Structure for ensuring force bearing of mating tapered roller bearings during overloading of wind turbine gearboxes

Abstract

This utility model provides a structure for ensuring the bearing capacity of mating tapered roller bearings under overload conditions in wind turbine gearboxes. Its features include: a cover plate fixedly mounted on the gearbox body; a gear shaft mounted inside the gearbox body with a cylindrical roller bearing on the left and mating tapered roller bearings on the left and right sides, extending beyond the through holes of the gearbox body and cover; a round nut screwed onto the gear shaft and abutting against the inner ring of the mating tapered roller bearing; and the outer ring of the mating tapered roller bearing abutting against the shoulder of the gearbox body. Multiple countersunk holes are provided on the cover plate; a right pressure plate is fitted over the gear shaft, closely adhering to the outer ring of the mating tapered roller bearing; the left end of a right spring presses against the right pressure plate, and the right end is positioned within the countersunk hole on the cover plate, abutting against the bottom of the countersunk hole. This utility model facilitates quick and easy assembly, requires minimal operational expertise, is highly efficient, and reduces the risk of damage to the mating tapered roller bearings during gearbox overload operation.

Description

Technical Field

[0001] This utility model relates to a structure of a wind turbine gearbox, specifically a structure for ensuring that the paired tapered roller bearings bear the force when the wind turbine gearbox is overloaded. Background Technology

[0002] Due to its advantages such as being pollution-free and having low construction costs, wind power generation has experienced rapid development in recent years.

[0003] With the development of the wind power industry, the bearing configuration used in the parallel stage of wind turbine gearboxes is constantly being updated. Currently, the main bearing configuration used in the parallel stage of wind turbine gearboxes is cylindrical roller bearings + matched tapered roller bearings. The matched tapered roller bearings must withstand both the radial and axial forces of the shaft system, providing radial and axial positioning. Because the temperature of the wind turbine gearbox varies within a certain range during operation, these temperature changes cause thermal expansion and contraction of components, leading to dimensional changes. To prevent the bearings from being over-compressed due to these dimensional changes during gearbox operation, which could result in excessive bearing temperature or even bearing seizure, a clearance must be allowed during the installation of the matched tapered roller bearings. However, to ensure the axial and radial positioning and load-bearing capabilities of the matched tapered roller bearings, the clearance cannot be too large to guarantee the normal operation of the shaft system.

[0004] The technical solution of existing technology 1 is as follows: Currently, when installing paired tapered roller bearings in wind turbine gearboxes, a clearance needs to be reserved. When reserving this clearance, a spacer is often placed between the outer rings of the two bearings. The required clearance during installation is ensured by machining the spacer to the correct thickness during assembly.

[0005] The disadvantages of existing technology 1 are: 1) To ensure the optimal performance of mated tapered roller bearings, the clearance value and range during assembly must be set very small. Due to the tolerances of parts and the bearing itself, each bearing requires the actual measurement and machining of the spacer thickness to guarantee the required clearance value. Misfitting the spacer dimensions easily leads to exceeding tolerances and scrapping, requiring high operational skills, incurring high costs and risks, and resulting in low efficiency. After bearing installation, the inner and outer rings are fixed, and the clearance remains, resulting in incomplete contact between the bearing rollers and raceways, poor stress distribution, and affecting the radial and axial positioning functions of the bearing, reducing positioning accuracy. Furthermore, when replacing bearings later in the engine room, it is difficult to accurately match the required clearance, making it difficult to ensure the long-term stable operation of the gearbox. Utility Model Content

[0006] This utility model provides a structure for ensuring the force of paired tapered roller bearings under overload conditions in wind turbine gearboxes. Its purpose is to overcome the shortcomings of existing technologies, make assembly convenient and quick, reduce operational requirements, increase efficiency, and reduce the risk of damage to paired tapered roller bearings when the gearbox is overloaded.

