Miniaturized wind power variable pitch speed reducer and assembling method thereof

Abstract

The invention relates to a miniaturized wind power variable pitch speed reducer and an assembling method thereof.The miniaturized wind power variable pitch speed reducer comprises an output gear shaft, the contact portion of the output gear shaft and an output end planet carrier is in a similar circular truncated cone shape, a taper hole used for being matched with the output gear shaft is formed in the output end planet carrier, and the output gear shaft and the output end planet carrier are connected in a conical interference fit mode; and a double-row reducing four-point contact ball bearing is arranged between the output end planet carrier structure and the lower box body. The double-row reducing four-point contact ball bearings are adopted for fixing and supporting, the supporting rigidity and the bearing capacity of the speed reducer are improved, the height of the whole machine is reduced, and the space occupancy rate of the speed reducer in a hub is reduced; the coaxiality of the inner ring and the outer ring is ensured while the contact surface is increased, the assembly process is greatly simplified, and the requirements on the process and equipment are further reduced.

Description

Technical Field

[0001] The invention relates to the field of speed reducers, and in particular to a miniaturized wind power variable pitch speed reducer and an assembly method thereof. Background Art

[0002] The variable pitch reducer in the wind turbine is a key component, which is responsible for adjusting the angle of the wind turbine blades to adapt to the changes in wind speeds and ensure the stable operation and efficient power generation of the wind turbine. The variable pitch reducer used in the wind turbine is installed in the hub and rotates 360 degrees in the air with the hub. Due to the limited space in the hub, the volume of the variable pitch reducer that can be accommodated is limited, but the current conventional variable pitch reducer usually uses two sets of tapered roller bearings installed back to back to fix the output shaft of the reducer. Due to the large volume of the tapered roller bearings and to ensure the reliability of the tapered roller bearings, the output end of the reducer needs to be of a higher size, which results in a higher overall height dimension of the reducer. In addition, the assembly process of conventional reducers has the following disadvantages: First, the tapered roller bearings need to compensate for the dimensional changes caused by temperature changes in the bearing components during the assembly process by freezing the outer ring and heating the inner ring to ensure that the bearings can be installed smoothly and maintain the correct fit, while freezing 1. The heating temperature needs to be precisely controlled. Too high or too low a temperature may damage the microstructure of the bearing parts and affect the performance and life of the bearing. The heating or freezing of the inner and outer rings also needs to be carried out evenly to avoid bending or twisting caused by uneven temperature. Secondly, the tightening torque of the upper and lower round nuts of the reducer needs to be more than 2500Nm, requiring special high-torque tightening tools and equipment. Thirdly, the tapered roller bearing needs to adjust the clearance to ensure that the bearing reaches the best working state, which puts high demands on the technical level of assembly; and conventional double-row, different-diameter four-point contact ball bearings use copper rods and hand hammers to gently tap the inner ring of the bearing, or use sleeves and presses for installation, which can easily cause bearing damage and the contact area between the ball bearing and the inner ring of the bearing is small, and the load-bearing capacity is insufficient. No technical solutions identical to the present invention were found through retrieval, but only some related comparative technical documents were found, mainly the following: 1. The patent with application number 202211369971.4 discloses an output shaft structure of a wind power yaw pitch reducer, including an output gear shaft, a housing, and a bearing. A cylindrical roller bearing is arranged at the upper end of the output gear shaft, and a self-lubricating sliding bearing is arranged at the lower end of the output gear shaft; a bearing seat housing is arranged outside the cylindrical roller bearing and the self-lubricating sliding bearing; the lower end of the invention adopts a self-lubricating sliding bearing, and the upper bearing adopts a cylindrical roller bearing arrangement structure. The self-lubricating sliding bearing transmits the bending moment transmitted by the cantilever support gear through the large axial contact surface, and directly transmits the bending at the shaft to the box body. Although the patent reduces the lateral size of the reducer through cylindrical roller bearings and self-lubricating sliding bearings, the vertical size of the self-lubricating sliding bearings cannot be reduced, so the aforementioned problems still exist, and the use of cylindrical roller bearings and self-lubricating sliding bearings for fixed support has a limited force area, and the cylindrical roller bearings and self-lubricating sliding bearings are prone to deformation or fatigue damage.

