Variable pitch system and mounting method

Abstract

The invention provides a variable pitch system and an installation method, and relates to the field of wind power generation. The variable pitch system comprises a hub, blades and a variable pitch bearing, the variable pitch bearing comprises an inner ring and an outer ring which are connected with each other, the inner ring is provided with a first mounting part, the first mounting part is connected with the blades in a matched mode, the outer ring is provided with a second mounting part, and the second mounting part is connected with the hub in a matched mode. The first mounting part and the second mounting part are connected with the corresponding blade and the hub in a sectional conical positioning connection mode, the blade and the hub are provided with a first detection piece and a second detection piece respectively, the first detection piece is used for detecting the gap distance between the inner ring and the blade, and the second detection piece is used for detecting the gap distance between the outer ring and the hub. By adopting the sectional type conical positioning connection structure, and arranging the first detection piece and the second detection piece on the blade and the hub respectively, the relative slippage phenomenon of the connection part of the variable pitch bearing in the operation process is effectively reduced, and meanwhile, the installation precision and the connection reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power generation, in particular to a variable pitch system and a mounting method. BACKGROUND

[0002] In a modern wind turbine, the variable pitch bearing is an important component connecting the hub and the blade, and the connection structure design has an important influence on the operation stability of the unit.

[0003] The connection method of the variable pitch system commonly used in the wind power industry at present is that the outer ring of the variable pitch bearing is connected and fixed with the hub through a set of high-strength bolts, and the inner ring is connected with the blade through another set of high-strength bolts, and the hub-variable pitch bearing-blade is composed into an integral transmission structure through this mechanical connection method. This connection method has two main problems in the operation process: first, this structure design lacks effective limitation on the circumferential and radial displacement, and under the action of long-term alternating load, the variable pitch bearing connection position is prone to slip movement, which causes the direct contact between the bolt and the hole wall, makes the bolt bear shear force, and is prone to fracture failure, which seriously affects the safe operation of the unit; second, due to the accumulation of manufacturing tolerances and installation errors, the bolt holes of the inner and outer rings of the variable pitch bearing and the threaded holes on the blade and the hub are prone to misalignment, which not only causes difficulty in removal during bolt replacement operation, and requires a large amount of manpower and material resources, significantly increasing the operation and maintenance cost and time, but also requires a large amount of time for positioning adjustment during the initial installation stage, which seriously affects the installation efficiency. SUMMARY

[0004] The present application provides a variable pitch system and a mounting method thereof, which adopts a segmented conical positioning connection structure, and first detection members and second detection members are respectively arranged on the blade and the hub, effectively reducing the relative slip phenomenon of the variable pitch bearing connection part during operation, and improving the installation precision and connection reliability.

[0005] Embodiments of the present application can be implemented as follows: In a first aspect, the present application provides a variable pitch system, comprising a hub, a blade and a variable pitch bearing, the variable pitch bearing comprising an inner ring and an outer ring connected with each other, the inner ring having a first mounting part, the first mounting part being connected with the blade in cooperation, the outer ring having a second mounting part, the second mounting part being connected with the hub in cooperation, wherein, The first mounting part and the second mounting part are connected with the corresponding hub and the blade in a segmented conical positioning connection mode, and first detection members and second detection members are respectively arranged on the blade and the hub, the first detection members being used for detecting the gap distance between the inner ring and the blade, and the second detection members being used for detecting the gap distance between the outer ring and the hub.

[0006] Optionally, the first mounting portion and the second mounting portion are sequentially arranged with a first conical surface, a first annular platform, a second conical surface and a second annular platform in the axial direction, the first conical surface and the second conical surface are coaxially arranged and separated by the first annular platform in the axial direction, and the second annular platform is located at the end of the second conical surface and connected with the outer surface of the inner ring and the outer ring.

[0007] Optionally, the number of the first detection members and the second detection members is more than three, and the more than three first detection members and the more than three second detection members are respectively arranged on the blade and the hub in the circumferential direction and arranged opposite to the second annular platform.

[0008] Optionally, a first mounting hole is arranged at the position opposite to the second annular platform on the blade, a second mounting hole is arranged at the position opposite to the second annular platform on the hub, the first detection member is arranged in the first mounting hole, the second detection member is arranged in the second mounting hole, and the end of the first detection member and the second detection member close to the second annular platform does not exceed the first mounting hole and the second mounting hole.