[0007] The technical solution adopted by this utility model to solve its technical problem is: A structure for ensuring the paired tapered roller bearings bear the load under overload conditions in wind turbine gearboxes. Its features are: The cover plate is fixedly installed on the housing. The gear shaft is installed in the housing with a cylindrical roller bearing on the left and a left-paired tapered roller bearing and a right-paired tapered roller bearing on the right, and extends out of the through hole of the housing and the cover. The round nut is screwed on the gear shaft and abuts against the inner ring of the right-paired tapered roller bearing, and the outer ring of the left-paired tapered roller bearing abuts against the shoulder of the housing. Multiple countersunk holes are provided on the cover plate; The right pressure plate is fitted over the gear shaft and is pressed against the outer ring of the right mating tapered roller bearing. The left end of the right spring presses against the right pressure plate, and the right end is located inside the countersunk hole on the cover plate, pressing against the bottom of the countersunk hole.

[0008] A left spring and a left pressure plate are provided between the left paired tapered roller bearing and the housing shoulder. There are multiple housing countersunk holes on the housing shoulder. The right end of the left spring presses against the left pressure plate, and the left end is inside the housing countersunk hole and presses against the bottom of the housing countersunk hole. The left pressure plate is in close contact with the outer ring end face of the left tapered roller bearing.

[0009] The multiple countersunk holes on the cover plate are evenly distributed around the circumference.

[0010] The right spring and the countersunk hole of the cover plate are clearance fit.

[0011] When the gearbox is fully loaded, the axial force provided by the right spring is greater than the axial force when the shaft system is fully loaded, but less than the axial force that the bearing itself can withstand.

[0012] The countersunk holes on the shoulder of the enclosure are evenly distributed around the circumference.

[0013] The left spring and the countersunk hole of the housing are clearance fit.

[0014] The advantages of this utility model are: 1. Ensures that the bearing rollers are always in full contact, resulting in better stress distribution, which is beneficial for bearing use and reduces the risk of damage to the paired tapered roller bearings during gearbox overload operation; 2. Eliminating internal clearance in the bearings improves positioning accuracy and facilitates long-term stable operation of the gearbox; 3. It has low requirements for clearance range, can meet a wide range of spring compression, is easy to guarantee, does not require measuring the dimensions of each bearing according to the actual situation and then machining the parts, is convenient and quick to assemble, has low operation requirements and high efficiency; 4. No need for actual machining of parts, which facilitates bearing replacement in the engine compartment and gearbox maintenance.

[0015] 5. A pressure plate is installed between the bearing and the spring to make the bearing more evenly stressed. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a cross-sectional view of the structural assembly of Embodiment 1 of this utility model; Figure 2 A schematic diagram of the right spring; Figure 3 This is a sectional view of the cover plate; Figure 4 This is a cross-sectional view of the structural assembly of Example 2; Figure 5 This is a sectional view of the box body in Example 2; Figure 6 This is a schematic diagram of the left spring. Detailed Implementation

[0018] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort. To facilitate understanding of this utility model, a more detailed description of this utility model will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0019] It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present 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, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Example 1: A preload structure for paired tapered roller bearings in a wind turbine gearbox (see structural assembly diagram). Figure 1 Includes: housing 1, cylindrical roller bearing 2, gear shaft 3, left paired tapered roller bearing 4, right paired tapered roller bearing 5, right pressure plate 6, right spring 7 (see...) Figure 2 8. Round nut, 9. Cover plate (see) Figure 3 ).

[0021] like Figure 1 , Figure 2 , Figure 3 As shown: The cover plate 9 is fixedly installed on the housing 1. The gear shaft 3 is installed inside the housing 1 by the cylindrical roller bearing 2 on the left and the left paired tapered roller bearing 4 and the right paired tapered roller bearing 5 on the right, and extends out of the through hole of the housing 1 and the cover 9. The round nut 8 is screwed on the gear shaft 3 and abuts against the inner ring of the right paired tapered roller bearing 5. The outer ring of the left paired tapered roller bearing 4 abuts against the shoulder 100 of the housing (see...). Figure 5 )superior.

