Shaft sealing structure, gearbox and wind turbine generator set

Abstract

This disclosure relates to a shaft sealing structure, a gearbox, and a wind turbine generator set. The gearbox includes: a housing; a through cover disposed on the housing, the through cover having a through hole communicating with the interior of the housing; and a shaft rotatably connected to the housing via a bearing, the shaft extending partially from the housing through the through hole, and a bushing corresponding to the inner wall surface of the through hole fitted onto the shaft. The inner wall surface of the through hole has at least one annular protrusion, the cross-sectional area of ​​which decreases radially inward, and the hardness of the bushing is less than the hardness of the annular protrusion. The technical solution provided by this disclosure can adaptively adjust the fitting clearance, improving the sealing effect.

Description

Technical Field

[0001] This disclosure relates to the technical field of shaft sealing, and particularly to a shaft sealing structure, a gearbox, and a wind turbine generator set. Background Technology

[0002] To prevent oil and oil mist from leaking out of the gearbox, the output shaft end generally adopts a non-contact labyrinth seal structure.

[0003] However, the fit clearance between the sealing structure and the output shaft is often related to bearing clearance, machining accuracy, assembly accuracy, etc. If the fit clearance is too large, the sealing effect will be poor; if the fit clearance is too small, there will be a risk of interference and wear, which will also affect the sealing effect. Utility Model Content

[0004] The purpose of this disclosure is to provide a shaft sealing structure, a gearbox, and a wind turbine generator set that can adaptively adjust the fitting clearance to improve the sealing effect.

[0005] According to one aspect of this disclosure, a gearbox is provided, the gearbox comprising:

[0006] Box;

[0007] A transparent cover is provided on the box body, and the transparent cover has a through hole communicating with the interior of the box body;

[0008] A shaft is rotatably connected to the housing via a bearing. Part of the shaft extends out of the housing through the through hole, and a bushing corresponding to the inner wall surface of the through hole is fitted onto the shaft.

[0009] The inner wall of the through hole is provided with at least one annular protrusion, the cross-sectional area of ​​the annular protrusion decreases radially inward, and the hardness of the bushing is less than the hardness of the annular protrusion.

[0010] The technical solution provided in this disclosure involves providing at least one annular protrusion on the inner wall of the through hole. The annular protrusion is arranged around the axis of the through hole, and the hardness of the bushing is less than that of the annular protrusion. Furthermore, the cross-sectional area of ​​the annular protrusion decreases radially inward. This design allows the inner diameter of the annular protrusion and the outer diameter of the bushing to be as close as possible. Therefore, before the gearbox is assembled and in operation, the fit between the annular protrusion and the bushing can be close to zero clearance. This allows for an initial minimum clearance setting. If, during subsequent use, the shaft experiences radial runout due to bearing clearance, machining accuracy, or assembly accuracy, the annular protrusion can be pressed into the bushing, which has a lower hardness, causing deformation of the bushing. This automatically forms the optimal fit clearance between the annular protrusion and the bushing based on the actual operating conditions of the shaft. In other words, the fit clearance between the annular protrusion and the bushing can adaptively form according to the actual operating conditions of the shaft, thereby avoiding excessive clearance, ensuring sealing performance, and reducing the possibility of oil leakage.

[0011] Meanwhile, the annular protrusion is a conical protrusion, which makes it easier for the annular protrusion to be pressed into the bushing, causing the bushing to deform and reducing the possibility of large-scale impact shock, thus ensuring the operational stability of the gearbox. Furthermore, it should be noted that this disclosure forms a sealing structure solely through the bushing and the inner ring of the cover, requiring fewer assembly parts, simplifying assembly and disassembly, and reducing costs.

[0012] Optionally, the inner wall surface of the through hole is provided with at least one annular groove; at least one of the annular grooves forms at least two annular retaining rings on the portion of the cover adjacent to the through hole, and each annular retaining ring is provided with at least one annular protrusion on its inner wall surface.

[0013] With the above solution, when the oil flows along the gap between the inner wall of the bushing and the through hole to the opening of the annular groove, the oil can be thrown into the annular groove under the action of centrifugal force as the shaft rotates, preventing the oil from continuing to flow along the gap between the inner wall of the bushing and the through hole, thereby further improving the sealing effect and reducing the possibility of oil leakage.