[0009] Optionally, the pitch system further comprises a locking pin, the locking pin penetrates through the pitch bearing and passes through the second conical surface, and is connected with the hub and the blade.

[0010] Optionally, the pitch system further comprises a friction member, the friction member is arranged between the first annular platform and the hub and between the first annular platform and the blade.

[0011] Optionally, a positioning groove is arranged on the first annular platform, and part of the friction member is arranged in the positioning groove.

[0012] Optionally, the first mounting portion and the second mounting portion further comprise an abutting portion, the abutting portion is connected with the first conical surface, the pitch system further comprises a first fixing bolt and a second fixing bolt, the first fixing bolt penetrates through the outer ring and is detachably connected with the hub, and the second fixing bolt penetrates through the inner ring and is detachably connected with the blade.

[0013] Optionally, the number of the first detection members and the second detection members is 8, the 8 first detection members are equally spaced on the blade, the 8 second detection members are equally spaced on the hub, and the first detection members and the second detection members are arranged opposite to the second annular platform, wherein, During the operation of the wind turbine generator, the first detection member is used to monitor the distance between the blade and the inner ring in the circumferential direction in real time, and the second detection member is used to monitor the distance between the hub and the outer ring in real time. The real-time distances measured by the first and second detection elements are compared with the corresponding initial installation distances. If the difference exceeds a preset allowable range, it is determined to be an abnormal distance. The pitch system also includes a main control system, which is electrically connected to the first and second detection elements. The main control system triggers corresponding monitoring alarm states in stages based on the number of first and second detection elements with abnormal distances. Secondly, the present invention provides a pitch system installation method. Both the first and second installation parts adopt a segmented conical positioning connection method to connect with the corresponding hub and blades. The first and second installation parts are sequentially arranged axially with a first conical surface, a first annular platform, a second conical surface, and a second annular platform. The first and second conical surfaces are coaxially arranged and axially separated by the first annular platform. The second annular platform is located at the end of the second conical surface and is connected to the outer surfaces of the inner and outer rings. The pitch system installation method includes the following installation steps: S01, the first detection element and the second detection element are respectively installed at intervals on the circumference of the blade and the hub, and the first detection element and the second detection element are opposite to the second annular platform; S02, the second mounting part is connected to the hub, and the first fixing bolt passes through the outer ring and is detachably connected to the hub to install the pitch bearing onto the hub; S03, the gap distance between the second mounting part and the wheel hub is collected by the second detection element, and the first fixing bolt is adjusted so that the gap distance reaches the preset value; S04, the first mounting part is connected to the blade, and the second fixing bolt passes through the inner ring and is detachably connected to the blade to install the blade onto the pitch bearing; S05, the gap distance between the first mounting part and the blade is collected by the first detection element, and the second fixing bolt is adjusted so that the gap distance reaches the preset value.

[0014] The beneficial effects of the pitch system and pitch system installation method of the present invention include: The inner and outer rings of the pitch bearing employ a segmented, tapered connection method with the corresponding blades and hub. This effectively distributes the load, reduces stress concentration, and consequently lowers the risk of slippage and breakage. Furthermore, the segmented structure allows for gradual adjustments during installation, aligning with the first and second detection elements on the blades and hub. This enables the system to monitor real-time changes in clearance between the outer ring and hub, and between the inner ring and blades. If any abnormality is detected, immediate adjustments can be made to prevent structural failure due to improper clearance, significantly improving the ease of system installation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the pitch system provided in this embodiment from a first-view perspective; Figure 2 This is a schematic diagram of the pitch system provided in this embodiment from a second perspective. Figure 3 for Figure 2 Cross-sectional view at point BB; Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0017] Icons: 1-Pitch system; 10-Hub; 11-First mounting hole; 12-Second mounting hole; 20-Blade; 30-Pitch bearing; 31-Inner ring; 311-First mounting part; 313-First conical surface; 314-First annular platform; 3141-Positioning groove; 316-Second conical surface; 317-Second annular platform; 318-Abutting part; 33-Outer ring; 331-Second mounting part; 51-First detection component; 52-Second detection component; 61-Locking pin; 63-Friction component; 65-First fixing bolt; 66-Second fixing bolt. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0021] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0022] Furthermore, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Also, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0023] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] It should also be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0025] As noted in the background section, under long-term alternating loads, the connection points of the pitch bearings in a pitch system are prone to slippage, which can eventually lead to structural fracture. Furthermore, the design of existing pitch systems suffers from inconvenient installation and maintenance, increasing system operation and maintenance costs and impacting overall operational efficiency and reliability.

