Miniaturized wind power variable pitch speed reducer and assembling method thereof

Abstract

The application relates to a miniaturized wind power variable-pitch speed reducer and an assembling method thereof, which comprises an output gear shaft, the contact part of the output gear shaft and an output end planet carrier is a circular truncated cone, the output end planet carrier is internally provided with a taper hole matched with the output gear shaft, the output gear shaft and the output end planet carrier are connected in a taper interference fit mode, and a double-row different-diameter four-point contact ball bearing is arranged between the structure of the output end planet carrier and a lower box body. The double-row different-diameter four-point contact ball bearing is adopted for fixed support, the support rigidity and the bearing capacity of the speed reducer are improved, the height of the whole machine is reduced, the space occupancy rate of the speed reducer in a wheel hub is reduced, the output end planet carrier and the output gear shaft are connected in a spline connection and taper interference fit mode, the contact surface is increased, the coaxialities of inner and outer rings are ensured, the assembling process is greatly simplified, and the requirements for the process and equipment are further reduced.

Description

Technical Field

[0001] This invention relates to the field of speed reducers, and in particular to a miniaturized wind turbine pitch reducer and its assembly method. Background Technology

[0002] The pitch reducer is a key component in wind turbine generators, responsible for adjusting the angle of the wind turbine blades to adapt to changes in wind speed, ensuring stable operation and efficient power generation. The pitch reducer is installed in the hub and rotates 360 degrees in the air with the hub. Due to limited space in the hub, the size of the pitch reducer that can be accommodated is limited. Currently, conventional pitch reducers typically use two sets of tapered roller bearings mounted back-to-back to fix the output shaft. Because tapered roller bearings are large, and to ensure their reliability, the output end of the reducer needs to be relatively tall, resulting in a high overall height. Furthermore, conventional reducer assembly has the following disadvantages: First, the tapered roller bearings require freezing the outer ring and heating the inner ring to compensate for dimensional changes in the bearing components caused by temperature variations during assembly, ensuring smooth installation and proper fit. First, the heating temperature needs precise control. Excessive or insufficient temperature can damage the microstructure of bearing components, affecting bearing performance and lifespan. The heating or freezing of the inner and outer rings must be uniform to avoid bending or twisting due to uneven temperature. Second, the tightening torque of the upper and lower round nuts of the reducer needs to be above 2500 Nm, requiring specialized high-torque tightening tools and equipment. Third, when adjusting the clearance of tapered roller bearings to ensure optimal bearing performance, high demands are placed on assembly skills. Conventional double-row, unequal-diameter, four-point contact ball bearings are easily damaged by gently tapping the inner ring with a copper rod and hammer, or by using sleeves and presses for installation. Furthermore, the contact area between the ball bearing and the inner ring is small, resulting in insufficient load-bearing capacity. A search revealed no identical technical solutions to this invention; only some related comparative technical documents were found, mainly the following:

[0003] 1. Patent application number 202211369971.4 discloses an output shaft structure for a wind turbine yaw and pitch reducer, including an output gear shaft, a housing, and bearings. A cylindrical roller bearing is installed at the upper end of the output gear shaft, and a self-lubricating sliding bearing is installed at the lower end. A bearing housing is provided outside the cylindrical roller bearing and the self-lubricating sliding bearing. This invention uses a self-lubricating sliding bearing at the lower end and a cylindrical roller bearing at the upper end. The self-lubricating sliding bearing directly transmits the bending moment from the cantilever support gear to the housing through a large axial contact surface. Although this patent reduces the lateral dimension of the reducer by using cylindrical roller bearings and self-lubricating sliding bearings, the vertical dimension of the self-lubricating sliding bearings cannot be reduced, so the aforementioned problem still exists. Moreover, using cylindrical roller bearings and self-lubricating sliding bearings for fixed support results in a limited force-bearing area, making the cylindrical roller bearings and self-lubricating sliding bearings prone to deformation or fatigue damage.