[0003] 2. The patent with application number 202321451635.4 proposes to provide an output end structure of a yaw pitch reducer and a wind power device. The disclosed output end structure includes a housing, an output shaft, a cylindrical roller group and an axial positioning bearing. Part of the output shaft is located in the housing. The cylindrical roller group includes a plurality of cylindrical rollers, which are arranged around the output shaft. The output shaft is rotatably matched with the housing through the cylindrical roller group. The cylindrical roller group is used to bear the radial force of the output shaft. The axial positioning bearing is sleeved on the outer periphery of the output shaft, and the axial positioning bearing is used to bear the axial force of the output shaft. Although the patent reduces the size of the reducer by arranging a plurality of cylindrical rollers around the output shaft, the contact area between the cylindrical rollers and the output shaft is limited, and deformation or fatigue damage is prone to occur. If the contact area is increased by arranging a plurality of cylindrical rollers, the size of the reducer will increase, so it still needs to be improved.

[0004] 3. The patent with application number 202110273845.8 provides an assembly method for the flexible output gear shaft of a wind power yaw reducer, including: heating the front body; assembling the outer ring of the rear tapered roller bearing; assembling the outer ring of the front tapered roller bearing on the front body; disassembling the tooling 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 pressing cylinder used to compact the inner ring of the front tapered roller bearing; hoisting the front body and assembling it with the output shaft; assembling the inner ring of the rear tapered roller bearing; inspecting the rotational torque of the bearing; installing the 4-stage planetary transmission device step by step until the assembly of the reducer parts is completed; turning the reducer around and fixing it on the fifth tooling; installing the end cover, seal and fixed pressure plate on the front body; installing the output gear on the output shaft and assembling the locking nut; disassembling the fifth tooling, and the assembly is completed. This assembly method requires freezing and heating the reducer parts, and the assembly process is cumbersome and has high requirements for the process and equipment.

[0005] Through the analysis of the above patents, it can be found that although the current wind turbine variable pitch reducer has the method of reducing the size of the reducer by setting cylindrical rollers around the output shaft, it does not take into account the limited contact area between the cylindrical rollers and the output shaft, which is prone to deformation or fatigue damage. In addition, the assembly process is cumbersome and has high requirements for technology and equipment. Therefore, the problems mentioned above still exist, and it is necessary to improve them. Summary of the invention

[0006] The technical problem to be solved by the present invention is: to provide a miniaturized wind turbine pitch reducer and an assembly method thereof, the volume of which is smaller than that of a conventional wind turbine pitch reducer, reducing the space occupancy of the reducer in the wheel hub, while the support stiffness and load-bearing capacity of the reducer are also improved, and the shortcomings of the current reducer assembly method, that is, the complicated assembly process and the high requirements on the process and equipment are overcome. In addition, the installation method of the double-row different-diameter four-point contact ball bearing is not easy to cause bearing damage, and the contact area between the ball bearing and the inner ring of the bearing is large, thereby increasing the load-bearing capacity.

[0007] The technical solution proposed in the present invention is: a miniaturized wind turbine variable pitch reducer, including an output gear shaft, the contact end of the output gear shaft and the output planetary frame is a quasi-truncated cone, a tapered hole for the output gear shaft to cooperate is provided in the output planetary frame, the output gear shaft and the output planetary frame are connected in the form of a tapered interference fit, which is convenient for installation while ensuring the coaxiality of the inner and outer rings, a double-row different-diameter four-point contact ball bearing is arranged between the output planetary frame structure and the lower box body, which plays a role of fixed support, and a baffle is also arranged above the output gear shaft for fixed connection, the baffle is connected to the output gear shaft by a fastening bolt, and the baffle is interference fit with the output planetary frame.

[0008] Furthermore, the double-row four-point contact ball bearing with different diameters includes a first bearing raceway, a second bearing raceway, a first rolling element assembly installed in the first bearing raceway, and a second rolling element assembly installed in the second bearing raceway.