[0022] The outer diameter of the right spring 7 is d1 and the height is h1. The cover plate 9 has multiple circumferentially distributed countersunk holes 901 of the same size to ensure that the right spring 7 is evenly compressed after installation, and the force is uniform and there is no off-center load. The diameter of the countersunk hole 901 is D1 and the depth is H1. The bottom 9011 is a plane.

[0023] After installation, the right pressure plate 6 is fitted over the gear shaft 3, and the right pressure plate 6 is pressed against the outer ring of the right mating tapered roller bearing 5. The left end of the right spring 7 presses against the right pressure plate 6, and the right end is located in the cover plate countersunk hole 901 on the cover plate 9, pressing against the bottom 9011 of the cover plate countersunk hole 901.

[0024] The outer diameter d1 of the right spring 7 is slightly smaller than the diameter D1 of the countersunk hole 901 in the cover plate, forming a small clearance fit. This allows the right spring 7 to compress or rebound smoothly without jamming, and also guides the right spring 7 during compression or rebound, preventing skewing. The bottom 9011 of the countersunk hole 901 in the cover plate is flat, which facilitates the force on the end face of the right spring 7 during compression. After installation, multiple evenly distributed right springs 7 are compressed equally, and the elastic force is evenly applied to the right pressure plate 6. The right pressure plate 6 then presses the left paired tapered roller bearing 4 and the right paired tapered roller bearing 5 together, making the force on the left paired tapered roller bearing 4 and the right paired tapered roller bearing 5 more even.

[0025] The height h1 of the right spring 7 is greater than the depth H1 of the countersunk hole 901 of the cover plate 9, and the difference between h1 and H1 is greater than the gap L1 between the left end face 902 of the cover plate 9 and the right pressure plate 6 after installation, ensuring that the right spring 7 is in a compressed state; h1-H1-L1 is the amount t of the right spring 7 being compressed. This value is determined by calculation based on the magnitude of the axial force N1 of the shaft system when the gearbox is running at full load, as well as the number and elastic coefficient of the right spring 7, and is guaranteed by the dimensions of related parts, such as by different thicknesses of the right pressure plate 6 or spring heights. To ensure that the axial force N2 provided by the right spring 7 is slightly greater than the axial force N1 when the shaft system is fully loaded during gearbox operation, and less than the axial force N3 that the bearing itself can withstand, this ensures that the rollers and raceways of the left and right paired tapered roller bearings 4 and 5 are always in complete contact without gaps during gearbox operation. This guarantees the axial and radial positioning and load-bearing capabilities of the paired left and right tapered roller bearings 4 and 5. The compression range t of the right spring 7 is relatively large, which can be guaranteed through machining. The dimensional tolerances of the parts and bearings have little impact on it, eliminating the need to determine the dimensions of each bearing through actual fitting machining. This is easy to guarantee, and all parts can be directly installed after unified machining, making it convenient and efficient.

[0026] The above technical solution has a simple structure and is easy to operate. The cover plate has multiple evenly distributed countersunk holes of the same size for installing the right spring. The bottom of the countersunk holes is flat, which facilitates the compression force of the right spring. The right spring and the countersunk holes are fitted with a small clearance, ensuring smooth and unobstructed compression and rebound of the right spring, and also guiding the right spring. The compression amount of the right spring is calculated and determined based on the axial force of the gearbox under full load, the elastic coefficient of the right spring, and the number of springs, and is guaranteed by machining the dimensions of relevant parts. The range is wide, and it can be guaranteed by uniform machining of parts, eliminating the need to machine parts specifically for each bearing to ensure clearance, thus facilitating assembly and increasing efficiency. It also facilitates the replacement of bearings on the tower later. It ensures that the bearing rollers and raceways are always in complete contact, resulting in better force distribution and improved bearing life; it eliminates internal bearing clearance, improves positioning accuracy, and promotes long-term stable operation of the gearbox. A right pressure plate is installed between the right spring and the bearing. The spring force is evenly distributed on the right pressure plate, and the right pressure plate presses the bearing, making the bearing more evenly stressed and preventing uneven load distribution, which is beneficial to bearing life.