[0026] Please refer to Figures 1 to 4 This application provides a pitch system 1 and an installation method, which can solve the above-mentioned technical problems.

[0027] The present invention provides a pitch system 1, which includes a hub 10, blades 20, and a pitch bearing 30. The pitch bearing 30 includes an inner ring 31 and an outer ring 33 connected to each other. The inner ring 31 has a first mounting part 311, which is connected to the blades 20. The outer ring 33 has a second mounting part 331, which is connected to the hub 10. The first mounting part 311 and the second mounting part 331 are both connected to the corresponding blades 20 and hub 10 using a segmented conical positioning connection method. The blades 20 and hub 10 are respectively provided with a first detection element 51 and a second detection element 52. The first detection element 51 is used to detect the gap distance between the inner ring 31 and the blades 20, and the second detection element 52 is used to detect the gap distance between the outer ring 33 and the hub 10.

[0028] The inner ring 31 and outer ring 33 of the pitch bearing 30 are connected to the corresponding blades 20 and hub 10 using a segmented tapered positioning connection method. This effectively distributes the load, reduces concentrated stress, and thus lowers the risk of slippage and breakage. Furthermore, the segmented structure allows for gradual adjustments during installation. Combined with the first detection element 51 and the second detection element 52 on the blades 20 and hub 10, the system can monitor the clearance changes between the inner ring 31 and the blades 20, and between the outer ring 33 and the hub 10 in real time. If an abnormality is detected, immediate adjustments or repairs can be taken to prevent structural failure due to improper clearance, significantly improving the ease of system installation and maintenance.

[0029] It is easy to understand that both the first mounting part 311 and the second mounting part 331 are connected to the corresponding hub 10 or blade 20 using a segmented conical positioning connection method. Specifically, the corresponding connection parts of the hub 10 and the blade 20 also use a segmented conical positioning connection method. The mating connection here means that the first mounting part 311 and the blade 20, and the second mounting part 331 and the hub 10 have mutually matching shapes, that is, the first mounting part 311 and the second mounting part 331 have concave structures, while the corresponding connection parts of the hub 10 and the blade 20 have convex structures.

[0030] It should be noted that the so-called segmented conical positioning refers to a conical assembly surface that includes multiple conical assembly surfaces with different planes, rather than being composed of a single continuous conical surface. This multi-segment conical design can more effectively distribute the load and improve the stability and reliability of the connection.

[0031] Further, please refer to Figure 3 and Figure 4The first mounting part 311 and the second mounting part 331 are each provided with a first conical surface 313, a first annular platform 314, a second conical surface 316 and a second annular platform 317 in sequence along the axial direction. The first conical surface 313 and the second conical surface 316 are coaxially arranged and are separated from each other by the first annular platform 314 in the axial direction. The second annular platform 317 is located at the end of the second conical surface 316 and is connected to the outer surface of the inner ring 31 and the outer ring 33.

[0032] By setting a first conical surface 313 and a second conical surface 316, and inserting a first annular platform 314 between them, more precise positioning and alignment can be achieved. The first annular platform 314 provides additional support points, further enhancing the rigidity and stability of the connection, ensuring a more robust connection between the pitch bearing 30 and the hub 10, and between the pitch bearing 30 and the blade 20, under long-term alternating loads.

[0033] Furthermore, there are three or more of the first detection element 51 and the second detection element 52. These three or more first detection elements 51 and second detection elements 52 are respectively arranged circumferentially on the blade 20 and the hub 10, and are positioned opposite to the second annular platform 317. By arranging multiple (three or more) distance detection elements (first detection element 51 and second detection element 52) ​​circumferentially on the blade 20 and the hub 10, comprehensive monitoring of the gaps between the outer ring 33 and the hub 10, and between the inner ring 31 and the blade 20, can be achieved. This multi-point detection method can cover the entire connection surface, ensuring that no area is missed, improving the comprehensiveness and accuracy of monitoring, and facilitating the smooth and precise installation and maintenance of the pitch system 1.