[0004] 2. Patent application number 202321451635.4 proposes an output end structure for a yaw and pitch reducer and related wind power equipment. The disclosed output end structure includes a housing, an output shaft, a cylindrical roller assembly, and an axial positioning bearing. The output shaft is located within the housing. The cylindrical roller assembly comprises multiple cylindrical rollers arranged around the output shaft. The output shaft is rotatably engaged with the housing via the cylindrical roller assembly. The cylindrical roller assembly bears the radial force of the output shaft. The axial positioning bearing is fitted around the outer circumference of the output shaft and bears the axial force of the output shaft. Although this patent reduces the reducer size by arranging multiple cylindrical rollers around the output shaft, the contact area between the cylindrical rollers and the output shaft is limited, making it prone to deformation or fatigue damage. Increasing the contact area by arranging multiple cylindrical rollers would increase the reducer size, so further improvement is still needed.

[0005] 3. Patent application number 202110273845.8 provides an assembly method for the flexible output gear shaft of a wind turbine yaw reducer, including: heating the front housing; assembling the outer ring of the rear tapered roller bearing; assembling the outer ring of the front tapered roller bearing on the front housing; disassembling the tooling used for assembling the outer rings of the front and rear tapered roller bearings; assembling the inner ring of the front tapered roller bearing; disassembling the pressure cylinder used to compact the inner ring of the front tapered roller bearing; hoisting the front housing and assembling it with the output shaft; assembling the inner ring of the rear tapered roller bearing; checking the bearing rotation torque; installing the four-stage planetary transmission device step by step until the components on the reducer are assembled; turning the reducer around and fixing it on the fifth tooling; installing the end cover, seals, and fixing pressure plate on the front housing; mounting the output gear on the output shaft and assembling the lock nut; disassembling the fifth tooling, and the assembly is complete. This assembly method requires freezing and heating the reducer components, the assembly process is cumbersome, and it has high requirements for technology and equipment.

[0006] Analysis of the aforementioned patents reveals that while current wind turbine pitch reducers reduce their size by using cylindrical rollers around the output shaft, none of them take into account the limited contact area between the cylindrical rollers and the output shaft, which makes them prone to deformation or fatigue damage. Furthermore, the assembly process is cumbersome and places high demands on the technology and equipment. Therefore, the aforementioned problems still exist, making it necessary to improve them. Summary of the Invention

[0007] The technical problem to be solved by this invention is to provide a miniaturized wind turbine pitch reducer and its assembly method. Compared with conventional wind turbine pitch reducers, its volume is reduced, thus reducing the space occupied by the reducer in the hub. At the same time, the support rigidity and load-bearing capacity of the reducer are also improved. Moreover, it overcomes the shortcomings of current reducer assembly methods, such as cumbersome assembly process and high requirements for technology and equipment. In addition, the installation method of double-row unequal diameter four-point contact ball bearings is less likely to cause bearing damage, and the contact area between the ball bearing and the inner ring of the bearing is large, increasing the load-bearing capacity.

[0008] The technical solution proposed in this invention is: a miniaturized wind turbine pitch reducer, including an output gear shaft, the contact end of which is quasi-frustum shaped with the output planetary carrier, a tapered hole for the output gear shaft to fit inside the output planetary carrier, and a tapered interference fit between the output gear shaft and the output planetary carrier to facilitate installation while ensuring the coaxiality of the inner and outer rings. A double-row, four-point contact ball bearing with different diameters is provided between the output planetary carrier structure and the lower housing to provide fixed support. A baffle is also provided above the output gear shaft for fixed connection. The baffle is connected to the output gear shaft by fastening bolts, and the baffle is interference fit with the output planetary carrier.

[0009] Furthermore, the double-row differential four-point contact ball bearing includes a bearing raceway one, a bearing raceway two, a rolling element assembly one installed in the bearing raceway one, and a rolling element assembly two installed in the bearing raceway two.

[0010] Furthermore, the rolling element assembly consists of a rolling element and a spacer block. The spacer block has arc-shaped surfaces on both sides that cooperate with the rolling element. The diameter of the rolling element in the first rolling element assembly is larger than that of the rolling element in the second rolling element assembly.

[0011] Furthermore, the first bearing raceway is composed of the first outer bearing raceway on the lower housing and the first inner bearing raceway on the output planetary carrier; the second bearing raceway is composed of the second outer bearing raceway on the lower housing and the second inner bearing raceway on the output planetary carrier; the cross-section of the bearing raceway consists of four circular arcs, the centers of which do not coincide, and the radius of the arcs is larger than the radius of the rolling element. Each arc has only one tangential contact with the rolling element, and the other positions do not contact each other. The bearing raceway can axially position the rolling element; the first bearing raceway is arranged near the output gear, and the second bearing raceway is arranged near the baffle.