[0009] Furthermore, the rolling element assembly is composed of a rolling element and an isolation block, the two sides of the isolation block are arc-shaped isolation block surfaces that cooperate with the rolling element, and the diameter of the rolling element of the rolling element assembly one is larger than that of the rolling element of the rolling element assembly two.

[0010] Furthermore, the bearing raceway 1 is composed of an outer bearing raceway 1 on the lower housing and an inner bearing raceway 1 on the output end planetary carrier; the bearing raceway 2 is composed of an outer bearing raceway 2 on the lower housing and an inner bearing raceway 2 on the output end planetary carrier; the cross section of the bearing raceway is composed of four arcs, the centers of the four arcs do not coincide, the radius of the arc is greater than the radius of the rolling body, each arc is in tangential contact with the rolling body at only one position, and the rest of the positions are not in contact, and the bearing raceway can axially position the rolling body; the bearing raceway 1 is arranged near the output end gear, and the bearing raceway 2 is arranged near the baffle.

[0011] Furthermore, a gap is left between the inner raceway of the output end planetary carrier of the bearing raceway and the outer raceway in the lower housing, but the gap is controlled at 1-2 mm to ensure that the contact angle of the rolling body and the inner raceway of the output end planetary carrier of the bearing raceway and the outer raceway in the lower housing forming a four-point contact is greater than 25 degrees.

[0012] Furthermore, the output end planetary carrier has an internal spline between the baffle mounting hole and the tapered hole for matching with the output gear shaft, and the outer side of the bottom end where the output gear shaft contacts the output end planetary carrier is an external spline. The output end planetary carrier and the output gear shaft are connected by a spline to transmit torque, thereby ensuring the smoothness of torque transmission.

[0013] Furthermore, two locating pins are installed on the output end planetary carrier, and locating pin 1 and locating pin 2 are connected to the output end planetary carrier by interference fit. Threaded holes are opened at the center positions of the two locating pins to facilitate disassembly during later maintenance. The front ends of the locating pins adopt a conical structure to facilitate the positioning of plug 1 and plug 2. The diameter of locating pin 1 is larger than the maximum external dimension of the plug to ensure that the plug can be installed normally.

[0014] Furthermore, the output end planetary carrier is provided with a first rolling element mounting hole in the first inner raceway of the bearing, and a second rolling element mounting hole in the second inner raceway of the bearing, wherein the rolling element mounting hole is a conical structure.

[0015] Furthermore, the plug adopts a conical structure, plug one is arranged in rolling element mounting hole one, plug two is arranged in rolling element mounting hole two, one side of the plug is an arc shape of the inner raceway of the bearing, and the other side is processed into an arc shape and cooperates with the positioning pin to realize the axial, radial and circumferential positioning of the plug.

[0016] Furthermore, the bottom of the output end planetary frame is sealed with an oil seal, and a pure copper sealing gasket is installed at the bottom of the connecting bolts between the baffle and the output gear shaft for sealing, thereby ensuring the reliability of the reducer sealing.

[0017] The present invention also relates to a method for assembling a miniaturized wind turbine variable pitch reducer, comprising the following steps: S1: Place the output planet carrier into the lower box from top to bottom, and place the output planet carrier and the lower box on the same plane; S2: Then, install the second rolling element and the isolation block one by one from the second rolling element installation hole into the bearing raceway, and place an isolation block every other rolling element until all the rolling elements and isolation blocks are installed. Insert the second plug into the second rolling element installation hole, and then knock the second positioning pin into the plug, and ensure that it is installed in place. S3: Turn the assembled lower housing and output planetary carrier 180°, and install the rolling element 1 and the isolation block in sequence according to the steps of S2 above. Install the plug 1 into the rolling element installation hole, and then knock the positioning pin into the positioning pin installation hole until it is fully installed, and then install the oil seal and positioning retaining ring into the lower housing. While ensuring the seal, the retaining ring prevents the axial movement of the oil seal; S4: Lift the lower housing and output planet carrier assembled in the above steps as a whole, install them from the small end of the output gear shaft from top to bottom, align the splines of the output planet carrier and the output gear shaft, and use gravity to make the output gear shaft fit the conical surface of the output planet carrier, and then install them in place; S5: Install the frozen baffle into the output planetary carrier, apply thread fastening glue to the bolts, and tighten the fastening bolts in sequence using a torque wrench in a cross-cross manner until the tightening torque reaches 200Nm; S6: After the above installation steps are completed, manually rotate the lower box, which should be able to rotate flexibly; S7: Complete the installation of the remaining planetary components of the reducer in a conventional manner; Furthermore, the cross method refers to tightening the bolts at intervals of 180 degrees.