[0034] In this embodiment, there are eight first detection elements 51 and eight second detection elements 52. The eight first detection elements 51 are equally spaced on the blade 20, and the eight second detection elements 52 are equally spaced on the hub 10, both of which are positioned opposite to the second annular platform 317. During the operation of the wind turbine generator, the multiple first detection elements 51 are used to monitor the distance between the blade 20 and the inner ring 31 in real time in the circumferential direction, while the multiple second detection elements 52 are used to monitor the distance between the hub 10 and the outer ring 33 in real time.

[0035] The real-time distance measured by each testing component is compared with its corresponding initial installation distance. If the difference exceeds the preset allowable range, it is judged as an abnormal distance. This preset range takes into account factors such as the assembly gap between components and elastic deformation that may occur under normal working conditions, ensuring that the judgment threshold has a reasonable engineering basis.

[0036] The pitch control system also includes a main control system, which is electrically connected to the first detection element 51 and the second detection element 52. The main control system triggers corresponding monitoring alarm states in stages based on the number of detection elements reporting abnormal distances (the first detection element 51 and the second detection element 52 are counted separately): when 1 to 2 detection elements report abnormalities, the system enters an "attention" state; when the number of abnormal detection elements reaches 3 to 4, it escalates to a "warning" state; if the number of abnormal elements reaches or exceeds 5 (i.e., more than 4), it is determined to be a serious abnormality, triggering a "fault" alarm. Once the system detects a fault-level abnormality, it will immediately execute a shutdown protection command and prompt maintenance personnel to conduct inspection and repair.

[0037] Through the aforementioned multi-point distributed, real-time dynamic gap monitoring mechanism, structural anomalies such as eccentricity, loosening, and deformation that may occur in the blade 20 or hub 10 during long-term operation can be effectively identified, thereby improving the safety and reliability of the pitch system 1. Furthermore, a first mounting hole 11 is provided at the position opposite to the second annular platform 317 on the blade 20, and a second mounting hole 12 is provided at the position opposite to the second annular platform 317 on the hub 10. A first detection element 51 is disposed within the first mounting hole 11, and a second detection element 52 is disposed within the second mounting hole 12. The ends of the first detection element 51 and the second detection element 52 closest to the second annular platform 317 do not extend beyond the first mounting hole 11 and the second mounting hole 12.

[0038] The design of the mounting holes (first mounting hole 11 and second mounting hole 12) can shield the test pieces from external environmental interference, such as dust and moisture, thereby ensuring the normal operation of the test pieces (first test piece 51 and second test piece 52) and the reliability of the data. Furthermore, the end of the test piece closest to the second annular platform 317 does not extend beyond the mounting hole, effectively preventing external mechanical damage or wear during operation. This protective measure extends the service life of the test pieces and reduces maintenance frequency.

[0039] Furthermore, in order to enhance the connection strength between the pitch bearing 30 and the hub 10 or the blade 20, and to ensure that the connection will not loosen or retract under high load and vibration conditions, the pitch system 1 also includes a locking pin 61, which passes through the pitch bearing 30 and through the second conical surface 316, and is connected to the hub 10 and the blade 20.

[0040] Furthermore, the pitch system 1 also includes a friction element 63, which is disposed between the first annular platform 314 and the hub 10, and between the first annular platform 314 and the blade 20. By increasing the friction coefficient of the mating surfaces, the friction element 63 can significantly increase the static friction in the circumferential direction. This greatly reduces the tendency of the hub 10 and the blade 20 to slide relative to the first annular platform 314 when subjected to external forces, thereby improving the overall stability of the system.

[0041] Furthermore, a positioning groove 3141 is provided on the first annular platform 314, and part of the friction component 63 is disposed in the positioning groove 3141. The design of the positioning groove 3141 provides a precise installation position for the friction component 63 and can effectively prevent the friction component 63 from shifting or deviating during use, especially under high load and vibration conditions. This design ensures that the friction component 63 is always in optimal working condition, improving the reliability and durability of the system.

[0042] Furthermore, the first mounting part 311 and the second mounting part 331 also include an abutment part 318, which is connected to the first conical surface 313. The pitch system 1 also includes a first fixing bolt 65 and a second fixing bolt 66. The first fixing bolt 65 passes through the outer ring 33 and is detachably connected to the hub 10. The second fixing bolt 66 passes through the inner ring 31 and is detachably connected to the blade 20.

[0043] The abutment portion 318 provides a precise positioning reference, ensuring alignment and tight fit between the first mounting portion 311 and the blade 20, and between the second mounting portion 331 and the hub 10. This precise positioning helps reduce installation errors and improves the overall performance of the system. Furthermore, the abutment portion 318 simplifies the assembly process of the pitch system 1, making installation more convenient and faster.