[0012] Furthermore, a gap is left between the inner raceway of the planetary carrier at the output end of the bearing raceway and the outer raceway inside the lower housing, but the gap is controlled at 1-2mm to ensure that the contact angle of the rolling element with the inner raceway of the planetary carrier at the output end of the raceway and the outer raceway inside the lower housing is greater than 25 degrees.

[0013] Furthermore, the output planetary carrier has an internal spline between the baffle mounting hole and the tapered hole for mating with the output gear shaft, and the outer side of the bottom contact end of the output gear shaft with the output planetary carrier has an external spline. The output planetary carrier and the output gear shaft are connected by a spline to transmit torque, ensuring the smoothness of torque transmission.

[0014] Furthermore, the output planetary carrier is equipped with two locating pins. Locating pin one and locating pin two are interference-fitted to the output planetary carrier. Both locating pins have threaded holes at their center positions to facilitate disassembly during later maintenance. The front ends of the locating pins are tapered to facilitate the positioning of plug one and plug two. The diameter of locating pin one is larger than the maximum external dimensions of the plug to ensure that the plug can be installed normally.

[0015] Furthermore, the output planetary carrier has a rolling element mounting hole one in the inner raceway one of the bearing and a rolling element mounting hole two in the inner raceway two of the bearing, wherein the rolling element mounting hole has a conical structure.

[0016] Furthermore, the plug adopts a conical structure. Plug one is arranged in rolling element mounting hole one, and plug two is arranged in rolling element mounting hole two. One side of the plug is the inner raceway arc of the bearing, and the other side is machined into an arc shape and cooperates with the locating pin to realize the axial, radial and circumferential positioning of the plug.

[0017] Furthermore, the bottom of the planetary carrier at the output end is sealed with an oil seal, and a pure copper sealing gasket is installed at the bottom of the bolt connecting the baffle and the output gear shaft to ensure the reliability of the reducer's seal.

[0018] This invention also relates to a method for assembling a miniaturized wind turbine pitch reducer, comprising the following steps:

[0019] S1: Place the output planetary carrier into the lower housing from top to bottom, with the output planetary carrier and the lower housing on the same plane;

[0020] S2: Next, load the rolling elements and spacers one by one into the bearing raceway through the rolling element mounting hole 2, placing a spacer every other rolling element until all rolling elements and spacers are loaded. Insert the plug 2 into the rolling element mounting hole 2, then hammer the locating pin 2 into the plug, ensuring that it is in place.

[0021] S3: Rotate the assembled lower housing and output planetary carrier 180° as a whole. Following the steps in S2 above, install the rolling element one and the spacer block in sequence. Insert the plug one into the rolling element mounting hole, and then hammer the locating pin into the locating pin mounting hole until it is fully installed. Then install the oil seal and locating retaining ring into the lower housing to ensure sealing while the retaining ring prevents axial movement of the oil seal.

[0022] S4: The lower housing and output planetary carrier assembled in the above steps are lifted as a whole and installed from top to bottom from the small end of the output gear shaft. Align the output planetary carrier with the spline of the output gear shaft and use gravity to make the output gear shaft fit into the conical surface of the output planetary carrier, that is, install it in place.

[0023] S5: Install the frozen baffle into the planetary carrier at the output end, apply thread-locking adhesive to the bolts, and tighten the bolts one by one using a torque wrench in a crisscross manner until a tightening torque of 200 Nm is reached.

[0024] S6: After completing the above installation steps, manually rotate the lower housing; it should be able to rotate freely.

[0025] S7: Complete the installation of the remaining planetary components of the reducer in a conventional manner;

[0026] Furthermore, the cross-tightening method refers to tightening the bolts at 180-degree intervals.

[0027] Furthermore, when tightening the bolts, a sealing gasket should be installed under the bolt head to seal the lubricating oil.