[0014] Optionally, there are two annular grooves, which are arranged along the axial direction of the through hole; correspondingly, there are three annular retaining rings, which are arranged along the axial direction of the through hole.

[0015] The above solution utilizes two annular grooves to receive the oil ejected by the bushing, increasing the probability of the oil detaching from the mating gap between the bushing and the inner wall of the through hole. At the same time, six annular protrusions, which cooperate with the bushing to seal and prevent the oil from flowing along the mating gap between the bushing and the inner wall of the through hole, effectively improve the sealing effect.

[0016] Optionally, the bottom end of the annular groove is provided with an oil drain hole.

[0017] The above solution allows the oil in the annular groove to be discharged through the drain hole, preventing excessive oil accumulation in the annular groove from flowing out from the gap between the inner wall of the bushing and the through hole, thus further improving the sealing effect on the oil.

[0018] Optionally, the outer wall surface of the bushing is provided with a plurality of annular oil storage grooves, and along the axial direction of the bushing, each annular groove has at least one annular oil storage groove in its opening.

[0019] With the above solution, when oil leaks out along the gap between the inner wall of the bushing and the through hole, the annular oil reservoir can accumulate oil, thereby increasing the probability that the oil will detach from the gap between the inner wall of the bushing and the through hole and enter the annular groove under the action of centrifugal force, and further improving the sealing effect.

[0020] Optionally, the cover has an annular groove communicating with the through hole on the side adjacent to the bearing; the outer wall of the bushing has an annular oil baffle, the annular oil baffle and the annular groove are fitted together, and the end of the fit gap between the annular oil baffle and the annular groove adjacent to the bearing is located in the radial direction outside the fit gap between the bearing and the shaft.

[0021] The above solution, by setting up an annular oil baffle and an annular mating groove, makes the positions of two adjacent mating gaps offset from each other, increasing the difficulty for oil to penetrate through the bearing to the mating gap between the annular oil baffle and the annular mating groove. In other words, it increases the difficulty for oil to penetrate through the bearing to the mating gap between the inner wall of the bushing and the through hole, thereby further improving the sealing effect of the oil and reducing the possibility of oil leakage.

[0022] Optionally, the transparent cover, the bearing, the shaft, and the annular oil baffle are arranged to form an annular oil baffle groove.

[0023] Through the above scheme, the annular oil baffle groove can collect the oil that is trapped by impacting the cover and the annular oil baffle, as well as the oil that is thrown into the annular oil baffle groove under centrifugal force, reducing the possibility of oil entering the gap between the annular oil baffle and the annular mating groove, thereby further improving the sealing effect of the oil and reducing the possibility of oil leakage.

[0024] Optionally, before the gearbox is in operation, the inner diameter of the annular protrusion is the same as the outer diameter of the shaft.

[0025] The above method can minimize the initial fit gap and ensure a good sealing effect.

[0026] Optionally, the cross-section of the annular protrusion is triangular or trapezoidal.

[0027] The above method facilitates the pressing of the annular protrusion into the bushing, forming an adaptive fit clearance.

[0028] Optionally, the shaft can be a high-speed shaft or a low-speed shaft.

[0029] According to another aspect of this disclosure, a gearbox is provided, the gearbox comprising:

[0030] Box;

[0031] A transparent cover is provided on the box body, and the transparent cover has a through hole communicating with the interior of the box body;

[0032] A shaft is rotatably connected to the housing via a bearing. Part of the shaft extends out of the housing through the through hole, and a bushing corresponding to the inner wall surface of the through hole is fitted onto the shaft.

[0033] The outer wall surface of the bushing is provided with at least one annular protrusion, the cross-sectional area of ​​the annular protrusion decreases radially outward, and the hardness of the cover adjacent to the inner wall surface of the through hole is less than the hardness of the annular protrusion.

