressure, preventing excessive friction caused by excessive pressure throughout the sealing area. Simultaneously, this feature synergizes with the gradually decreasing pitch structure. The gradual pitch eliminates geometric abrupt changes, ensuring a uniform stress distribution along the axial gradient, avoiding localized stress concentrations. This reduces localized overheating and accelerated wear at stress concentration points on the sealing lip, effectively extending the service life of the sealing structure.

[0027] Reference Figure 4 and Figure 5When the ends of the first sealing part 111 and the second sealing part 112 contact the main shaft 100, they can both bend, and after bending, the first sealing part 111 and the second sealing part 112 tilt towards the bearing 102. Specifically, in some embodiments, when installed, the free ends of the first sealing part 111 and the second sealing part 112 extend radially toward the main shaft 100, and when they contact the outer peripheral wall of the main shaft 100, they will produce a certain elastic bending deformation. This tilted and flexible structure brings the following beneficial effects: First, since the sealing part is tilted toward the bearing 102 side, when the main shaft 100 rotates, the high-pressure lubricating medium on the bearing side acts on the tilted surface of the sealing part, generating a radial component force that presses the sealing lip more tightly toward the main shaft 100, that is, a "self-tightening" effect is achieved. The higher the rotational speed or the greater the pressure, the stronger the sealing contact force, thereby improving the reliability of the seal without the need to add an additional interference fit. Second, the inclined direction towards the bearing side reduces the bending stress on the roots of the first sealing part 111 and the second sealing part 112, while the lip end can flexibly follow the slight radial runout or eccentric movement of the main shaft 100, maintaining a stable contact state and avoiding seal failure due to excessive rigidity. Third, this inclined direction, combined with the gradually decreasing pitch structure, forms a continuous guide slope (or arc surface) towards the bearing side from the outside to the inside of the entire sealing area, further promoting the backflow of the leaked medium to the bearing side, thereby ensuring sealing performance under shaft eccentricity and vibration conditions.

[0028] Reference Figure 3 In some embodiments, both the first sealing portion 111 and the second sealing portion 112 are inclined toward the bearing 102 in a radial direction toward the main shaft 100. Specifically, starting from the inner wall of the base 110, the first sealing portion 111 and the second sealing portion 112 extend radially inward while also being inclined toward the bearing 102, thereby ensuring that the inclination angles of the first sealing portion 111 and the second sealing portion 112 are consistent in the circumferential direction, ensuring uniform contact between the sealing lip and the main shaft 100 throughout the entire circumferential direction. Simultaneously, this inclination direction ensures that when the sealing portion is subjected to pressure from the bearing side, its deformation direction is consistent with the inclination direction, which helps maintain a stable contact pressure distribution.

[0029] Reference Figure 2In some embodiments, the second sealing section 112 includes an inlet region 115 and a return region 116, with the helical lead of the inlet region 115 being greater than that of the return region 116. The inlet region 115 is located on the side of the second sealing section 112 relatively far from the bearing 102, and its larger helical lead means fewer helical turns and a gentler helix; the return region 116 is located on the side relatively close to the bearing 102, and its smaller helical lead means more helical turns and a tighter helix. This partitioned structure makes the functional division of the second sealing section 112 clearer: the inlet region 115 is responsible for collecting the lubricating medium leaking from the bearing side and guiding it into the return region 116; the return region 116 is responsible for efficiently pumping this medium back to the bearing 102. The two regions work together to ensure both sufficient medium capture range and adequate return oil power.