[0028] The beneficial effects of the present invention are: (1) The pitch reducer integrates a double-row, different-diameter, four-point contact ball bearing, which improves the support stiffness and load-bearing capacity of the reducer, reduces the overall height, and reduces the space occupied by the reducer in the hub. (2) The rolling element assembly adopts the method of filling the rolling elements through the filling hole and is isolated by the double-sided inner arc-shaped curved surface isolation pad, which can effectively reduce the radial dimension of the entire rolling element assembly, greatly reducing the weight and volume of the overall structure, and facilitating subsequent assembly and transportation. (3) Due to the use of filling the rolling elements, not only can the radial dimension of the rolling assembly be reduced, but the gap between the inner raceway of the planetary carrier at the output end and the outer raceway in the lower housing can also be reduced. This can lengthen the contact length between the rolling elements and the raceway, change the four-point contact, and make the four-point contact ball bearing better stressed. (4) The reduced inner volume of the pitch reducer can reduce the amount of lubricating oil used. (5) The method of loading the rolling elements and the isolation blocks one by one into the bearing raceway through the rolling element mounting hole 2 reduces the gap between the output end planetary carrier and the lower housing, and increases the contact area of ​​the four points of the rolling elements, making it less likely to damage the ball bearing. (6) The process of freezing the outer ring and heating the inner ring during the assembly of tapered roller bearings is eliminated. (7) The original structure requires a tightening torque of more than 2500 Nm for the round nut, while the bolt tightening torque of this patent is only about 200 Nm, and no special high torque tightening tools and equipment are required. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the miniaturized wind turbine pitch reducer provided in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the rolling element assembly.

[0031] Figure 3 This is a schematic diagram of the isolation block.

[0032] Figure 4 This is a schematic diagram of the output planetary carrier.

[0033] Figure 5 This is a structural diagram of the lower box.

[0034] Figure 6 This is a schematic diagram of the output gear shaft.

[0035] Figure 7 This is a three-dimensional structural diagram of the output gear shaft.

[0036] Figure 8 This is a schematic diagram of the three-dimensional structure of the plug.

[0037] Figure 9 This is a schematic diagram of the inner raceway of a bearing.

[0038] Figure 10 This is a three-dimensional structural diagram of a wind turbine pitch reducer.

[0039] Explanation of reference numerals in the attached drawings: 1. Output gear shaft; 2. Oil seal; 3. Output end planetary carrier; 4. Rolling element assembly one; 5. Lower housing; 6. Baffle; 7. Rolling element assembly two; 8. Sealing gasket; 9. Fastening bolt; 10. Plug two; 11. Locating pin one; 12. Plug one; 13. Inner raceway arc shape of bearing 1201; 14. Arc shape of bearing 1202; 15. Locating pin two; 16. Isolating block; 17. Arc surface of isolation block 1401; 18. Rolling element; 19. Outer raceway one of bearing; 502. Outer raceway two of bearing; 503. External spline; 103. Tapered hole for output gear shaft mating; 301. Inner raceway one of bearing; 302. Internal spline; 303. Inner raceway two of bearing; 304. Rolling element mounting hole one; 307. Rolling element mounting hole two; 308. Detailed Implementation

[0040] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0041] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0042] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they 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. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0043] like Figures 1-9As shown, a miniaturized wind turbine pitch reducer and its assembly method are disclosed. The miniaturized wind turbine pitch reducer includes an input shaft 16, a planetary reduction system 17, and an output gear shaft 1. The contact portion between the output gear shaft 1 and the output end planetary carrier 3 is frustum-shaped. The output end planetary carrier 3 has a tapered hole 301 for mating with the output gear shaft. The output gear shaft 1 and the output end planetary carrier 3 are connected by a tapered interference fit, which facilitates installation while ensuring the coaxiality of the inner and outer rings. A double-row, four-point contact ball bearing with different diameters is provided between the output end planetary carrier 3 and the lower housing 5. A baffle 6 is also provided above the output gear shaft 1 for fixed connection. The baffle 6 is connected to the output gear shaft 1 by fastening bolts 9, and the baffle 6 is interference-fitted with the output end planetary carrier 3.

[0044] Furthermore, the double-row differential four-point contact ball bearing includes a bearing raceway one, a bearing raceway two, a rolling element assembly one 4 installed in the bearing raceway one, and a rolling element assembly two 7 installed in the bearing raceway two.