[0034] Through the above scheme, the outer diameter of the annular protrusion and the inner diameter of the through hole can be made as close as possible during the design. This allows the fit between the annular protrusion and the inner wall of the through hole to be close to zero clearance before the gearbox is assembled and in operation. In this way, a minimum fit clearance can be initially set. If the shaft experiences radial runout due to bearing clearance, machining accuracy, assembly accuracy, or other reasons during subsequent use, the annular protrusion can be pressed into the inner wall of the through hole, which has a lower hardness than the protrusion. This causes deformation of the inner wall of the through hole, thereby automatically forming the optimal fit clearance between the annular protrusion and the inner wall of the through hole based on the actual operating conditions of the shaft. In other words, the fit clearance between the annular protrusion and the inner wall of the through hole can be adaptively formed according to the actual operating conditions of the shaft, thus avoiding excessive fit clearance, ensuring sealing effect, and reducing the possibility of oil leakage. Meanwhile, the annular protrusion is a conical protrusion, which makes it easier for the annular protrusion to be pressed into the inner wall of the through hole, causing the inner wall of the through hole to deform, reducing the possibility of large-scale collision and shock, and ensuring the operational stability of the gearbox.

[0035] According to another aspect of this disclosure, a wind turbine generator set is provided, the wind turbine generator set including the aforementioned gearbox.

[0036] The above solutions can reduce oil leakage from the gearbox, improve the stability and reliability of wind turbine operation, and reduce the need for oil replenishment and cleaning maintenance.

[0037] According to another aspect of this disclosure, a shaft sealing structure is provided, the shaft sealing structure comprising:

[0038] A through-hole is provided in the through-hole.

[0039] A shaft member, wherein a portion of the shaft member passes through the through hole, and a bushing corresponding to the inner wall surface of the through hole is fitted onto the shaft member;

[0040] Wherein, the inner wall surface of the through hole is provided with at least one annular protrusion, the cross-sectional area of ​​the annular protrusion decreases radially inward, and the hardness of the bushing is less than the hardness of the annular protrusion; or, the outer wall surface of the bushing is provided with at least one annular protrusion, the cross-sectional area of ​​the annular protrusion decreases radially outward, and the hardness of the cover at least adjacent to the inner wall surface of the through hole is less than the hardness of the annular protrusion.

[0041] By adopting the above solution, the equipment using this shaft sealing structure can improve the sealing effect at the shaft end and reduce the possibility of oil leakage. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 A partial structural schematic diagram of a gearbox according to an embodiment of the present disclosure is shown;

[0044] Figure 2 It shows Figure 1 A magnified schematic diagram of part of the structure.

[0045] Explanation of reference numerals in the attached figures:

[0046] 100. Box body;

[0047] 200. Through cover; 210. Through hole; 211. Annular protrusion; 212. Annular groove; 213. Annular retaining ring; 220. Annular mating groove;

[0048] 300. Shaft components;

[0049] 400. Bearings;

[0050] 500. Bushing; 510. Annular oil reservoir; 520. Annular oil baffle;

[0051] 600. Annular oil baffle groove. Detailed Implementation

[0052] The gearbox is a crucial component of wind turbine equipment, and its reliability directly impacts the safe operation of the wind turbine generator set. The gearbox housing contains a large amount of lubricating oil, which is distributed to all moving parts of the gearbox via oil circuits, ensuring lubrication and heat dissipation for gears and bearings. To prevent oil and oil mist from leaking out of the gearbox, a sealing structure is required to prevent internal oil leakage from the output shaft end. Since contact seals have a short lifespan and require frequent replacement, the commonly used sealing structure in wind turbine gearboxes is a labyrinth-type non-contact seal. This means that the output shaft end typically uses a non-contact labyrinth seal structure.

[0053] However, the fit clearance between the sealing structure and the output shaft is often affected by bearing clearance, machining accuracy, assembly accuracy, etc. In other words, bearing clearance, machining accuracy, assembly accuracy, etc., will cause the output shaft to produce a certain degree of radial runout. If the labyrinth clearance is too small, the radial runout of the output shaft will cause interference wear risk, making the sealing structure vulnerable and possibly affecting the normal operation of the equipment. If the fit clearance is deliberately set too large to avoid interference problems caused by subsequent radial runout, the sealing effect will be affected.