[0027] In the above embodiment 1, due to the characteristics of the working environment of the wind turbine gearbox, the wind turbine gearbox is prone to overload when there is a sudden increase in wind speed. When overloaded, the axial force of the shaft system exceeds the axial force provided by the preload spring. Because the preload spring has a certain clearance for the thermal expansion and contraction of the shaft system, the preload spring is further compressed. The shaft system, the inner rings and rollers of the two tapered roller bearings, and the outer ring of the right tapered roller bearing move to the right. The outer ring of the left tapered roller bearing is not subjected to the axial force to the right and remains stationary in its original position. At this time, the rollers of the left tapered roller bearing disengage from the raceway, and the left bearing is no longer under force. Only the right tapered roller bearing is under force, which reduces the overall load-bearing capacity of the paired tapered roller bearings and easily leads to damage to the bearing on the stressed side.

[0028] To ensure that both bearings of the mating tapered roller bearings can still bear force when the gearbox is overloaded, and to reduce the risk of damage to the mating tapered roller bearings during gearbox overload, a further improvement is made as Example 2: like Figure 4 , Figure 5 , Figure 6 As shown: When the gearbox is running, the axial force of the shaft system is to the right. After installation, a certain gap L1 is left between the right pressure plate 6 and the cover plate 9 to ensure that the bearings are not overly compressed or jammed when the shaft system components and bearings change size due to temperature changes. The right spring 7 is located between the right pressure plate 6 and the cover plate 9 and is in a compressed state, providing a preload force to the left. The preload force is slightly greater than the sum of the axial force of the shaft system when it is fully loaded and the axial force provided by the left spring 10, but less than the axial force that the bearing can withstand. This ensures that the rollers of the mating tapered roller bearings are always in contact with the raceway, ensuring good bearing force and positioning accuracy.

[0029] A left spring 10 and a left pressure plate 11 are disposed between the left paired tapered roller bearing 4 and the housing shoulder 100 of the housing 1. The housing shoulder 100 has multiple circumferentially distributed countersunk holes 101 of the same size for mounting the left spring 10. The right end of the left spring 10 presses against the left pressure plate 6, and the left end is located inside the countersunk hole 101, pressing against the bottom of the countersunk hole 101. The left pressure plate 11 is in close contact with the outer ring end face of the left tapered roller bearing 4.

[0030] The countersunk hole in the housing has a diameter of D2 and a depth of H2, with a flat bottom. The outer diameter of the left spring 10 is d2, and its height is h2. The outer diameter d2 of the left spring 10 is slightly smaller than the diameter D2 of the countersunk hole 101 in the housing, creating a small clearance fit. This allows the left spring 10 to compress and rebound smoothly without jamming, and also guides the left spring 10 during compression and rebound, preventing skewing. The flat bottom of the countersunk hole 101 facilitates the force on the end face of the left spring 10 during compression. The height h2 of the left spring 10 is greater than the depth H2 of the countersunk hole 101. After installation, the left pressure plate 11 is pressed tightly against the outer ring end face of the left tapered roller bearing 4. Multiple evenly distributed left springs 10 are compressed equally, and the elastic force is evenly applied to the left pressure plate 11, and then through the left pressure plate 11 to the outer ring end face of the left tapered roller bearing 4, making the bearing force more even. The compression of the left spring 10 is h2 - H2. The left spring 10 provides a very small axial force, which is only enough to move the outer ring of the left tapered roller bearing 4, and should not increase the overall axial force to the right of the shaft system. In some cases, when the gearbox is overloaded and the axial force to the right of the shaft system exceeds the preload force to the left provided by the right spring 7, the right spring 7 is further compressed, the clearance L1 decreases, and the entire shaft system moves to the right. At this time, the left pressure plate 11 and the outer ring of the left tapered roller bearing 4 move to the right under the action of the axial force to the right provided by the left spring 10 when it rebounds, ensuring that the outer ring of the left tapered roller bearing 4 is always in contact with the rollers, ensuring that the bearings are under force, so that both bearings of the mating tapered roller bearings can still be under force when the gearbox shaft system is overloaded. When the load is reduced to the rated load, the entire shaft system moves to the left under the action of the preload force of the right spring 7, the left spring 10 is compressed into the countersunk hole 100 of the housing, and the left pressure plate 11 and the end face of the outer ring of the left tapered roller bearing 4 are pressed together again.