[0018] Furthermore, when tightening the fastening bolt, a sealing gasket needs to be installed under the bolt head to seal the lubricating oil.

[0019] The beneficial effects of the present invention are as follows: (1) The variable pitch reducer integrates double-row different-diameter four-point contact ball bearings, which improves the support stiffness and load-bearing capacity of the reducer, reduces the height of the whole machine, and reduces the space occupancy rate of the reducer in the wheel hub. (2) The rolling element assembly adopts the method of pouring rolling elements through the pouring hole and isolating them through the double-sided inner arc surface isolation pad, which can effectively reduce the radial size 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 poured rolling elements, not only the radial size of the rolling assembly can be reduced, but also the gap between the inner raceway of the output end planetary frame and the outer raceway in the lower housing can be reduced, so that the contact length between the rolling element and the raceway can be lengthened, the four-point contact can be changed, and the four-point contact can be better stressed. (4) The volume of the inner cavity of the variable pitch reducer is reduced, which can reduce the amount of lubricating oil used. (5) The method of assembling the rolling element 2 and the isolation block one by one from the rolling element mounting hole 2 into the bearing raceway is adopted, and the gap between the output end planetary carrier and the lower housing is reduced, and the area of ​​the rolling element's four-point contact is increased and it is not easy to damage the ball bearing. (6) The process of freezing the outer ring and heating the inner ring during the assembly of the tapered roller bearing is eliminated. (7) The tightening torque of the round nut of the original structure needs to be more than 2500Nm, while the tightening torque of the bolt of this patent is only about 200Nm, and no special high-torque tightening tools and equipment are required. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a miniaturized wind turbine variable pitch reducer provided in an embodiment of the present invention.

[0021] Figure 2 It is a structural diagram of the rolling element assembly.

[0022] Figure 3 It is a structural diagram of the isolation block.

[0023] Figure 4 It is a schematic diagram of the structure of the planetary carrier at the output end.

[0024] Figure 5 It is a structural diagram of the lower box.

[0025] Figure 6 It is a schematic diagram of the structure of the output gear shaft.

[0026] Figure 7 It is a schematic diagram of the three-dimensional structure of the output gear shaft.

[0027] Figure 8 It is a three-dimensional structural diagram of the plug.

[0028] Fig. 9 It is a schematic diagram of the structure of the inner raceway of the bearing.

[0029] Fig.10 It is a three-dimensional structural diagram of a wind turbine variable pitch reducer.

[0030] Explanation of the reference numerals: output gear shaft 1, oil seal 2, output end planetary carrier 3, rolling element assembly 1, lower housing 5, baffle 6, rolling element assembly 2, sealing gasket 8, fastening bolt 9, plug 2, locating pin 1, plug 1, 12, arc 1201 of inner raceway of bearing, circular arc 1202, locating pin 2, isolation block 14, arc surface 1401 of isolation block, rolling element 15, outer raceway 1 502 of bearing, outer raceway 2 503 of bearing, external spline 103, tapered hole 301 for matching of output gear shaft, inner raceway 1 302 of bearing, internal spline 303, inner raceway 2 304 of bearing, rolling element mounting hole 1 307, rolling element mounting hole 2 308. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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 only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0032] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0033] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0034] like Figures 1 to 9As shown, a miniaturized wind turbine variable pitch reducer and an assembly method thereof, the miniaturized wind turbine variable pitch reducer comprises 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 planet carrier 3 is truncated cone-shaped, the output end planet carrier 3 has a tapered hole 301 for the output gear shaft to match, the output gear shaft 1 and the output end planet carrier 3 are connected in the form of a tapered interference fit, which is convenient for installation while ensuring the coaxiality of the inner and outer rings, a double-row reducing four-point contact ball bearing is arranged between the output end planet carrier 3 and the lower box body 5, a baffle 6 is also arranged above the output gear shaft 1 for fixed connection, the baffle 6 is connected to the output gear shaft 1 by a fastening bolt 9, and the baffle 6 is interference fit with the output end planet carrier 3.