[0054] Based on this, this disclosure utilizes a bushing fixedly connected to the output shaft, with the bushing and end cap engaging for sealing. The hardness of one of the bushing and end cap is less than the hardness of the other, and the assembly is performed with a clearance as close to zero as possible. Thus, during subsequent use, the radial runout of the output shaft causes the harder material in the bushing and end cap to press into the softer material. This avoids the risk of hard impacts and allows the bushing and end cap to achieve an optimal fit clearance according to actual operating conditions, ensuring a good seal and reducing the possibility of oil leakage.

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this disclosure, but not all embodiments.

[0056] like Figure 1 and Figure 2 As shown, this disclosure provides a gearbox that can be used in wind turbine generator sets. Its core function is to connect the wind turbine and the generator, effectively converting the low speed generated by the wind turbine capturing wind energy into the high speed required by the generator to generate electricity through mechanical transmission, thereby ensuring the efficient operation of the generator set. Of course, the gearbox can also be used in other equipment that requires high / low speed regulation or torque regulation, and is not specifically limited here.

[0057] Specifically, the gearbox may include a housing 100, a cover 200, and shafts 300. The housing 100, as the main structure of the gearbox, primarily supports and protects other components. The cover 200 is mounted on the housing 100 and has a through hole 210 communicating with the interior of the housing 100. For example, the cover 200 can be detachably connected to the housing 100 as a separate component to facilitate subsequent maintenance and replacement. Specifically, the housing 100 may have an opening on its side, and the cover 200 is detachably connected to the housing 100 and covers this opening. Alternatively, the cover 200 can be an integral part of the housing 100.

[0058] The shaft 300 is rotatably connected to the housing 100 via a bearing 400. A portion of the shaft 300 extends from the housing 100 through a through hole 210. A bushing 500 may also be fitted onto the shaft 300. The bushing 500 is positioned opposite the inner wall of the through hole 210, or in other words, the outer wall of the bushing 500 is face-to-face with the inner wall of the through hole 210. For example, the bushing 500 and the shaft 300 may be interference-fitted to reduce the clearance between them and prevent oil leakage. Alternatively, the bushing 500 and the shaft 300 may be connected by fasteners such as locking screws. Correspondingly, a sealing element may be provided between the bushing 500 and the shaft 300 to seal the clearance and prevent oil leakage.

[0059] The inner wall surface of the through hole 210 may be provided with at least one annular protrusion 211. The annular protrusion 211 is arranged around the axis of the through hole 210. The hardness of the bushing 500 is less than the hardness of the annular protrusion 211, and the cross-sectional area of ​​the annular protrusion 211 decreases radially inward. In other words, the annular protrusion 211 is approximately conical in shape inward. In this way, during the design phase, the inner diameter of the annular protrusion 211 and the outer diameter of the bushing 500 can be made as close as possible. This allows the fit between the annular protrusion 211 and the bushing 500 to be close to zero clearance before the gearbox is assembled and put into operation. This allows for the initial setting of a minimum fit clearance. If the shaft 300 experiences radial runout due to bearing clearance, machining accuracy, assembly accuracy, or other reasons during subsequent use, the annular protrusion 211 can be pressed into the bushing 500, which has a lower hardness than the protrusion 211, causing the bushing 500 to deform. This automatically forms the optimal fit clearance between the annular protrusion 211 and the bushing 500 based on the actual operating conditions of the shaft 300. In other words, the fit clearance between the annular protrusion 211 and the bushing 500 can be adaptively formed according to the actual operating conditions of the shaft 300, thereby avoiding excessive fit clearance, ensuring sealing effect, and reducing the possibility of oil leakage. Meanwhile, the annular protrusion 211 is a conical protrusion, which makes it easier for the annular protrusion 211 to be pressed into the bushing 500, causing the bushing 500 to deform, reducing the possibility of large-scale impact and shock, and ensuring the operational stability of the gearbox. Furthermore, it should be noted that this disclosure forms a sealing structure only through the bushing 500 and the inner ring of the cover 200, requiring fewer assembly parts, simplifying assembly and disassembly, and reducing costs. For example, before the gearbox is in operation, the inner diameter of the annular protrusion 211 is the same as or nearly the same as the outer diameter of the shaft 300, minimizing the initial fit clearance and ensuring a good seal.