[0044] Furthermore, the first mounting part 311 is interference-fitted with the hub 10, and the second mounting part 331 is interference-fitted with the blade 20. By precisely controlling the interference fit through axial displacement, accurate regulation of static friction can be achieved. This design allows the static friction to be adjusted according to actual working conditions, ensuring optimal friction performance under different load conditions.

[0045] In another aspect, the present invention provides a method for installing a pitch system 1. Both the first mounting part 311 and the second mounting part 331 are connected to the corresponding blades 20 and hub 10 using a segmented conical positioning connection method. The first mounting part 311 and the second mounting part 331 are each sequentially arranged axially with a first conical surface 313, a first annular platform 314, a second conical surface 316, and a second annular platform 317. The first conical surface 313 and the second conical surface 316 are coaxially arranged and axially separated by the first annular platform 314. The second annular platform 317 is located at the end of the second conical surface 316 and is connected to the outer surfaces of the inner ring 31 and the outer ring 33. The method for installing the pitch system 1 includes the following installation steps: S01, the first detection element 51 and the second detection element 52 are respectively installed at intervals on the circumference of the blade 20 and the hub 10, and the first detection element 51 and the second detection element 52 are respectively opposite to the second annular platform 317; S02, the second mounting part 331 is connected to the hub 10, and the first fixing bolt 65 passes through the outer ring 33 and is detachably connected to the hub 10 to install the pitch bearing 30 onto the hub 10; S03, the gap distance between the second mounting part 331 and the hub 10 is collected by the second detection element 52, and the first fixing bolt 65 is adjusted so that the gap distance reaches the preset value; S04, the first mounting part 311 is connected to the blade 20, and the second fixing bolt 66 passes through the inner ring 31 and is detachably connected to the blade 20 so as to install the blade 20 onto the pitch bearing 30; S05, the gap distance between the first mounting part 311 and the blade 20 is collected by the first detection element 51, and the second fixing bolt 66 is adjusted so that the gap distance reaches the preset value.

[0046] During assembly, the guiding and positioning function of the conical surface facilitates installation and docking. Simultaneously, the first annular platform 314 provides additional support points, further enhancing the rigidity and stability of the connection points, ensuring a more robust connection between the pitch bearing 30 and the hub 10, and between the pitch bearing 30 and the blade 20, under long-term alternating loads. Furthermore, the first detection element 51 and the second detection element 52 enable comprehensive monitoring of the clearances between the pitch bearing 30 and the blade 20, and between the pitch bearing 30 and the hub 10, simplifying the installation process and facilitating adjustments, thereby ensuring the stability and reliability of the system.

[0047] In summary, the embodiments of the present invention provide a pitch system 1 and an installation method. By adopting a segmented conical positioning connection structure and setting a first detection element 51 and a second detection element 52 on the blade 20 and the hub 10 respectively, the relative slippage phenomenon of the pitch bearing 30 connection part during operation is effectively reduced, while improving the installation accuracy and connection reliability.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A pitch control system, characterized in that, include: Hub (10) and blade (20); A pitch bearing (30) includes an inner ring (31) and an outer ring (33) connected to each other. The inner ring (31) has a first mounting portion (311) that is connected to the blade (20). The outer ring (33) has a second mounting portion (331) that is connected to the hub (10). The first mounting part (311) and the second mounting part (331) are connected to the corresponding blade (20) and the hub (10) respectively by a segmented conical positioning connection method. The blade (20) and the hub (10) are respectively provided with a first detection element (51) and a second detection element (52). The first detection element (51) is used to detect the gap distance between the inner ring (31) and the blade (20), and the second detection element (52) is used to detect the gap distance between the outer ring (33) and the hub (10).

2. The pitch system according to claim 1, characterized in that, The first mounting part (311) and the second mounting part (331) are arranged in sequence along the axial direction with a first conical surface (313), a first annular platform (314), a second conical surface (316) and a second annular platform (317). The first conical surface (313) and the second conical surface (316) are coaxially arranged and are separated from each other by the first annular platform (314) in the axial direction. The second annular platform (317) is located at the end of the second conical surface (316) and is connected to the outer surface of the inner ring (31) and the outer ring (33).