[0030] In some embodiments, the helix angle of the inlet zone 115 is α, requiring 15°≤α≤35°, and the helix angle of the return zone 116 is β, requiring 5°≤β≤15°. The helix angle refers to the angle between the tangent of the helix and the axis of the main shaft 100. When the helix angle α of the inlet zone 115 is in the range of 15° to 35°, a better medium capture and guiding effect can be obtained: if α is less than 15°, the helix is ​​too tight, and the resistance to the medium entering the channel is large; if α is greater than 35°, the helix is ​​too flat, the pumping effect is weakened, and the return oil efficiency decreases. When the helix angle β of the return zone 116 is in the range of 5° to 15°, a stable and sufficiently strong hydrodynamic pumping effect can be generated: if β is less than 5°, the helix is ​​too tight, the frictional resistance increases, and it is easy to cause local overheating; if β is greater than 15°, the pumping pressure is insufficient, and it is difficult to overcome the pressure difference on both sides of the seal to completely pump the medium back. The optimal range of the helix angle ensures that the gradual rotary seal structure can maintain efficient oil return capability under low viscosity thin oil conditions, while controlling frictional heat generation within a reasonable range.

[0031] Furthermore, a skeleton 117 is embedded within the base 110, which is used to improve the structural strength of the base 110. Specifically, the skeleton 117 can be a ring-shaped steel wire made of metal (such as...). Figures 1 to 3 (as shown) or steel strip (such as) Figure 4 As shown, the skeleton 117 is embedded in the base 110 using a vulcanization integral molding method. The skeleton 117 provides radial stiffness support, preventing the sealing structure from shrinking, deforming, or twisting due to material stress relaxation or temperature changes during long-term use, which is particularly important for wind power generation equipment. Simultaneously, the skeleton 117 can also be asymmetrically distributed, with more reinforcing material arranged axially closer to the bearing side. This causes the sealing structure to undergo offset deformation towards the bearing side under pressure, further enhancing the contact pressure between the sealing lip and the main shaft 100. This feature solves the problem of dimensional shrinkage and sealing performance degradation that traditional pure rubber oil seals easily experience during long-term operation.

[0032] In some embodiments, along the radial direction of the main shaft 100, the length of the first sealing portion 111 is greater than the length of the second sealing portion 112, and the interference fit between the first sealing portion 111 and the main shaft 100 is less than the interference fit between the second sealing portion 112 and the main shaft 100. The first sealing portion 111, as an outer auxiliary seal, has a longer cantilever structure that provides greater flexibility, better adapting to the slight eccentric movements of the main shaft 100. Simultaneously, the smaller interference fit results in lower contact pressure with the main shaft 100, less frictional heat generation, and helps reduce the temperature rise of the entire sealing structure. The second sealing portion 112, as the main seal and active oil return component, has a shorter length that provides higher rigidity and stability, while the larger interference fit ensures sufficiently high contact pressure in the main sealing area to resist lubricant leakage. This differentiated design of a "long and loose" outer seal and a "short and tight" inner seal reflects an optimized functional division of labor: the outer seal focuses on dust prevention and low friction, while the inner seal focuses on high-pressure sealing and active oil return. The difference in interference fit between the two also creates a gradient in contact pressure that gradually increases from the outside to the inside along the axial direction. This, combined with the gradually decreasing pitch structure, achieves a better balance between sealing effect and friction loss.

[0033] During actual installation, after cleaning the main shaft 100 at the output shaft of the main gearbox of the wind power generator, apply an appropriate amount of lubricant to the sealing installation groove to assist in installation. The gradient rotary sealing structure of this embodiment is then fitted onto the main shaft 100, with the second sealing part 112 facing the bearing 102 and the first sealing part 111 facing away from the bearing 102. The base 110 is pressed and fixed into the installation groove 104 of the end cover 101 by the pressure plate 103, ensuring that the lips of both the first sealing part 111 and the second sealing part 112 form an interference contact with the outer peripheral wall of the main shaft 100. At this time, both the first sealing part 111 and the second sealing part 112 elastically bend along the direction close to the bearing 102, maintaining a tight fit with the main shaft 100.