[0035] Furthermore, the double-row four-point contact ball bearing with different diameters includes a first bearing raceway, a second bearing raceway, a rolling element assembly 1 4 installed in the first bearing raceway, and a rolling element assembly 2 7 installed in the second bearing raceway.

[0036] Furthermore, the rolling element assembly is composed of a rolling element and an isolation block 14, and both sides of the isolation block 14 are isolation block arc surfaces 1401 that cooperate with the rolling element. The diameter of the rolling element 15 of the rolling element assembly 1 4 is larger than that of the rolling element 15 of the rolling element assembly 2 7.

[0037] Furthermore, the bearing raceway 1 is composed of a bearing outer raceway 502 on the lower housing 5 and a bearing inner raceway 302 on the output end planetary carrier 3; the bearing raceway 2 is composed of a bearing outer raceway 503 on the lower housing 5 and a bearing inner raceway 304 on the output end planetary carrier 3; the cross-section of the bearing raceway is composed of four arcs, the centers of the four arcs do not coincide, the radius of the arc is greater than the radius of the rolling body, each arc is in tangential contact with the rolling body 15 at only one position, and the rest of the positions are not in contact, and the bearing raceway can axially position the rolling body 15; the bearing raceway 1 is arranged near the output end gear, and the bearing raceway 2 is arranged near the baffle 6.

[0038] Furthermore, a gap is left between the inner raceway of the output end planetary carrier of the bearing raceway and the outer raceway in the lower housing, but the gap is controlled at 1-2 mm to ensure that the contact angle of the rolling body and the inner raceway of the output end planetary carrier of the bearing raceway and the outer raceway in the lower housing forming a four-point contact is greater than 25 degrees.

[0039] Furthermore, the first bearing raceway is arranged at a position close to the output end gear, and the second bearing raceway is arranged at a position close to the baffle 6 .

[0040] Furthermore, the output planet carrier 3 has an internal spline 303 between the mounting hole of the baffle 6 and the matching tapered hole of the output gear shaft 1, and the outer side of the bottom end where the output gear shaft 1 contacts the output planet carrier 3 is an external spline 103. The output planet carrier 3 and the output gear shaft 1 are connected by a spline to transmit torque, thereby ensuring the smoothness of torque transmission.

[0041] Furthermore, two locating pins are installed on the output end planetary carrier 3, and the locating pin 11 and the locating pin 2 13 are connected to the output end planetary carrier 3 by interference fit. Threaded holes are opened at the center positions of the two locating pins to facilitate disassembly during later maintenance. The front ends of the locating pins adopt a conical structure to facilitate the positioning of the plug 12 and the plug 2 10. The diameter of the locating pin 11 is larger than the maximum external dimension of the plug to ensure that the plug can be installed normally.

[0042] Furthermore, the output end planet carrier 3 is provided with a first rolling body mounting hole 307 in the first bearing inner raceway 302, and a second rolling body mounting hole 308 in the second bearing inner raceway 304, wherein the rolling body mounting hole is a conical structure.

[0043] Furthermore, the plug adopts a conical structure, plug 12 is arranged in rolling element mounting hole 1 307, plug 2 10 is arranged in rolling element mounting hole 2 308, one side of plug 12 is an arc 1201 of the inner raceway of the bearing, and the other side is processed into an arc shape 1202 and cooperates with a positioning pin to realize axial, radial and circumferential positioning of the plug.

[0044] Furthermore, the bottom of the output end 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 bolts between the baffle 6 and the output gear shaft 1 for sealing, thereby ensuring the reliability of the reducer sealing.