[0060] In practical applications, shaft 300 can be a high-speed shaft or a low-speed shaft on a gearbox. Bushing 500 can be made of a material with relatively low hardness and certain self-lubricating properties, such as copper or PTTE (polytetrafluoroethylene). Cover 200 can be made of a material with relatively high hardness, such as steel. The cross-section of the annular protrusion 211 can be approximately triangular, trapezoidal, or semi-circular. During assembly, grease can be applied to the annular protrusion 211 to reduce friction and facilitate assembly. Furthermore, when the annular protrusion 211 is pressed into the bushing 500 to self-adapt the fit clearance, it can reduce frictional heat generation.

[0061] It should be noted that the number of annular protrusions 211 can be set as many as possible. Multiple annular protrusions 211 are arranged along the axis of the through hole 210, thereby forming multiple sealing structures with the outer wall surface of the bushing 500 on the oil leakage path by using multiple annular protrusions 211, thereby improving the sealing effect.

[0062] In some embodiments, see again Figure 1 and Figure 2 As shown, the inner wall surface of the through hole 210 is provided with at least one annular groove 212, which surrounds the inner wall surface of the through hole 210. The at least one annular groove 212 constructs at least two annular retaining rings 213 on the portion of the cover 200 adjacent to the through hole 210, and each annular retaining ring 213 has at least one of the aforementioned annular protrusions 211 on its inner wall surface. Thus, when oil flows along the mating gap between the bushing 500 and the inner wall surface of the through hole 210 to the opening of the annular groove 212, as the shaft 300 rotates, the oil can be flung into the annular groove 212 under centrifugal force, preventing the oil from continuing to flow along the mating gap between the bushing 500 and the inner wall surface of the through hole 210, thereby further improving the sealing effect and reducing the possibility of oil leakage.

[0063] The number of annular retaining rings 213 is one more than the number of annular grooves 212. For example, when there are n annular grooves 212, the number of annular retaining rings 213 is n+1. The number of annular grooves 212 can be set to be as many as possible, thereby increasing the possibility that oil on the bushing 500 is thrown into the annular grooves 212. Correspondingly, the number of annular retaining rings 213 is also increased, that is, the number of annular protrusions 211 is increased, thereby further improving the sealing effect.

[0064] Taking two annular grooves 212 as an example, the two annular grooves 212 are arranged axially along the through hole 210. Correspondingly, there are three annular retaining rings 213, which are arranged axially along the through hole 210. Each annular retaining ring 213 has two annular protrusions 211 arranged axially along the through hole 210 on its inner wall surface. In this way, the two annular grooves 212 can be used to receive the oil thrown out by the bushing 500, increasing the probability of the oil separating from the mating gap between the bushing 500 and the inner wall surface of the through hole 210. At the same time, the six annular protrusions 211 cooperate with the bushing 500 to seal and prevent the oil from flowing along the mating gap between the bushing 500 and the inner wall surface of the through hole 210, which can effectively improve the sealing effect.

[0065] To prevent excessive oil accumulation in the annular groove 212 from flowing out through the gap between the inner wall of the bushing 500 and the through hole 210, in some embodiments, an oil drain hole (not shown) may be provided at the bottom end of the annular groove 212, allowing the oil in the annular groove 212 to be discharged through the oil drain hole. It should be noted that the bottom end of the annular groove 212 refers to the bottom end of the annular groove 212 or its vicinity when the gearbox is in use, so that the oil can be concentrated near the oil drain hole by gravity for easy collection.

[0066] The oil drain hole can be connected to the inside of the gearbox via the pump body, allowing the oil discharged from the drain hole to be drawn by the pump body and pumped back into the gearbox for reuse, reducing the frequency of gearbox oil replenishment. The oil discharged from the drain hole can also be collected manually.

[0067] Furthermore, the outer wall surface of the bushing 500 may be provided with a plurality of annular oil reservoirs 510. The annular oil reservoirs 510 are constructed as groove structures arranged around the axis of the bushing 500 along the outer wall surface of the bushing 500. Along the axial direction of the bushing 500, each annular groove 212 has at least one annular oil reservoir 510 in its opening. Thus, when oil leaks out along the fit gap between the inner wall surface of the bushing 500 and the through hole 210, the annular oil reservoirs 510 can accumulate oil, thereby increasing the probability that the oil will detach from the fit gap between the inner wall surface of the bushing 500 and the through hole 210 and enter the annular groove 212 under the action of centrifugal force, further improving the sealing effect.