[0034] When the wind power generation equipment is running, the main shaft 100 rotates in a predetermined direction. During rotation, the relative motion between the spiral portion 113 on the second sealing portion 112 and the main shaft 100 generates a hydrodynamic pressure effect. The lubricating medium leaking from the second sealing portion 112 can first enter the oil guide channel 114 of the inlet zone 115. Due to the large spiral lead and wide and deep channel of the inlet zone 115, the medium is smoothly collected and transported along the spiral direction. As the medium moves towards the return zone 116, the width and depth of the oil guide channel 114 gradually decrease, the pitch also gradually decreases, the medium flow velocity increases, and the pressure rises. Under the tight spiral push of the return zone 116, the medium is forced to be pumped back to the bearing 102 side, realizing dynamic oil return. When a small amount of medium that is not returned continues to leak outward, it will encounter the first sealing portion 111. Because the first sealing part 111 has a long cantilever structure and a small interference fit, it forms a low-friction auxiliary barrier with the main shaft 100, and its inclined direction towards the bearing 102 further hinders the escape of the medium. When dust or moisture in the outside air tries to enter the seal, it will also be blocked by the first sealing part 111.

[0035] During long-term operation, because the pitch of the second sealing part 112 and the dimensions of the oil guide channel 114 are both gradually changing, the sealing contact pressure is evenly distributed along the axial direction, avoiding local stress concentration and overheating. The skeleton 117 embedded in the base 110 ensures the dimensional stability of the sealing structure, and no significant shrinkage or deformation will occur even after long-term service. When the spindle 100 experiences a certain degree of radial runout or eccentricity due to manufacturing tolerances or long-term wear, the first sealing part 111 and the second sealing part 112 can follow the movement of the spindle 100 by relying on their elastic bending ability, always maintaining a stable contact state, thereby ensuring long-term sealing stability.

[0036] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A gradient rotary seal structure, sleeved on the outer circumference of a spindle, characterized in that, include: The base has a first sealing part and a second sealing part on its inner side wall that can abut against the outer peripheral wall of the main shaft. The second sealing part extends circumferentially spirally around the base. The first sealing part is located on the side of the second sealing part away from the bearing. Along the direction close to the bearing, the pitch of the second sealing part gradually decreases.

2. The gradient rotary sealing structure according to claim 1, characterized in that, The second sealing part has a plurality of spiral parts spaced apart along the axial direction of the main shaft, and an oil guide channel is defined between two adjacent spiral parts. The width of the oil guide channel gradually decreases along the axial direction of the main shaft in the direction close to the bearing.

3. The gradient rotary sealing structure according to claim 2, characterized in that, Along the direction close to the bearing, the depth of the oil guide channel gradually decreases in the radial direction of the bearing.

4. The gradient rotary sealing structure according to claim 1, characterized in that, Both the first and second sealing portions can bend when they contact the spindle, and both the first and second sealing portions tilt toward the bearing.

5. The gradient rotary sealing structure according to claim 1, characterized in that, Along the radial direction toward the main shaft, both the first sealing portion and the second sealing portion are inclined toward the bearing.

6. The gradient rotary sealing structure according to claim 1, characterized in that, The second sealing part includes an inlet area and a return area, wherein the spiral lead of the inlet area is greater than the spiral lead of the return area.

7. The gradient rotary sealing structure according to claim 6, characterized in that, The helix angle of the inlet zone is α, with a requirement of 15°≤α≤35°, and the helix angle of the return zone is β, with a requirement of 5°≤β≤15°.

8. The gradient rotary sealing structure according to claim 1, characterized in that, The base is embedded with a skeleton, which is used to improve the structural strength of the base.

9. A gradient rotary sealing structure according to claim 1, characterized in that, Along the radial direction of the main shaft, the length of the first sealing part is greater than the length of the second sealing part, and the interference fit between the first sealing part and the main shaft is less than the interference fit between the second sealing part and the main shaft.

10. Wind power generation equipment, characterized in that, Includes a gradient rotary sealing structure as described in any one of claims 1 to 9.

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