[0045] Furthermore, the rolling element assembly consists of a rolling element and a spacer block 14. The spacer block 14 has two arc-shaped surfaces 1401 on both sides that cooperate with the rolling element. The diameter of the rolling element 15 of the rolling element assembly 14 is larger than that of the rolling element 15 of the rolling element assembly 27.

[0046] Furthermore, the first bearing raceway is composed of the outer bearing raceway 502 on the lower housing 5 and the inner bearing raceway 302 on the output planetary carrier 3; the second bearing raceway is composed of the outer bearing raceway 503 on the lower housing 5 and the inner bearing raceway 304 on the output planetary carrier 3; the cross-section of the bearing raceway is composed of four circular arcs, the centers of the four circular arcs do not coincide, the radius of the circular arc is larger than the radius of the rolling element, and each circular arc is in tangential contact with the rolling element 15 at only one position, and does not contact the other positions. The bearing raceway can axially position the rolling element 15; the first bearing raceway is arranged near the output gear, and the second bearing raceway is arranged near the baffle 6.

[0047] Furthermore, a gap is left between the inner raceway of the planetary carrier at the output end of the bearing raceway and the outer raceway inside the lower housing, but the gap is controlled at 1-2mm to ensure that the contact angle of the rolling element with the inner raceway of the planetary carrier at the output end of the raceway and the outer raceway inside the lower housing is greater than 25 degrees.

[0048] Furthermore, the first bearing raceway is arranged near the output gear, and the second bearing raceway is arranged near the baffle 6.

[0049] Furthermore, the output planetary carrier 3 has an internal spline 303 between the mounting hole of the baffle 6 and the tapered hole for mating with the output gear shaft 1, and an external spline 103 on the outer side of the bottom contact end of the output gear shaft 1 and the output planetary carrier 3. The output planetary carrier 3 and the output gear shaft 1 are connected by a spline to transmit torque, ensuring the smoothness of torque transmission.

[0050] Furthermore, the output planetary carrier 3 is equipped with two positioning pins. Positioning pin 11 and positioning pin 213 are interference-fitted with the output planetary carrier 3. Both positioning pins have threaded holes at their center positions to facilitate disassembly during later maintenance. The front ends of the positioning pins are tapered to facilitate the positioning of plug 12 and plug 210. The diameter of positioning pin 11 is larger than the maximum external dimensions of the plug to ensure that the plug can be installed normally.

[0051] Furthermore, the output end planetary carrier 3 has a rolling element mounting hole 307 in the inner raceway 302 of the bearing and a rolling element mounting hole 308 in the inner raceway 304 of the bearing, wherein the rolling element mounting hole has a conical structure.

[0052] Furthermore, the plug adopts a conical structure. Plug 12 is arranged in the rolling element mounting hole 307, and plug 20 is arranged in the rolling element mounting hole 308. One side of plug 12 is the inner raceway arc 1201 of the bearing, and the other side is machined into an arc 1202 and cooperates with the locating pin to realize the axial, radial and circumferential positioning of the plug.

[0053] Furthermore, the bottom of the output planetary carrier 3 is sealed with an oil seal 2, and a pure copper sealing gasket 8 is installed at the bottom of the bolt connecting the baffle 6 and the output gear shaft 1 to ensure the reliability of the reducer seal.

[0054] In this embodiment, the transmission principle is as follows: the contact part between the output gear shaft 1 and the output planetary carrier 3 is shaped like a frustum, and is axially positioned on the output planetary carrier 3 in the form of a conical interference fit, which facilitates installation while ensuring the coaxiality of the inner and outer rings. The baffle 6 is connected to the output gear shaft 1 by fastening bolts 9 and is interference-fitted with the output planetary carrier 3. The positioning pin 11 and positioning pin 23 are interference-fitted with the output planetary carrier 3. A double-row, different-diameter, four-point contact ball bearing is provided between the structure of the output planetary carrier 3 and the lower housing 5 to play a fixed support role.

[0055] This invention also relates to a method for assembling a miniaturized wind turbine pitch reducer, comprising the following steps:

[0056] S1: Place the output planetary carrier 3 into the lower housing 5 from top to bottom, with the output planetary carrier 3 and the lower housing 5 on the same plane;

[0057] S2: Next, the rolling elements 2 and the spacer blocks are loaded one by one into the bearing raceway through the rolling element mounting hole 2 304. A spacer block 14 is placed every other rolling element until all rolling elements and spacer blocks 14 are loaded. The plug 2 10 is inserted into the rolling element mounting hole 2 304. Then, the positioning pin 2 11 is hammered into the plug and ensured that it is installed in place.