3. The pitch system according to claim 2, characterized in that, The number of the first detection element (51) and the second detection element (52) is three or more. The three or more first detection elements (51) and second detection elements (52) are respectively arranged on the blade (20) and the hub (10) at intervals along the circumference and are arranged opposite to the second annular platform (317).

4. The pitch system according to claim 3, characterized in that, The number of the first detection element (51) and the second detection element (52) is eight in total. The eight first detection elements (51) are equally spaced on the blade (20), and the eight second detection elements (52) are equally spaced on the hub (10). Both the first detection elements (51) and the second detection elements (52) are arranged opposite to the second annular platform (317). During the operation of the wind turbine generator set, the first detection element (51) is used to monitor the distance between the blade (20) and the inner ring (31) in real time in the circumferential direction, and the second detection element (52) is used to monitor the distance between the hub (10) and the outer ring (33) in real time. The real-time distance measured by the first detection element (51) and the second detection element (52) will be compared with the corresponding initial installation distance. If the difference exceeds the preset allowable range, it will be determined as an abnormal distance. The pitch system (1) also includes a main control system. The main control system is electrically connected to the first detection element (51) and the second detection element (52). The main control system triggers the corresponding monitoring alarm status in stages according to the number of the first detection element (51) and the second detection element (52) with abnormal distances.

5. The pitch system according to claim 3, characterized in that, The blade (20) has a first mounting hole (11) at a position opposite to the second annular platform (317), and the hub (10) has a second mounting hole (12) at a position opposite to the second annular platform (317). The first detection element (51) is disposed in the first mounting hole (11), and the second detection element (52) is disposed in the second mounting hole (12). The ends of the first detection element (51) and the second detection element (52) near the second annular platform (317) do not extend beyond the first mounting hole (11) and the second mounting hole (12).

6. The pitch system according to claim 2, characterized in that, The pitch system (1) also includes a locking pin (61) that passes through the pitch bearing (30) and through the second conical surface (316) and is connected to the hub (10) and the blade (20).

7. The pitch system according to claim 2, characterized in that, The pitch system (1) further includes a friction element (63) disposed between the first annular platform (314) and the hub (10) and between the first annular platform (314) and the blade (20).

8. The pitch system according to claim 7, characterized in that, The first annular platform (314) has a positioning groove (3141), and part of the friction element (63) is disposed in the positioning groove (3141).

9. The pitch system according to claim 2, characterized in that, The first mounting part (311) and the second mounting part (331) further include an abutment part (318), which is connected to the first conical surface (313). The pitch system (1) further includes a first fixing bolt (65) and a second fixing bolt (66). The first fixing bolt (65) passes through the outer ring (33) and is detachably connected to the hub (10). The second fixing bolt (66) passes through the inner ring (31) and is detachably connected to the blade (20).

10. A method for installing a pitch system, characterized in that, Both the first mounting part (311) and the second mounting part (331) are connected to the corresponding hub (10) and blade (20) using a segmented conical positioning connection method. The first mounting part (311) and the second mounting part (331) are arranged sequentially along the axial direction with a first conical surface (313), a first annular platform (314), a second conical surface (316), and a second annular platform (317). The first conical surface (313) and the second conical surface (316) are coaxially arranged and are separated from each other by the first annular platform (314) in the axial direction. The second annular platform (317) is located at the end of the second conical surface (316) and is connected to the outer surface of the inner ring (31) and the outer ring (33). The installation method of the pitch system (1) includes the following installation steps: S01, the first detection element (51) and the second detection element (52) are respectively installed at intervals on the circumference of the blade (20) and the hub (10), and the first detection element (51) and the second detection element (52) are opposite to the second annular platform (317); S02, the second mounting part (331) is connected to the hub (10) and is detachably connected to the hub (10) by passing through the outer ring (33) with the first fixing bolt (65) to install the pitch bearing (30) onto the hub (10); S03, the gap distance between the second mounting part (331) and the hub (10) is collected by the second detection element (52), and the first fixing bolt (65) is adjusted to make the gap distance reach the preset value; S04, the first mounting part (311) is connected to the blade (20) and is detachably connected to the blade (20) by passing through the inner ring (31) with the second fixing bolt (66) so as to install the blade (20) onto the pitch bearing (30); S05, the gap distance between the first mounting part (311) and the blade (20) is collected by the first detection element (51), and the second fixing bolt (66) is adjusted so that the gap distance reaches the preset value.

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