[0045] In this embodiment, the transmission principle is as follows: the contact portion between the output gear shaft 1 and the output end planet carrier 3 is truncated cone-like, and is axially positioned on the output end planet 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 through a fastening bolt 9, and is interference-connected with the output end planet carrier 3. The locating pin 1 11 and the locating pin 2 13 are interference-connected with the output end planet carrier 3. A double-row, different-diameter four-point contact ball bearing is arranged between the output end planet carrier 3 structure and the lower box body 5 to play a role of fixed support.

[0046] The present invention also relates to a method for assembling a miniaturized wind turbine variable pitch reducer, comprising the following steps: S1: Place the output end planetary carrier 3 into the lower box body 5 from top to bottom, and place the output end planetary carrier 3 and the lower box body 5 on the same plane; S2: Then, the second rolling element and the isolation block are loaded one by one from the second rolling element mounting hole 304 into the bearing raceway, and an isolation block 14 is placed every other rolling element until all the rolling elements and isolation blocks 14 are loaded, and the second plug 10 is inserted into the second rolling element mounting hole 304, and then the second positioning pin 11 is knocked into the plug, and it is ensured to be installed in place; S3: Turn the assembled lower housing and output end planetary carrier 180° as a whole, and install the rolling element 1 and the isolation block 14 in sequence according to the steps of S2 above. Install the plug 12 into the rolling element installation hole, and then knock the positioning pin 13 into the positioning pin installation hole until it is fully installed, and then install the oil seal 2 and the positioning retaining ring into the lower housing 5. While ensuring the seal, the retaining ring prevents the axial movement of the oil seal; S4: Lift the lower housing and output planet carrier assembled in the above steps as a whole, install them from the small end of the output gear shaft 1 from top to bottom, align the splines of the output planet carrier and the output gear shaft, and use gravity to make the output gear shaft fit the conical surface of the output planet carrier, that is, install them in place; S5: Install the frozen baffle 6 into the output end planetary carrier, apply thread fastening glue to the bolts, and tighten the fastening bolts 9 in sequence using a torque wrench in a cross-cross manner until a tightening torque of 200 Nm is reached; S6: After the above installation steps are completed, manually rotate the lower box, which should be able to rotate flexibly; S7: Complete the installation of the remaining planetary components of the reducer in a conventional manner; Furthermore, the cross method refers to tightening the bolts at intervals of 180 degrees.

[0047] Furthermore, when tightening the fastening bolt 9, a sealing gasket 8 needs to be installed under the bolt head to seal the lubricating oil.

[0048] The beneficial effects of the present invention are as follows: (1) The variable pitch reducer integrates double-row different-diameter four-point contact ball bearings, which improves the support stiffness and load-bearing capacity of the reducer, reduces the height of the whole machine, and reduces the space occupancy rate of the reducer in the wheel hub. (2) The rolling element assembly adopts the method of pouring rolling elements through the pouring hole and isolating them through the double-sided inner arc surface isolation pad, which can effectively reduce the radial size 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 poured rolling elements, not only the radial size of the rolling assembly can be reduced, but also the gap between the inner raceway of the output end planetary frame and the outer raceway in the lower housing can be reduced, so that the contact length between the rolling element and the raceway can be lengthened, the four-point contact can be changed, and the four-point contact can be better stressed. (4) The volume of the inner cavity of the variable pitch reducer is reduced, which can reduce the amount of lubricating oil used. (5) The method of assembling the rolling element 2 and the isolation block one by one from the rolling element mounting hole 2 into the bearing raceway is adopted, and the gap between the output end planetary carrier and the lower housing is reduced, and the area of ​​the rolling element's four-point contact is increased and it is not easy to damage the ball bearing. (6) The process of freezing the outer ring and heating the inner ring during the assembly of the tapered roller bearing is eliminated. (7) The tightening torque of the round nut of the original structure needs to be more than 2500Nm, while the tightening torque of the bolt of this patent is only about 200Nm, and no special high-torque tightening tools and equipment are required.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A miniaturized wind turbine variable pitch reducer, characterized in that: The invention comprises an output gear shaft (1), wherein the contact portion between the output gear shaft (1) and the output end planetary frame (3) is quasi-truncated cone-shaped, the output end planetary frame (3) has a tapered hole (301) for matching with the output gear shaft, the output gear shaft (1) and the output end planetary frame (3) are connected in the form of a tapered interference fit, a double-row reducing four-point contact ball bearing is arranged between the output end planetary frame (3) structure and the lower housing (5), a baffle (6) is also arranged above the output gear shaft (1) for fixed connection, the baffle (6) is connected to the output gear shaft (1) by a fastening bolt (9), and the baffle (6) and the output end planetary frame (3) are interference fit.