[0058] S3: Rotate the assembled lower housing and output planetary carrier 180° as a whole. Following the steps in S2 above, install the rolling element 1 and the spacer block 14 in sequence. Insert the plug 12 into the rolling element mounting hole, and then hammer the locating pin 13 into the locating pin mounting hole until it is fully installed. Then install the oil seal 2 and the locating retaining ring into the lower housing 5 to ensure sealing while the retaining ring prevents axial movement of the oil seal.

[0059] S4: The lower housing and output planetary carrier assembled in the above steps are lifted as a whole and installed from top to bottom from the small end of the output gear shaft 1. Align the output planetary carrier with the spline of the output gear shaft and use gravity to make the output gear shaft fit with the cone surface of the output planetary carrier, that is, install it in place.

[0060] S5: Install the frozen baffle 6 into the planetary carrier at the output end, apply thread-locking adhesive to the bolts, and tighten the bolts 9 one by one using a torque wrench in a crisscross manner until a tightening torque of 200 Nm is reached.

[0061] S6: After completing the above installation steps, manually rotate the lower housing; it should be able to rotate freely.

[0062] S7: Complete the installation of the remaining planetary components of the reducer in a conventional manner;

[0063] Furthermore, the cross-tightening method refers to tightening the bolts at 180-degree intervals.

[0064] Furthermore, when tightening the fastening bolt 9, a sealing gasket 8 should be installed under the bolt head to seal the lubricating oil.

[0065] The beneficial effects of the present invention are: (1) The pitch reducer integrates a double-row, different-diameter, four-point contact ball bearing, which improves the support stiffness and load-bearing capacity of the reducer, reduces the overall height, and reduces the space occupied by the reducer in the hub. (2) The rolling element assembly adopts the method of filling the rolling elements through the filling hole and is isolated by the double-sided inner arc-shaped curved surface isolation pad, which can effectively reduce the radial dimension of the entire rolling element assembly, greatly reducing the weight and volume of the overall structure, and facilitating subsequent assembly and transportation. (3) Due to the use of filling the rolling elements, not only can the radial dimension of the rolling assembly be reduced, but the gap between the inner raceway of the planetary carrier at the output end and the outer raceway in the lower housing can also be reduced. This can lengthen the contact length between the rolling elements and the raceway, change the four-point contact, and make the four-point contact ball bearing better stressed. (4) The reduced inner volume of the pitch reducer can reduce the amount of lubricating oil used. (5) The method of loading the rolling elements and the isolation blocks one by one into the bearing raceway through the rolling element mounting hole 2 reduces the gap between the output end planetary carrier and the lower housing, and increases the contact area of ​​the four points of the rolling elements, making it less likely to damage the ball bearing. (6) The process of freezing the outer ring and heating the inner ring during the assembly of tapered roller bearings is eliminated. (7) The original structure requires a tightening torque of more than 2500 Nm for the round nut, while the bolt tightening torque of this patent is only about 200 Nm, and no special high torque tightening tools and equipment are required.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A miniaturized wind turbine pitch reducer, characterized in that: The system includes an output gear shaft (1), the contact portion of which is frustum-shaped with the output planetary carrier (3), a tapered hole (301) for the output gear shaft to fit inside the output planetary carrier (3), and a tapered interference fit between the output gear shaft (1) and the output planetary carrier (3). A double-row, four-point contact ball bearing with different diameters is provided between the structure of the output planetary carrier (3) and the lower housing (5). A baffle (6) is also provided above the output gear shaft (1) for fixed connection. The baffle (6) is connected to the output gear shaft (1) by fastening bolts (9). The gear shaft (1) is connected, and the baffle (6) is interference-fitted with the output end planetary carrier (3); the double-row unequal diameter four-point contact ball bearing includes bearing raceway one, bearing raceway two, rolling element assembly one (4) installed in bearing raceway one, and rolling element assembly two (7) installed in bearing raceway two; the rolling element assembly consists of rolling elements and spacer blocks (14), the two sides of the spacer block (14) are spacer block arc surfaces (1401) that cooperate with the rolling elements, and the diameter of the rolling element (15) of rolling element assembly one (4) is larger than that of rolling element assembly two (7). The rolling element (15); the output end planetary carrier (3) is equipped with two locating pins, locating pin one (11) and locating pin two (13) are interference-fitted with the output end planetary carrier (3), and both locating pins have threaded holes at their center positions for easy disassembly during later maintenance. The front ends of the locating pins are tapered to facilitate the positioning of plug one (12) and plug two (10). The diameter of locating pin one (11) is larger than the maximum external dimensions of the plug to ensure that the plug can be installed normally; the output end planetary carrier (3) is located in the bearing inner raceway one (302). A rolling element mounting hole 1 (307) is provided, and a rolling element mounting hole 2 (308) is provided in the inner raceway 2 (304) of the bearing. The rolling element mounting hole is a conical structure. The plug adopts a conical structure. The plug 1 (12) is arranged in the rolling element mounting hole 1 (307), and the plug 2 (10) is arranged in the rolling element mounting hole 2 (308). One side of the plug 1 (12) is the inner raceway arc (1201) of the bearing, and the other side is machined into an arc shape (1202) and cooperates with the positioning pin to realize the axial, radial and circumferential positioning of the plug.