[0068] For example, along the axial direction of the bushing 500, each annular groove 212 may have two annular oil reservoirs 510 within its opening.

[0069] In some embodiments, the side of the cover 200 adjacent to the bearing 400 is provided with an annular mating groove 220, which communicates with the through hole 210. Correspondingly, the outer wall surface of the bushing 500 is provided with an annular oil baffle 520, which mates with the annular mating groove 220. The mating gap between the annular oil baffle 520 and the annular mating groove 220 is located radially outside the mating gap between the bearing 400 and the shaft 300 at one end adjacent to the bearing 400. That is, by setting the annular oil baffle 520 and the annular mating groove 220 to mate, the positions of two adjacent mating gaps are offset from each other, increasing the difficulty for oil to penetrate through the bearing 400 to the mating gap between the annular oil baffle 520 and the annular mating groove 220, thus increasing the difficulty for oil to penetrate through the bearing 400 to the mating gap between the inner wall surface of the bushing 500 and the through hole 210, thereby further improving the sealing effect of the oil and reducing the possibility of oil leakage.

[0070] Furthermore, the annular oil baffle 520 and the annular mating groove 220 are inclined inward along the direction from the bearing 400 to the through hole 210. In this way, the part of the annular oil baffle 520 and the annular mating groove 220 that is above the axis of the shaft 300 is positioned higher, which can reduce the possibility of oil entering. Although the part of the annular oil baffle 520 and the annular mating groove 220 that is below the axis of the shaft 300 is positioned lower, the inclined arrangement can effectively block the possibility of oil entering, thereby further improving the sealing effect of the oil and reducing the possibility of oil leakage.

[0071] In some embodiments, the bearing 400 is spaced apart from the cover 200 and the annular oil baffle 520 along the axial direction of the shaft 300, and the cover 200, shaft 300, bearing 400, and annular oil baffle 520 surround to form an annular oil baffle groove 600. In this way, the annular oil baffle groove 600 can collect oil that impacts the cover 200 and the annular oil baffle 520 and is retained thereon, as well as oil that is thrown into the annular oil baffle groove 600 under centrifugal force, reducing the possibility of oil entering the mating gap between the annular oil baffle 520 and the annular mating groove 220, thereby further improving the sealing effect on the oil and reducing the possibility of oil leakage.

[0072] Correspondingly, the bottom end of the annular oil baffle groove 600 can be provided with an oil drain hole (not shown), allowing the oil in the annular oil baffle groove 600 to be discharged through the drain hole. It should be noted that the bottom end of the annular oil baffle groove 600 refers to the bottom end or its vicinity when the gearbox is in use, allowing gravity to concentrate the oil near the drain port for easy collection. The drain hole of the annular oil baffle groove 600 can be connected to the inside of the gearbox via the pump body, allowing the oil discharged from the drain hole to be pumped back into the gearbox for reuse, reducing the frequency of gearbox oil replenishment. The oil discharged from the drain hole can also be collected manually. The drain port of the annular oil baffle groove 600 can also be connected to the drain port of the annular groove 212 to share the same pump body.

[0073] According to another aspect of this disclosure, a gearbox is also provided, the gearbox including a housing 100, a cover 200, and a shaft 300. The cover 200 is disposed on the housing 100 and has a through hole 210 communicating with the interior of the housing 100. The shaft 300 is rotatably connected to the housing 100 via a bearing 400, and a portion of the shaft 300 extends out of the housing 100 through the through hole 210. A bushing 500 corresponding to the inner wall surface of the through hole 210 is fitted onto the shaft 300. The outer wall surface of the bushing 500 has at least one annular protrusion 211, the cross-sectional area of ​​the annular protrusion 211 decreasing radially outward, and the hardness of the inner wall surface of the cover 200, at least adjacent to the through hole 210, is less than the hardness of the annular protrusion 211.