2. A miniaturized wind turbine variable pitch reducer according to claim 1, characterized in that: The double-row four-point contact ball bearing comprises a first bearing raceway, a second bearing raceway, a first rolling element assembly (4) installed in the first bearing raceway, and a second rolling element assembly (7) installed in the second bearing raceway; the rolling element assembly comprises a rolling element and an isolation block (14); both sides of the isolation block (14) are arcuate isolation block surfaces (1401) that cooperate with the rolling element; the diameter of the rolling element (15) of the first rolling element assembly (4) is larger than that of the rolling element (15) of the second rolling element assembly (7).

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

4. The miniaturized wind turbine variable pitch reducer according to claim 1, characterized in that: The output end planet carrier (3) has an internal spline (303) between the mounting hole of the baffle (6) and the tapered hole (301) for matching with the output gear shaft, and the outer side of the bottom end where the output gear shaft (1) and the output end planet carrier (3) contact each other is an external spline (103). The output end planet carrier (3) and the output gear shaft (1) are connected by splines to transmit torque, thereby ensuring smooth torque transmission.

5. The miniaturized wind turbine variable pitch reducer according to claim 1, characterized in that: The output end planet carrier (3) is provided with two positioning pins, and the positioning pin 1 (11) and the positioning pin 2 (13) are connected to the output end planet carrier (3) by interference fit. The center positions of the two positioning pins are provided with threaded holes to facilitate disassembly during later maintenance. The front ends of the positioning pins are provided with a conical structure to facilitate the positioning of the plug 1 (12) and the plug 2 (10). The diameter of the positioning pin 1 (11) is larger than the maximum outer dimension of the plug to ensure that the plug can be installed normally. The output end planet carrier (3) is provided with a rolling element mounting hole 1 (307) in the inner raceway 1 (302) of the bearing, and a rolling element mounting hole 2 (308) in the inner raceway 2 (304) of the bearing, wherein the rolling element mounting holes are conical structures.

6. A miniaturized wind turbine variable pitch reducer according to claim 5, characterized in that: The plug adopts a conical structure, plug one (12) is arranged in rolling element mounting hole one (307), plug two (10) is arranged in rolling element mounting hole two (308), one side of plug one (12) is an arc shape (1201) of the inner raceway of the bearing, and the other side is processed into an arc shape (1202) and cooperates with a positioning pin to realize axial, radial and circumferential positioning of the plug.

7. The miniaturized wind turbine variable pitch reducer according to claim 1, characterized in that: The bottom of the output end 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 bolts between the baffle plate (6) and the output gear shaft (1) for sealing, thereby ensuring the reliability of the reducer sealing.

8. A method for assembling a miniaturized wind turbine variable pitch reducer according to any one of claims 1 to 7, characterized in that : Install the rolling elements and spacer blocks (14) one by one from the rolling element mounting hole into the bearing raceway, placing a spacer block (14) every other rolling element until all the rolling elements and spacer blocks (14) are installed. Insert the plug into the rolling element mounting hole, then knock the positioning pin into the plug and ensure that it is installed in place.

9. A method for assembling a miniaturized wind turbine variable pitch reducer according to claim 8, characterized in that: Before the rolling elements and the isolation block (14) are loaded, the output end planetary carrier (3) and the lower box body (5) are tightly fitted, and the output end planetary carrier 3 and the lower box body 5 are placed on the same plane.

10. A method for assembling a miniaturized wind turbine variable pitch reducer according to claim 8, characterized in that: Lift the assembled lower housing and output planet carrier as a whole, and install them from the small end of the output gear shaft (1) from top to bottom. Align the splines of the output planet carrier and the output gear shaft, and use gravity to make the output gear shaft fit the conical surface of the output planet carrier. Then install them in place.

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