[0031] This utility model patent discloses a structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes. The structure is simple and easy to operate. The gearbox shoulder has multiple evenly distributed countersunk holes of uniform size for installing springs. The bottom of these countersunk holes is flat, facilitating spring compression. The left spring has a small clearance fit with the countersunk hole, ensuring smooth compression and rebound without jamming, and also providing guidance for the left spring. When the gearbox operates below its rated load, the left spring is always fully compressed within the countersunk hole on the shoulder, providing a very small axial force. This axial force is sufficient to move the bearing outer ring without significantly increasing the overall axial force on the shaft system, ensuring that the total axial force never exceeds the bearing's withstand capability. When the gearbox is overloaded beyond the preload of the right spring, the outer ring of the left mating tapered roller bearing moves to the right with the shaft system under the axial force provided by the spring's rebound. This ensures that the rollers and raceways of the left mating tapered roller bearing remain in contact and bear load, resulting in better overall stress distribution and higher positioning accuracy for the mating tapered roller bearing, which is beneficial for the long-term stable operation of the gearbox. A left pressure plate is placed between the left spring and the left mating tapered roller bearing. The spring force is evenly distributed on the left pressure plate, which then presses the bearing together, making the bearing more evenly stressed and preventing uneven load distribution, thus improving bearing performance.

[0032] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes, characterized in that: The cover plate is fixedly installed on the housing. The gear shaft is installed in the housing with a cylindrical roller bearing on the left and a left-paired tapered roller bearing and a right-paired tapered roller bearing on the right, and extends out of the housing and through the cover hole. A round nut is screwed on the gear shaft and abuts against the inner ring of the right-paired tapered roller bearing. The outer ring of the left-paired tapered roller bearing abuts against the housing shoulder. Multiple cover plate countersunk holes are opened on the cover plate. The right pressure plate is sleeved on the gear shaft and is close to the outer ring of the right-paired tapered roller bearing. The left end of the right spring presses against the right pressure plate, and the right end is in the cover plate countersunk hole on the cover plate and abuts against the bottom of the cover plate countersunk hole.

2. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes as described in claim 1, characterized in that: A left spring and a left pressure plate are provided between the left paired tapered roller bearing and the housing shoulder. There are multiple housing countersunk holes on the housing shoulder. The right end of the left spring presses against the left pressure plate, and the left end is inside the housing countersunk hole and presses against the bottom of the housing countersunk hole. The left pressure plate is in close contact with the outer ring end face of the left tapered roller bearing.

3. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes as described in claim 1, characterized in that: The multiple countersunk holes on the cover plate are evenly distributed around the circumference.

4. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes as described in claim 1, characterized in that: The right spring and the countersunk hole of the cover plate are clearance fit.

5. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes as described in claim 1, characterized in that: When the gearbox is fully loaded, the axial force provided by the right spring is greater than the axial force when the shaft system is fully loaded, but less than the axial force that the bearing itself can withstand.

6. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in a wind turbine gearbox as described in claim 2, characterized in that: The countersunk holes on the shoulder of the enclosure are evenly distributed around the circumference.

7. The structure for ensuring the force distribution of paired tapered roller bearings under overload conditions in wind turbine gearboxes as described in claim 2, characterized in that: The left spring and the countersunk hole of the housing are clearance fit.

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