[0074] In this embodiment, the main difference between this gearbox and the gearbox in the above embodiments lies in the location of the annular protrusion 211 and the hardness of the two mating and sealing components. In this embodiment, the annular protrusion 211 is positioned on the outer wall of the bushing 500, and the hardness of the inner wall of the cover 200, at least adjacent to the through hole 210, is less than the hardness of the annular protrusion 211. Similarly, in the design, the outer diameter of the annular protrusion 211 and the inner diameter of the through hole 210 can be made as close as possible. Therefore, before the gearbox is assembled and operated, the fit between the annular protrusion 211 and the inner wall of the through hole 210 can be close to a zero-clearance fit. This allows for an initial minimum fit clearance setting. If, during subsequent use, the shaft 300 experiences bearing clearance... When radial runout occurs due to factors such as machining accuracy and assembly accuracy, the annular protrusion 211 can be pressed into the inner wall surface of the through hole 210, which has a lower hardness than the protrusion. This causes deformation of the inner wall surface of the through hole 210, thereby automatically forming the optimal fit clearance between the annular protrusion 211 and the inner wall surface of the through hole 210 based on the actual operating conditions of the shaft 300. In other words, the fit clearance between the annular protrusion 211 and the inner wall surface of the through hole 210 can be adaptively formed according to the actual operating conditions of the shaft 300, thus avoiding excessive fit clearance, ensuring sealing effect, and reducing the possibility of oil leakage. At the same time, the annular protrusion 211 is constructed as a conical protrusion, which makes it easier for the annular protrusion 211 to be pressed into the inner wall surface of the through hole 210, causing deformation of the inner wall surface of the through hole 210, reducing the possibility of large-scale collision and vibration, and ensuring the operational stability of the gearbox. For example, the material of the inner wall surface of the through cover 200, at least adjacent to the through hole 210, may be the same as or different from the rest of the material of the through cover 200. The material of the annular protrusion 211 and the bushing 500 may be the same as or different.

[0075] It should be noted that the specific structures of the housing 100, the cover 200, and the shaft 300 can be roughly referred to the contents of the above embodiments, and will not be repeated here.

[0076] According to another aspect of this disclosure, a wind turbine generator set is also provided, which includes the aforementioned gearbox. This reduces oil leakage from the gearbox, improves the stability and reliability of the wind turbine generator set operation, and reduces the need for oil replenishment and cleaning maintenance.

[0077] According to another aspect of this disclosure, a shaft sealing structure is also provided, the shaft sealing structure comprising:

[0078] The through cover 200 has a through hole 210.

[0079] Shaft 300, part of shaft 300 passes through through hole 210, and shaft sleeve 500 corresponding to the inner wall surface of through hole 210 is fitted on shaft 300.

[0080] The inner wall surface of the through hole 210 is provided with at least one annular protrusion 211, the cross-sectional area of ​​the annular protrusion 211 decreases radially inward, and the hardness of the bushing 500 is less than the hardness of the annular protrusion 211; or, the outer wall surface of the bushing 500 is provided with at least one annular protrusion 211, the cross-sectional area of ​​the annular protrusion 211 decreases radially outward, and the hardness of the cover 200 at least adjacent to the inner wall surface of the through hole 210 is less than the hardness of the annular protrusion 211.

[0081] It should be noted that the specific structures of the cover 200, shaft 300, and bushing 500 can be found in the descriptions in the above embodiments. This shaft sealing structure can be used not only in the gearboxes described above, but also in other equipment that requires sealing of the shaft ends to prevent oil leakage, such as pump bodies and spindle boxes.

[0082] The terms "upper" and "lower" used in this disclosure are used to describe the relative positional relationship of the various structures in the accompanying drawings. They are only for the purpose of clarity of description and are not intended to limit the scope of implementation of this disclosure. Changes or adjustments to the relative relationships without substantially altering the technical content should also be considered as part of the scope of implementation of this disclosure.