2. The miniaturized wind turbine pitch reducer according to claim 1, characterized in that: The bearing raceway one is composed of the outer bearing raceway one (502) on the lower housing (5) and the inner bearing raceway one (302) on the output planetary carrier (3); the bearing raceway two is composed of the outer bearing raceway two (503) on the lower housing (5) and the inner bearing raceway two (304) on the output planetary carrier (3); the cross section of the bearing raceway is composed of four circular arcs, the centers of the four circular arcs do not coincide, the radius of the circular arc is greater than the radius of the rolling element, and each circular arc has only a small overlap with the rolling element (15). One position is in tangential contact, and the other positions are not in contact. The bearing raceway can axially position the rolling element (15). The first bearing raceway is arranged near the output end gear, and the second bearing raceway is arranged near the baffle (6). There is a gap between the inner raceway of the planetary carrier at the output end of the bearing raceway and the outer raceway in the lower housing, but the gap is controlled at 1-2mm to ensure that the contact angle of the rolling element with the inner raceway of the planetary carrier at the output end of the raceway and the outer raceway in the lower housing is greater than 25 degrees.

3. The miniaturized wind turbine pitch reducer according to claim 1, characterized in that: The output planetary carrier (3) has an internal spline (303) between the mounting hole of the baffle (6) and the tapered hole (301) for the output gear shaft. The outer side of the bottom contact point between the output gear shaft (1) and the output planetary carrier (3) is an external spline (103). The output planetary carrier (3) and the output gear shaft (1) are connected by a spline to transmit torque, ensuring the smoothness of torque transmission.

4. A miniaturized wind turbine pitch reducer according to claim 1, characterized in that: The bottom of the output planetary carrier (3) is sealed with an oil seal (2), and a pure copper sealing gasket (8) is installed at the bottom of the connecting bolt between the baffle (6) and the output gear shaft (1) to ensure the reliability of the reducer seal.

5. An assembly method for a miniaturized wind turbine pitch reducer according to any one of claims 1 to 4, characterized in that... The rolling elements and spacers (14) are loaded one by one from the rolling element mounting holes into the bearing raceway. A spacer (14) is placed every other rolling element until all rolling elements and spacers (14) are loaded. The plug is then inserted into the rolling element mounting hole, and the locating pin is hammered into the plug to ensure that it is in place.

6. The assembly method of a miniaturized wind turbine pitch reducer according to claim 5, characterized in that: Before the rolling element and the isolation block (14) are filled, the output end planetary carrier (3) and the lower housing (5) are tightly fitted together, and the output end planetary carrier (3) and the lower housing (5) are placed on the same plane.

7. The assembly method of a miniaturized wind turbine pitch reducer according to claim 5, characterized in that: The assembled lower housing and output planetary carrier are lifted as a whole and installed from top to bottom from the small end of the output gear shaft (1). The output planetary carrier and the output gear shaft spline are aligned, and gravity is used to make the output gear shaft fit into the cone surface of the output planetary carrier, thus completing the installation.

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