[0083] It should be noted that, in this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0084] Furthermore, in this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. A gearbox, characterized in that, The gearbox includes: Box (100); A through cover (200) is provided on the box body (100), and the through cover (200) is provided with a through hole (210) communicating with the interior of the box body (100); A shaft (300) is rotatably connected to the housing (100) via a bearing (400). Part of the shaft (300) extends out of the housing (100) through the through hole (210). A bushing (500) corresponding to the inner wall surface of the through hole (210) is fitted on the shaft (300). The inner wall of the through hole (210) is provided with at least one annular protrusion (211), the cross-sectional area of ​​the annular protrusion (211) decreases radially inward, and the hardness of the bushing (500) is less than the hardness of the annular protrusion (211).

2. The gearbox according to claim 1, characterized in that, The inner wall surface of the through hole (210) is provided with at least one annular groove (212); At least one of the annular grooves (212) forms at least two annular retaining rings (213) on the portion of the cover (200) adjacent to the through hole (210), and each annular retaining ring (213) has at least one annular protrusion (211) on its inner wall surface.

3. The gearbox according to claim 2, characterized in that, There are two annular grooves (212), and the two annular grooves (212) are arranged along the axial direction of the through hole (210); Accordingly, there are three annular retaining rings (213), which are arranged along the axial direction of the through hole (210).

4. The gearbox according to claim 2, characterized in that, The bottom end of the annular groove (212) is provided with an oil drain hole.

5. The gearbox according to claim 2, characterized in that, The outer wall surface of the bushing (500) is provided with a plurality of annular oil storage grooves (510), and along the axial direction of the bushing (500), each annular groove (212) has at least one annular oil storage groove (510) in its opening.

6. The gearbox according to claim 1, characterized in that, The through cover (200) has an annular mating groove (220) on the side adjacent to the bearing (400) that communicates with the through hole (210); The outer wall of the bushing (500) is provided with an annular oil baffle (520), which is engaged with the annular mating groove (220). The mating clearance between the annular oil baffle (520) and the annular mating groove (220) is located on the outer side of the mating clearance between the bearing (400) and the shaft (300) in the radial direction.

7. The gearbox according to claim 6, characterized in that, The transparent cover (200), the bearing (400), the shaft (300), and the annular oil baffle (520) are arranged to form an annular oil baffle groove (600).

8. The gearbox according to any one of claims 1 to 7, characterized in that, Before the gearbox is in operation, the inner diameter of the annular protrusion (211) is the same as the outer diameter of the shaft (300).

9. The gearbox according to any one of claims 1 to 7, characterized in that, The cross-section of the annular protrusion (211) is triangular or trapezoidal.

10. The gearbox according to any one of claims 1 to 7, characterized in that, The shaft (300) is a high-speed shaft or a low-speed shaft.

11. A gearbox, characterized in that, The gearbox includes: Box (100); A through cover (200) is provided on the box body (100), and the through cover (200) is provided with a through hole (210) communicating with the interior of the box body (100); A shaft (300) is rotatably connected to the housing (100) via a bearing (400). Part of the shaft (300) extends out of the housing (100) through the through hole (210). A bushing (500) corresponding to the inner wall surface of the through hole (210) is fitted on the shaft (300). The bushing (500) has at least one annular protrusion (211) on its outer wall surface. The cross-sectional area of ​​the annular protrusion (211) decreases radially outward. The hardness of the inner wall surface of the cover (200) adjacent to the through hole (210) is less than the hardness of the annular protrusion (211).

12. A wind turbine generator set, characterized in that, The wind turbine generator set includes the gearbox according to any one of claims 1 to 11.

13. A shaft sealing structure, characterized in that, The shaft sealing structure includes: A through cover (200) is provided with a through hole (210); A shaft (300) is provided, wherein a portion of the shaft (300) passes through the through hole (210), and a bushing (500) corresponding to the inner wall surface of the through hole (210) is fitted on the shaft (300); The inner wall of the through hole (210) is provided with at least one annular protrusion (211), the cross-sectional area of ​​the annular protrusion (211) is radially reduced inward, and the hardness of the bushing (500) is less than the hardness of the annular protrusion (211); or, the outer wall of the bushing (500) is provided with at least one annular protrusion (211), the cross-sectional area of ​​the annular protrusion (211) is radially reduced outward, and the hardness of the cover (200) at least adjacent to the inner wall of the through hole (210) is less than the hardness of the annular protrusion (211).

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